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author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2012-11-27 20:55:33 (GMT) |
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committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2013-07-30 13:02:15 (GMT) |
commit | c052de2693498bee6ff2e1b5bcd32309c4f8780b (patch) | |
tree | 60239a7327fdfb812549a66a16b6992abf636a0a /arch/arm/common/bL_switcher.c | |
parent | 71ce1deeff8f9341ae3b21983e9bdde28e8c96fe (diff) | |
download | linux-c052de2693498bee6ff2e1b5bcd32309c4f8780b.tar.xz |
ARM: bL_switcher: simplify stack isolation
We now have a dedicated thread for each logical CPU. That's plenty
of stack space for our needs.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Diffstat (limited to 'arch/arm/common/bL_switcher.c')
-rw-r--r-- | arch/arm/common/bL_switcher.c | 23 |
1 files changed, 8 insertions, 15 deletions
diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c index 407c4cc..4caca71 100644 --- a/arch/arm/common/bL_switcher.c +++ b/arch/arm/common/bL_switcher.c @@ -53,12 +53,6 @@ static void bL_do_switch(void *_unused) { unsigned mpidr, cpuid, clusterid, ob_cluster, ib_cluster; - /* - * We now have a piece of stack borrowed from the init task's. - * Let's also switch to init_mm right away to match it. - */ - cpu_switch_mm(init_mm.pgd, &init_mm); - pr_debug("%s\n", __func__); mpidr = read_mpidr(); @@ -93,22 +87,21 @@ static void bL_do_switch(void *_unused) } /* - * Stack isolation. To ensure 'current' remains valid, we just borrow - * a slice of the init/idle task which should be fairly lightly used. - * The borrowed area starts just above the thread_info structure located - * at the very bottom of the stack, aligned to a cache line. + * Stack isolation. To ensure 'current' remains valid, we just use another + * piece of our thread's stack space which should be fairly lightly used. + * The selected area starts just above the thread_info structure located + * at the very bottom of the stack, aligned to a cache line, and indexed + * with the cluster number. */ -#define STACK_SIZE 256 +#define STACK_SIZE 512 extern void call_with_stack(void (*fn)(void *), void *arg, void *sp); static int bL_switchpoint(unsigned long _arg) { unsigned int mpidr = read_mpidr(); - unsigned int cpuid = MPIDR_AFFINITY_LEVEL(mpidr, 0); unsigned int clusterid = MPIDR_AFFINITY_LEVEL(mpidr, 1); - unsigned int cpu_index = cpuid + clusterid * MAX_CPUS_PER_CLUSTER; - void *stack = &init_thread_info + 1; + void *stack = current_thread_info() + 1; stack = PTR_ALIGN(stack, L1_CACHE_BYTES); - stack += cpu_index * STACK_SIZE + STACK_SIZE; + stack += clusterid * STACK_SIZE + STACK_SIZE; call_with_stack(bL_do_switch, (void *)_arg, stack); BUG(); } |