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+Excerpt from UltraSPARC Virtual Machine Specification
+Compiled from version 3.0.20+15
+Publication date 2017-09-25 08:21
+Copyright © 2008, 2015 Oracle and/or its affiliates. All rights reserved.
+Extracted via "pdftotext -f 547 -l 572 -layout sun4v_20170925.pdf"
+Authors:
+ Charles Kunzman
+ Sam Glidden
+ Mark Cianchetti
+
+
+Chapter 36. Coprocessor services
+ The following APIs provide access via the Hypervisor to hardware assisted data processing functionality.
+ These APIs may only be provided by certain platforms, and may not be available to all virtual machines
+ even on supported platforms. Restrictions on the use of these APIs may be imposed in order to support
+ live-migration and other system management activities.
+
+36.1. Data Analytics Accelerator
+ The Data Analytics Accelerator (DAX) functionality is a collection of hardware coprocessors that provide
+ high speed processoring of database-centric operations. The coprocessors may support one or more of
+ the following data query operations: search, extraction, compression, decompression, and translation. The
+ functionality offered may vary by virtual machine implementation.
+
+ The DAX is a virtual device to sun4v guests, with supported data operations indicated by the virtual device
+ compatibilty property. Functionality is accessed through the submission of Command Control Blocks
+ (CCBs) via the ccb_submit API function. The operations are processed asynchronously, with the status
+ of the submitted operations reported through a Completion Area linked to each CCB. Each CCB has a
+ separate Completion Area and, unless execution order is specifically restricted through the use of serial-
+ conditional flags, the execution order of submitted CCBs is arbitrary. Likewise, the time to completion
+ for a given CCB is never guaranteed.
+
+ Guest software may implement a software timeout on CCB operations, and if the timeout is exceeded, the
+ operation may be cancelled or killed via the ccb_kill API function. It is recommended for guest software
+ to implement a software timeout to account for certain RAS errors which may result in lost CCBs. It is
+ recommended such implementation use the ccb_info API function to check the status of a CCB prior to
+ killing it in order to determine if the CCB is still in queue, or may have been lost due to a RAS error.
+
+ There is no fixed limit on the number of outstanding CCBs guest software may have queued in the virtual
+ machine, however, internal resource limitations within the virtual machine can cause CCB submissions
+ to be temporarily rejected with EWOULDBLOCK. In such cases, guests should continue to attempt
+ submissions until they succeed; waiting for an outstanding CCB to complete is not necessary, and would
+ not be a guarantee that a future submission would succeed.
+
+ The availablility of DAX coprocessor command service is indicated by the presence of the DAX virtual
+ device node in the guest MD (Section 8.24.17, “Database Analytics Accelerators (DAX) virtual-device
+ node”).
+
+36.1.1. DAX Compatibility Property
+ The query functionality may vary based on the compatibility property of the virtual device:
+
+36.1.1.1. "ORCL,sun4v-dax" Device Compatibility
+ Available CCB commands:
+
+ • No-op/Sync
+
+ • Extract
+
+ • Scan Value
+
+ • Inverted Scan Value
+
+ • Scan Range
+
+
+ 509
+ Coprocessor services
+
+
+ • Inverted Scan Range
+
+ • Translate
+
+ • Inverted Translate
+
+ • Select
+
+ See Section 36.2.1, “Query CCB Command Formats” for the corresponding CCB input and output formats.
+
+ Only version 0 CCBs are available.
+
+36.1.1.2. "ORCL,sun4v-dax-fc" Device Compatibility
+ "ORCL,sun4v-dax-fc" is compatible with the "ORCL,sun4v-dax" interface, and includes additional CCB
+ bit fields and controls.
+
+36.1.1.3. "ORCL,sun4v-dax2" Device Compatibility
+ Available CCB commands:
+
+ • No-op/Sync
+
+ • Extract
+
+ • Scan Value
+
+ • Inverted Scan Value
+
+ • Scan Range
+
+ • Inverted Scan Range
+
+ • Translate
+
+ • Inverted Translate
+
+ • Select
+
+ See Section 36.2.1, “Query CCB Command Formats” for the corresponding CCB input and output formats.
+
+ Version 0 and 1 CCBs are available. Only version 0 CCBs may use Huffman encoded data, whereas only
+ version 1 CCBs may use OZIP.
+
+36.1.2. DAX Virtual Device Interrupts
+ The DAX virtual device has multiple interrupts associated with it which may be used by the guest if
+ desired. The number of device interrupts available to the guest is indicated in the virtual device node of the
+ guest MD (Section 8.24.17, “Database Analytics Accelerators (DAX) virtual-device node”). If the device
+ node indicates N interrupts available, the guest may use any value from 0 to N - 1 (inclusive) in a CCB
+ interrupt number field. Using values outside this range will result in the CCB being rejected for an invalid
+ field value.
+
+ The interrupts may be bound and managed using the standard sun4v device interrupts API (Chapter 16,
+ Device interrupt services). Sysino interrupts are not available for DAX devices.
+
+36.2. Coprocessor Control Block (CCB)
+ CCBs are either 64 or 128 bytes long, depending on the operation type. The exact contents of the CCB
+ are command specific, but all CCBs contain at least one memory buffer address. All memory locations
+
+
+ 510
+ Coprocessor services
+
+
+referenced by a CCB must be pinned in memory until the CCB either completes execution or is killed
+via the ccb_kill API call. Changes in virtual address mappings occurring after CCB submission are not
+guaranteed to be visible, and as such all virtual address updates need to be synchronized with CCB
+execution.
+
+All CCBs begin with a common 32-bit header.
+
+Table 36.1. CCB Header Format
+Bits Field Description
+[31:28] CCB version. For API version 2.0: set to 1 if CCB uses OZIP encoding; set to 0 if the CCB
+ uses Huffman encoding; otherwise either 0 or 1. For API version 1.0: always set to 0.
+[27] When API version 2.0 is negotiated, this is the Pipeline Flag [512]. It is reserved in
+ API version 1.0
+[26] Long CCB flag [512]
+[25] Conditional synchronization flag [512]
+[24] Serial synchronization flag
+[23:16] CCB operation code:
+ 0x00 No Operation (No-op) or Sync
+ 0x01 Extract
+ 0x02 Scan Value
+ 0x12 Inverted Scan Value
+ 0x03 Scan Range
+ 0x13 Inverted Scan Range
+ 0x04 Translate
+ 0x14 Inverted Translate
+ 0x05 Select
+[15:13] Reserved
+[12:11] Table address type
+ 0b'00 No address
+ 0b'01 Alternate context virtual address
+ 0b'10 Real address
+ 0b'11 Primary context virtual address
+[10:8] Output/Destination address type
+ 0b'000 No address
+ 0b'001 Alternate context virtual address
+ 0b'010 Real address
+ 0b'011 Primary context virtual address
+ 0b'100 Reserved
+ 0b'101 Reserved
+ 0b'110 Reserved
+ 0b'111 Reserved
+[7:5] Secondary source address type
+
+
+ 511
+ Coprocessor services
+
+
+Bits Field Description
+ 0b'000 No address
+ 0b'001 Alternate context virtual address
+ 0b'010 Real address
+ 0b'011 Primary context virtual address
+ 0b'100 Reserved
+ 0b'101 Reserved
+ 0b'110 Reserved
+ 0b'111 Reserved
+[4:2] Primary source address type
+ 0b'000 No address
+ 0b'001 Alternate context virtual address
+ 0b'010 Real address
+ 0b'011 Primary context virtual address
+ 0b'100 Reserved
+ 0b'101 Reserved
+ 0b'110 Reserved
+ 0b'111 Reserved
+[1:0] Completion area address type
+ 0b'00 No address
+ 0b'01 Alternate context virtual address
+ 0b'10 Real address
+ 0b'11 Primary context virtual address
+
+The Long CCB flag indicates whether the submitted CCB is 64 or 128 bytes long; value is 0 for 64 bytes
+and 1 for 128 bytes.
+
+The Serial and Conditional flags allow simple relative ordering between CCBs. Any CCB with the Serial
+flag set will execute sequentially relative to any previous CCB that is also marked as Serial in the same
+CCB submission. CCBs without the Serial flag set execute independently, even if they are between CCBs
+with the Serial flag set. CCBs marked solely with the Serial flag will execute upon the completion of the
+previous Serial CCB, regardless of the completion status of that CCB. The Conditional flag allows CCBs
+to conditionally execute based on the successful execution of the closest CCB marked with the Serial flag.
+A CCB may only be conditional on exactly one CCB, however, a CCB may be marked both Conditional
+and Serial to allow execution chaining. The flags do NOT allow fan-out chaining, where multiple CCBs
+execute in parallel based on the completion of another CCB.
+
+The Pipeline flag is an optimization that directs the output of one CCB (the "source" CCB) directly to
+the input of the next CCB (the "target" CCB). The target CCB thus does not need to read the input from
+memory. The Pipeline flag is advisory and may be dropped.
+
+Both the Pipeline and Serial bits must be set in the source CCB. The Conditional bit must be set in the
+target CCB. Exactly one CCB must be made conditional on the source CCB; either 0 or 2 target CCBs
+is invalid. However, Pipelines can be extended beyond two CCBs: the sequence would start with a CCB
+with both the Pipeline and Serial bits set, proceed through CCBs with the Pipeline, Serial, and Conditional
+bits set, and terminate at a CCB that has the Conditional bit set, but not the Pipeline bit.
+
+
+ 512
+ Coprocessor services
+
+
+ The input of the target CCB must start within 64 bytes of the output of the source CCB or the pipeline flag
+ will be ignored. All CCBs in a pipeline must be submitted in the same call to ccb_submit.
