linux-toradex.git/arch/mips/math-emu, branch v3.17 Linux kernel for Apalis and Colibri modules MIPS: Fix MFC1 & MFHC1 emulation for 64-bit MIPS systems 2014-09-26T09:33:11+00:00 Paul Burton paul.burton@imgtec.com 2014-09-24T09:45:37+00:00 c8c0da6bdf0f0d6f59fc23aab6ee373a131df82d Commit bbd426f542cb "MIPS: Simplify FP context access" modified the SIFROMREG & SIFROMHREG macros such that they return unsigned rather than signed 32b integers. I had believed that to be fine, but inadvertently missed the MFC1 & MFHC1 cases which write to a struct pt_regs regs element. On MIPS32 this is fine, but on 64 bit those saved regs' fields are 64 bit wide. Using unsigned values caused the 32 bit value from the FP register to be zero rather than sign extended as the architecture specifies, causing incorrect emulation of the MFC1 & MFHc1 instructions. Fix by reintroducing the casts to signed integers, and therefore the sign extension. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: stable@vger.kernel.org # v3.15+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7848/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Commit bbd426f542cb "MIPS: Simplify FP context access" modified the
SIFROMREG & SIFROMHREG macros such that they return unsigned rather
than signed 32b integers. I had believed that to be fine, but
inadvertently missed the MFC1 & MFHC1 cases which write to a struct
pt_regs regs element. On MIPS32 this is fine, but on 64 bit those
saved regs' fields are 64 bit wide. Using unsigned values caused the
32 bit value from the FP register to be zero rather than sign extended
as the architecture specifies, causing incorrect emulation of the
MFC1 & MFHc1 instructions. Fix by reintroducing the casts to signed
integers, and therefore the sign extension.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: stable@vger.kernel.org # v3.15+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7848/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: math-emu: Fix instruction decoding. 2014-07-30T17:13:35+00:00 Rob Kendrick rob.kendrick@codethink.co.uk 2014-07-23T09:03:58+00:00 c3b9b945e02e011c63522761e91133ea43eb6939 Tested-by: Aurelien Jarno <aurelien@aurel32.net> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: math-emu: Reduce code duplication. 2014-06-26T09:47:55+00:00 Ralf Baechle ralf@linux-mips.org 2014-06-13T14:36:45+00:00 fb738f8544d8ceb3599598f3500f33bf6ff2fca4 The fix in the preceeding commit did do exactly the same thing in two places showing some code cleanup was due. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
The fix in the preceeding commit did do exactly the same thing in two
places showing some code cleanup was due.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: math-emu: Work around limitations of older GCC. 2014-06-16T11:47:47+00:00 Ralf Baechle ralf@linux-mips.org 2014-06-13T14:26:14+00:00 91496ea9f86f55e87be78ecc88c8a6b7e3802601 Older GCC doesn't get named initializations of anonymous structs right, that is members are not initializable in the containing structure through name however old style initializations are working fine. The issue exists with gcc up to 4.5.x. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Older GCC doesn't get named initializations of anonymous structs right,
that is members are not initializable in the containing structure through
name however old style initializations are working fine.

The issue exists with gcc up to 4.5.x.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: OCTEON: Enable use of FPU 2014-05-30T19:01:09+00:00 David Daney david.daney@cavium.com 2014-05-28T21:52:04+00:00 a36d8225bceba4b7be47ade34d175945f85cffbc Some versions of the assembler will not assemble CFC1 for OCTEON, so override the ISA for these. Add r4k_fpu.o to handle low level FPU initialization. Modify octeon_switch.S to save the FPU registers. And include r4k_switch.S to pick up more FPU support. Get rid of "#define cpu_has_fpu 0" Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Andreas Herrmann <andreas.herrmann@caviumnetworks.com> Cc: linux-mips@linux-mips.org Cc: James Hogan <james.hogan@imgtec.com> Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7006/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Some versions of the assembler will not assemble CFC1 for OCTEON, so
override the ISA for these.

Add r4k_fpu.o to handle low level FPU initialization.

Modify octeon_switch.S to save the FPU registers.  And include
r4k_switch.S to pick up more FPU support.

