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>
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

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;