BMC/Intel-BMC/linux.git/arch/mips/kernel/r4k_fpu.S, branch dev

MIPS: Push .set mips64r* into the functions needing it

2015-03-27T18:42:42+00:00

The {save,restore}_fp_context{,32} functions require that the assembler allows the use of sdc instructions on any FP register, and this is acomplished by setting the arch to mips64r2 or mips64r6 (using MIPS_ISA_ARCH_LEVEL_RAW). However this has the effect of enabling the assembler to use mips64 instructions in the expansion of pseudo-instructions. This was done in the (now-reverted) commit eec43a224cf1 "MIPS: Save/restore MSA context around signals" which led to my mistakenly believing that there was an assembler bug, when in reality the assembler was just emitting mips64 instructions. Avoid the issue for future commits which will add code to r4k_fpu.S by pushing the .set MIPS_ISA_ARCH_LEVEL_RAW directives into the functions that require it, and remove the spurious assertion declaring the assembler bug. Signed-off-by: Paul Burton [james.hogan@imgtec.com: Rebase on v4.0-rc1 and reword commit message to reflect use of MIPS_ISA_ARCH_LEVEL_RAW] Signed-off-by: James Hogan Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9612/ Signed-off-by: Ralf Baechle

MIPS: kernel: r4k_fpu: Add support for MIPS R6

2015-02-17T15:37:27+00:00

Add the MIPS R6 related preprocessor definitions for FPU signal related functions. MIPS R6 only has FR=1 so avoid checking that bit on the C0/Status register. Signed-off-by: Leonid Yegoshin Signed-off-by: Markos Chandras

MIPS: Fix build with binutils 2.24.51+

2014-11-07T14:07:36+00:00

Starting with version 2.24.51.20140728 MIPS binutils complain loudly about mixing soft-float and hard-float object files, leading to this build failure since GCC is invoked with "-msoft-float" on MIPS: {standard input}: Warning: .gnu_attribute 4,3 requires `softfloat' LD arch/mips/alchemy/common/built-in.o mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o uses -msoft-float (set by arch/mips/alchemy/common/prom.o), arch/mips/alchemy/common/sleeper.o uses -mhard-float To fix this, we detect if GAS is new enough to support "-msoft-float" command option, and if it does, we can let GCC pass it to GAS; but then we also need to sprinkle the files which make use of floating point registers with the necessary ".set hardfloat" directives. Signed-off-by: Manuel Lauss Cc: Linux-MIPS Cc: Matthew Fortune Cc: Markos Chandras Cc: Maciej W. Rozycki Patchwork: https://patchwork.linux-mips.org/patch/8355/ Signed-off-by: Ralf Baechle

Revert "MIPS: Save/restore MSA context around signals"

2014-06-26T09:48:18+00:00

This reverts commit eec43a224cf1 "MIPS: Save/restore MSA context around signals" and the MSA parts of ca750649e08c "MIPS: kernel: signal: Prevent save/restore FPU context in user memory" (the restore path of which appears incorrect anyway...). The reverted patch took care not to break compatibility with userland users of struct sigcontext, but inadvertantly changed the offset of the uc_sigmask field of struct ucontext. Thus Linux v3.15 breaks the userland ABI. The MSA context will need to be saved via some other opt-in mechanism, but for now revert the change to reduce the fallout. This will have minimal impact upon use of MSA since the only supported CPU which includes it (the P5600) is 32-bit and therefore requires that the experimental CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option be selected before the kernel will set FR=1 for a task, a requirement for MSA use. Thus the users of MSA are limited to known small groups of people & this patch won't be breaking any previously working MSA-using userland outside of experimental settings. [ralf@linux-mips.org: Fixed rejects.] Cc: stable@vger.kernel.org Reported-by: Joseph S. Myers Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7107/ Signed-off-by: Ralf Baechle

Merge branch '3.14-fixes' into mips-for-linux-next

2014-03-31T16:17:33+00:00

MIPS: Fix gigaton of warning building with microMIPS.

2014-03-31T16:17:12+00:00

With binutils 2.24 the attempt to switch with microMIPS mode to MIPS III mode through .set mips3 results in *lots* of warnings like {standard input}: Assembler messages: {standard input}:397: Warning: the 64-bit MIPS architecture does not support the `smartmips' extension during a kernel build. Fixed by using .set arch=r4000 instead. This breaks support for building the kernel with binutils 2.13 which was supported for 32 bit kernels only anyway and 2.14 which was a bad vintage for MIPS anyway. Signed-off-by: Ralf Baechle

MIPS: Save/restore MSA context around signals

2014-03-26T22:09:11+00:00

This patch extends sigcontext in order to hold the most significant 64 bits of each vector register in addition to the MSA control & status register. The least significant 64 bits are already saved as the scalar FP context. This makes things a little awkward since the least & most significant 64 bits of each vector register are not contiguous in memory. Thus the copy_u & insert instructions are used to transfer the values of the most significant 64 bits via GP registers. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6533/ Signed-off-by: Ralf Baechle

MIPS: FPU: Fix conflict of register usage

2014-03-14T16:49:23+00:00

In _restore_fp_context/_restore_fp_context32, t0 is used for both CP0_Status and CP1_FCSR. This is a mistake and cause FP exeception on boot, so fix it. Signed-off-by: Huacai Chen Tested-by: Aaro Koskinen Tested-by: Andreas Barth Cc: John Crispin Cc: Steven J. Hill Cc: Aurelien Jarno Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang Cc: Zhangjin Wu Patchwork: https://patchwork.linux-mips.org/patch/6507/ Signed-off-by: Ralf Baechle

MIPS: Replace CONFIG_MIPS64 and CONFIG_MIPS32_R2

2014-03-14T16:49:16+00:00

Commit 597ce1723e0f ("MIPS: Support for 64-bit FP with O32 binaries") introduced references to two undefined Kconfig macros. CONFIG_MIPS32_R2 should clearly be replaced with CONFIG_CPU_MIPS32_R2. And CONFIG_MIPS64 should be replaced with CONFIG_64BIT. Signed-off-by: Paul Bolle Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/6522/ Tested-by: Aaro Koskinen Signed-off-by: Ralf Baechle

MIPS: Support for 64-bit FP with O32 binaries

2014-01-13T22:40:56+00:00

CPUs implementing MIPS32 R2 may include a 64-bit FPU, just as MIPS64 CPUs do. In order to preserve backwards compatibility a 64-bit FPU will act like a 32-bit FPU (by accessing doubles from the least significant 32 bits of an even-odd pair of FP registers) when the Status.FR bit is zero, again just like a mips64 CPU. The standard O32 ABI is defined expecting a 32-bit FPU, however recent toolchains support use of a 64-bit FPU from an O32 MIPS32 executable. When an ELF executable is built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF header. With this patch the kernel will check the EF_MIPS_FP64 flag when executing an O32 binary, and set Status.FR accordingly. The addition of O32 64-bit FP support lessens the opportunity for optimisation in the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is introduced to allow this support to be disabled for those that don't require it. Inspired by an earlier patch by Leonid Yegoshin, but implemented more cleanly & correctly. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/6154/ Signed-off-by: Ralf Baechle