[RFC v2 PATCH 1/1] ARM64: KGDB: Add FP/SIMD debug support
vijay.kilari at gmail.com
vijay.kilari at gmail.com
Mon Nov 18 07:06:57 EST 2013
From: Vijaya Kumar K <Vijaya.Kumar at caviumnetworks.com>
Add KGDB debug support for FP/SIMD processor.This support
only debugging of FP/SIMD in kernel mode.
With this patch one can view or set FP/SIMD registers in
kernel context
Signed-off-by: Vijaya Kumar K <Vijaya.Kumar at caviumnetworks.com>
---
arch/arm64/include/asm/fpsimd.h | 1 +
arch/arm64/kernel/fpsimd.c | 5 ++
arch/arm64/kernel/kgdb.c | 105 +++++++++++++++++++++++++--------------
3 files changed, 73 insertions(+), 38 deletions(-)
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index 609bc44..5039d6d 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -60,6 +60,7 @@ extern void fpsimd_load_state(struct fpsimd_state *state);
extern void fpsimd_thread_switch(struct task_struct *next);
extern void fpsimd_flush_thread(void);
extern void fpsimd_reload_fpstate(void);
+extern int fpsimd_thread_state(void);
#endif
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 5b13c17..27604c1 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -124,6 +124,11 @@ void fpsimd_flush_thread(void)
set_thread_flag(TIF_FOREIGN_FPSTATE);
}
+int fpsimd_thread_state(void)
+{
+ return (current->mm && test_thread_flag(TIF_FOREIGN_FPSTATE)) ? 1 : 0;
+}
+
void fpsimd_reload_fpstate(void)
{
preempt_disable();
diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
index f10f2ba..5e34852 100644
--- a/arch/arm64/kernel/kgdb.c
+++ b/arch/arm64/kernel/kgdb.c
@@ -23,6 +23,14 @@
#include <linux/kdebug.h>
#include <linux/kgdb.h>
#include <asm/traps.h>
+#include <asm/fpsimd.h>
+
+#ifdef CONFIG_KERNEL_MODE_NEON
+/*
+ * Structure to hold FP/SIMD register contents
+ */
+struct fpsimd_state kgdb_fpsimd_regs;
+#endif
struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
{ "x0", 8, offsetof(struct pt_regs, regs[0])},
@@ -59,40 +67,40 @@ struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
{ "sp", 8, offsetof(struct pt_regs, sp)},
{ "pc", 8, offsetof(struct pt_regs, pc)},
{ "pstate", 4, offsetof(struct pt_regs, pstate)},
- { "v0", 16, -1 },
- { "v1", 16, -1 },
- { "v2", 16, -1 },
- { "v3", 16, -1 },
- { "v4", 16, -1 },
- { "v5", 16, -1 },
- { "v6", 16, -1 },
- { "v7", 16, -1 },
- { "v8", 16, -1 },
- { "v9", 16, -1 },
- { "v10", 16, -1 },
- { "v11", 16, -1 },
- { "v12", 16, -1 },
- { "v13", 16, -1 },
- { "v14", 16, -1 },
- { "v15", 16, -1 },
- { "v16", 16, -1 },
- { "v17", 16, -1 },
- { "v18", 16, -1 },
- { "v19", 16, -1 },
- { "v20", 16, -1 },
- { "v21", 16, -1 },
- { "v22", 16, -1 },
- { "v23", 16, -1 },
- { "v24", 16, -1 },
- { "v25", 16, -1 },
- { "v26", 16, -1 },
- { "v27", 16, -1 },
- { "v28", 16, -1 },
- { "v29", 16, -1 },
- { "v30", 16, -1 },
- { "v31", 16, -1 },
- { "fpsr", 4, -1 },
- { "fpcr", 4, -1 },
+ { "v0", 16, offsetof(struct fpsimd_state, vregs[0])},
+ { "v1", 16, offsetof(struct fpsimd_state, vregs[1])},
+ { "v2", 16, offsetof(struct fpsimd_state, vregs[2])},
+ { "v3", 16, offsetof(struct fpsimd_state, vregs[3])},
+ { "v4", 16, offsetof(struct fpsimd_state, vregs[4])},
