diff options
author | Stuart Menefy <stuart.menefy@st.com> | 2007-11-30 16:12:36 +0900 |
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committer | Paul Mundt <lethal@linux-sh.org> | 2008-01-28 13:18:58 +0900 |
commit | 1efe4ce3ca126da77e450d5a83f7201949d76f62 (patch) | |
tree | fbae9902aa4103a9e86d06f841d580f24682e7b3 /arch/sh/kernel | |
parent | 53ff09422e5e7a6d6198b767c8f494e43ec8e3ae (diff) | |
download | linux-stable-1efe4ce3ca126da77e450d5a83f7201949d76f62.tar.gz linux-stable-1efe4ce3ca126da77e450d5a83f7201949d76f62.tar.bz2 linux-stable-1efe4ce3ca126da77e450d5a83f7201949d76f62.zip |
sh: GUSA atomic rollback support.
This implements kernel-level atomic rollback built on top of gUSA,
as an alternative non-IRQ based atomicity method. This is generally
a faster method for platforms that are lacking the LL/SC pairs that
SH-4A and later use, and is only supportable on legacy cores.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/kernel')
-rw-r--r-- | arch/sh/kernel/cpu/sh3/entry.S | 24 | ||||
-rw-r--r-- | arch/sh/kernel/entry-common.S | 19 | ||||
-rw-r--r-- | arch/sh/kernel/process_32.c | 19 | ||||
-rw-r--r-- | arch/sh/kernel/signal_32.c | 18 |
4 files changed, 23 insertions, 57 deletions
diff --git a/arch/sh/kernel/cpu/sh3/entry.S b/arch/sh/kernel/cpu/sh3/entry.S index 0d12a124055c..4004073f98cd 100644 --- a/arch/sh/kernel/cpu/sh3/entry.S +++ b/arch/sh/kernel/cpu/sh3/entry.S @@ -13,8 +13,9 @@ #include <linux/linkage.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> -#include <asm/cpu/mmu_context.h> #include <asm/unistd.h> +#include <asm/cpu/mmu_context.h> +#include <asm/page.h> ! NOTE: ! GNU as (as of 2.9.1) changes bf/s into bt/s and bra, when the address @@ -409,6 +410,27 @@ ENTRY(handle_exception) ! Using k0, k1 for scratch registers (r0_bank1, r1_bank), ! save all registers onto stack. ! + +#ifdef CONFIG_GUSA + ! Check for roll back gRB (User and Kernel) + mov r15, k0 + shll k0 + bf/s 1f + shll k0 + bf/s 1f + stc spc, k1 + stc r0_bank, k0 + cmp/hs k0, k1 ! test k1 (saved PC) >= k0 (saved r0) + bt/s 2f + stc r1_bank, k1 + + add #-2, k0 + add r15, k0 + ldc k0, spc ! PC = saved r0 + r15 - 2 +2: mov k1, r15 ! SP = r1 +1: +#endif + stc ssr, k0 ! Is it from kernel space? shll k0 ! Check MD bit (bit30) by shifting it into... shll k0 ! ...the T bit diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S index 397ac71d97f1..926b2e7b11c1 100644 --- a/arch/sh/kernel/entry-common.S +++ b/arch/sh/kernel/entry-common.S @@ -176,25 +176,6 @@ work_notifysig: jmp @r1 lds r0, pr work_resched: -#if defined(CONFIG_GUSA) && !defined(CONFIG_PREEMPT) - ! gUSA handling - mov.l @(OFF_SP,r15), r0 ! get user space stack pointer - mov r0, r1 - shll r0 - bf/s 1f - shll r0 - bf/s 1f - mov #OFF_PC, r0 - ! SP >= 0xc0000000 : gUSA mark - mov.l @(r0,r15), r2 ! get user space PC (program counter) - mov.l @(OFF_R0,r15), r3 ! end point - cmp/hs r3, r2 ! r2 >= r3? - bt 1f - add r3, r1 ! rewind point #2 - mov.l r1, @(r0,r15) ! reset PC to rewind point #2 - ! -1: -#endif mov.l 1f, r1 jsr @r1 ! schedule nop diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c index b48324867eee..9ab1926b9d10 100644 --- a/arch/sh/kernel/process_32.c +++ b/arch/sh/kernel/process_32.c @@ -322,25 +322,6 @@ struct task_struct *__switch_to(struct task_struct *prev, unlazy_fpu(prev, task_pt_regs(prev)); #endif -#if defined(CONFIG_GUSA) && defined(CONFIG_PREEMPT) - { - struct pt_regs *regs; - - preempt_disable(); - regs = task_pt_regs(prev); - if (user_mode(regs) && regs->regs[15] >= 0xc0000000) { - int offset = (int)regs->regs[15]; - - /* Reset stack pointer: clear critical region mark */ - regs->regs[15] = regs->regs[1]; - if (regs->pc < regs->regs[0]) - /* Go to rewind point */ - regs->pc = regs->regs[0] + offset; - } - preempt_enable_no_resched(); - } -#endif - #ifdef CONFIG_MMU /* * Restore the kernel mode register diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c index ca754fd42437..f6b5fbfe75c4 100644 --- a/arch/sh/kernel/signal_32.c +++ b/arch/sh/kernel/signal_32.c @@ -507,24 +507,6 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, ctrl_inw(regs->pc - 4)); break; } -#ifdef CONFIG_GUSA - } else { - /* gUSA handling */ - preempt_disable(); - - if (regs->regs[15] >= 0xc0000000) { - int offset = (int)regs->regs[15]; - - /* Reset stack pointer: clear critical region mark */ - regs->regs[15] = regs->regs[1]; - if (regs->pc < regs->regs[0]) - /* Go to rewind point #1 */ - regs->pc = regs->regs[0] + offset - - instruction_size(ctrl_inw(regs->pc-4)); - } - - preempt_enable_no_resched(); -#endif } /* Set up the stack frame */ |