+
+ The various address type fields indicate how the various address values used in the CCB should be
+ interpreted by the virtual machine. Not all of the types specified are used by every CCB format. Types
+ which are not applicable to the given CCB command should be indicated as type 0 (No address). Virtual
+ addresses used in the CCB must have translation entries present in either the TLB or a configured TSB
+ for the submitting virtual processor. Virtual addresses which cannot be translated by the virtual machine
+ will result in the CCB submission being rejected, with the causal virtual address indicated. The CCB
+ may be resubmitted after inserting the translation, or the address may be translated by guest software and
+ resubmitted using the real address translation.
+
+36.2.1. Query CCB Command Formats
+36.2.1.1. Supported Data Formats, Elements Sizes and Offsets
+ Data for query commands may be encoded in multiple possible formats. The data query commands use a
+ common set of values to indicate the encoding formats of the data being processed. Some encoding formats
+ require multiple data streams for processing, requiring the specification of both primary data formats (the
+ encoded data) and secondary data streams (meta-data for the encoded data).
+
+36.2.1.1.1. Primary Input Format
+
+ The primary input format code is a 4-bit field when it is used. There are 10 primary input formats available.
+ The packed formats are not endian neutral. Code values not listed below are reserved.
+
+ Code Format Description
+ 0x0 Fixed width byte packed Up to 16 bytes
+ 0x1 Fixed width bit packed Up to 15 bits (CCB version 0) or 23 bits (CCB version
+ 1); bits are read most significant bit to least significant bit
+ within a byte
+ 0x2 Variable width byte packed Data stream of lengths must be provided as a secondary
+ input
+ 0x4 Fixed width byte packed with run Up to 16 bytes; data stream of run lengths must be
+ length encoding provided as a secondary input
+ 0x5 Fixed width bit packed with run Up to 15 bits (CCB version 0) or 23 bits (CCB version
+ length encoding 1); bits are read most significant bit to least significant bit
+ within a byte; data stream of run lengths must be provided
+ as a secondary input
+ 0x8 Fixed width byte packed with Up to 16 bytes before the encoding; compressed stream
+ Huffman (CCB version 0) or bits are read most significant bit to least significant bit
+ OZIP (CCB version 1) encoding within a byte; pointer to the encoding table must be
+ provided
+ 0x9 Fixed width bit packed with Up to 15 bits (CCB version 0) or 23 bits (CCB version
+ Huffman (CCB version 0) or 1); compressed stream bits are read most significant bit to
+ OZIP (CCB version 1) encoding least significant bit within a byte; pointer to the encoding
+ table must be provided
+ 0xA Variable width byte packed with Up to 16 bytes before the encoding; compressed stream
+ Huffman (CCB version 0) or bits are read most significant bit to least significant bit
+ OZIP (CCB version 1) encoding within a byte; data stream of lengths must be provided as
+ a secondary input; pointer to the encoding table must be
+ provided
+
+
+ 513
+ Coprocessor services
+
+
+ Code Format Description
+ 0xC Fixed width byte packed with Up to 16 bytes before the encoding; compressed stream
+ run length encoding, followed by bits are read most significant bit to least significant bit
+ Huffman (CCB version 0) or within a byte; data stream of run lengths must be provided
+ OZIP (CCB version 1) encoding as a secondary input; pointer to the encoding table must
+ be provided
+ 0xD Fixed width bit packed with Up to 15 bits (CCB version 0) or 23 bits(CCB version 1)
+ run length encoding, followed by before the encoding; compressed stream bits are read most
+ Huffman (CCB version 0) or significant bit to least significant bit within a byte; data
+ OZIP (CCB version 1) encoding stream of run lengths must be provided as a secondary
+ input; pointer to the encoding table must be provided
+
+ If OZIP encoding is used, there must be no reserved bytes in the table.
+
+36.2.1.1.2. Primary Input Element Size
+
+ For primary input data streams with fixed size elements, the element size must be indicated in the CCB
+ command. The size is encoded as the number of bits or bytes, minus one. The valid value range for this
+ field depends on the input format selected, as listed in the table above.
+
+36.2.1.1.3. Secondary Input Format
+
+ For primary input data streams which require a secondary input stream, the secondary input stream is
+ always encoded in a fixed width, bit-packed format. The bits are read from most significant bit to least
+ significant bit within a byte. There are two encoding options for the secondary input stream data elements,
+ depending on whether the value of 0 is needed:
+
+ Secondary Input Description
+ Format Code
+ 0 Element is stored as value minus 1 (0 evalutes to 1, 1 evalutes
+ to 2, etc)
+ 1 Element is stored as value
+
+36.2.1.1.4. Secondary Input Element Size
+
+ Secondary input element size is encoded as a two bit field:
+
+ Secondary Input Size Description
+ Code
+ 0x0 1 bit
+ 0x1 2 bits
+ 0x2 4 bits
+ 0x3 8 bits
+
+36.2.1.1.5. Input Element Offsets
+
+ Bit-wise input data streams may have any alignment within the base addressed byte. The offset, specified
+ from most significant bit to least significant bit, is provided as a fixed 3 bit field for each input type. A
+ value of 0 indicates that the first input element begins at the most significant bit in the first byte, and a
+ value of 7 indicates it begins with the least significant bit.
+
+ This field should be zero for any byte-wise primary input data streams.
+
+
+ 514
+ Coprocessor services
+
+
+36.2.1.1.6. Output Format
+
+ Query commands support multiple sizes and encodings for output data streams. There are four possible
+ output encodings, and up to four supported element sizes per encoding. Not all output encodings are
+ supported for every command. The format is indicated by a 4-bit field in the CCB:
+
+ Output Format Code Description
+ 0x0 Byte aligned, 1 byte elements
+ 0x1 Byte aligned, 2 byte elements
+ 0x2 Byte aligned, 4 byte elements
+ 0x3 Byte aligned, 8 byte elements
+ 0x4 16 byte aligned, 16 byte elements
+ 0x5 Reserved
+ 0x6 Reserved
+ 0x7 Reserved
+ 0x8 Packed vector of single bit elements
+ 0x9 Reserved
+ 0xA Reserved
+ 0xB Reserved
+ 0xC Reserved
+ 0xD 2 byte elements where each element is the index value of a bit,
+ from an bit vector, which was 1.
+ 0xE 4 byte elements where each element is the index value of a bit,
+ from an bit vector, which was 1.
+ 0xF Reserved
+
+36.2.1.1.7. Application Data Integrity (ADI)
+
+ On platforms which support ADI, the ADI version number may be specified for each separate memory
+ access type used in the CCB command. ADI checking only occurs when reading data. When writing data,
+ the specified ADI version number overwrites any existing ADI value in memory.
+
+ An ADI version value of 0 or 0xF indicates the ADI checking is disabled for that data access, even if it is
+ enabled in memory. By setting the appropriate flag in CCB_SUBMIT (Section 36.3.1, “ccb_submit”) it is
+ also an option to disable ADI checking for all inputs accessed via virtual address for all CCBs submitted
+ during that hypercall invocation.
+
+ The ADI value is only guaranteed to be checked on the first 64 bytes of each data access. Mismatches on
+ subsequent data chunks may not be detected, so guest software should be careful to use page size checking
+ to protect against buffer overruns.
+
+36.2.1.1.8. Page size checking
+
+ All data accesses used in CCB commands must be bounded within a single memory page. When addresses
+ are provided using a virtual address, the page size for checking is extracted from the TTE for that virtual
+ address. When using real addresses, the guest must supply the page size in the same field as the address
+ value. The page size must be one of the sizes supported by the underlying virtual machine. Using a value
+ that is not supported may result in the CCB submission being rejected or the generation of a CCB parsing
+ error in the completion area.
+
+
+ 515
+ Coprocessor services
+
+
+36.2.1.2. Extract command
+
+ Converts an input vector in one format to an output vector in another format. All input format types are
+ supported.
+
+ The only supported output format is a padded, byte-aligned output stream, using output codes 0x0 - 0x4.
+ When the specified output element size is larger than the extracted input element size, zeros are padded to
+ the extracted input element. First, if the decompressed input size is not a whole number of bytes, 0 bits are
+ padded to the most significant bit side till the next byte boundary. Next, if the output element size is larger
+ than the byte padded input element, bytes of value 0 are added based on the Padding Direction bit in the
+ CCB. If the output element size is smaller than the byte-padded input element size, the input element is
+ truncated by dropped from the least significant byte side until the selected output size is reached.
+
+ The return value of the CCB completion area is invalid. The “number of elements processed” field in the
+ CCB completion area will be valid.
+
+ The extract CCB is a 64-byte “short format” CCB.
+
+ The extract CCB command format can be specified by the following packed C structure for a big-endian
+ machine:
+
+
+ struct extract_ccb {
+ uint32_t header;
+ uint32_t control;
+ uint64_t completion;
+ uint64_t primary_input;
+ uint64_t data_access_control;
+ uint64_t secondary_input;
+ uint64_t reserved;
+ uint64_t output;
+ uint64_t table;
+ };
+
+
+ The exact field offsets, sizes, and composition are as follows:
+
+ Offset Size Field Description
+ 0 4 CCB header (Table 36.1, “CCB Header Format”)
+ 4 4 Command control
+ Bits Field Description
+ [31:28] Primary Input Format (see Section 36.2.1.1.1, “Primary Input
+ Format”)
+ [27:23] Primary Input Element Size (see Section 36.2.1.1.2, “Primary
+ Input Element Size”)
+ [22:20] Primary Input Starting Offset (see Section 36.2.1.1.5, “Input
+ Element Offsets”)
+ [19] Secondary Input Format (see Section 36.2.1.1.3, “Secondary
+ Input Format”)
+ [18:16] Secondary Input Starting Offset (see Section 36.2.1.1.5, “Input
+ Element Offsets”)
+
+
+ 516
+ Coprocessor services
+
+
+Offset Size Field Description
+ Bits Field Description
+ [15:14] Secondary Input Element Size (see Section 36.2.1.1.4,
+ “Secondary Input Element Size”
+ [13:10] Output Format (see Section 36.2.1.1.6, “Output Format”)
+ [9] Padding Direction selector: A value of 1 causes padding bytes
+ to be added to the left side of output elements. A value of 0
+ causes padding bytes to be added to the right side of output
+ elements.
