linux-dev/arch/arm/common/Kconfig, branch master

ARM/dma-mapping: remove dmabounce

2022-07-07T16:18:56Z

Remove the now unused dmabounce code. Signed-off-by: Christoph Hellwig Reviewed-by: Arnd Bergmann

ARM: sa1100/assabet: move dmabounce hack to ohci driver

2022-07-07T16:18:47Z

The sa1111 platform is one of the two remaining users of the old Arm specific "dmabounce" code, which is an earlier implementation of the generic swiotlb. Linus Walleij submitted a patch that removes dmabounce support from the ixp4xx, and I had a look at the other user, which is the sa1111 companion chip. Looking at how dmabounce is used, I could narrow it down to one driver one three machines: - dmabounce is only initialized on assabet/neponset, jornada720 and badge4, which are the platforms that have an sa1111 and support DMA on it. - All three of these suffer from "erratum #7" that requires only doing DMA to half the memory sections based on one of the address lines, in addition, the neponset also can't DMA to the RAM that is connected to sa1111 itself. - the pxa lubbock machine also has sa1111, but does not support DMA on it and does not set dmabounce. - only the OHCI and audio devices on sa1111 support DMA, but as there is no audio driver for this hardware, only OHCI remains. In the OHCI code, I noticed that two other platforms already have a local bounce buffer support in the form of the "local_mem" allocator. Specifically, TMIO and SM501 use this on a few other ARM boards with 16KB or 128KB of local SRAM that can be accessed from the OHCI and from the CPU. While this is not the same problem as on sa1111, I could not find a reason why we can't re-use the existing implementation but replace the physical SRAM address mapping with a locally allocated DMA buffer. There are two main downsides: - rather than using a dynamically sized pool, this buffer needs to be allocated at probe time using a fixed size. Without having any idea of what it should be, I picked a size of 64KB, which is between what the other two OHCI front-ends use in their SRAM. If anyone has a better idea what that size is reasonable, this can be trivially changed. - Previously, only USB transfers to unaddressable memory needed to go through the bounce buffer, now all of them do, which may impact runtime performance for USB endpoints that do a lot of transfers. On the upside, the local_mem support uses write-combining buffers, which should be a bit faster for transfers to the device compared to normal uncached coherent memory as used in dmabounce. Cc: Linus Walleij Cc: Russell King Cc: Christoph Hellwig Cc: Laurentiu Tudor Cc: linux-usb@vger.kernel.org Signed-off-by: Arnd Bergmann Reviewed-by: Greg Kroah-Hartman Acked-by: Alan Stern Signed-off-by: Christoph Hellwig

ARM: Add Krait L2 register accessor functions

2018-10-17T20:14:33Z

Krait CPUs have a handful of L2 cache controller registers that live behind a cp15 based indirection register. First you program the indirection register (l2cpselr) to point the L2 'window' register (l2cpdr) at what you want to read/write. Then you read/write the 'window' register to do what you want. The l2cpselr register is not banked per-cpu so we must lock around accesses to it to prevent other CPUs from re-pointing l2cpdr underneath us. Cc: Mark Rutland Cc: Russell King Acked-by: Bjorn Andersson Signed-off-by: Stephen Boyd Signed-off-by: Sricharan R Tested-by: Craig Tatlor Signed-off-by: Stephen Boyd

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

ARM/clk: move the ICST library to drivers/clk

2017-04-07T09:58:12Z

This moves the ICST clock divider helper library from arch/arm/common to drivers/clk/versatile so it is maintained with the other clock drivers. We keep the structure as a helper library intact and do not fuse it with the clk-icst.c Versatile ICST clock driver: there may be other users out there that need to use this library for their clocking, and then it will be helpful to keep the library contained. (The icst.[c|h] files could just be moved to drivers/clk/lib or a similar location to share the library.) Acked-by: Stephen Boyd Signed-off-by: Linus Walleij

ARM/dmaengine: edma: Merge the two drivers under drivers/dma/

2015-10-14T14:27:11Z

Move the code out from arch/arm/common and merge it inside of the dmaengine driver. This change is done with as minimal (if eny) functional change to the code as possible to avoid introducing regression. Signed-off-by: Peter Ujfalusi Acked-by: Tony Lindgren Signed-off-by: Vinod Koul

ARM: davinci: move private EDMA API to arm/common

2013-06-18T05:22:03Z

Move mach-davinci/dma.c to common/edma.c so it can be used by OMAP (specifically AM33xx) as well. Signed-off-by: Matt Porter Acked-by: Chris Ball # davinci_mmc.c Acked-by: Mark Brown Acked-by: Olof Johansson [nsekhar@ti.com: dropped davinci sffsdr changes] Signed-off-by: Sekhar Nori

irqchip: Move ARM VIC to drivers/irqchip

2013-01-12T16:52:14Z

Now that we have drivers/irqchip, move VIC irqchip to drivers/irqchip. Signed-off-by: Rob Herring Cc: Russell King Cc: Thomas Gleixner

irqchip: Move ARM GIC to drivers/irqchip

2013-01-12T16:47:31Z

Now that we have drivers/irqchip, move GIC irqchip to drivers/irqchip. This is necessary to share the GIC with arm and arm64. Signed-off-by: Rob Herring Cc: Russell King Cc: Thomas Gleixner

ARM: config: sort select statements alphanumerically

2012-10-13T16:11:28Z

As suggested by Andrew Morton: This is a pet peeve of mine. Any time there's a long list of items (header file inclusions, kconfig entries, array initalisers, etc) and someone wants to add a new item, they *always* go and stick it at the end of the list. Guys, don't do this. Either put the new item into a randomly-chosen position or, probably better, alphanumerically sort the list. lets sort all our select statements alphanumerically. This commit was created by the following perl: while (<>) { while (/\\\s*$/) { $_ .= <>; } undef %selects if /^\s*config\s+/; if (/^\s+select\s+(\w+).*/) { if (defined($selects{$1})) { if ($selects{$1} eq $_) { print STDERR "Warning: removing duplicated $1 entry\n"; } else { print STDERR "Error: $1 differently selected\n". "\tOld: $selects{$1}\n". "\tNew: $_\n"; exit 1; } } $selects{$1} = $_; next; } if (%selects and (/^\s*$/ or /^\s+help/ or /^\s+---help---/ or /^endif/ or /^endchoice/)) { foreach $k (sort (keys %selects)) { print "$selects{$k}"; } undef %selects; } print; } if (%selects) { foreach $k (sort (keys %selects)) { print "$selects{$k}"; } } It found two duplicates: Warning: removing duplicated S5P_SETUP_MIPIPHY entry Warning: removing duplicated HARDIRQS_SW_RESEND entry and they are identical duplicates, hence the shrinkage in the diffstat of two lines. We have four testers reporting success of this change (Tony, Stephen, Linus and Sekhar.) Acked-by: Jason Cooper Acked-by: Tony Lindgren Acked-by: Stephen Warren Acked-by: Linus Walleij Acked-by: Sekhar Nori Signed-off-by: Russell King