From 8c13f5999997d36fc5fb296809efedc13c801704 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 28 Jul 2016 10:57:38 +0800 Subject: [PATCH] powerpc/ptrace: Enable support for NT_PPC_CVMX This patch enables support for TM checkpointed VMX register set ELF core note NT_PPC_CVMX based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding a register set REGSET_CVMX in powerpc corresponding to the ELF core note section added. It implements the get, set and active functions for this new register set added. Signed-off-by: Anshuman Khandual Signed-off-by: Simon Guo Signed-off-by: Michael Ellerman --- arch/powerpc/include/uapi/asm/elf.h | 1 + arch/powerpc/kernel/ptrace.c | 158 ++++++++++++++++++++++++++++ 2 files changed, 159 insertions(+) diff --git a/arch/powerpc/include/uapi/asm/elf.h b/arch/powerpc/include/uapi/asm/elf.h index c2d21d11c2d2..ecb4e84cb22c 100644 --- a/arch/powerpc/include/uapi/asm/elf.h +++ b/arch/powerpc/include/uapi/asm/elf.h @@ -91,6 +91,7 @@ #define ELF_NGREG 48 /* includes nip, msr, lr, etc. */ #define ELF_NFPREG 33 /* includes fpscr */ +#define ELF_NVMX 34 /* includes all vector registers */ typedef unsigned long elf_greg_t64; typedef elf_greg_t64 elf_gregset_t64[ELF_NGREG]; diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index b216c397b84f..6e42137c0175 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -64,6 +64,8 @@ struct pt_regs_offset { {.name = STR(gpr##num), .offset = offsetof(struct pt_regs, gpr[num])} #define REG_OFFSET_END {.name = NULL, .offset = 0} +#define TVSO(f) (offsetof(struct thread_vr_state, f)) + static const struct pt_regs_offset regoffset_table[] = { GPR_OFFSET_NAME(0), GPR_OFFSET_NAME(1), @@ -1147,6 +1149,151 @@ static int tm_cfpr_set(struct task_struct *target, target->thread.fp_state.fpscr = buf[32]; return 0; } + +/** + * tm_cvmx_active - get active number of registers in CVMX + * @target: The target task. + * @regset: The user regset structure. + * + * This function checks for the active number of available + * regisers in checkpointed VMX category. + */ +static int tm_cvmx_active(struct task_struct *target, + const struct user_regset *regset) +{ + if (!cpu_has_feature(CPU_FTR_TM)) + return -ENODEV; + + if (!MSR_TM_ACTIVE(target->thread.regs->msr)) + return 0; + + return regset->n; +} + +/** + * tm_cvmx_get - get CMVX registers + * @target: The target task. + * @regset: The user regset structure. + * @pos: The buffer position. + * @count: Number of bytes to copy. + * @kbuf: Kernel buffer to copy from. + * @ubuf: User buffer to copy into. + * + * This function gets in transaction checkpointed VMX registers. + * + * When the transaction is active 'vr_state' and 'vr_save' hold + * the checkpointed values for the current transaction to fall + * back on if it aborts in between. The userspace interface buffer + * layout is as follows. + * + * struct data { + * vector128 vr[32]; + * vector128 vscr; + * vector128 vrsave; + *}; + */ +static int tm_cvmx_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + int ret; + + BUILD_BUG_ON(TVSO(vscr) != TVSO(vr[32])); + + if (!cpu_has_feature(CPU_FTR_TM)) + return -ENODEV; + + if (!MSR_TM_ACTIVE(target->thread.regs->msr)) + return -ENODATA; + + /* Flush the state */ + flush_fp_to_thread(target); + flush_altivec_to_thread(target); + flush_tmregs_to_thread(target); + + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &target->thread.vr_state, 0, + 33 * sizeof(vector128)); + if (!ret) { + /* + * Copy out only the low-order word of vrsave. + */ + union { + elf_vrreg_t reg; + u32 word; + } vrsave; + memset(&vrsave, 0, sizeof(vrsave)); + vrsave.word = target->thread.vrsave; + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &vrsave, + 33 * sizeof(vector128), -1); + } + + return ret; +} + +/** + * tm_cvmx_set - set CMVX registers + * @target: The target task. + * @regset: The user regset structure. + * @pos: The buffer position. + * @count: Number of bytes to copy. + * @kbuf: Kernel buffer to copy into. + * @ubuf: User buffer to copy from. + * + * This function sets in transaction checkpointed VMX registers. + * + * When the transaction is active 'vr_state' and 'vr_save' hold + * the checkpointed values for the current transaction to fall + * back on if it aborts in between. The userspace interface buffer + * layout is as follows. + * + * struct data { + * vector128 vr[32]; + * vector128 vscr; + * vector128 vrsave; + *}; + */ +static int tm_cvmx_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int ret; + + BUILD_BUG_ON(TVSO(vscr) != TVSO(vr[32])); + + if (!cpu_has_feature(CPU_FTR_TM)) + return -ENODEV; + + if (!MSR_TM_ACTIVE(target->thread.regs->msr)) + return -ENODATA; + + flush_fp_to_thread(target); + flush_altivec_to_thread(target); + flush_tmregs_to_thread(target); + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &target->thread.vr_state, 0, + 33 * sizeof(vector128)); + if (!ret && count > 0) { + /* + * We use only the low-order word of vrsave. + */ + union { + elf_vrreg_t reg; + u32 word; + } vrsave; + memset(&vrsave, 0, sizeof(vrsave)); + vrsave.word = target->thread.vrsave; + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &vrsave, + 33 * sizeof(vector128), -1); + if (!ret) + target->thread.vrsave = vrsave.word; + } + + return ret; +} #endif /* @@ -1167,6 +1314,7 @@ enum powerpc_regset { #ifdef CONFIG_PPC_TRANSACTIONAL_MEM REGSET_TM_CGPR, /* TM checkpointed GPR registers */ REGSET_TM_CFPR, /* TM checkpointed FPR registers */ + REGSET_TM_CVMX, /* TM checkpointed VMX registers */ #endif }; @@ -1213,6 +1361,11 @@ static const struct user_regset native_regsets[] = { .size = sizeof(double), .align = sizeof(double), .active = tm_cfpr_active, .get = tm_cfpr_get, .set = tm_cfpr_set }, + [REGSET_TM_CVMX] = { + .core_note_type = NT_PPC_TM_CVMX, .n = ELF_NVMX, + .size = sizeof(vector128), .align = sizeof(vector128), + .active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set + }, #endif }; @@ -1450,6 +1603,11 @@ static const struct user_regset compat_regsets[] = { .size = sizeof(double), .align = sizeof(double), .active = tm_cfpr_active, .get = tm_cfpr_get, .set = tm_cfpr_set }, + [REGSET_TM_CVMX] = { + .core_note_type = NT_PPC_TM_CVMX, .n = ELF_NVMX, + .size = sizeof(vector128), .align = sizeof(vector128), + .active = tm_cvmx_active, .get = tm_cvmx_get, .set = tm_cvmx_set + }, #endif }; -- 2.20.1