2012-10-25 06:43:56

by “tiejun.chen”

[permalink] [raw]
Subject: [PATCH 1/3] powerpc/book3e: load critical/machine/debug exception stack

We always alloc critical/machine/debug check exceptions. This is
different from the normal exception. So we should load these exception
stack properly like we did for booke.

Signed-off-by: Tiejun Chen <[email protected]>
---
arch/powerpc/kernel/exceptions-64e.S | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 4684e33..43b654a 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -36,6 +36,30 @@
*/
#define SPECIAL_EXC_FRAME_SIZE INT_FRAME_SIZE

+/* only on book3e */
+#define DBG_STACK_BASE dbgirq_ctx
+#define MC_STACK_BASE mcheckirq_ctx
+#define CRIT_STACK_BASE critirq_ctx
+
+#ifdef CONFIG_SMP
+#define BOOK3E_LOAD_EXC_LEVEL_STACK(level) \
+ std r14,PACA_EX##level+EX_R14(r13); \
+ mfspr r14,SPRN_PIR; \
+ slwi r14,r14,3; \
+ LOAD_REG_ADDR(r10, level##_STACK_BASE); \
+ add r10,r10,r14; \
+ ld r10,0(r10); \
+ addi r10,r10,THREAD_SIZE; \
+ std r10,PACA_DBG_STACK(r13); \
+ ld r14,PACA_EX##level+EX_R14(r13);
+#else
+#define BOOK3E_LOAD_EXC_LEVEL_STACK(level) \
+ LOAD_REG_ADDR(r10, level##_STACK_BASE); \
+ ld r10,0(r10); \
+ addi r10,r10,THREAD_SIZE; \
+ std r10,PACA_DBG_STACK(r13);
+#endif
+
/* Exception prolog code for all exceptions */
#define EXCEPTION_PROLOG(n, intnum, type, addition) \
mtspr SPRN_SPRG_##type##_SCRATCH,r13; /* get spare registers */ \
@@ -68,18 +92,21 @@
#define SPRN_GDBELL_SRR1 SPRN_GSRR1

#define CRIT_SET_KSTACK \
+ BOOK3E_LOAD_EXC_LEVEL_STACK(CRIT); \
ld r1,PACA_CRIT_STACK(r13); \
subi r1,r1,SPECIAL_EXC_FRAME_SIZE;
#define SPRN_CRIT_SRR0 SPRN_CSRR0
#define SPRN_CRIT_SRR1 SPRN_CSRR1

#define DBG_SET_KSTACK \
+ BOOK3E_LOAD_EXC_LEVEL_STACK(DBG); \
ld r1,PACA_DBG_STACK(r13); \
subi r1,r1,SPECIAL_EXC_FRAME_SIZE;
#define SPRN_DBG_SRR0 SPRN_DSRR0
#define SPRN_DBG_SRR1 SPRN_DSRR1

#define MC_SET_KSTACK \
+ BOOK3E_LOAD_EXC_LEVEL_STACK(MC); \
ld r1,PACA_MC_STACK(r13); \
subi r1,r1,SPECIAL_EXC_FRAME_SIZE;
#define SPRN_MC_SRR0 SPRN_MCSRR0
--
1.7.9.5


2012-10-25 06:43:51

by “tiejun.chen”

[permalink] [raw]
Subject: [PATCH 2/3] powerpc/book3e: support kgdb for kernel space

Currently we need to skip this for supporting KGDB.

Signed-off-by: Tiejun Chen <[email protected]>
---
arch/powerpc/kernel/exceptions-64e.S | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 43b654a..c5564d4 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -566,11 +566,14 @@ kernel_dbg_exc:
rfdi

/* Normal debug exception */
+1:
+#ifndef CONFIG_KGDB
/* XXX We only handle coming from userspace for now since we can't
* quite save properly an interrupted kernel state yet
*/
-1: andi. r14,r11,MSR_PR; /* check for userspace again */
+ andi. r14,r11,MSR_PR; /* check for userspace again */
beq kernel_dbg_exc; /* if from kernel mode */
+#endif

/* Now we mash up things to make it look like we are coming on a
* normal exception
--
1.7.9.5

2012-10-25 06:44:04

by “tiejun.chen”

[permalink] [raw]
Subject: [PATCH 3/3] kgdb/kgdbts: support ppc64

We can't look up the address of the entry point of the function simply
via that function symbol for all architectures.

For PPC64 ABI, actually there is a function descriptors structure.

A function descriptor is a three doubleword data structure that contains
the following values:
* The first doubleword contains the address of the entry point of
the function.
* The second doubleword contains the TOC base address for
the function.
* The third doubleword contains the environment pointer for
languages such as Pascal and PL/1.

So we should call a wapperred dereference_function_descriptor() to get
the address of the entry point of the function.

Note this is also safe for other architecture after refer to
"include/asm-generic/sections.h" since:

dereference_function_descriptor(p) always is (p) if without arched definition.

Signed-off-by: Tiejun Chen <[email protected]>
---
drivers/misc/kgdbts.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
index 3aa9a96..4799e1f 100644
--- a/drivers/misc/kgdbts.c
+++ b/drivers/misc/kgdbts.c
@@ -103,6 +103,7 @@
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/module.h>
+#include <asm/sections.h>

#define v1printk(a...) do { \
if (verbose) \
@@ -222,6 +223,7 @@ static unsigned long lookup_addr(char *arg)
addr = (unsigned long)do_fork;
else if (!strcmp(arg, "hw_break_val"))
addr = (unsigned long)&hw_break_val;
+ addr = (unsigned long )dereference_function_descriptor((void *)addr);
return addr;
}

--
1.7.9.5