+ [8:0] Reserved
+8 8 Completion
+ Bits Field Description
+ [63:60] ADI version (see Section 36.2.1.1.7, “Application Data
+ Integrity (ADI)”)
+ [59] If set to 1, a virtual device interrupt will be generated using
+ the device interrupt number specified in the lower bits of this
+ completion word. If 0, the lower bits of this completion word
+ are ignored.
+ [58:6] Completion area address bits [58:6]. Address type is
+ determined by CCB header.
+ [5:0] Virtual device interrupt number for completion interrupt, if
+ enabled.
+16 8 Primary Input
+ Bits Field Description
+ [63:60] ADI version (see Section 36.2.1.1.7, “Application Data
+ Integrity (ADI)”)
+ [59:56] If using real address, these bits should be filled in with the
+ page size code for the page boundary checking the guest wants
+ the virtual machine to use when accessing this data stream
+ (checking is only guaranteed to be performed when using API
+ version 1.1 and later). If using a virtual address, this field will
+ be used as as primary input address bits [59:56].
+ [55:0] Primary input address bits [55:0]. Address type is determined
+ by CCB header.
+24 8 Data Access Control
+ Bits Field Description
+ [63:62] Flow Control
+ Value Description
+ 0b'00 Disable flow control
+ 0b'01 Enable flow control (only valid with "ORCL,sun4v-
+ dax-fc" compatible virtual device variants)
+ 0b'10 Reserved
+ 0b'11 Reserved
+ [61:60] Reserved (API 1.0)
+
+
+ 517
+ Coprocessor services
+
+
+Offset Size Field Description
+ Bits Field Description
+ Pipeline target (API 2.0)
+ Value Description
+ 0b'00 Connect to primary input
+ 0b'01 Connect to secondary input
+ 0b'10 Reserved
+ 0b'11 Reserved
+ [59:40] Output buffer size given in units of 64 bytes, minus 1. Value of
+ 0 means 64 bytes, value of 1 means 128 bytes, etc. Buffer size is
+ only enforced if flow control is enabled in Flow Control field.
+ [39:32] Reserved
+ [31:30] Output Data Cache Allocation
+ Value Description
+ 0b'00 Do not allocate cache lines for output data stream.
+ 0b'01 Force cache lines for output data stream to be
+ allocated in the cache that is local to the submitting
+ virtual cpu.
+ 0b'10 Allocate cache lines for output data stream, but allow
+ existing cache lines associated with the data to remain
+ in their current cache instance. Any memory not
+ already in cache will be allocated in the cache local
+ to the submitting virtual cpu.
+ 0b'11 Reserved
+ [29:26] Reserved
+ [25:24] Primary Input Length Format
+ Value Description
+ 0b'00 Number of primary symbols
+ 0b'01 Number of primary bytes
+ 0b'10 Number of primary bits
+ 0b'11 Reserved
+ [23:0] Primary Input Length
+ Format Field Value
+ # of primary symbols Number of input elements to process,
+ minus 1. Command execution stops
+ once count is reached.
+ # of primary bytes Number of input bytes to process,
+ minus 1. Command execution stops
+ once count is reached. The count is
+ done before any decompression or
+ decoding.
+ # of primary bits Number of input bits to process,
+ minus 1. Command execution stops
+
+
+
+ 518
+ Coprocessor services
+
+
+ Offset Size Field Description
+ Bits Field Description
+ Format Field Value
+ once count is reached. The count is
+ done before any decompression or
+ decoding, and does not include any
+ bits skipped by the Primary Input
+ Offset field value of the command
+ control word.
+ 32 8 Secondary Input, if used by Primary Input Format. Same fields as Primary
+ Input.
+ 40 8 Reserved
+ 48 8 Output (same fields as Primary Input)
+ 56 8 Symbol Table (if used by Primary Input)
+ Bits Field Description
+ [63:60] ADI version (see Section 36.2.1.1.7, “Application Data
+ Integrity (ADI)”)
+ [59:56] If using real address, these bits should be filled in with the
+ page size code for the page boundary checking the guest wants
+ the virtual machine to use when accessing this data stream
+ (checking is only guaranteed to be performed when using API
+ version 1.1 and later). If using a virtual address, this field will
+ be used as as symbol table address bits [59:56].
+ [55:4] Symbol table address bits [55:4]. Address type is determined
+ by CCB header.
+ [3:0] Symbol table version
+ Value Description
+ 0 Huffman encoding. Must use 64 byte aligned table
+ address. (Only available when using version 0 CCBs)
+ 1 OZIP encoding. Must use 16 byte aligned table
+ address. (Only available when using version 1 CCBs)
+
+
+36.2.1.3. Scan commands
+
+ The scan commands search a stream of input data elements for values which match the selection criteria.
+ All the input format types are supported. There are multiple formats for the scan commands, allowing the
+ scan to search for exact matches to one value, exact matches to either of two values, or any value within
+ a specified range. The specific type of scan is indicated by the command code in the CCB header. For the
+ scan range commands, the boundary conditions can be specified as greater-than-or-equal-to a value, less-
+ than-or-equal-to a value, or both by using two boundary values.
+
+ There are two supported formats for the output stream: the bit vector and index array formats (codes 0x8,
+ 0xD, and 0xE). For the standard scan command using the bit vector output, for each input element there
+ exists one bit in the vector that is set if the input element matched the scan criteria, or clear if not. The
+ inverted scan command inverts the polarity of the bits in the output. The most significant bit of the first
+ byte of the output stream corresponds to the first element in the input stream. The standard index array
+ output format contains one array entry for each input element that matched the scan criteria. Each array
+
+
+
+ 519
+ Coprocessor services
+
+
+entry is the index of an input element that matched the scan criteria. An inverted scan command produces
+a similar array, but of all the input elements which did NOT match the scan criteria.
+
+The return value of the CCB completion area contains the number of input elements found which match
+the scan criteria (or number that did not match for the inverted scans). The “number of elements processed”
+field in the CCB completion area will be valid, indicating the number of input elements processed.
+
+These commands are 128-byte “long format” CCBs.
+
+The scan CCB command format can be specified by the following packed C structure for a big-endian
+machine:
+
+
+ struct scan_ccb {
+ uint32_t header;
+ uint32_t control;
+ uint64_t completion;
+ uint64_t primary_input;
+ uint64_t data_access_control;
+ uint64_t secondary_input;
+ uint64_t match_criteria0;
+ uint64_t output;
+ uint64_t table;
+ uint64_t match_criteria1;
+ uint64_t match_criteria2;
+ uint64_t match_criteria3;
+ uint64_t reserved[5];
+ };
+
+
+The exact field offsets, sizes, and composition are as follows:
+
+Offset Size Field Description
+0 4 CCB header (Table 36.1, “CCB Header Format”)
+4 4 Command control
+ Bits Field Description
+ [31:28] Primary Input Format (see Section 36.2.1.1.1, “Primary Input
+ Format”)
+ [27:23] Primary Input Element Size (see Section 36.2.1.1.2, “Primary
+ Input Element Size”)
+ [22:20] Primary Input Starting Offset (see Section 36.2.1.1.5, “Input
+ Element Offsets”)
+ [19] Secondary Input Format (see Section 36.2.1.1.3, “Secondary
+ Input Format”)
+ [18:16] Secondary Input Starting Offset (see Section 36.2.1.1.5, “Input
+ Element Offsets”)
+ [15:14] Secondary Input Element Size (see Section 36.2.1.1.4,
+ “Secondary Input Element Size”
+ [13:10] Output Format (see Section 36.2.1.1.6, “Output Format”)
+ [9:5] Operand size for first scan criteria value. In a scan value
+ operation, this is one of two potential extact match values.
+ In a scan range operation, this is the size of the upper range
+
+
+ 520
+ Coprocessor services
+
+
+Offset Size Field Description
+ Bits Field Description
+ boundary. The value of this field is the number of bytes in the
+ operand, minus 1. Values 0xF-0x1E are reserved. A value of
+ 0x1F indicates this operand is not in use for this scan operation.
+ [4:0] Operand size for second scan criteria value. In a scan value
+ operation, this is one of two potential extact match values.
+ In a scan range operation, this is the size of the lower range
+ boundary. The value of this field is the number of bytes in the
+ operand, minus 1. Values 0xF-0x1E are reserved. A value of
+ 0x1F indicates this operand is not in use for this scan operation.
+8 8 Completion (same fields as Section 36.2.1.2, “Extract command”)
+16 8 Primary Input (same fields as Section 36.2.1.2, “Extract command”)
+24 8 Data Access Control (same fields as Section 36.2.1.2, “Extract command”)
+32 8 Secondary Input, if used by Primary Input Format. Same fields as Primary
+ Input.
+40 4 Most significant 4 bytes of first scan criteria operand. If first operand is less
+ than 4 bytes, the value is left-aligned to the lowest address bytes.
+44 4 Most significant 4 bytes of second scan criteria operand. If second operand
+ is less than 4 bytes, the value is left-aligned to the lowest address bytes.
