sh: Fix up DSP context save/restore.

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>

1 files changed, 4 insertions, 2 deletions

diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
index 29ca09d24ef8..f7b22dd83b0c 100644
--- a/arch/sh/kernel/ptrace_32.c
+++ b/arch/sh/kernel/ptrace_32.c
@@ -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,