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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6 

* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6:
  avr32: pm_standby low-power ram bug fix
  avr32: Fix lockup after Java stack underflow in user mode
This commit is contained in:
Linus Torvalds 2008-09-08 15:55:18 -07:00
parent c1bad36054 84c4f2f21a
commit 82a28c794f
3 changed files with 64 additions and 3 deletions
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6
arch/avr32/kernel/asm-offsets.c
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@ -4,6 +4,8 @@
* to extract and format the required data.
*/
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/thread_info.h>
#include <linux/kbuild.h>
@ -17,4 +19,8 @@ void foo(void)
OFFSET(TI_rar_saved, thread_info, rar_saved);
OFFSET(TI_rsr_saved, thread_info, rsr_saved);
OFFSET(TI_restart_block, thread_info, restart_block);
BLANK();
OFFSET(TSK_active_mm, task_struct, active_mm);
BLANK();
OFFSET(MM_pgd, mm_struct, pgd);
}

59
arch/avr32/kernel/entry-avr32b.S
View File

@ -334,9 +334,64 @@ save_full_context_ex:
/* Low-level exception handlers */
handle_critical:
/*
* AT32AP700x errata:
*
* After a Java stack overflow or underflow trap, any CPU
* memory access may cause erratic behavior. This will happen
* when the four least significant bits of the JOSP system
* register contains any value between 9 and 15 (inclusive).
*
* Possible workarounds:
* - Don't use the Java Extension Module
* - Ensure that the stack overflow and underflow trap
* handlers do not do any memory access or trigger any
* exceptions before the overflow/underflow condition is
* cleared (by incrementing or decrementing the JOSP)
* - Make sure that JOSP does not contain any problematic
* value before doing any exception or interrupt
* processing.
* - Set up a critical exception handler which writes a
* known-to-be-safe value, e.g. 4, to JOSP before doing
* any further processing.
*
* We'll use the last workaround for now since we cannot
* guarantee that user space processes don't use Java mode.
* Non-well-behaving userland will be terminated with extreme
* prejudice.
*/
#ifdef CONFIG_CPU_AT32AP700X
/*
* There's a chance we can't touch memory, so temporarily
* borrow PTBR to save the stack pointer while we fix things
* up...
*/
mtsr SYSREG_PTBR, sp
mov sp, 4
mtsr SYSREG_JOSP, sp
mfsr sp, SYSREG_PTBR
sub pc, -2
/* Push most of pt_regs on stack. We'll do the rest later */
sub sp, 4
stmts --sp, r0-lr
rcall save_full_context_ex
pushm r0-r12
/* PTBR mirrors current_thread_info()->task->active_mm->pgd */
get_thread_info r0
ld.w r1, r0[TI_task]
ld.w r2, r1[TSK_active_mm]
ld.w r3, r2[MM_pgd]
mtsr SYSREG_PTBR, r3
#else
sub sp, 4
pushm r0-r12
#endif
sub r0, sp, -(14 * 4)
mov r1, lr
mfsr r2, SYSREG_RAR_EX
mfsr r3, SYSREG_RSR_EX
pushm r0-r3
mfsr r12, SYSREG_ECR
mov r11, sp
rcall do_critical_exception

2
arch/avr32/mach-at32ap/pm-at32ap700x.S
View File

@ -134,7 +134,7 @@ pm_standby:
mov r11, SDRAMC_LPR_LPCB_SELF_RFR
bfins r10, r11, 0, 2 /* LPCB <- self Refresh */
sync 0 /* flush write buffer */
st.w r12[SDRAMC_LPR], r11 /* put SDRAM in self-refresh mode */
st.w r12[SDRAMC_LPR], r10 /* put SDRAM in self-refresh mode */
ld.w r11, r12[SDRAMC_LPR]
unmask_interrupts
sleep CPU_SLEEP_FROZEN