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 <khandual@linux.vnet.ibm.com>
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Anshuman Khandual 2016-07-28 10:57:38 +08:00 committed by Michael Ellerman
parent 19cbcbf75a
commit 8c13f59999
2 changed files with 159 additions and 0 deletions

View file

@ -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];

View file

@ -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
};