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sh: Fix up DSP context save/restore.

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There were a number of issues with the DSP context save/restore code,
mostly left-over relics from when it was introduced on SH3-DSP with
little follow-up testing, resulting in things like task_pt_dspregs()
referencing incorrect state on the stack.

This follows the MIPS convention of tracking the DSP state in the
thread_struct and handling the state save/restore in switch_to() and
finish_arch_switch() respectively. The regset interface is also updated,
which allows us to finally be rid of task_pt_dspregs() and the special
cased task_pt_regs().

Signed-off-by: Michael Trimarchi <michael@evidence.eu.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Michael Trimarchi 2009-04-03 17:32:33 +00:00 committed by Paul Mundt
parent a27873cd23
commit 01ab10393c
7 changed files with 161 additions and 137 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
arch/sh/include/asm/processor_32.h
View File

@ -57,6 +57,14 @@ asmlinkage void __init sh_cpu_init(void);
#define SR_IMASK 0x000000f0
#define SR_FD 0x00008000
/*
* DSP structure and data
*/
struct sh_dsp_struct {
unsigned long dsp_regs[14];
long status;
};
/*
* FPU structure and data
*/
@ -96,6 +104,11 @@ struct thread_struct {
/* floating point info */
union sh_fpu_union fpu;
#ifdef CONFIG_SH_DSP
/* Dsp status information */
struct sh_dsp_struct dsp_status;
#endif
};
/* Count of active tasks with UBC settings */

8
arch/sh/include/asm/ptrace.h
View File

@ -119,16 +119,8 @@ struct task_struct;
extern void user_enable_single_step(struct task_struct *);
extern void user_disable_single_step(struct task_struct *);
#ifdef CONFIG_SH_DSP
#define task_pt_regs(task) \
((struct pt_regs *) (task_stack_page(task) + THREAD_SIZE \
- sizeof(struct pt_dspregs)) - 1)
#define task_pt_dspregs(task) \
((struct pt_dspregs *) (task_stack_page(task) + THREAD_SIZE) - 1)
#else
#define task_pt_regs(task) \
((struct pt_regs *) (task_stack_page(task) + THREAD_SIZE) - 1)
#endif
static inline unsigned long profile_pc(struct pt_regs *regs)
{