+48 8 Output (same fields as Primary Input)
+56 8 Symbol Table (if used by Primary Input). Same fields as Section 36.2.1.2,
+ “Extract command”
+64 4 Next 4 most significant bytes of first scan criteria operand occuring after the
+ bytes specified at offset 40, if needed by the operand size. If first operand
+ is less than 8 bytes, the valid bytes are left-aligned to the lowest address.
+68 4 Next 4 most significant bytes of second scan criteria operand occuring after
+ the bytes specified at offset 44, if needed by the operand size. If second
+ operand is less than 8 bytes, the valid bytes are left-aligned to the lowest
+ address.
+72 4 Next 4 most significant bytes of first scan criteria operand occuring after the
+ bytes specified at offset 64, if needed by the operand size. If first operand
+ is less than 12 bytes, the valid bytes are left-aligned to the lowest address.
+76 4 Next 4 most significant bytes of second scan criteria operand occuring after
+ the bytes specified at offset 68, if needed by the operand size. If second
+ operand is less than 12 bytes, the valid bytes are left-aligned to the lowest
+ address.
+80 4 Next 4 most significant bytes of first scan criteria operand occuring after the
+ bytes specified at offset 72, if needed by the operand size. If first operand
+ is less than 16 bytes, the valid bytes are left-aligned to the lowest address.
+84 4 Next 4 most significant bytes of second scan criteria operand occuring after
+ the bytes specified at offset 76, if needed by the operand size. If second
+ operand is less than 16 bytes, the valid bytes are left-aligned to the lowest
+ address.
+
+
+
+
+ 521
+ Coprocessor services
+
+
+36.2.1.4. Translate commands
+
+ The translate commands takes an input array of indicies, and a table of single bit values indexed by those
+ indicies, and outputs a bit vector or index array created by reading the tables bit value at each index in
+ the input array. The output should therefore contain exactly one bit per index in the input data stream,
+ when outputing as a bit vector. When outputing as an index array, the number of elements depends on the
+ values read in the bit table, but will always be less than, or equal to, the number of input elements. Only
+ a restricted subset of the possible input format types are supported. No variable width or Huffman/OZIP
+ encoded input streams are allowed. The primary input data element size must be 3 bytes or less.
+
+ The maximum table index size allowed is 15 bits, however, larger input elements may be used to provide
+ additional processing of the output values. If 2 or 3 byte values are used, the least significant 15 bits are
+ used as an index into the bit table. The most significant 9 bits (when using 3-byte input elements) or single
+ bit (when using 2-byte input elements) are compared against a fixed 9-bit test value provided in the CCB.
+ If the values match, the value from the bit table is used as the output element value. If the values do not
+ match, the output data element value is forced to 0.
+
+ In the inverted translate operation, the bit value read from bit table is inverted prior to its use. The additional
+ additional processing based on any additional non-index bits remains unchanged, and still forces the output
+ element value to 0 on a mismatch. The specific type of translate command is indicated by the command
+ code in the CCB header.
+
+ There are two supported formats for the output stream: the bit vector and index array formats (codes 0x8,
+ 0xD, and 0xE). The index array format is an array of indicies of bits which would have been set if the
+ output format was a bit array.
+
+ The return value of the CCB completion area contains the number of bits set in the output bit vector,
+ or number of elements in the output index array. The “number of elements processed” field in the CCB
+ completion area will be valid, indicating the number of input elements processed.
+
+ These commands are 64-byte “short format” CCBs.
+
+ The translate CCB command format can be specified by the following packed C structure for a big-endian
+ machine:
+
+
+ struct translate_ccb {
+ uint32_t header;
+ uint32_t control;
+ uint64_t completion;
+ uint64_t primary_input;
+ uint64_t data_access_control;
+ uint64_t secondary_input;
+ uint64_t reserved;
+ uint64_t output;
+ uint64_t table;
+ };
+
+
+ The exact field offsets, sizes, and composition are as follows:
+
+
+ Offset Size Field Description
+ 0 4 CCB header (Table 36.1, “CCB Header Format”)
+
+
+ 522
+ Coprocessor services
+
+
+Offset Size Field Description
+4 4 Command control
+ Bits Field Description
+ [31:28] Primary Input Format (see Section 36.2.1.1.1, “Primary Input
+ Format”)
+ [27:23] Primary Input Element Size (see Section 36.2.1.1.2, “Primary
+ Input Element Size”)
+ [22:20] Primary Input Starting Offset (see Section 36.2.1.1.5, “Input
+ Element Offsets”)
+ [19] Secondary Input Format (see Section 36.2.1.1.3, “Secondary
+ Input Format”)
+ [18:16] Secondary Input Starting Offset (see Section 36.2.1.1.5, “Input
+ Element Offsets”)
+ [15:14] Secondary Input Element Size (see Section 36.2.1.1.4,
+ “Secondary Input Element Size”
+ [13:10] Output Format (see Section 36.2.1.1.6, “Output Format”)
+ [9] Reserved
+ [8:0] Test value used for comparison against the most significant bits
+ in the input values, when using 2 or 3 byte input elements.
+8 8 Completion (same fields as Section 36.2.1.2, “Extract command”
+16 8 Primary Input (same fields as Section 36.2.1.2, “Extract command”
+24 8 Data Access Control (same fields as Section 36.2.1.2, “Extract command”,
+ except Primary Input Length Format may not use the 0x0 value)
+32 8 Secondary Input, if used by Primary Input Format. Same fields as Primary
+ Input.
+40 8 Reserved
+48 8 Output (same fields as Primary Input)
+56 8 Bit Table
+ Bits Field Description
+ [63:60] ADI version (see Section 36.2.1.1.7, “Application Data
+ Integrity (ADI)”)
+ [59:56] If using real address, these bits should be filled in with the
+ page size code for the page boundary checking the guest wants
+ the virtual machine to use when accessing this data stream
+ (checking is only guaranteed to be performed when using API
+ version 1.1 and later). If using a virtual address, this field will
+ be used as as bit table address bits [59:56]
+ [55:4] Bit table address bits [55:4]. Address type is determined by
+ CCB header. Address must be 64-byte aligned (CCB version
+ 0) or 16-byte aligned (CCB version 1).
+ [3:0] Bit table version
+ Value Description
+ 0 4KB table size
+ 1 8KB table size
+
+
+
+ 523
+ Coprocessor services
+
+
+36.2.1.5. Select command
+ The select command filters the primary input data stream by using a secondary input bit vector to determine
+ which input elements to include in the output. For each bit set at a given index N within the bit vector,
+ the Nth input element is included in the output. If the bit is not set, the element is not included. Only a
+ restricted subset of the possible input format types are supported. No variable width or run length encoded
+ input streams are allowed, since the secondary input stream is used for the filtering bit vector.
+
+ The only supported output format is a padded, byte-aligned output stream. The stream follows the same
+ rules and restrictions as padded output stream described in Section 36.2.1.2, “Extract command”.
+
+ The return value of the CCB completion area contains the number of bits set in the input bit vector. The
+ "number of elements processed" field in the CCB completion area will be valid, indicating the number
+ of input elements processed.
+
+ The select CCB is a 64-byte “short format” CCB.
+
+ The select CCB command format can be specified by the following packed C structure for a big-endian
+ machine:
+
+
+ struct select_ccb {
+ uint32_t header;
+ uint32_t control;
+ uint64_t completion;
+ uint64_t primary_input;
+ uint64_t data_access_control;
+ uint64_t secondary_input;
+ uint64_t reserved;
+ uint64_t output;
+ uint64_t table;
+ };
+
+
+ The exact field offsets, sizes, and composition are as follows:
+
+ Offset Size Field Description
+ 0 4 CCB header (Table 36.1, “CCB Header Format”)
+ 4 4 Command control
+ Bits Field Description
+ [31:28] Primary Input Format (see Section 36.2.1.1.1, “Primary Input
+ Format”)
+ [27:23] Primary Input Element Size (see Section 36.2.1.1.2, “Primary
+ Input Element Size”)
+ [22:20] Primary Input Starting Offset (see Section 36.2.1.1.5, “Input
+ Element Offsets”)
+ [19] Secondary Input Format (see Section 36.2.1.1.3, “Secondary
+ Input Format”)
+ [18:16] Secondary Input Starting Offset (see Section 36.2.1.1.5, “Input
+ Element Offsets”)
+ [15:14] Secondary Input Element Size (see Section 36.2.1.1.4,
+ “Secondary Input Element Size”
+
+
+ 524
+ Coprocessor services
+
+
+ Offset Size Field Description
+ Bits Field Description
+ [13:10] Output Format (see Section 36.2.1.1.6, “Output Format”)
+ [9] Padding Direction selector: A value of 1 causes padding bytes
+ to be added to the left side of output elements. A value of 0
+ causes padding bytes to be added to the right side of output
+ elements.
+ [8:0] Reserved
+ 8 8 Completion (same fields as Section 36.2.1.2, “Extract command”
+ 16 8 Primary Input (same fields as Section 36.2.1.2, “Extract command”
+ 24 8 Data Access Control (same fields as Section 36.2.1.2, “Extract command”)
+ 32 8 Secondary Bit Vector Input. Same fields as Primary Input.
+ 40 8 Reserved
+ 48 8 Output (same fields as Primary Input)
+ 56 8 Symbol Table (if used by Primary Input). Same fields as Section 36.2.1.2,
+ “Extract command”
+
+36.2.1.6. No-op and Sync commands
+ The no-op (no operation) command is a CCB which has no processing effect. The CCB, when processed
+ by the virtual machine, simply updates the completion area with its execution status. The CCB may have
+ the serial-conditional flags set in order to restrict when it executes.
