Commit ca87b7ad authored by Graf Yang's avatar Graf Yang Committed by Bryan Wu
Browse files

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: default avatarGraf Yang <graf.yang@analog.com>
Signed-off-by: default avatarBryan Wu <cooloney@kernel.org>
parent 7d98c881

arch/blackfin/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -629,6 +629,15 @@ config CPLB_SWITCH_TAB_L1 
	  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"

arch/blackfin/include/asm/mmu_context.h

+42 −37
Original line number Diff line number Diff line
@@ -45,49 +45,12 @@ extern unsigned long l1_stack_len; 
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 @@ static inline void switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_m 
	}

#endif



#ifdef CONFIG_APP_STACK_L1

	/* L1 stack switching.  */

	if (!next_mm->context.l1_stack_save)

		return;
@@ -144,6 +108,7 @@ static inline void switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_m 
	}

	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 @@ static inline void update_protections(struct mm_struct *mm) 
}

#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