88
arch/sh/include/asm/system_32.h
View File

@ -3,6 +3,66 @@
#include <linux/types.h>
#ifdef CONFIG_SH_DSP
#define is_dsp_enabled(tsk) \
(!!(tsk->thread.dsp_status.status & SR_DSP))
#define __restore_dsp(tsk) \
do { \
register u32 *__ts2 __asm__ ("r2") = \
(u32 *)&tsk->thread.dsp_status; \
__asm__ __volatile__ ( \
".balign 4\n\t" \
"movs.l @r2+, a1\n\t" \
"movs.l @r2+, a0g\n\t" \
"movs.l @r2+, a1g\n\t" \
"movs.l @r2+, m0\n\t" \
"movs.l @r2+, m1\n\t" \
"movs.l @r2+, a0\n\t" \
"movs.l @r2+, x0\n\t" \
"movs.l @r2+, x1\n\t" \
"movs.l @r2+, y0\n\t" \
"movs.l @r2+, y1\n\t" \
"lds.l @r2+, dsr\n\t" \
"ldc.l @r2+, rs\n\t" \
"ldc.l @r2+, re\n\t" \
"ldc.l @r2+, mod\n\t" \
: : "r" (__ts2)); \
} while (0)
#define __save_dsp(tsk) \
do { \
register u32 *__ts2 __asm__ ("r2") = \
(u32 *)&tsk->thread.dsp_status + 14; \
\
__asm__ __volatile__ ( \
".balign 4\n\t" \
"stc.l mod, @-r2\n\t" \
"stc.l re, @-r2\n\t" \
"stc.l rs, @-r2\n\t" \
"sts.l dsr, @-r2\n\t" \
"sts.l y1, @-r2\n\t" \
"sts.l y0, @-r2\n\t" \
"sts.l x1, @-r2\n\t" \
"sts.l x0, @-r2\n\t" \
"sts.l a0, @-r2\n\t" \
".word 0xf653 ! movs.l a1, @-r2\n\t" \
".word 0xf6f3 ! movs.l a0g, @-r2\n\t" \
".word 0xf6d3 ! movs.l a1g, @-r2\n\t" \
".word 0xf6c3 ! movs.l m0, @-r2\n\t" \
".word 0xf6e3 ! movs.l m1, @-r2\n\t" \
: : "r" (__ts2)); \
} while (0)
#else
#define is_dsp_enabled(tsk) (0)
#define __save_dsp(tsk) do { } while (0)
#define __restore_dsp(tsk) do { } while (0)
#endif
struct task_struct *__switch_to(struct task_struct *prev,
struct task_struct *next);
@ -11,14 +71,24 @@ struct task_struct *__switch_to(struct task_struct *prev,
*/
#define switch_to(prev, next, last) \
do { \
register u32 *__ts1 __asm__ ("r1") = (u32 *)&prev->thread.sp; \
register u32 *__ts2 __asm__ ("r2") = (u32 *)&prev->thread.pc; \
register u32 *__ts4 __asm__ ("r4") = (u32 *)prev; \
register u32 *__ts5 __asm__ ("r5") = (u32 *)next; \
register u32 *__ts6 __asm__ ("r6") = (u32 *)&next->thread.sp; \
register u32 __ts7 __asm__ ("r7") = next->thread.pc; \
register u32 *__ts1 __asm__ ("r1"); \
register u32 *__ts2 __asm__ ("r2"); \
register u32 *__ts4 __asm__ ("r4"); \
register u32 *__ts5 __asm__ ("r5"); \
register u32 *__ts6 __asm__ ("r6"); \
register u32 __ts7 __asm__ ("r7"); \
struct task_struct *__last; \
\
if (is_dsp_enabled(prev)) \
__save_dsp(prev); \
\
__ts1 = (u32 *)&prev->thread.sp; \
__ts2 = (u32 *)&prev->thread.pc; \
__ts4 = (u32 *)prev; \
__ts5 = (u32 *)next; \
__ts6 = (u32 *)&next->thread.sp; \
__ts7 = next->thread.pc; \
\
__asm__ __volatile__ ( \
".balign 4\n\t" \
"stc.l gbr, @-r15\n\t" \
@ -58,6 +128,12 @@ do { \
last = __last; \
} while (0)
#define finish_arch_switch(prev) \
do { \
if (is_dsp_enabled(prev)) \
__restore_dsp(prev); \
} while (0)
#define __uses_jump_to_uncached \
noinline __attribute__ ((__section__ (".uncached.text")))

