[PATCH 2.6.17-rc1-mm2] m32r: Fix pt_regs for!COFNIG_ISA_DSP_LEVEL2 target

From: Hirokazu Takata
Date: Thu Apr 13 2006 - 09:43:20 EST

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Hi,

This modification is required to fix debugging function for
m32r targets with !CONFIG_ISA_DSP_LEVEL2, by unifying
'struct pt_regs' and 'struct sigcontext' size for all M32R ISA.

Some m32r processor core with !CONFIG_ISA_DSP_LEVEL2 configuration
has only single accumulator a0 (ex. VDEC2 core, M32102 core, etc.),
the others with CONFIG_ISA_DSP_LEVEL2 has two accumulators, a0 and a1.

This means there are two variations of thread context.
So far, we reduced and changed stackframe size at a syscall
for their context size. However, this causes a problem that
a GDB for processors with CONFIG_ISA_DSP_LEVEL2 cannot be used
for processors with !CONFIG_ISA_DSP_LEVEL2.

>From the viewpoint of GDB support, we should reduce such variation of
stackframe size for simplicity.
In this patch, dummy members are added to 'struct pt_regs' and
'struct sigcontext' to adjust their size for !CONFIG_ISA_DSP_LEVEL2.

This modification is also a one step for a GDB update in future.
Currently, on the m32r, GDB can access process's context by using
ptrace functions in a simple way of register by register access.
By unifying stackframe size, we have a possibility to make use of
ptrace functions of not only a single register access but also
block register access, PTRACE_{GETREGS,PUTREGS}.

However, for this purpose, we might have to modify stackframe
structure some more; for example, PSW (processor status word) register
should be pre-processed before pushing to stack at a syscall, and so on.
In this case, we must update carefully both kernel and GDB at a time...

Signed-off-by: Hayato Fujiwara <fujiwara@xxxxxxxxxxxxxx>
Signed-off-by: Hirokazu Takata <takata@xxxxxxxxxxxxxx>
Cc: Kei Sakamoto <ksakamot@xxxxxxxxxxxxxx>
---

arch/m32r/kernel/entry.S | 49 ++++++++++++++++--------------------------
arch/m32r/kernel/signal.c | 4 +++
include/asm-m32r/assembler.h | 5 ++++
include/asm-m32r/ptrace.h | 25 ++++++++-------------
include/asm-m32r/sigcontext.h | 2 +
5 files changed, 40 insertions(+), 45 deletions(-)

Index: linux-2.6.17-rc1-mm2/arch/m32r/kernel/entry.S
===================================================================
--- linux-2.6.17-rc1-mm2.orig/arch/m32r/kernel/entry.S 2006-04-10 10:37:48.379298460 +0900
+++ linux-2.6.17-rc1-mm2/arch/m32r/kernel/entry.S 2006-04-10 11:06:21.561851775 +0900
@@ -20,7 +20,7 @@
* Stack layout in 'ret_from_system_call':
* ptrace needs to have all regs on the stack.
* if the order here is changed, it needs to be
- * updated in fork.c:copy_process, signal.c:do_signal,
+ * updated in fork.c:copy_thread, signal.c:do_signal,
* ptrace.c and ptrace.h
*
* M32Rx/M32R2 M32R
@@ -41,18 +41,17 @@
* @(0x38,sp) - syscall_nr ditto
* @(0x3c,sp) - acc0h @(0x3c,sp) - acch
* @(0x40,sp) - acc0l @(0x40,sp) - accl
- * @(0x44,sp) - acc1h @(0x44,sp) - psw
- * @(0x48,sp) - acc1l @(0x48,sp) - bpc
- * @(0x4c,sp) - psw @(0x4c,sp) - bbpsw
- * @(0x50,sp) - bpc @(0x50,sp) - bbpc
- * @(0x54,sp) - bbpsw @(0x54,sp) - spu (cr3)
- * @(0x58,sp) - bbpc @(0x58,sp) - fp (r13)
- * @(0x5c,sp) - spu (cr3) @(0x5c,sp) - lr (r14)
- * @(0x60,sp) - fp (r13) @(0x60,sp) - spi (cr12)
- * @(0x64,sp) - lr (r14) @(0x64,sp) - orig_r0
- * @(0x68,sp) - spi (cr2)
- * @(0x6c,sp) - orig_r0
- *
+ * @(0x44,sp) - acc1h @(0x44,sp) - dummy_acc1h
+ * @(0x48,sp) - acc1l @(0x48,sp) - dummy_acc1l
+ * @(0x4c,sp) - psw ditto
+ * @(0x50,sp) - bpc ditto
+ * @(0x54,sp) - bbpsw ditto
+ * @(0x58,sp) - bbpc ditto
+ * @(0x5c,sp) - spu (cr3) ditto
+ * @(0x60,sp) - fp (r13) ditto
+ * @(0x64,sp) - lr (r14) ditto
+ * @(0x68,sp) - spi (cr2) ditto
+ * @(0x6c,sp) - orig_r0 ditto
*/

#include <linux/config.h>
@@ -102,6 +101,12 @@
#define ACC0L(reg) @(0x40,reg)
#define ACC1H(reg) @(0x44,reg)
#define ACC1L(reg) @(0x48,reg)
+#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
+#define ACCH(reg) @(0x3C,reg)
+#define ACCL(reg) @(0x40,reg)
+#else
+#error unknown isa configuration
+#endif
#define PSW(reg) @(0x4C,reg)
#define BPC(reg) @(0x50,reg)
#define BBPSW(reg) @(0x54,reg)
@@ -111,21 +116,6 @@
#define LR(reg) @(0x64,reg)
#define SP(reg) @(0x68,reg)
#define ORIG_R0(reg) @(0x6C,reg)
-#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
-#define ACCH(reg) @(0x3C,reg)
-#define ACCL(reg) @(0x40,reg)
-#define PSW(reg) @(0x44,reg)
-#define BPC(reg) @(0x48,reg)
-#define BBPSW(reg) @(0x4C,reg)
-#define BBPC(reg) @(0x50,reg)
-#define SPU(reg) @(0x54,reg)
-#define FP(reg) @(0x58,reg) /* FP = R13 */
-#define LR(reg) @(0x5C,reg)
-#define SP(reg) @(0x60,reg)
-#define ORIG_R0(reg) @(0x64,reg)
-#else
-#error unknown isa configuration
-#endif