+ { "v5", 16, offsetof(struct fpsimd_state, vregs[5])},
+ { "v6", 16, offsetof(struct fpsimd_state, vregs[6])},
+ { "v7", 16, offsetof(struct fpsimd_state, vregs[7])},
+ { "v8", 16, offsetof(struct fpsimd_state, vregs[8])},
+ { "v9", 16, offsetof(struct fpsimd_state, vregs[9])},
+ { "v10", 16, offsetof(struct fpsimd_state, vregs[10])},
+ { "v11", 16, offsetof(struct fpsimd_state, vregs[11])},
+ { "v12", 16, offsetof(struct fpsimd_state, vregs[12])},
+ { "v13", 16, offsetof(struct fpsimd_state, vregs[13])},
+ { "v14", 16, offsetof(struct fpsimd_state, vregs[14])},
+ { "v15", 16, offsetof(struct fpsimd_state, vregs[15])},
+ { "v16", 16, offsetof(struct fpsimd_state, vregs[16])},
+ { "v17", 16, offsetof(struct fpsimd_state, vregs[17])},
+ { "v18", 16, offsetof(struct fpsimd_state, vregs[18])},
+ { "v19", 16, offsetof(struct fpsimd_state, vregs[19])},
+ { "v20", 16, offsetof(struct fpsimd_state, vregs[20])},
+ { "v21", 16, offsetof(struct fpsimd_state, vregs[21])},
+ { "v22", 16, offsetof(struct fpsimd_state, vregs[22])},
+ { "v23", 16, offsetof(struct fpsimd_state, vregs[23])},
+ { "v24", 16, offsetof(struct fpsimd_state, vregs[24])},
+ { "v25", 16, offsetof(struct fpsimd_state, vregs[25])},
+ { "v26", 16, offsetof(struct fpsimd_state, vregs[26])},
+ { "v27", 16, offsetof(struct fpsimd_state, vregs[27])},
+ { "v28", 16, offsetof(struct fpsimd_state, vregs[28])},
+ { "v29", 16, offsetof(struct fpsimd_state, vregs[29])},
+ { "v30", 16, offsetof(struct fpsimd_state, vregs[30])},
+ { "v31", 16, offsetof(struct fpsimd_state, vregs[31])},
+ { "fpsr", 4, offsetof(struct fpsimd_state, fpsr)},
+ { "fpcr", 4, offsetof(struct fpsimd_state, fpcr)},
};
char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
@@ -100,11 +108,22 @@ char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
if (regno >= DBG_MAX_REG_NUM || regno < 0)
return NULL;
- if (dbg_reg_def[regno].offset != -1)
+ if (dbg_reg_def[regno].offset != -1 && regno < _GP_REGS)
memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
dbg_reg_def[regno].size);
- else
+ else {
+#ifdef CONFIG_KERNEL_MODE_NEON
+ if (fpsimd_thread_state()) {
+ fpsimd_save_state(&kgdb_fpsimd_regs);
+ memcpy(mem, (void *)&kgdb_fpsimd_regs +
+ dbg_reg_def[regno].offset,
+ dbg_reg_def[regno].size);
+ } else
+ memset(mem, 0, dbg_reg_def[regno].size);
+#else
memset(mem, 0, dbg_reg_def[regno].size);
+#endif
+ }
return dbg_reg_def[regno].name;
}
@@ -113,9 +132,19 @@ int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
if (regno >= DBG_MAX_REG_NUM || regno < 0)
return -EINVAL;
- if (dbg_reg_def[regno].offset != -1)
+ if (dbg_reg_def[regno].offset != -1 && regno < _GP_REGS)
memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
- dbg_reg_def[regno].size);
+ dbg_reg_def[regno].size);
+#ifdef CONFIG_KERNEL_MODE_NEON
+ else {
+ if (fpsimd_thread_state()) {
+ memcpy((void *)&kgdb_fpsimd_regs +
+ dbg_reg_def[regno].offset,
+ mem, dbg_reg_def[regno].size);
+ fpsimd_load_state(&kgdb_fpsimd_regs);
+ }
+ }
+#endif
return 0;
}
--
1.7.9.5
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