+
+ The sync command is a variant of the no-op command which with restricted execution timing. A sync
+ command CCB will only execute when all previous commands submitted in the same request have
+ completed. This is stronger than the conditional flag sequencing, which is only dependent on a single
+ previous serial CCB. While the relative ordering is guaranteed, virtual machine implementations with
+ shared hardware resources may cause the sync command to wait for longer than the minimum required
+ time.
+
+ The return value of the CCB completion area is invalid for these CCBs. The “number of elements
+ processed” field is also invalid for these CCBs.
+
+ These commands are 64-byte “short format” CCBs.
+
+ The no-op CCB command format can be specified by the following packed C structure for a big-endian
+ machine:
+
+
+ struct nop_ccb {
+ uint32_t header;
+ uint32_t control;
+ uint64_t completion;
+ uint64_t reserved[6];
+ };
+
+
+ The exact field offsets, sizes, and composition are as follows:
+
+ Offset Size Field Description
+ 0 4 CCB header (Table 36.1, “CCB Header Format”)
+
+
+ 525
+ Coprocessor services
+
+
+ Offset Size Field Description
+ 4 4 Command control
+ Bits Field Description
+ [31] If set, this CCB functions as a Sync command. If clear, this
+ CCB functions as a No-op command.
+ [30:0] Reserved
+ 8 8 Completion (same fields as Section 36.2.1.2, “Extract command”
+ 16 46 Reserved
+
+36.2.2. CCB Completion Area
+ All CCB commands use a common 128-byte Completion Area format, which can be specified by the
+ following packed C structure for a big-endian machine:
+
+
+ struct completion_area {
+ uint8_t status_flag;
+ uint8_t error_note;
+ uint8_t rsvd0[2];
+ uint32_t error_values;
+ uint32_t output_size;
+ uint32_t rsvd1;
+ uint64_t run_time;
+ uint64_t run_stats;
+ uint32_t elements;
+ uint8_t rsvd2[20];
+ uint64_t return_value;
+ uint64_t extra_return_value[8];
+ };
+
+
+ The Completion Area must be a 128-byte aligned memory location. The exact layout can be described
+ using byte offsets and sizes relative to the memory base:
+
+ Offset Size Field Description
+ 0 1 CCB execution status
+ 0x0 Command not yet completed
+ 0x1 Command ran and succeeded
+ 0x2 Command ran and failed (partial results may be been
+ produced)
+ 0x3 Command ran and was killed (partial execution may
+ have occurred)
+ 0x4 Command was not run
+ 0x5-0xF Reserved
+ 1 1 Error reason code
+ 0x0 Reserved
+ 0x1 Buffer overflow
+
+
+ 526
+ Coprocessor services
+
+
+Offset Size Field Description
+ 0x2 CCB decoding error
+ 0x3 Page overflow
+ 0x4-0x6 Reserved
+ 0x7 Command was killed
+ 0x8 Command execution timeout
+ 0x9 ADI miscompare error
+ 0xA Data format error
+ 0xB-0xD Reserved
+ 0xE Unexpected hardware error (Do not retry)
+ 0xF Unexpected hardware error (Retry is ok)
+ 0x10-0x7F Reserved
+ 0x80 Partial Symbol Warning
+ 0x81-0xFF Reserved
+2 2 Reserved
+4 4 If a partial symbol warning was generated, this field contains the number
+ of remaining bits which were not decoded.
+8 4 Number of bytes of output produced
+12 4 Reserved
+16 8 Runtime of command (unspecified time units)
+24 8 Reserved
+32 4 Number of elements processed
+36 20 Reserved
+56 8 Return value
+64 64 Extended return value
+
+The CCB completion area should be treated as read-only by guest software. The CCB execution status
+byte will be cleared by the Hypervisor to reflect the pending execution status when the CCB is submitted
+successfully. All other fields are considered invalid upon CCB submission until the CCB execution status
+byte becomes non-zero.
+
+CCBs which complete with status 0x2 or 0x3 may produce partial results and/or side effects due to partial
+execution of the CCB command. Some valid data may be accessible depending on the fault type, however,
+it is recommended that guest software treat the destination buffer as being in an unknown state. If a CCB
+completes with a status byte of 0x2, the error reason code byte can be read to determine what corrective
+action should be taken.
+
+A buffer overflow indicates that the results of the operation exceeded the size of the output buffer indicated
+in the CCB. The operation can be retried by resubmitting the CCB with a larger output buffer.
+
+A CCB decoding error indicates that the CCB contained some invalid field values. It may be also be
+triggered if the CCB output is directed at a non-existent secondary input and the pipelining hint is followed.
+
+A page overflow error indicates that the operation required accessing a memory location beyond the page
+size associated with a given address. No data will have been read or written past the page boundary, but
+partial results may have been written to the destination buffer. The CCB can be resubmitted with a larger
+page size memory allocation to complete the operation.
+
+
+ 527
+ Coprocessor services
+
+
+ In the case of pipelined CCBs, a page overflow error will be triggered if the output from the pipeline source
+ CCB ends before the input of the pipeline target CCB. Page boundaries are ignored when the pipeline
+ hint is followed.
+
+ Command kill indicates that the CCB execution was halted or prevented by use of the ccb_kill API call.
+
+ Command timeout indicates that the CCB execution began, but did not complete within a pre-determined
+ limit set by the virtual machine. The command may have produced some or no output. The CCB may be
+ resubmitted with no alterations.
+
+ ADI miscompare indicates that the memory buffer version specified in the CCB did not match the value
+ in memory when accessed by the virtual machine. Guest software should not attempt to resubmit the CCB
+ without determining the cause of the version mismatch.
+
+ A data format error indicates that the input data stream did not follow the specified data input formatting
+ selected in the CCB.
+
+ Some CCBs which encounter hardware errors may be resubmitted without change. Persistent hardware
+ errors may result in multiple failures until RAS software can identify and isolate the faulty component.
+
+ The output size field indicates the number of bytes of valid output in the destination buffer. This field is
+ not valid for all possible CCB commands.
+
+ The runtime field indicates the execution time of the CCB command once it leaves the internal virtual
+ machine queue. The time units are fixed, but unspecified, allowing only relative timing comparisons
+ by guest software. The time units may also vary by hardware platform, and should not be construed to
+ represent any absolute time value.
+
+ Some data query commands process data in units of elements. If applicable to the command, the number of
+ elements processed is indicated in the listed field. This field is not valid for all possible CCB commands.
+
+ The return value and extended return value fields are output locations for commands which do not use
+ a destination output buffer, or have secondary return results. The field is not valid for all possible CCB
+ commands.
+
+36.3. Hypervisor API Functions
+36.3.1. ccb_submit
+ trap# FAST_TRAP
+ function# CCB_SUBMIT
+ arg0 address
+ arg1 length
+ arg2 flags
+ arg3 reserved
+ ret0 status
+ ret1 length
+ ret2 status data
+ ret3 reserved
+
+ Submit one or more coprocessor control blocks (CCBs) for evaluation and processing by the virtual
+ machine. The CCBs are passed in a linear array indicated by address. length indicates the size of
+ the array in bytes.
+
+
+ 528
+ Coprocessor services
+
+
+The address should be aligned to the size indicated by length, rounded up to the nearest power of
+two. Virtual machines implementations may reject submissions which do not adhere to that alignment.
+length must be a multiple of 64 bytes. If length is zero, the maximum supported array length will be
+returned as length in ret1. In all other cases, the length value in ret1 will reflect the number of bytes
+successfully consumed from the input CCB array.
+
+ Implementation note
+ Virtual machines should never reject submissions based on the alignment of address if the
+ entire array is contained within a single memory page of the smallest page size supported by the
+ virtual machine.
+
+A guest may choose to submit addresses used in this API function, including the CCB array address,
+as either a real or virtual addresses, with the type of each address indicated in flags. Virtual addresses
+must be present in either the TLB or an active TSB to be processed. The translation context for virtual
+addresses is determined by a combination of CCB contents and the flags argument.
+
+The flags argument is divided into multiple fields defined as follows:
+
+
+Bits Field Description
+[63:16] Reserved
+[15] Disable ADI for VA reads (in API 2.0)
+ Reserved (in API 1.0)
+[14] Virtual addresses within CCBs are translated in privileged context
+[13:12] Alternate translation context for virtual addresses within CCBs:
+ 0b'00 CCBs requesting alternate context are rejected
+ 0b'01 Reserved
+ 0b'10 CCBs requesting alternate context use secondary context
+ 0b'11 CCBs requesting alternate context use nucleus context
+[11:9] Reserved
+[8] Queue info flag
+[7] All-or-nothing flag
+[6] If address is a virtual address, treat its translation context as privileged
+[5:4] Address type of address:
+ 0b'00 Real address
+ 0b'01 Virtual address in primary context
+ 0b'10 Virtual address in secondary context
+ 0b'11 Virtual address in nucleus context
+[3:2] Reserved
+[1:0] CCB command type:
+ 0b'00 Reserved
+ 0b'01 Reserved
+ 0b'10 Query command
+ 0b'11 Reserved
+
+
+
+ 529
+ Coprocessor services
+
+
+ The CCB submission type and address type for the CCB array must be provided in the flags argument.
+ All other fields are optional values which change the default behavior of the CCB processing.
+
+ When set to one, the "Disable ADI for VA reads" bit will turn off ADI checking when using a virtual
+ address to load data. ADI checking will still be done when loading real-addressed memory. This bit is only
+ available when using major version 2 of the coprocessor API group; at major version 1 it is reserved. For
+ more information about using ADI and DAX, see Section 36.2.1.1.7, “Application Data Integrity (ADI)”.
+
+ By default, all virtual addresses are treated as user addresses. If the virtual address translations are
+ privileged, they must be marked as such in the appropriate flags field. The virtual addresses used within
+ the submitted CCBs must all be translated with the same privilege level.
