ARCv2: ptrace: provide regset for accumulator/r30 regs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

3 files changed, 65 insertions, 3 deletions

diff --git a/arch/arc/include/uapi/asm/elf.h b/arch/arc/include/uapi/asm/elf.h
index 0037a587320d..06d95e611616 100644
--- a/arch/arc/include/uapi/asm/elf.h
+++ b/arch/arc/include/uapi/asm/elf.h
@@ -27,6 +27,7 @@ typedef unsigned long elf_greg_t;
 typedef unsigned long elf_fpregset_t;
 
 #define ELF_NGREG       (sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
+#define ELF_ARCV2REG    (sizeof(struct user_regs_arcv2) / sizeof(elf_greg_t))
 
 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
 
diff --git a/arch/arc/include/uapi/asm/ptrace.h b/arch/arc/include/uapi/asm/ptrace.h
index 0b3ef63d4a03..dd206e6b482c 100644
--- a/arch/arc/include/uapi/asm/ptrace.h
+++ b/arch/arc/include/uapi/asm/ptrace.h
@@ -47,6 +47,11 @@ struct user_regs_struct {
         unsigned long efa;      /* break pt addr, for break points in delay slots */
         unsigned long stop_pc;  /* give dbg stop_pc after ensuring brkpt trap */
 };
+
+struct user_regs_arcv2 {
+        unsigned long r30, r58, r59;
+};
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _UAPI__ASM_ARC_PTRACE_H */
diff --git a/arch/arc/kernel/ptrace.c b/arch/arc/kernel/ptrace.c
index 31150060d38b..5ee4676f135d 100644
--- a/arch/arc/kernel/ptrace.c
+++ b/arch/arc/kernel/ptrace.c
@@ -184,19 +184,75 @@ static int genregs_set(struct task_struct *target,
         return ret;
 }
 
+#ifdef CONFIG_ISA_ARCV2
+static int arcv2regs_get(struct task_struct *target,
+                       const struct user_regset *regset,
+                       unsigned int pos, unsigned int count,
+                       void *kbuf, void __user *ubuf)
+{
+        const struct pt_regs *regs = task_pt_regs(target);
+        int ret, copy_sz;
+
+        if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
+                copy_sz = sizeof(struct user_regs_arcv2);
+        else
+                copy_sz = 4;    /* r30 only */
+
+        /*
+         * itemized copy not needed like above as layout of regs (r30,r58,r59)
+         * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
+         */
+        ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs->r30,
+                                  0, copy_sz);
+
+        return ret;
+}
+
+static int arcv2regs_set(struct task_struct *target,
+                       const struct user_regset *regset,
+                       unsigned int pos, unsigned int count,
+                       const void *kbuf, const void __user *ubuf)
+{
+        const struct pt_regs *regs = task_pt_regs(target);
+        int ret, copy_sz;
+
+        if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
+                copy_sz = sizeof(struct user_regs_arcv2);
+        else
+                copy_sz = 4;    /* r30 only */
+
+        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
+                                  0, copy_sz);
+
+        return ret;
+}
+
+#endif
+
 enum arc_getset {
-        REGSET_GENERAL,
+        REGSET_CMN,
+        REGSET_ARCV2,
 };
 
 static const struct user_regset arc_regsets[] = {
-        [REGSET_GENERAL] = {
+        [REGSET_CMN] = {
                .core_note_type = NT_PRSTATUS,
                .n = ELF_NGREG,
                .size = sizeof(unsigned long),
                .align = sizeof(unsigned long),
                .get = genregs_get,
                .set = genregs_set,
-        }
+        },
+#ifdef CONFIG_ISA_ARCV2
+        [REGSET_ARCV2] = {
+               .core_note_type = NT_ARC_V2,
+               .n = ELF_ARCV2REG,
+               .size = sizeof(unsigned long),
+               .align = sizeof(unsigned long),
+               .get = arcv2regs_get,
+               .set = arcv2regs_set,
+        },
+#endif
 };
 
 static const struct user_regset_view user_arc_view = {