Re: [PATCH v4 1/9] selftests/powerpc: Test the preservation of FPU and VMX regs across syscall
flat view
From: Naveen N. Rao <hidden>
Date: 2016-02-15 16:59:35
On 2016/02/15 04:07PM, Cyril Bur wrote:
quoted hunk ↗ jump to hunk
Test that the non volatile floating point and Altivec registers get correctly preserved across the fork() syscall. fork() works nicely for this purpose, the registers should be the same for both parent and child Signed-off-by: Cyril Bur <redacted> --- tools/testing/selftests/powerpc/Makefile | 3 +- tools/testing/selftests/powerpc/basic_asm.h | 30 ++++ tools/testing/selftests/powerpc/math/.gitignore | 2 + tools/testing/selftests/powerpc/math/Makefile | 14 ++ tools/testing/selftests/powerpc/math/fpu_asm.S | 161 +++++++++++++++++ tools/testing/selftests/powerpc/math/fpu_syscall.c | 90 ++++++++++ tools/testing/selftests/powerpc/math/vmx_asm.S | 193 +++++++++++++++++++++ tools/testing/selftests/powerpc/math/vmx_syscall.c | 92 ++++++++++ 8 files changed, 584 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/basic_asm.h create mode 100644 tools/testing/selftests/powerpc/math/.gitignore create mode 100644 tools/testing/selftests/powerpc/math/Makefile create mode 100644 tools/testing/selftests/powerpc/math/fpu_asm.S create mode 100644 tools/testing/selftests/powerpc/math/fpu_syscall.c create mode 100644 tools/testing/selftests/powerpc/math/vmx_asm.S create mode 100644 tools/testing/selftests/powerpc/math/vmx_syscall.cdiff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile index 0c2706b..19e8191 100644 --- a/tools/testing/selftests/powerpc/Makefile +++ b/tools/testing/selftests/powerpc/Makefile@@ -22,7 +22,8 @@ SUB_DIRS = benchmarks \ switch_endian \ syscalls \ tm \ - vphn + vphn \ + math endifdiff --git a/tools/testing/selftests/powerpc/basic_asm.h b/tools/testing/selftests/powerpc/basic_asm.h new file mode 100644 index 0000000..f243da0 --- /dev/null +++ b/tools/testing/selftests/powerpc/basic_asm.h@@ -0,0 +1,30 @@ +#include <ppc-asm.h> +#include <asm/unistd.h> + +#define LOAD_REG_IMMEDIATE(reg,expr) \ + lis reg,(expr)@highest; \ + ori reg,reg,(expr)@higher; \ + rldicr reg,reg,32,31; \ + oris reg,reg,(expr)@high; \ + ori reg,reg,(expr)@l; + +/* It is very important to note here that _extra is the extra amount of + * stack space needed. + * This space must be accessed at sp + 32!
This looks to be specific to ABIv2. Is this series limited to ppc64le? If so, you might want to ensure this only builds there. Also: #define PPC_ABIV2_MIN_STACK_SIZE 32 or just: #define PPC_MIN_STACK 32 ... is helpful. And, you might want to base the rest of your code that use PUSH_BASIC_STACK() on that. If we ever want to have these tests run anywhere else, that'll help a lot. (See further below)
quoted hunk ↗ jump to hunk
+ */ +#define PUSH_BASIC_STACK(_extra) \ + mflr r0; \ + std r0,16(sp); \ + stdu sp,-(_extra + 32)(sp); \ + mfcr r0; \ + stw r0,8(sp); \ + std 2,24(sp);
^^ Better to use r2 here and below.
