blackbird-op-linux/arch/powerpc/lib/copyuser_64.S, branch master

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

powerpc/64: Copy as much as possible in __copy_tofrom_user

2018-08-07T14:32:36+00:00

In __copy_tofrom_user, if we encounter an exception on a store, we stop copying and return the number of bytes not copied. However, if the store is wider than one byte and is to an unaligned address, it is possible that the store operand overlaps a page boundary and the exception occurred on the latter part of the store operand, meaning that it would be possible to copy a few more bytes. Since copy_to_user is generally expected to copy as much as possible, it would be better to copy those extra few bytes. This adds code to do that. Since this edge case is not performance-critical, the code has been written to be compact rather than as fast as possible. Signed-off-by: Paul Mackerras Signed-off-by: Michael Ellerman

selftests/powerpc/64: Test all paths through copy routines

2018-08-07T14:32:35+00:00

The hand-coded assembler 64-bit copy routines include feature sections that select one code path or another depending on which CPU we are executing on. The self-tests for these copy routines end up testing just one path. This adds a mechanism for selecting any desired code path at compile time, and makes 2 or 3 versions of each test, each using a different code path, so as to cover all the possible paths. Signed-off-by: Paul Mackerras [mpe: Add -mcpu=power4 to CFLAGS for older compilers] Signed-off-by: Michael Ellerman

powerpc/64: Make exception table clearer in __copy_tofrom_user_base

2018-08-07T14:32:34+00:00

This aims to make the generation of exception table entries for the loads and stores in __copy_tofrom_user_base clearer and easier to verify. Instead of having a series of local labels on the loads and stores, with a series of corresponding labels later for the exception handlers, we now use macros to generate exception table entries at the point of each load and store that could potentially trap. We do this with the macros lex (load exception) and stex (store exception). These macros are used right before the load or store to which they apply. Some complexity is introduced by the fact that we have some more work to do after hitting an exception, because we need to calculate and return the number of bytes not copied. The code uses r3 as the current pointer into the destination buffer, that is, the address of the first byte of the destination that has not been modified. However, at various points in the copy loops, r3 can be 4, 8, 16 or 24 bytes behind that point. To express this offset in an understandable way, we define a symbol r3_offset which is updated at various points so that it equal to the difference between the address of the first unmodified byte of the destination and the value in r3. (In fact it only needs to be accurate at the point of each lex or stex macro invocation.) The rules for updating r3_offset are as follows: * It starts out at 0 * An addi r3,r3,N instruction decreases r3_offset by N * A store instruction (stb, sth, stw, std) to N(r3) increases r3_offset by the width of the store (1, 2, 4, 8) * A store with update instruction (stbu, sthu, stwu, stdu) to N(r3) sets r3_offset to the width of the store. There is some trickiness to the way that the lex and stex macros and the associated exception handlers work. I would have liked to use the current value of r3_offset in the name of the symbol used as the exception handler, as in ".Lld_exc_$(r3_offset)" and then have symbols .Lld_exc_0, .Lld_exc_8, .Lld_exc_16 etc. corresponding to the offsets that needed to be added to r3. However, I couldn't see a way to do that with gas. Instead, the exception handler address is .Lld_exc - r3_offset or .Lst_exc - r3_offset, that is, the distance ahead of .Lld_exc/.Lst_exc that we start executing is equal to the amount that we need to add to r3. This works because r3_offset is always a small multiple of 4, and our instructions are 4 bytes long. This means that before .Lld_exc and .Lst_exc, we have a sequence of instructions that increments r3 by 4, 8, 16 or 24 depending on where we start. The sequence increments r3 by 4 per instruction (on average). We also replace the exception table for the 4k copy loop by a macro per load or store. These loads and stores all use exactly the same exception handler, which simply resets the argument registers r3, r4 and r5 to there original values and re-does the whole copy using the slower loop. Signed-off-by: Paul Mackerras Signed-off-by: Michael Ellerman

powerpc: clean inclusions of asm/feature-fixups.h

2018-07-30T12:48:17+00:00

files not using feature fixup don't need asm/feature-fixups.h files using feature fixup need asm/feature-fixups.h Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: move ASM_CONST and stringify_in_c() into asm-const.h

2018-07-30T12:48:16+00:00

This patch moves ASM_CONST() and stringify_in_c() into dedicated asm-const.h, then cleans all related inclusions. Signed-off-by: Christophe Leroy [mpe: asm-compat.h should include asm-const.h] Signed-off-by: Michael Ellerman

powerpc/64s: Set assembler machine type to POWER4

2018-03-31T13:47:49+00:00

Rather than override the machine type in .S code (which can hide wrong or ambiguous code generation for the target), set the type to power4 for all assembly. This also means we need to be careful not to build power4-only code when we're not building for Book3S, such as the "power7" versions of copyuser/page/memcpy. Signed-off-by: Nicholas Piggin [mpe: Fix Book3E build, don't build the "power7" variants for non-Book3S] Signed-off-by: Michael Ellerman

powerpc: get rid of zeroing, switch to RAW_COPY_USER

2017-04-06T19:08:42+00:00

Signed-off-by: Al Viro

powerpc: EX_TABLE macro for exception tables

2016-11-14T00:11:51+00:00

This macro is taken from s390, and allows more flexibility in changing exception table format. mpe: Put it in ppc_asm.h and only define one version using stringinfy_in_c(). Add some empty definitions and headers to keep the selftests happy. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2016-10-14T21:26:58+00:00

Pull kbuild updates from Michal Marek: - EXPORT_SYMBOL for asm source by Al Viro. This does bring a regression, because genksyms no longer generates checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is working on a patch to fix this. Plus, we are talking about functions like strcpy(), which rarely change prototypes. - Fixes for PPC fallout of the above by Stephen Rothwell and Nick Piggin - fixdep speedup by Alexey Dobriyan. - preparatory work by Nick Piggin to allow architectures to build with -ffunction-sections, -fdata-sections and --gc-sections - CONFIG_THIN_ARCHIVES support by Stephen Rothwell - fix for filenames with colons in the initramfs source by me. * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits) initramfs: Escape colons in depfile ppc: there is no clear_pages to export powerpc/64: whitelist unresolved modversions CRCs kbuild: -ffunction-sections fix for archs with conflicting sections kbuild: add arch specific post-link Makefile kbuild: allow archs to select link dead code/data elimination kbuild: allow architectures to use thin archives instead of ld -r kbuild: Regenerate genksyms lexer kbuild: genksyms fix for typeof handling fixdep: faster CONFIG_ search ia64: move exports to definitions sparc32: debride memcpy.S a bit [sparc] unify 32bit and 64bit string.h sparc: move exports to definitions ppc: move exports to definitions arm: move exports to definitions s390: move exports to definitions m68k: move exports to definitions alpha: move exports to actual definitions x86: move exports to actual definitions ...