85
arch/sh/kernel/cpu/sh3/entry.S
View File

@ -254,40 +254,6 @@ restore_all:
lds k2, pr ! restore pr
!
#ifdef CONFIG_SH_DSP
mov.l @r15+, k0 ! DSP mode marker
mov.l 5f, k1
cmp/eq k0, k1 ! Do we have a DSP stack frame?
bf skip_restore
stc sr, k0 ! Enable CPU DSP mode
or k1, k0 ! (within kernel it may be disabled)
ldc k0, sr
mov r2, k0 ! Backup r2
! Restore DSP registers from stack
mov r15, r2
movs.l @r2+, a1
movs.l @r2+, a0g
movs.l @r2+, a1g
movs.l @r2+, m0
movs.l @r2+, m1
mov r2, r15
lds.l @r15+, a0
lds.l @r15+, x0
lds.l @r15+, x1
lds.l @r15+, y0
lds.l @r15+, y1
lds.l @r15+, dsr
ldc.l @r15+, rs
ldc.l @r15+, re
ldc.l @r15+, mod
mov k0, r2 ! Restore r2
skip_restore:
#endif
!
! Calculate new SR value
mov k3, k2 ! original SR value
mov #0xf0, k1
@ -358,7 +324,7 @@ general_exception:
add k0, k4
0:
! Setup stack and save DSP context (k0 contains original r15 on return)
bsr prepare_stack_save_dsp
bsr prepare_stack
nop
! Save registers / Switch to bank 0
@ -374,15 +340,14 @@ general_exception:
1: .long EXPEVT
#endif
! prepare_stack_save_dsp()
! prepare_stack()
! - roll back gRB
! - switch to kernel stack
! - save DSP
! k0 returns original sp (after roll back)
! k1 trashed
! k2 trashed
prepare_stack_save_dsp:
prepare_stack:
#ifdef CONFIG_GUSA
! Check for roll back gRB (User and Kernel)
mov r15, k0
@ -416,47 +381,9 @@ prepare_stack_save_dsp:
mov k1, r15 ! change to kernel stack
!
1:
#ifdef CONFIG_SH_DSP
! Save DSP context if needed
stc sr, k1
mov #0x10, k2
shll8 k2 ! DSP=1 (0x00001000)
tst k2, k1 ! Check if in DSP mode (passed in k2)
bt/s skip_save
mov #0, k1 ! Set marker for no stack frame
mov k2, k1 ! Save has-frame marker
! Save DSP registers on stack
stc.l mod, @-r15
stc.l re, @-r15
stc.l rs, @-r15
sts.l dsr, @-r15
sts.l y1, @-r15
sts.l y0, @-r15
sts.l x1, @-r15
sts.l x0, @-r15
sts.l a0, @-r15
! GAS is broken, does not generate correct "movs.l Ds,@-As" instr.
! FIXME: Make sure that this is still the case with newer toolchains,
! as we're not at all interested in supporting ancient toolchains at
! this point. -- PFM.
mov r15, k2
.word 0xf653 ! movs.l a1, @-r2
.word 0xf6f3 ! movs.l a0g, @-r2
.word 0xf6d3 ! movs.l a1g, @-r2
.word 0xf6c3 ! movs.l m0, @-r2
.word 0xf6e3 ! movs.l m1, @-r2
mov k2, r15
skip_save:
mov.l k1, @-r15 ! Push DSP mode marker onto stack
#endif
rts
nop
!
! 0x400: Instruction and Data TLB miss exception vector
!
@ -468,7 +395,7 @@ handle_exception:
mova exception_data, k0
! Setup stack and save DSP context (k0 contains original r15 on return)
bsr prepare_stack_save_dsp
bsr prepare_stack
PREF(k0)
! Save registers / Switch to bank 0
@ -572,7 +499,7 @@ ENTRY(handle_interrupt)
mova exception_data, k0
! Setup stack and save DSP context (k0 contains original r15 on return)
bsr prepare_stack_save_dsp
bsr prepare_stack
PREF(k0)
! Save registers / Switch to bank 0

14
arch/sh/kernel/process_32.c
View File

@ -176,14 +176,26 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
#if defined(CONFIG_SH_FPU)
#if defined(CONFIG_SH_FPU) || defined(CONFIG_SH_DSP)
struct task_struct *tsk = current;
#endif
#if defined(CONFIG_SH_FPU)
unlazy_fpu(tsk, regs);
p->thread.fpu = tsk->thread.fpu;
copy_to_stopped_child_used_math(p);
#endif
#if defined(CONFIG_SH_DSP)
if (is_dsp_enabled(tsk)) {
/* We can use the __save_dsp or just copy the struct:
* __save_dsp(p);
* p->thread.dsp_status.status |= SR_DSP
*/
p->thread.dsp_status = tsk->thread.dsp_status;
}
#endif
childregs = task_pt_regs(p);
*childregs = *regs;

6
arch/sh/kernel/ptrace_32.c
View File

@ -200,7 +200,8 @@ static int dspregs_get(struct task_struct *target,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
const struct pt_dspregs *regs = task_pt_dspregs(target);
const struct pt_dspregs *regs =
(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
int ret;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
@ -217,7 +218,8 @@ static int dspregs_set(struct task_struct *target,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct pt_dspregs *regs = task_pt_dspregs(target);
struct pt_dspregs *regs =
(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
int ret;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,

2
arch/sh/kernel/traps_32.c
View File

@ -664,6 +664,8 @@ asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
if (is_dsp_inst(regs)) {
/* Enable DSP mode, and restart instruction. */
regs->sr |= SR_DSP;
/* Save DSP mode */
tsk->thread.dsp_status.status |= SR_DSP;
return;
}
#endif