+
+ By default, all virtual addresses used within the submitted CCBs are translated using the primary context
+ active at the time of the submission. The address type field within a CCB allows each address to request
+ translation in an alternate address context. The address context used when the alternate address context is
+ requested is selected in the flags argument.
+
+ The all-or-nothing flag specifies whether the virtual machine should allow partial submissions of the
+ input CCB array. When using CCBs with serial-conditional flags, it is strongly recommended to use
+ the all-or-nothing flag to avoid broken conditional chains. Using long CCB chains on a machine under
+ high coprocessor load may make this impractical, however, and require submitting without the flag.
+ When submitting serial-conditional CCBs without the all-or-nothing flag, guest software must manually
+ implement the serial-conditional behavior at any point where the chain was not submitted in a single API
+ call, and resubmission of the remaining CCBs should clear any conditional flag that might be set in the
+ first remaining CCB. Failure to do so will produce indeterminate CCB execution status and ordering.
+
+ When the all-or-nothing flag is not specified, callers should check the value of length in ret1 to determine
+ how many CCBs from the array were successfully submitted. Any remaining CCBs can be resubmitted
+ without modifications.
+
+ The value of length in ret1 is also valid when the API call returns an error, and callers should always
+ check its value to determine which CCBs in the array were already processed. This will additionally
+ identify which CCB encountered the processing error, and was not submitted successfully.
+
+ If the queue info flag is used during submission, and at least one CCB was successfully submitted, the
+ length value in ret1 will be a multi-field value defined as follows:
+ Bits Field Description
+ [63:48] DAX unit instance identifier
+ [47:32] DAX queue instance identifier
+ [31:16] Reserved
+ [15:0] Number of CCB bytes successfully submitted
+
+ The value of status data depends on the status value. See error status code descriptions for details.
+ The value is undefined for status values that do not specifically list a value for the status data.
+
+ The API has a reserved input and output register which will be used in subsequent minor versions of this
+ API function. Guest software implementations should treat that register as voltile across the function call
+ in order to maintain forward compatibility.
+
+36.3.1.1. Errors
+ EOK One or more CCBs have been accepted and enqueued in the virtual machine
+ and no errors were been encountered during submission. Some submitted
+ CCBs may not have been enqueued due to internal virtual machine limitations,
+ and may be resubmitted without changes.
+
+
+ 530
+ Coprocessor services
+
+
+EWOULDBLOCK An internal resource conflict within the virtual machine has prevented it from
+ being able to complete the CCB submissions sufficiently quickly, requiring
+ it to abandon processing before it was complete. Some CCBs may have been
+ successfully enqueued prior to the block, and all remaining CCBs may be
+ resubmitted without changes.
+EBADALIGN CCB array is not on a 64-byte boundary, or the array length is not a multiple
+ of 64 bytes.
+ENORADDR A real address used either for the CCB array, or within one of the submitted
+ CCBs, is not valid for the guest. Some CCBs may have been enqueued prior
+ to the error being detected.
+ENOMAP A virtual address used either for the CCB array, or within one of the submitted
+ CCBs, could not be translated by the virtual machine using either the TLB
+ or TSB contents. The submission may be retried after adding the required
+ mapping, or by converting the virtual address into a real address. Due to the
+ shared nature of address translation resources, there is no theoretical limit on
+ the number of times the translation may fail, and it is recommended all guests
+ implement some real address based backup. The virtual address which failed
+ translation is returned as status data in ret2. Some CCBs may have been
+ enqueued prior to the error being detected.
+EINVAL The virtual machine detected an invalid CCB during submission, or invalid
+ input arguments, such as bad flag values. Note that not all invalid CCB values
+ will be detected during submission, and some may be reported as errors in the
+ completion area instead. Some CCBs may have been enqueued prior to the
+ error being detected. This error may be returned if the CCB version is invalid.
+ETOOMANY The request was submitted with the all-or-nothing flag set, and the array size is
+ greater than the virtual machine can support in a single request. The maximum
+ supported size for the current virtual machine can be queried by submitting a
+ request with a zero length array, as described above.
+ENOACCESS The guest does not have permission to submit CCBs, or an address used in a
+ CCBs lacks sufficient permissions to perform the required operation (no write
+ permission on the destination buffer address, for example). A virtual address
+ which fails permission checking is returned as status data in ret2. Some
+ CCBs may have been enqueued prior to the error being detected.
+EUNAVAILABLE The requested CCB operation could not be performed at this time. The
+ restricted operation availability may apply only to the first unsuccessfully
+ submitted CCB, or may apply to a larger scope. The status should not be
+ interpreted as permanent, and the guest should attempt to submit CCBs in
+ the future which had previously been unable to be performed. The status
+ data provides additional information about scope of the retricted availability
+ as follows:
+ Value Description
+ 0 Processing for the exact CCB instance submitted was unavailable,
+ and it is recommended the guest emulate the operation. The
+ guest should continue to submit all other CCBs, and assume no
+ restrictions beyond this exact CCB instance.
+ 1 Processing is unavailable for all CCBs using the requested opcode,
+ and it is recommended the guest emulate the operation. The
+ guest should continue to submit all other CCBs that use different
+ opcodes, but can expect continued rejections of CCBs using the
+ same opcode in the near future.
+
+
+ 531
+ Coprocessor services
+
+
+ Value Description
+ 2 Processing is unavailable for all CCBs using the requested CCB
+ version, and it is recommended the guest emulate the operation.
+ The guest should continue to submit all other CCBs that use
+ different CCB versions, but can expect continued rejections of
+ CCBs using the same CCB version in the near future.
+ 3 Processing is unavailable for all CCBs on the submitting vcpu,
+ and it is recommended the guest emulate the operation or resubmit
+ the CCB on a different vcpu. The guest should continue to submit
+ CCBs on all other vcpus but can expect continued rejections of all
+ CCBs on this vcpu in the near future.
+ 4 Processing is unavailable for all CCBs, and it is recommended
+ the guest emulate the operation. The guest should expect all CCB
+ submissions to be similarly rejected in the near future.
+
+
+36.3.2. ccb_info
+
+ trap# FAST_TRAP
+ function# CCB_INFO
+ arg0 address
+ ret0 status
+ ret1 CCB state
+ ret2 position
+ ret3 dax
+ ret4 queue
+
+ Requests status information on a previously submitted CCB. The previously submitted CCB is identified
+ by the 64-byte aligned real address of the CCBs completion area.
+
+ A CCB can be in one of 4 states:
+
+
+ State Value Description
+ COMPLETED 0 The CCB has been fetched and executed, and is no longer active in
+ the virtual machine.
+ ENQUEUED 1 The requested CCB is current in a queue awaiting execution.
+ INPROGRESS 2 The CCB has been fetched and is currently being executed. It may still
+ be possible to stop the execution using the ccb_kill hypercall.
+ NOTFOUND 3 The CCB could not be located in the virtual machine, and does not
+ appear to have been executed. This may occur if the CCB was lost
+ due to a hardware error, or the CCB may not have been successfully
+ submitted to the virtual machine in the first place.
+
+ Implementation note
+ Some platforms may not be able to report CCBs that are currently being processed, and therefore
+ guest software should invoke the ccb_kill hypercall prior to assuming the request CCB will never
+ be executed because it was in the NOTFOUND state.
+
+
+ 532
+ Coprocessor services
+
+
+ The position return value is only valid when the state is ENQUEUED. The value returned is the number
+ of other CCBs ahead of the requested CCB, to provide a relative estimate of when the CCB may execute.
+
+ The dax return value is only valid when the state is ENQUEUED. The value returned is the DAX unit
+ instance indentifier for the DAX unit processing the queue where the requested CCB is located. The value
+ matches the value that would have been, or was, returned by ccb_submit using the queue info flag.
+
+ The queue return value is only valid when the state is ENQUEUED. The value returned is the DAX
+ queue instance indentifier for the DAX unit processing the queue where the requested CCB is located. The
+ value matches the value that would have been, or was, returned by ccb_submit using the queue info flag.
+
+36.3.2.1. Errors
+
+ EOK The request was proccessed and the CCB state is valid.
+ EBADALIGN address is not on a 64-byte aligned.
+ ENORADDR The real address provided for address is not valid.
+ EINVAL The CCB completion area contents are not valid.
+ EWOULDBLOCK Internal resource contraints prevented the CCB state from being queried at this
+ time. The guest should retry the request.
+ ENOACCESS The guest does not have permission to access the coprocessor virtual device
+ functionality.
+
+36.3.3. ccb_kill
+
+ trap# FAST_TRAP
+ function# CCB_KILL
+ arg0 address
+ ret0 status
+ ret1 result
+
+ Request to stop execution of a previously submitted CCB. The previously submitted CCB is identified by
+ the 64-byte aligned real address of the CCBs completion area.
+
+ The kill attempt can produce one of several values in the result return value, reflecting the CCB state
+ and actions taken by the Hypervisor:
+
+ Result Value Description
+ COMPLETED 0 The CCB has been fetched and executed, and is no longer active in
+ the virtual machine. It could not be killed and no action was taken.
+ DEQUEUED 1 The requested CCB was still enqueued when the kill request was
+ submitted, and has been removed from the queue. Since the CCB
+ never began execution, no memory modifications were produced by
+ it, and the completion area will never be updated. The same CCB may
+ be submitted again, if desired, with no modifications required.
+ KILLED 2 The CCB had been fetched and was being executed when the kill
+ request was submitted. The CCB execution was stopped, and the CCB
+ is no longer active in the virtual machine. The CCB completion area
+ will reflect the killed status, with the subsequent implications that
+ partial results may have been produced. Partial results may include full
+
+
+ 533
+ Coprocessor services
+
+
+ Result Value Description
+ command execution if the command was stopped just prior to writing
+ to the completion area.
