kernel.git/arch/powerpc/math-emu, branch linux-6.0.y

powerpc/math_emu/efp: Include module.h

2022-10-21T10:38:55Z

[ Upstream commit cfe0d370e0788625ce0df3239aad07a2506c1796 ] When building with a recent version of clang, there are a couple of errors around the call to module_init(): arch/powerpc/math-emu/math_efp.c:927:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int] module_init(spe_mathemu_init); ^ int arch/powerpc/math-emu/math_efp.c:927:13: error: a parameter list without types is only allowed in a function definition module_init(spe_mathemu_init); ^ 2 errors generated. module_init() is a macro, which is not getting expanded because module.h is not included in this file. Add the include so that the macro can expand properly, clearing up the build failure. Fixes: ac6f120369ff ("powerpc/85xx: Workaroudn e500 CPU erratum A005") [chleroy: added fixes tag] Reported-by: kernel test robot Signed-off-by: Nathan Chancellor Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Reviewed-by: Christophe Leroy Link: https://lore.kernel.org/r/8403854a4c187459b2f4da3537f51227b70b9223.1662134272.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin

powerpc/64s: avoid reloading (H)SRR registers if they are still valid

2021-06-24T14:06:55Z

When an interrupt is taken, the SRR registers are set to return to where it left off. Unless they are modified in the meantime, or the return address or MSR are modified, there is no need to reload these registers when returning from interrupt. Introduce per-CPU flags that track the validity of SRR and HSRR registers. These are cleared when returning from interrupt, when using the registers for something else (e.g., OPAL calls), when adjusting the return address or MSR of a context, and when context switching (which changes the return address and MSR). This improves the performance of interrupt returns. Signed-off-by: Nicholas Piggin [mpe: Fold in fixup patch from Nick] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com

powerpc/math: Fix missing __user qualifier for get_user() and other sparse warnings

2021-03-29T02:22:12Z

Sparse reports the following problems: arch/powerpc/math-emu/math.c:228:21: warning: Using plain integer as NULL pointer arch/powerpc/math-emu/math.c:228:31: warning: Using plain integer as NULL pointer arch/powerpc/math-emu/math.c:228:41: warning: Using plain integer as NULL pointer arch/powerpc/math-emu/math.c:228:51: warning: Using plain integer as NULL pointer arch/powerpc/math-emu/math.c:237:13: warning: incorrect type in initializer (different address spaces) arch/powerpc/math-emu/math.c:237:13: expected unsigned int [noderef] __user *_gu_addr arch/powerpc/math-emu/math.c:237:13: got unsigned int [usertype] * arch/powerpc/math-emu/math.c:226:1: warning: symbol 'do_mathemu' was not declared. Should it be static? Add missing __user qualifier when casting pointer used in get_user() Use NULL instead of 0 to initialise opX local variables. Add a prototype for do_mathemu() (Added in processor.h like sparc) Reported-by: kernel test robot Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/e4d1aae7604d89c98a52dfd8ce8443462e595670.1615809591.git.christophe.leroy@csgroup.eu

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

2019-05-30T18:26:32Z

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: math-emu: remove unneeded header search paths

2019-01-14T09:39:27Z

The header search path -I. in kernel Makefiles is very suspicious; it allows the compiler to search for headers in the top of $(srctree), where obviously no header file exists. -Iinclude/math-emu seems unnecessary because all files include headers in the form of #include . I was able to build without these header search paths. Signed-off-by: Masahiro Yamada Signed-off-by: Michael Ellerman

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

Replace with globally

2016-12-24T19:46:01Z

This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*' sed -i -e "s!$PATT!#include !" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro Signed-off-by: Linus Torvalds

powerpc: Correct emulated mtfsf instruction

2014-04-07T00:33:11Z

The emulated (CONFIG_MATH_EMULATION_FULL) PowerPC Floating Point instruction mtfsf does not correctly copy bits from its source register to the Floating Point Status and Register (FPSCR). The error is in the preparation of the mask used to select the bits to be copied from the source to the FPSCR. Execution of the mtfsf instruction does not produce the same results on a MPC8548 platform (emulated floating point) as on MPC7410 or 440EP platforms (hardware floating point). This error has been detected using a Freescale MPC8548 based platform and the patch below tested using that platform. The patch is based on the patch(es) provided by Gabriel Paubert and analysis by Gabriel, James Yang and David Laight. Signed-off-by: Stephen Chivers Signed-off-by: Gabriel Paubert Tested-by: Stephen Chivers Signed-off-by: Benjamin Herrenschmidt

powerpc: fix e500 SPE float SIGFPE generation

2014-01-08T00:43:42Z

The e500 SPE floating-point emulation code is called from SPEFloatingPointException and SPEFloatingPointRoundException in arch/powerpc/kernel/traps.c. Those functions have support for generating SIGFPE, but do_spe_mathemu and speround_handler don't generate a return value to indicate that this should be done. Such a return value should depend on whether an exception is raised that has been set via prctl to generate SIGFPE. This patch adds the relevant logic in these functions so that SIGFPE is generated as expected by the glibc testsuite. Signed-off-by: Joseph Myers Signed-off-by: Scott Wood

