powerpc/ptrace: Enable support for TM SPR state

This patch enables support for TM SPR state related ELF core
note NT_PPC_TM_SPR based ptrace requests through PTRACE_GETREGSET,
PTRACE_SETREGSET calls. This is achieved through adding a register
set REGSET_TM_SPR 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>

diff --git a/arch/powerpc/include/uapi/asm/elf.h b/arch/powerpc/include/uapi/asm/elf.h
index 1549172..e703c64 100644 (file)
--- a/arch/powerpc/include/uapi/asm/elf.h
+++ b/arch/powerpc/include/uapi/asm/elf.h
@@ -93,6 +93,7 @@
 #define ELF_NFPREG     33      /* includes fpscr */
 #define ELF_NVMX       34      /* includes all vector registers */
 #define ELF_NVSX       32      /* includes all VSX registers */
+#define ELF_NTMSPRREG  3       /* include tfhar, tfiar, texasr */
 
 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 df6afe7..f654224 100644 (file)
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -66,6 +66,7 @@ struct pt_regs_offset {
 
 #define TVSO(f)        (offsetof(struct thread_vr_state, f))
 #define TFSO(f)        (offsetof(struct thread_fp_state, f))
+#define TSO(f) (offsetof(struct thread_struct, f))
 
 static const struct pt_regs_offset regoffset_table[] = {
        GPR_OFFSET_NAME(0),
@@ -1412,7 +1413,136 @@ static int tm_cvsx_set(struct task_struct *target,
 
        return ret;
 }
-#endif
+
+/**
+ * tm_spr_active - get active number of registers in TM SPR
+ * @target:    The target task.
+ * @regset:    The user regset structure.
+ *
+ * This function checks the active number of available
+ * regisers in the transactional memory SPR category.
+ */
+static int tm_spr_active(struct task_struct *target,
+                        const struct user_regset *regset)
+{
+       if (!cpu_has_feature(CPU_FTR_TM))
+               return -ENODEV;
+
+       return regset->n;
+}
+
+/**
+ * tm_spr_get - get the TM related SPR 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 transactional memory related SPR registers.
+ * The userspace interface buffer layout is as follows.
+ *
+ * struct {
+ *     u64             tm_tfhar;
+ *     u64             tm_texasr;
+ *     u64             tm_tfiar;
+ * };
+ */
+static int tm_spr_get(struct task_struct *target,
+                     const struct user_regset *regset,
+                     unsigned int pos, unsigned int count,
+                     void *kbuf, void __user *ubuf)
+{
+       int ret;
+
+       /* Build tests */
+       BUILD_BUG_ON(TSO(tm_tfhar) + sizeof(u64) != TSO(tm_texasr));
+       BUILD_BUG_ON(TSO(tm_texasr) + sizeof(u64) != TSO(tm_tfiar));
+       BUILD_BUG_ON(TSO(tm_tfiar) + sizeof(u64) != TSO(ckpt_regs));
+
+       if (!cpu_has_feature(CPU_FTR_TM))
+               return -ENODEV;
+
+       /* Flush the states */
+       flush_fp_to_thread(target);
+       flush_altivec_to_thread(target);
+       flush_tmregs_to_thread(target);
+
+       /* TFHAR register */
+       ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                               &target->thread.tm_tfhar, 0, sizeof(u64));
+
+       /* TEXASR register */
+       if (!ret)
+               ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                               &target->thread.tm_texasr, sizeof(u64),
+                               2 * sizeof(u64));
+
+       /* TFIAR register */
+       if (!ret)
+               ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                               &target->thread.tm_tfiar,
+                               2 * sizeof(u64), 3 * sizeof(u64));
+       return ret;
+}
+
+/**
+ * tm_spr_set - set the TM related SPR 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 transactional memory related SPR registers.
+ * The userspace interface buffer layout is as follows.
+ *
+ * struct {
+ *     u64             tm_tfhar;
+ *     u64             tm_texasr;
+ *     u64             tm_tfiar;
+ * };
+ */
+static int tm_spr_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 tests */
+       BUILD_BUG_ON(TSO(tm_tfhar) + sizeof(u64) != TSO(tm_texasr));
+       BUILD_BUG_ON(TSO(tm_texasr) + sizeof(u64) != TSO(tm_tfiar));
+       BUILD_BUG_ON(TSO(tm_tfiar) + sizeof(u64) != TSO(ckpt_regs));
+
+       if (!cpu_has_feature(CPU_FTR_TM))
+               return -ENODEV;
+
+       /* Flush the states */
+       flush_fp_to_thread(target);
+       flush_altivec_to_thread(target);
+       flush_tmregs_to_thread(target);
+
+       /* TFHAR register */
+       ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                               &target->thread.tm_tfhar, 0, sizeof(u64));
+
+       /* TEXASR register */
+       if (!ret)
+               ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                               &target->thread.tm_texasr, sizeof(u64),
+                               2 * sizeof(u64));
+
+       /* TFIAR register */
+       if (!ret)
+               ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+                               &target->thread.tm_tfiar,
+                                2 * sizeof(u64), 3 * sizeof(u64));
+       return ret;
+}
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
 /*
  * These are our native regset flavors.
@@ -1434,6 +1564,7 @@ enum powerpc_regset {
        REGSET_TM_CFPR,         /* TM checkpointed FPR registers */
        REGSET_TM_CVMX,         /* TM checkpointed VMX registers */
        REGSET_TM_CVSX,         /* TM checkpointed VSX registers */
+       REGSET_TM_SPR,          /* TM specific SPR registers */
 #endif
 };
 
@@ -1490,6 +1621,11 @@ static const struct user_regset native_regsets[] = {
                .size = sizeof(double), .align = sizeof(double),
                .active = tm_cvsx_active, .get = tm_cvsx_get, .set = tm_cvsx_set
        },
+       [REGSET_TM_SPR] = {
+               .core_note_type = NT_PPC_TM_SPR, .n = ELF_NTMSPRREG,
+               .size = sizeof(u64), .align = sizeof(u64),
+               .active = tm_spr_active, .get = tm_spr_get, .set = tm_spr_set
+       },
 #endif
 };
 
@@ -1737,6 +1873,11 @@ static const struct user_regset compat_regsets[] = {
                .size = sizeof(double), .align = sizeof(double),
                .active = tm_cvsx_active, .get = tm_cvsx_get, .set = tm_cvsx_set
        },
+       [REGSET_TM_SPR] = {
+               .core_note_type = NT_PPC_TM_SPR, .n = ELF_NTMSPRREG,
+               .size = sizeof(u64), .align = sizeof(u64),
+               .active = tm_spr_active, .get = tm_spr_get, .set = tm_spr_set
+       },
 #endif
 };