+ NOTFOUND 3 The CCB could not be located in the virtual machine, and does not
+ appear to have been executed. This may occur if the CCB was lost
+ due to a hardware error, or the CCB may not have been successfully
+ submitted to the virtual machine in the first place. CCBs in the state
+ are guaranteed to never execute in the future unless resubmitted.
+
+36.3.3.1. Interactions with Pipelined CCBs
+
+ If the pipeline target CCB is killed but the pipeline source CCB was skipped, the completion area of the
+ target CCB may contain status (4,0) "Command was skipped" instead of (3,7) "Command was killed".
+
+ If the pipeline source CCB is killed, the pipeline target CCB's completion status may read (1,0) "Success".
+ This does not mean the target CCB was processed; since the source CCB was killed, there was no
+ meaningful output on which the target CCB could operate.
+
+36.3.3.2. Errors
+
+ EOK The request was proccessed and the result is valid.
+ EBADALIGN address is not on a 64-byte aligned.
+ ENORADDR The real address provided for address is not valid.
+ EINVAL The CCB completion area contents are not valid.
+ EWOULDBLOCK Internal resource contraints prevented the CCB from being killed at this time.
+ The guest should retry the request.
+ ENOACCESS The guest does not have permission to access the coprocessor virtual device
+ functionality.
+
+36.3.4. dax_info
+ trap# FAST_TRAP
+ function# DAX_INFO
+ ret0 status
+ ret1 Number of enabled DAX units
+ ret2 Number of disabled DAX units
+
+ Returns the number of DAX units that are enabled for the calling guest to submit CCBs. The number of
+ DAX units that are disabled for the calling guest are also returned. A disabled DAX unit would have been
+ available for CCB submission to the calling guest had it not been offlined.
+
+36.3.4.1. Errors
+
+ EOK The request was proccessed and the number of enabled/disabled DAX units
+ are valid.
+
+
+
+
+ 534
+
diff --git a/Documentation/sparc/oradax/oracle-dax.txt b/Documentation/sparc/oradax/oracle-dax.txt
new file mode 100644
index 000000000000..9d53ac93286f
--- /dev/null
+++ b/Documentation/sparc/oradax/oracle-dax.txt
@@ -0,0 +1,429 @@
+Oracle Data Analytics Accelerator (DAX)
+---------------------------------------
+
+DAX is a coprocessor which resides on the SPARC M7 (DAX1) and M8
+(DAX2) processor chips, and has direct access to the CPU's L3 caches
+as well as physical memory. It can perform several operations on data
+streams with various input and output formats. A driver provides a
+transport mechanism and has limited knowledge of the various opcodes
+and data formats. A user space library provides high level services
+and translates these into low level commands which are then passed
+into the driver and subsequently the Hypervisor and the coprocessor.
+The library is the recommended way for applications to use the
+coprocessor, and the driver interface is not intended for general use.
+This document describes the general flow of the driver, its
+structures, and its programmatic interface. It also provides example
+code sufficient to write user or kernel applications that use DAX
+functionality.
+
+The user library is open source and available at:
+ https://oss.oracle.com/git/gitweb.cgi?p=libdax.git
+
+The Hypervisor interface to the coprocessor is described in detail in
+the accompanying document, dax-hv-api.txt, which is a plain text
+excerpt of the (Oracle internal) "UltraSPARC Virtual Machine
+Specification" version 3.0.20+15, dated 2017-09-25.
+
+
+High Level Overview
+-------------------
+
+A coprocessor request is described by a Command Control Block
+(CCB). The CCB contains an opcode and various parameters. The opcode
+specifies what operation is to be done, and the parameters specify
+options, flags, sizes, and addresses. The CCB (or an array of CCBs)
+is passed to the Hypervisor, which handles queueing and scheduling of
+requests to the available coprocessor execution units. A status code
+returned indicates if the request was submitted successfully or if
+there was an error. One of the addresses given in each CCB is a
+pointer to a "completion area", which is a 128 byte memory block that
+is written by the coprocessor to provide execution status. No
+interrupt is generated upon completion; the completion area must be
+polled by software to find out when a transaction has finished, but
+the M7 and later processors provide a mechanism to pause the virtual
+processor until the completion status has been updated by the
+coprocessor. This is done using the monitored load and mwait
+instructions, which are described in more detail later. The DAX
+coprocessor was designed so that after a request is submitted, the
+kernel is no longer involved in the processing of it. The polling is
+done at the user level, which results in almost zero latency between
+completion of a request and resumption of execution of the requesting
+thread.
+
+
+Addressing Memory
+-----------------
+
+The kernel does not have access to physical memory in the Sun4v
+architecture, as there is an additional level of memory virtualization
+present. This intermediate level is called "real" memory, and the
+kernel treats this as if it were physical. The Hypervisor handles the
+translations between real memory and physical so that each logical
+domain (LDOM) can have a partition of physical memory that is isolated
+from that of other LDOMs. When the kernel sets up a virtual mapping,
+it specifies a virtual address and the real address to which it should
+be mapped.
+
+The DAX coprocessor can only operate on physical memory, so before a
+request can be fed to the coprocessor, all the addresses in a CCB must
+be converted into physical addresses. The kernel cannot do this since
+it has no visibility into physical addresses. So a CCB may contain
+either the virtual or real addresses of the buffers or a combination
+of them. An "address type" field is available for each address that
+may be given in the CCB. In all cases, the Hypervisor will translate
+all the addresses to physical before dispatching to hardware. Address
+translations are performed using the context of the process initiating
+the request.
+
+
+The Driver API
+--------------
+
+An application makes requests to the driver via the write() system
+call, and gets results (if any) via read(). The completion areas are
+made accessible via mmap(), and are read-only for the application.
+
+The request may either be an immediate command or an array of CCBs to
+be submitted to the hardware.
+
+Each open instance of the device is exclusive to the thread that
+opened it, and must be used by that thread for all subsequent
+operations. The driver open function creates a new context for the
+thread and initializes it for use. This context contains pointers and
+values used internally by the driver to keep track of submitted
+requests. The completion area buffer is also allocated, and this is
+large enough to contain the completion areas for many concurrent
+requests. When the device is closed, any outstanding transactions are
+flushed and the context is cleaned up.
+
+On a DAX1 system (M7), the device will be called "oradax1", while on a
+DAX2 system (M8) it will be "oradax2". If an application requires one
+or the other, it should simply attempt to open the appropriate
+device. Only one of the devices will exist on any given system, so the
+name can be used to determine what the platform supports.
+
+The immediate commands are CCB_DEQUEUE, CCB_KILL, and CCB_INFO. For
+all of these, success is indicated by a return value from write()
+equal to the number of bytes given in the call. Otherwise -1 is
+returned and errno is set.
+
+CCB_DEQUEUE
+
+Tells the driver to clean up resources associated with past
+requests. Since no interrupt is generated upon the completion of a
+request, the driver must be told when it may reclaim resources. No
+further status information is returned, so the user should not
+subsequently call read().
+
+CCB_KILL
+
+Kills a CCB during execution. The CCB is guaranteed to not continue
+executing once this call returns successfully. On success, read() must
+be called to retrieve the result of the action.
+
+CCB_INFO
+
+Retrieves information about a currently executing CCB. Note that some
+Hypervisors might return 'notfound' when the CCB is in 'inprogress'
+state. To ensure a CCB in the 'notfound' state will never be executed,
+CCB_KILL must be invoked on that CCB. Upon success, read() must be
+called to retrieve the details of the action.
+
+Submission of an array of CCBs for execution
+
+A write() whose length is a multiple of the CCB size is treated as a
+submit operation. The file offset is treated as the index of the
+completion area to use, and may be set via lseek() or using the
+pwrite() system call. If -1 is returned then errno is set to indicate
+the error. Otherwise, the return value is the length of the array that
+was actually accepted by the coprocessor. If the accepted length is
+equal to the requested length, then the submission was completely
+successful and there is no further status needed; hence, the user
+should not subsequently call read(). Partial acceptance of the CCB
+array is indicated by a return value less than the requested length,
+and read() must be called to retrieve further status information. The
+status will reflect the error caused by the first CCB that was not
+accepted, and status_data will provide additional data in some cases.
+
+MMAP
+
+The mmap() function provides access to the completion area allocated
+in the driver. Note that the completion area is not writeable by the
+user process, and the mmap call must not specify PROT_WRITE.
+
+
+Completion of a Request
+-----------------------
+
+The first byte in each completion area is the command status which is
+updated by the coprocessor hardware. Software may take advantage of
+new M7/M8 processor capabilities to efficiently poll this status byte.
+First, a "monitored load" is achieved via a Load from Alternate Space
+(ldxa, lduba, etc.) with ASI 0x84 (ASI_MONITOR_PRIMARY). Second, a
+"monitored wait" is achieved via the mwait instruction (a write to
+%asr28). This instruction is like pause in that it suspends execution
+of the virtual processor for the given number of nanoseconds, but in
+addition will terminate early when one of several events occur. If the
+block of data containing the monitored location is modified, then the
+mwait terminates. This causes software to resume execution immediately
+(without a context switch or kernel to user transition) after a
+transaction completes. Thus the latency between transaction completion
+and resumption of execution may be just a few nanoseconds.
+
+
+Application Life Cycle of a DAX Submission
+------------------------------------------
+
+ - open dax device
+ - call mmap() to get the completion area address
+ - allocate a CCB and fill in the opcode, flags, parameters, addresses, etc.