quoted hunk ↗ jump to hunk
+ +#define POP_BASIC_STACK(_extra) \ + ld 2,24(sp); \ + lwz r0,8(sp); \ + mtcr r0; \ + addi sp,sp,(_extra + 32); \ + ld r0,16(sp); \ + mtlr r0; +diff --git a/tools/testing/selftests/powerpc/math/.gitignore b/tools/testing/selftests/powerpc/math/.gitignore new file mode 100644 index 0000000..b19b269 --- /dev/null +++ b/tools/testing/selftests/powerpc/math/.gitignore@@ -0,0 +1,2 @@ +fpu_syscall +vmx_syscalldiff --git a/tools/testing/selftests/powerpc/math/Makefile b/tools/testing/selftests/powerpc/math/Makefile new file mode 100644 index 0000000..418bef1 --- /dev/null +++ b/tools/testing/selftests/powerpc/math/Makefile@@ -0,0 +1,14 @@ +TEST_PROGS := fpu_syscall vmx_syscall + +all: $(TEST_PROGS) + +$(TEST_PROGS): ../harness.c +$(TEST_PROGS): CFLAGS += -O2 -g -pthread -m64 -maltivec + +fpu_syscall: fpu_asm.S +vmx_syscall: vmx_asm.S + +include ../../lib.mk + +clean: + rm -f $(TEST_PROGS) *.odiff --git a/tools/testing/selftests/powerpc/math/fpu_asm.S b/tools/testing/selftests/powerpc/math/fpu_asm.S new file mode 100644 index 0000000..8733874 --- /dev/null +++ b/tools/testing/selftests/powerpc/math/fpu_asm.S@@ -0,0 +1,161 @@ +/* + * Copyright 2015, Cyril Bur, IBM Corp. + * + * 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. + */ + +#include "../basic_asm.h" + +#define PUSH_FPU(pos) \ + stfd f14,pos(sp); \ + stfd f15,pos+8(sp); \ + stfd f16,pos+16(sp); \ + stfd f17,pos+24(sp); \ + stfd f18,pos+32(sp); \ + stfd f19,pos+40(sp); \ + stfd f20,pos+48(sp); \ + stfd f21,pos+56(sp); \ + stfd f22,pos+64(sp); \ + stfd f23,pos+72(sp); \ + stfd f24,pos+80(sp); \ + stfd f25,pos+88(sp); \ + stfd f26,pos+96(sp); \ + stfd f27,pos+104(sp); \ + stfd f28,pos+112(sp); \ + stfd f29,pos+120(sp); \ + stfd f30,pos+128(sp); \ + stfd f31,pos+136(sp); + +#define POP_FPU(pos) \ + lfd f14,pos(sp); \ + lfd f15,pos+8(sp); \ + lfd f16,pos+16(sp); \ + lfd f17,pos+24(sp); \ + lfd f18,pos+32(sp); \ + lfd f19,pos+40(sp); \ + lfd f20,pos+48(sp); \ + lfd f21,pos+56(sp); \ + lfd f22,pos+64(sp); \ + lfd f23,pos+72(sp); \ + lfd f24,pos+80(sp); \ + lfd f25,pos+88(sp); \ + lfd f26,pos+96(sp); \ + lfd f27,pos+104(sp); \ + lfd f28,pos+112(sp); \ + lfd f29,pos+120(sp); \ + lfd f30,pos+128(sp); \ + lfd f31,pos+136(sp); + +#Careful calling this, it will 'clobber' fpu (by design) +#Don't call this from C +FUNC_START(load_fpu) + lfd f14,0(r3) + lfd f15,8(r3) + lfd f16,16(r3) + lfd f17,24(r3) + lfd f18,32(r3) + lfd f19,40(r3) + lfd f20,48(r3) + lfd f21,56(r3) + lfd f22,64(r3) + lfd f23,72(r3) + lfd f24,80(r3) + lfd f25,88(r3) + lfd f26,96(r3) + lfd f27,104(r3) + lfd f28,112(r3) + lfd f29,120(r3) + lfd f30,128(r3) + lfd f31,136(r3) + blr +FUNC_END(load_fpu) + +FUNC_START(check_fpu) + mr r4,r3 + li r3,1 #assume a bad result + lfd f0,0(r4) + fcmpu cr1,f0,f14 + bne cr1,1f + lfd f0,8(r4) + fcmpu cr1,f0,f15 + bne cr1,1f + lfd f0,16(r4) + fcmpu cr1,f0,f16 + bne cr1,1f + lfd f0,24(r4) + fcmpu cr1,f0,f17 + bne cr1,1f + lfd f0,32(r4) + fcmpu cr1,f0,f18 + bne cr1,1f + lfd f0,40(r4) + fcmpu cr1,f0,f19 + bne cr1,1f + lfd f0,48(r4) + fcmpu cr1,f0,f20 + bne cr1,1f + lfd f0,56(r4) + fcmpu cr1,f0,f21 + bne cr1,1f + lfd f0,64(r4) + fcmpu cr1,f0,f22 + bne cr1,1f + lfd f0,72(r4) + fcmpu cr1,f0,f23 + bne cr1,1f + lfd f0,80(r4) + fcmpu cr1,f0,f24 + bne cr1,1f + lfd f0,88(r4) + fcmpu cr1,f0,f25 + bne cr1,1f + lfd f0,96(r4) + fcmpu cr1,f0,f26 + bne cr1,1f + lfd f0,104(r4) + fcmpu cr1,f0,f27 + bne cr1,1f + lfd f0,112(r4) + fcmpu cr1,f0,f28 + bne cr1,1f + lfd f0,120(r4) + fcmpu cr1,f0,f29 + bne cr1,1f + lfd f0,128(r4) + fcmpu cr1,f0,f30 + bne cr1,1f + lfd f0,136(r4) + fcmpu cr1,f0,f31 + bne cr1,1f + li r3,0 #Sucess!!! +1: blr + +FUNC_START(test_fpu) + #r3 holds pointer to where to put the result of fork + #r4 holds pointer to the pid + #f14-f31 are non volatiles + PUSH_BASIC_STACK(256) + std r3,40(sp) #Address of darray
So, this could be: PUSH_BASIC_STACK(256) std r3,PPC_MIN_STACK+8(sp) ... though I wonder why there is +8 here? - Naveen