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Diffstat (limited to 'include/cxl/mailbox.h')
| -rw-r--r-- | include/cxl/mailbox.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/include/cxl/mailbox.h b/include/cxl/mailbox.h new file mode 100644 index 000000000000..c4e99e2e3a9d --- /dev/null +++ b/include/cxl/mailbox.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright(c) 2024 Intel Corporation. */ +#ifndef __CXL_MBOX_H__ +#define __CXL_MBOX_H__ +#include <linux/rcuwait.h> +#include <cxl/features.h> +#include <uapi/linux/cxl_mem.h> + +/** + * struct cxl_mbox_cmd - A command to be submitted to hardware. + * @opcode: (input) The command set and command submitted to hardware. + * @payload_in: (input) Pointer to the input payload. + * @payload_out: (output) Pointer to the output payload. Must be allocated by + * the caller. + * @size_in: (input) Number of bytes to load from @payload_in. + * @size_out: (input) Max number of bytes loaded into @payload_out. + * (output) Number of bytes generated by the device. For fixed size + * outputs commands this is always expected to be deterministic. For + * variable sized output commands, it tells the exact number of bytes + * written. + * @min_out: (input) internal command output payload size validation + * @poll_count: (input) Number of timeouts to attempt. + * @poll_interval_ms: (input) Time between mailbox background command polling + * interval timeouts. + * @return_code: (output) Error code returned from hardware. + * + * This is the primary mechanism used to send commands to the hardware. + * All the fields except @payload_* correspond exactly to the fields described in + * Command Register section of the CXL 2.0 8.2.8.4.5. @payload_in and + * @payload_out are written to, and read from the Command Payload Registers + * defined in CXL 2.0 8.2.8.4.8. + */ +struct cxl_mbox_cmd { + u16 opcode; + void *payload_in; + void *payload_out; + size_t size_in; + size_t size_out; + size_t min_out; + int poll_count; + int poll_interval_ms; + u16 return_code; +}; + +/** + * struct cxl_mailbox - context for CXL mailbox operations + * @host: device that hosts the mailbox + * @enabled_cmds: mailbox commands that are enabled by the driver + * @exclusive_cmds: mailbox commands that are exclusive to the kernel + * @payload_size: Size of space for payload + * (CXL 3.1 8.2.8.4.3 Mailbox Capabilities Register) + * @mbox_mutex: mutex protects device mailbox and firmware + * @mbox_wait: rcuwait for mailbox + * @mbox_send: @dev specific transport for transmitting mailbox commands + * @feat_cap: Features capability + */ +struct cxl_mailbox { + struct device *host; + DECLARE_BITMAP(enabled_cmds, CXL_MEM_COMMAND_ID_MAX); + DECLARE_BITMAP(exclusive_cmds, CXL_MEM_COMMAND_ID_MAX); + size_t payload_size; + struct mutex mbox_mutex; /* lock to protect mailbox context */ + struct rcuwait mbox_wait; + int (*mbox_send)(struct cxl_mailbox *cxl_mbox, struct cxl_mbox_cmd *cmd); + enum cxl_features_capability feat_cap; +}; + +int cxl_mailbox_init(struct cxl_mailbox *cxl_mbox, struct device *host); + +#endif |