+ - submit CCB via write() or pwrite()
+ - go into a loop executing monitored load + monitored wait and
+ terminate when the command status indicates the request is complete
+ (CCB_KILL or CCB_INFO may be used any time as necessary)
+ - perform a CCB_DEQUEUE
+ - call munmap() for completion area
+ - close the dax device
+
+
+Memory Constraints
+------------------
+
+The DAX hardware operates only on physical addresses. Therefore, it is
+not aware of virtual memory mappings and the discontiguities that may
+exist in the physical memory that a virtual buffer maps to. There is
+no I/O TLB or any scatter/gather mechanism. All buffers, whether input
+or output, must reside in a physically contiguous region of memory.
+
+The Hypervisor translates all addresses within a CCB to physical
+before handing off the CCB to DAX. The Hypervisor determines the
+virtual page size for each virtual address given, and uses this to
+program a size limit for each address. This prevents the coprocessor
+from reading or writing beyond the bound of the virtual page, even
+though it is accessing physical memory directly. A simpler way of
+saying this is that a DAX operation will never "cross" a virtual page
+boundary. If an 8k virtual page is used, then the data is strictly
+limited to 8k. If a user's buffer is larger than 8k, then a larger
+page size must be used, or the transaction size will be truncated to
+8k.
+
+Huge pages. A user may allocate huge pages using standard interfaces.
+Memory buffers residing on huge pages may be used to achieve much
+larger DAX transaction sizes, but the rules must still be followed,
+and no transaction will cross a page boundary, even a huge page. A
+major caveat is that Linux on Sparc presents 8Mb as one of the huge
+page sizes. Sparc does not actually provide a 8Mb hardware page size,
+and this size is synthesized by pasting together two 4Mb pages. The
+reasons for this are historical, and it creates an issue because only
+half of this 8Mb page can actually be used for any given buffer in a
+DAX request, and it must be either the first half or the second half;
+it cannot be a 4Mb chunk in the middle, since that crosses a
+(hardware) page boundary. Note that this entire issue may be hidden by
+higher level libraries.
+
+
+CCB Structure
+-------------
+A CCB is an array of 8 64-bit words. Several of these words provide
+command opcodes, parameters, flags, etc., and the rest are addresses
+for the completion area, output buffer, and various inputs:
+
+ struct ccb {
+ u64 control;
+ u64 completion;
+ u64 input0;
+ u64 access;
+ u64 input1;
+ u64 op_data;
+ u64 output;
+ u64 table;
+ };
+
+See libdax/common/sys/dax1/dax1_ccb.h for a detailed description of
+each of these fields, and see dax-hv-api.txt for a complete description
+of the Hypervisor API available to the guest OS (ie, Linux kernel).
+
+The first word (control) is examined by the driver for the following:
+ - CCB version, which must be consistent with hardware version
+ - Opcode, which must be one of the documented allowable commands
+ - Address types, which must be set to "virtual" for all the addresses
+ given by the user, thereby ensuring that the application can
+ only access memory that it owns
+
+
+Example Code
+------------
+
+The DAX is accessible to both user and kernel code. The kernel code
+can make hypercalls directly while the user code must use wrappers
+provided by the driver. The setup of the CCB is nearly identical for
+both; the only difference is in preparation of the completion area. An
+example of user code is given now, with kernel code afterwards.
+
+In order to program using the driver API, the file
+arch/sparc/include/uapi/asm/oradax.h must be included.
+
+First, the proper device must be opened. For M7 it will be
+/dev/oradax1 and for M8 it will be /dev/oradax2. The simplest
+procedure is to attempt to open both, as only one will succeed:
+
+ fd = open("/dev/oradax1", O_RDWR);
+ if (fd < 0)
+ fd = open("/dev/oradax2", O_RDWR);
+ if (fd < 0)
+ /* No DAX found */
+
+Next, the completion area must be mapped:
+
+ completion_area = mmap(NULL, DAX_MMAP_LEN, PROT_READ, MAP_SHARED, fd, 0);
+
+All input and output buffers must be fully contained in one hardware
+page, since as explained above, the DAX is strictly constrained by
+virtual page boundaries. In addition, the output buffer must be
+64-byte aligned and its size must be a multiple of 64 bytes because
+the coprocessor writes in units of cache lines.
+
+This example demonstrates the DAX Scan command, which takes as input a
+vector and a match value, and produces a bitmap as the output. For
+each input element that matches the value, the corresponding bit is
+set in the output.
+
+In this example, the input vector consists of a series of single bits,
+and the match value is 0. So each 0 bit in the input will produce a 1
+in the output, and vice versa, which produces an output bitmap which
+is the input bitmap inverted.
+
+For details of all the parameters and bits used in this CCB, please
+refer to section 36.2.1.3 of the DAX Hypervisor API document, which
+describes the Scan command in detail.
+
+ ccb->control = /* Table 36.1, CCB Header Format */
+ (2L << 48) /* command = Scan Value */
+ | (3L << 40) /* output address type = primary virtual */
+ | (3L << 34) /* primary input address type = primary virtual */
+ /* Section 36.2.1, Query CCB Command Formats */
+ | (1 << 28) /* 36.2.1.1.1 primary input format = fixed width bit packed */
+ | (0 << 23) /* 36.2.1.1.2 primary input element size = 0 (1 bit) */
+ | (8 << 10) /* 36.2.1.1.6 output format = bit vector */
+ | (0 << 5) /* 36.2.1.3 First scan criteria size = 0 (1 byte) */
+ | (31 << 0); /* 36.2.1.3 Disable second scan criteria */
+
+ ccb->completion = 0; /* Completion area address, to be filled in by driver */
+
+ ccb->input0 = (unsigned long) input; /* primary input address */
+
+ ccb->access = /* Section 36.2.1.2, Data Access Control */
+ (2 << 24) /* Primary input length format = bits */
+ | (nbits - 1); /* number of bits in primary input stream, minus 1 */
+
+ ccb->input1 = 0; /* secondary input address, unused */
+
+ ccb->op_data = 0; /* scan criteria (value to be matched) */
+
+ ccb->output = (unsigned long) output; /* output address */
+
+ ccb->table = 0; /* table address, unused */
+
+The CCB submission is a write() or pwrite() system call to the
+driver. If the call fails, then a read() must be used to retrieve the
+status:
+
+ if (pwrite(fd, ccb, 64, 0) != 64) {
+ struct ccb_exec_result status;
+ read(fd, &status, sizeof(status));
+ /* bail out */
+ }
+
+After a successful submission of the CCB, the completion area may be
+polled to determine when the DAX is finished. Detailed information on
+the contents of the completion area can be found in section 36.2.2 of
+the DAX HV API document.
+
+ while (1) {
+ /* Monitored Load */
+ __asm__ __volatile__("lduba [%1] 0x84, %0\n"
+ : "=r" (status)
+ : "r" (completion_area));
+
+ if (status) /* 0 indicates command in progress */
+ break;
+
+ /* MWAIT */
+ __asm__ __volatile__("wr %%g0, 1000, %%asr28\n" ::); /* 1000 ns */
+ }
+
+A completion area status of 1 indicates successful completion of the
+CCB and validity of the output bitmap, which may be used immediately.
+All other non-zero values indicate error conditions which are
+described in section 36.2.2.
+
+ if (completion_area[0] != 1) { /* section 36.2.2, 1 = command ran and succeeded */
+ /* completion_area[0] contains the completion status */
+ /* completion_area[1] contains an error code, see 36.2.2 */
+ }
+
+After the completion area has been processed, the driver must be
+notified that it can release any resources associated with the
+request. This is done via the dequeue operation:
+
+ struct dax_command cmd;
+ cmd.command = CCB_DEQUEUE;
+ if (write(fd, &cmd, sizeof(cmd)) != sizeof(cmd)) {
+ /* bail out */
+ }
+
+Finally, normal program cleanup should be done, i.e., unmapping
+completion area, closing the dax device, freeing memory etc.
+
+[Kernel example]
+
+The only difference in using the DAX in kernel code is the treatment
+of the completion area. Unlike user applications which mmap the
+completion area allocated by the driver, kernel code must allocate its
+own memory to use for the completion area, and this address and its
+type must be given in the CCB:
+
+ ccb->control |= /* Table 36.1, CCB Header Format */
+ (3L << 32); /* completion area address type = primary virtual */
+
+ ccb->completion = (unsigned long) completion_area; /* Completion area address */
+
+The dax submit hypercall is made directly. The flags used in the
+ccb_submit call are documented in the DAX HV API in section 36.3.1.
+
+#include <asm/hypervisor.h>
+
+ hv_rv = sun4v_ccb_submit((unsigned long)ccb, 64,
+ HV_CCB_QUERY_CMD |
+ HV_CCB_ARG0_PRIVILEGED | HV_CCB_ARG0_TYPE_PRIMARY |
+ HV_CCB_VA_PRIVILEGED,
+ 0, &bytes_accepted, &status_data);
+
+ if (hv_rv != HV_EOK) {
+ /* hv_rv is an error code, status_data contains */
+ /* potential additional status, see 36.3.1.1 */
+ }
+
+After the submission, the completion area polling code is identical to
+that in user land:
+
+ while (1) {
+ /* Monitored Load */
+ __asm__ __volatile__("lduba [%1] 0x84, %0\n"
+ : "=r" (status)
+ : "r" (completion_area));
+
+ if (status) /* 0 indicates command in progress */
+ break;
+
+ /* MWAIT */
+ __asm__ __volatile__("wr %%g0, 1000, %%asr28\n" ::); /* 1000 ns */
+ }
+
+ if (completion_area[0] != 1) { /* section 36.2.2, 1 = command ran and succeeded */
+ /* completion_area[0] contains the completion status */
+ /* completion_area[1] contains an error code, see 36.2.2 */
+ }
+
+The output bitmap is ready for consumption immediately after the
+completion status indicates success.
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.