Get rid of "#define cpu_has_fpu		0"

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7006/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: math-emu: Add IEEE754 exception statistics to debugfs 2014-05-30T09:55:23+00:00 Deng-Cheng Zhu dengcheng.zhu@imgtec.com 2014-05-29T19:26:45+00:00 c410352699e2a1adc77969f19eb63030e610d048 Sometimes it's useful to let the user, while doing performance research, know what in the IEEE754 exceptions has caused many times of FP emulation when running a specific application. This patch adds 5 more files to /sys/kernel/debug/mips/fpuemustats/, whose filenames begin with "ieee754". These stats are in addition to the existing cp1ops, cp1xops, errors, loads and stores, which may not be useful in understanding the reasons of ieee754 exceptions. [ralf@linux-mips.org: Fixed reject due to other changes to the kernel FP assist software.] Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Steven.Hill@imgtec.com Cc: james.hogan@imgtec.com Patchwork: http://patchwork.linux-mips.org/patch/7044/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Sometimes it's useful to let the user, while doing performance research,
know what in the IEEE754 exceptions has caused many times of FP emulation
when running a specific application. This patch adds 5 more files to
/sys/kernel/debug/mips/fpuemustats/, whose filenames begin with "ieee754".
These stats are in addition to the existing cp1ops, cp1xops, errors, loads
and stores, which may not be useful in understanding the reasons of ieee754
exceptions.

[ralf@linux-mips.org: Fixed reject due to other changes to the kernel
FP assist software.]

Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven.Hill@imgtec.com
Cc: james.hogan@imgtec.com
Patchwork: http://patchwork.linux-mips.org/patch/7044/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: math-emu: Reduce microMIPS bloat. 2014-05-23T13:12:38+00:00 Ralf Baechle ralf@linux-mips.org 2014-04-30T09:09:44+00:00 70e4c234aa48e11c0575364939dfab4cb27b2172 Move microMIPS32_to_MIPS32() to a separate file which only gets built for mipsMIPS configurations; for other configurations the optimizer eleminates calls to microMIPS32_to_MIPS32(). Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Move microMIPS32_to_MIPS32() to a separate file which only gets built
for mipsMIPS configurations; for other configurations the optimizer
eleminates calls to microMIPS32_to_MIPS32().

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: math-emu: Switch to using the MIPS rounding modes. 2014-05-23T13:12:38+00:00 Ralf Baechle ralf@linux-mips.org 2014-04-30T09:21:55+00:00 56a6473339dbd2e908cf8c6f2856d5de2bf8d15b Previously math-emu was using the IEEE-754 constants internally. These were differing by having the constants for rounding to +/- infinity switched, so a conversion was necessary. This would be entirely avoidable if the MIPS constants were used throughout, so get rid of the bloat. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Previously math-emu was using the IEEE-754 constants internally.  These
were differing by having the constants for rounding to +/- infinity
switched, so a conversion was necessary.  This would be entirely
avoidable if the MIPS constants were used throughout, so get rid of
the bloat.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: math-emu: Nuke alternative names for IEEE-754 rounding modes. 2014-05-23T13:12:37+00:00 Ralf Baechle ralf@linux-mips.org 2014-04-29T23:17:19+00:00 aef3fb76aa1390ef864db888d06d8fcd5510df2d Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Sort out mm_isBranchInstr. 2014-05-23T13:12:37+00:00 Ralf Baechle ralf@linux-mips.org 2014-04-29T13:21:24+00:00 76fbfc318de2eb0eb4823095ece020f999a17c63 mm_isBranchInstr() did reside in the math emu code even though it logically is separate and also is used outside the math emu code. In addition GCC 4.9.0 leaves the following unnnecessarily bloated function body for a non-microMIPS configuration: <mm_isBranchInstr>: 105c: afa50004 sw a1,4(sp) 1060: afa60008 sw a2,8(sp) 1064: afa7000c sw a3,12(sp) 1068: 03e00008 jr ra 106c: 00001021 move v0,zero which stores arguments that are never going to be used on the stack frame. Move mm_isBranchInstr() from cp1emu.c to branch.c, then split mm_isBranchInstr() into a __mm_isBranchInstr() core and a mm_isBranchInstr() wrapper inline function which only invokes __mm_isBranchInstr() on microMIPS configurations. This shaves off 112 bytes off the kernel and improves code flow a bit. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
mm_isBranchInstr() did reside in the math emu code even though it logically
is separate and also is used outside the math emu code.  In addition GCC 4.9.0
leaves the following unnnecessarily bloated function body for a non-microMIPS
configuration:

<mm_isBranchInstr>:
    105c:       afa50004        sw      a1,4(sp)
    1060:       afa60008        sw      a2,8(sp)
    1064:       afa7000c        sw      a3,12(sp)
    1068:       03e00008        jr      ra
    106c:       00001021        move    v0,zero

which stores arguments that are never going to be used on the stack frame.

Move mm_isBranchInstr() from cp1emu.c to branch.c, then split mm_isBranchInstr()
into a __mm_isBranchInstr() core and a mm_isBranchInstr() wrapper inline function
which only invokes __mm_isBranchInstr() on microMIPS configurations.

This shaves off 112 bytes off the kernel and improves code flow a bit.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>