CF_MASK = 0x00000001
TF_MASK = 0x00000100
@@ -231,7 +221,7 @@ restore_all:
RESTORE_ALL

# perform work that needs to be done immediately before resumption
- # r9 : frags
+ # r9 : flags
ALIGN
work_pending:
and3 r4, r9, #_TIF_NEED_RESCHED
@@ -1015,4 +1005,3 @@ ENTRY(sys_call_table)
.long sys_waitid

syscall_table_size=(.-sys_call_table)
-
Index: linux-2.6.17-rc1-mm2/arch/m32r/kernel/signal.c
===================================================================
--- linux-2.6.17-rc1-mm2.orig/arch/m32r/kernel/signal.c 2006-04-10 10:37:48.423291494 +0900
+++ linux-2.6.17-rc1-mm2/arch/m32r/kernel/signal.c 2006-04-10 10:54:25.721816023 +0900
@@ -118,6 +118,8 @@ restore_sigcontext(struct pt_regs *regs,
#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
COPY(acch);
COPY(accl);
+ COPY(dummy_acc1h);
+ COPY(dummy_acc1l);
#else
#error unknown isa configuration
#endif
@@ -203,6 +205,8 @@ setup_sigcontext(struct sigcontext __use
#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
COPY(acch);
COPY(accl);
+ COPY(dummy_acc1h);
+ COPY(dummy_acc1l);
#else
#error unknown isa configuration
#endif
Index: linux-2.6.17-rc1-mm2/include/asm-m32r/assembler.h
===================================================================
--- linux-2.6.17-rc1-mm2.orig/include/asm-m32r/assembler.h 2006-04-10 10:37:29.471292397 +0900
+++ linux-2.6.17-rc1-mm2/include/asm-m32r/assembler.h 2006-04-10 10:54:25.731814445 +0900
@@ -109,6 +109,9 @@
push r13
mvfachi r13
push r13
+ ldi r13, #0
+ push r13 ; dummy push acc1h
+ push r13 ; dummy push acc1l
#else
#error unknown isa configuration
#endif
@@ -156,6 +159,8 @@
pop r13
mvtaclo r13, a1
#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
+ pop r13 ; dummy pop acc1h
+ pop r13 ; dummy pop acc1l
pop r13
mvtachi r13
pop r13
Index: linux-2.6.17-rc1-mm2/include/asm-m32r/ptrace.h
===================================================================
--- linux-2.6.17-rc1-mm2.orig/include/asm-m32r/ptrace.h 2006-04-10 10:37:29.796240944 +0900
+++ linux-2.6.17-rc1-mm2/include/asm-m32r/ptrace.h 2006-04-10 10:54:25.737813499 +0900
@@ -43,6 +43,14 @@
#define PT_ACC1L 18
#define PT_ACCH PT_ACC0H
#define PT_ACCL PT_ACC0L
+#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
+#define PT_ACCH 15
+#define PT_ACCL 16
+#define PT_DUMMY_ACC1H 17
+#define PT_DUMMY_ACC1L 18
+#else
+#error unknown isa conifiguration
+#endif
#define PT_PSW 19
#define PT_BPC 20
#define PT_BBPSW 21
@@ -52,21 +60,6 @@
#define PT_LR 25
#define PT_SPI 26
#define PT_ORIGR0 27
-#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
-#define PT_ACCH 15
-#define PT_ACCL 16
-#define PT_PSW 17
-#define PT_BPC 18
-#define PT_BBPSW 19
-#define PT_BBPC 20
-#define PT_SPU 21
-#define PT_FP 22
-#define PT_LR 23
-#define PT_SPI 24
-#define PT_ORIGR0 25
-#else
-#error unknown isa conifiguration
-#endif

/* virtual pt_reg entry for gdb */
#define PT_PC 30
@@ -121,6 +114,8 @@ struct pt_regs {
#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
unsigned long acch;
unsigned long accl;
+ unsigned long dummy_acc1h;
+ unsigned long dummy_acc1l;
#else
#error unknown isa configuration
#endif
Index: linux-2.6.17-rc1-mm2/include/asm-m32r/sigcontext.h
===================================================================
--- linux-2.6.17-rc1-mm2.orig/include/asm-m32r/sigcontext.h 2006-04-10 10:37:29.851232236 +0900
+++ linux-2.6.17-rc1-mm2/include/asm-m32r/sigcontext.h 2006-04-10 10:54:25.743812553 +0900
@@ -32,6 +32,8 @@ struct sigcontext {
#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
unsigned long sc_acch;
unsigned long sc_accl;
+ unsigned long sc_dummy_acc1h;
+ unsigned long sc_dummy_acc1l;
#else
#error unknown isa configuration
#endif

--
Hirokazu Takata <takata@xxxxxxxxxxxxxx>
Linux/M32R Project: http://www.linux-m32r.org/
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Next message: Christoph Hellwig: "Re: [PATCH] pids: simplify do_each_task_pid/while_each_task_pid"
Previous message: Herbert Poetzl: "Re: [Devel] Re: [RFC] Virtualization steps"
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