powerpc: fix e500 SPE float to integer and fixed-point conversions

2014-01-08T00:38:59Z

The e500 SPE floating-point emulation code has several problems in how it handles conversions to integer and fixed-point fractional types. There are the following 20 relevant instructions. These can convert to signed or unsigned 32-bit integers, either rounding towards zero (as correct for C casts from floating-point to integer) or according to the current rounding mode, or to signed or unsigned 32-bit fixed-point values (values in the range [-1, 1) or [0, 1)). For conversion from double precision there are also instructions to convert to 64-bit integers, rounding towards zero, although as far as I know those instructions are completely theoretical (they are only defined for implementations that support both SPE and classic 64-bit, and I'm not aware of any such hardware even though the architecture definition permits that combination). #define EFSCTUI 0x2d4 #define EFSCTSI 0x2d5 #define EFSCTUF 0x2d6 #define EFSCTSF 0x2d7 #define EFSCTUIZ 0x2d8 #define EFSCTSIZ 0x2da #define EVFSCTUI 0x294 #define EVFSCTSI 0x295 #define EVFSCTUF 0x296 #define EVFSCTSF 0x297 #define EVFSCTUIZ 0x298 #define EVFSCTSIZ 0x29a #define EFDCTUIDZ 0x2ea #define EFDCTSIDZ 0x2eb #define EFDCTUI 0x2f4 #define EFDCTSI 0x2f5 #define EFDCTUF 0x2f6 #define EFDCTSF 0x2f7 #define EFDCTUIZ 0x2f8 #define EFDCTSIZ 0x2fa The emulation code, for the instructions that come in variants rounding either towards zero or according to the current rounding direction, uses "if (func & 0x4)" as a condition for using _FP_ROUND (otherwise _FP_ROUND_ZERO is used). The condition is correct, but the code it controls isn't. Whether _FP_ROUND or _FP_ROUND_ZERO is used makes no difference, as the effect of those soft-fp macros is to round an intermediate floating-point result using the low three bits (the last one sticky) of the working format. As these operations are dealing with a freshly unpacked floating-point input, those low bits are zero and no rounding occurs. The emulation code then uses the FP_TO_INT_* macros for the actual integer conversion, with the effect of always rounding towards zero; for rounding according to the current rounding direction, it should be using FP_TO_INT_ROUND_*. The instructions in question have semantics defined (in the Power ISA documents) for out-of-range values and NaNs: out-of-range values saturate and NaNs are converted to zero. The emulation does nothing to follow those semantics for NaNs (the soft-fp handling is to treat them as infinities), and messes up the saturation semantics. For single-precision conversion to integers, (((func & 0x3) != 0) || SB_s) is the condition used for doing a signed conversion. The first part is correct, but the second isn't: negative numbers should result in saturation to 0 when converted to unsigned. Double-precision conversion to 64-bit integers correctly uses ((func & 0x1) == 0). Double-precision conversion to 32-bit integers uses (((func & 0x3) != 0) || DB_s), with correct first part and incorrect second part. And vector float conversion to integers uses (((func & 0x3) != 0) || SB0_s) (and similar for the other vector element), where the sign bit check is again wrong. The incorrect handling of negative numbers converted to unsigned was introduced in commit afc0a07d4a283599ac3a6a31d7454e9baaeccca0. The rationale given there was a C testcase with cast from float to unsigned int. Conversion of out-of-range floating-point numbers to integer types in C is undefined behavior in the base standard, defined in Annex F to produce an unspecified value. That is, the C testcase used to justify that patch is incorrect - there is no ISO C requirement for a particular value resulting from this conversion - and in any case, the correct semantics for such emulation are the semantics for the instruction (unsigned saturation, which is what it does in hardware when the emulation is disabled). The conversion to fixed-point values has its own problems. That code doesn't try to do a full emulation; it relies on the trap handler only being called for arguments that are infinities, NaNs, subnormal or out of range. That's fine, but the logic ((vb.wp[1] >> 23) == 0xff && ((vb.wp[1] & 0x7fffff) > 0)) for NaN detection won't detect negative NaNs as being NaNs (the same applies for the double-precision case), and subnormals are mapped to 0 rather than respecting the rounding mode; the code should also explicitly raise the "invalid" exception. The code for vectors works by executing the scalar float instruction with the trapping disabled, meaning at least subnormals won't be handled correctly. As well as all those problems in the main emulation code, the rounding handler - used to emulate rounding upward and downward when not supported in hardware and when no higher priority exception occurred - has its own problems. * It gets called in some cases even for the instructions rounding to zero, and then acts according to the current rounding mode when it should just leave alone the truncated result provided by hardware. * It presumes that the result is a single-precision, double-precision or single-precision vector as appropriate for the instruction type, determines the sign of the result accordingly, and then adjusts the result based on that sign and the rounding mode. - In the single-precision cases at least the sign determination for an integer result is the same as for a floating-point result; in the double-precision case, converted to 32-bit integer or fixed point, the sign of a double-precision value is in the high part of the register but it's the low part of the register that has the result of the conversion. - If the result is unsigned fixed-point, its sign may be wrongly determined as negative (does not actually cause problems, because inexact unsigned fixed-point results with the high bit set can only appear when converting from double, in which case the sign determination is instead wrongly using the high part of the register). - If the sign of the result is correctly determined as negative, any adjustment required to change the truncated result to one correct for the rounding mode should be in the opposite direction for two's-complement integers as for sign-magnitude floating-point values. - And if the integer result is zero, the correct sign can only be determined by examining the original operand, and not at all (as far as I can tell) if the operand and result are the same register. This patch fixes all these problems (as far as possible, given the inability to determine the correct sign in the rounding handler when the truncated result is 0, the conversion is to a signed type and the truncated result has overwritten the original operand). Conversion to fixed-point now uses full emulation, and does not use "asm" in the vector case; the semantics are exactly those of converting to integer according to the current rounding direction, once the exponent has been adjusted, so the code makes such an adjustment then uses the FP_TO_INT_ROUND macros. The testcase I used for verifying that the instructions (other than the theoretical conversions to 64-bit integers) produce the correct results is at . Signed-off-by: Joseph Myers Signed-off-by: Scott Wood