Blackfin arch: add CONFIG_APP_STACKS_L1 to enable or disable putting kernel stacks in L1
use CONFIG_APP_STACKS_L1 to enable or disable putting kernel stacks in L1,
default is enabled, SMP kernel need turn it off
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index c507a92..9d936a3 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -629,6 +629,15 @@
If enabled, the CPLB Switch Tables are linked
into L1 data memory. (less latency)
+config APP_STACK_L1
+ bool "Support locating application stack in L1 Scratch Memory"
+ default y
+ help
+ If enabled the application stack can be located in L1
+ scratch memory (less latency).
+
+ Currently only works with FLAT binaries.
+
comment "Speed Optimizations"
config BFIN_INS_LOWOVERHEAD
bool "ins[bwl] low overhead, higher interrupt latency"
diff --git a/arch/blackfin/include/asm/mmu_context.h b/arch/blackfin/include/asm/mmu_context.h
index 8529552..35593dd 100644
--- a/arch/blackfin/include/asm/mmu_context.h
+++ b/arch/blackfin/include/asm/mmu_context.h
@@ -45,49 +45,12 @@
extern int l1sram_free(const void*);
extern void *l1sram_alloc_max(void*);
-static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
-{
-}
-
-/* Called when creating a new context during fork() or execve(). */
-static inline int
-init_new_context(struct task_struct *tsk, struct mm_struct *mm)
-{
-#ifdef CONFIG_MPU
- unsigned long p = __get_free_pages(GFP_KERNEL, page_mask_order);
- mm->context.page_rwx_mask = (unsigned long *)p;
- memset(mm->context.page_rwx_mask, 0,
- page_mask_nelts * 3 * sizeof(long));
-#endif
- return 0;
-}
-
static inline void free_l1stack(void)
{
nr_l1stack_tasks--;
if (nr_l1stack_tasks == 0)
l1sram_free(l1_stack_base);
}
-static inline void destroy_context(struct mm_struct *mm)
-{
- struct sram_list_struct *tmp;
-
- if (current_l1_stack_save == mm->context.l1_stack_save)
- current_l1_stack_save = NULL;
- if (mm->context.l1_stack_save)
- free_l1stack();
-
- while ((tmp = mm->context.sram_list)) {
- mm->context.sram_list = tmp->next;
- sram_free(tmp->addr);
- kfree(tmp);
- }
-#ifdef CONFIG_MPU
- if (current_rwx_mask == mm->context.page_rwx_mask)
- current_rwx_mask = NULL;
- free_pages((unsigned long)mm->context.page_rwx_mask, page_mask_order);
-#endif
-}
static inline unsigned long
alloc_l1stack(unsigned long length, unsigned long *stack_base)
@@ -134,6 +97,7 @@
}
#endif
+#ifdef CONFIG_APP_STACK_L1
/* L1 stack switching. */
if (!next_mm->context.l1_stack_save)
return;
@@ -144,6 +108,7 @@
}
current_l1_stack_save = next_mm->context.l1_stack_save;
memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len);
+#endif
}
#ifdef CONFIG_MPU
@@ -180,4 +145,44 @@
}
#endif
+static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+}
+
+/* Called when creating a new context during fork() or execve(). */
+static inline int
+init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+#ifdef CONFIG_MPU
+ unsigned long p = __get_free_pages(GFP_KERNEL, page_mask_order);
+ mm->context.page_rwx_mask = (unsigned long *)p;
+ memset(mm->context.page_rwx_mask, 0,
+ page_mask_nelts * 3 * sizeof(long));
+#endif
+ return 0;
+}
+
+static inline void destroy_context(struct mm_struct *mm)
+{
+ struct sram_list_struct *tmp;
+
+#ifdef CONFIG_APP_STACK_L1
+ if (current_l1_stack_save == mm->context.l1_stack_save)
+ current_l1_stack_save = 0;
+ if (mm->context.l1_stack_save)
+ free_l1stack();
+#endif
+
+ while ((tmp = mm->context.sram_list)) {
+ mm->context.sram_list = tmp->next;
+ sram_free(tmp->addr);
+ kfree(tmp);
+ }
+#ifdef CONFIG_MPU
+ if (current_rwx_mask == mm->context.page_rwx_mask)
+ current_rwx_mask = NULL;
+ free_pages((unsigned long)mm->context.page_rwx_mask, page_mask_order);
+#endif
+}
+
#endif
