Commit de885d14 authored by Nicolas Pitre's avatar Nicolas Pitre
Browse files

ARM: mcpm: add a simple poke mechanism to the early entry code 



This allows to poke a predetermined value into a specific address
upon entering the early boot code in bL_head.S.

Signed-off-by: default avatarNicolas Pitre <nico@linaro.org>
parent 5135d875

arch/arm/common/mcpm_entry.c

+12 −0
Original line number Diff line number Diff line
@@ -27,6 +27,18 @@ void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr) 
	sync_cache_w(&mcpm_entry_vectors[cluster][cpu]);

}



extern unsigned long mcpm_entry_early_pokes[MAX_NR_CLUSTERS][MAX_CPUS_PER_CLUSTER][2];



void mcpm_set_early_poke(unsigned cpu, unsigned cluster,

			 unsigned long poke_phys_addr, unsigned long poke_val)

{

	unsigned long *poke = &mcpm_entry_early_pokes[cluster][cpu][0];

	poke[0] = poke_phys_addr;

	poke[1] = poke_val;

	__cpuc_flush_dcache_area((void *)poke, 8);

	outer_clean_range(__pa(poke), __pa(poke + 2));

}



static const struct mcpm_platform_ops *platform_ops;



int __init mcpm_platform_register(const struct mcpm_platform_ops *ops)

arch/arm/common/mcpm_head.S

+14 −2
Original line number Diff line number Diff line
@@ -71,12 +71,19 @@ ENTRY(mcpm_entry_point) 
	 * position independent way.

	 */

	adr	r5, 3f

	ldmia	r5, {r6, r7, r8, r11}

	ldmia	r5, {r0, r6, r7, r8, r11}

	add	r0, r5, r0			@ r0 = mcpm_entry_early_pokes

	add	r6, r5, r6			@ r6 = mcpm_entry_vectors

	ldr	r7, [r5, r7]			@ r7 = mcpm_power_up_setup_phys

	add	r8, r5, r8			@ r8 = mcpm_sync

	add	r11, r5, r11			@ r11 = first_man_locks



	@ Perform an early poke, if any

	add	r0, r0, r4, lsl #3

	ldmia	r0, {r0, r1}

	teq	r0, #0

	strne	r1, [r0]



	mov	r0, #MCPM_SYNC_CLUSTER_SIZE

	mla	r8, r0, r10, r8			@ r8 = sync cluster base
@@ -195,7 +202,8 @@ mcpm_entry_gated: 


	.align	2



3:	.word	mcpm_entry_vectors - .

3:	.word	mcpm_entry_early_pokes - .

	.word	mcpm_entry_vectors - 3b

	.word	mcpm_power_up_setup_phys - 3b

	.word	mcpm_sync - 3b

	.word	first_man_locks - 3b
@@ -214,6 +222,10 @@ first_man_locks: 
ENTRY(mcpm_entry_vectors)

	.space	4 * MAX_NR_CLUSTERS * MAX_CPUS_PER_CLUSTER



	.type	mcpm_entry_early_pokes, #object

ENTRY(mcpm_entry_early_pokes)

	.space	8 * MAX_NR_CLUSTERS * MAX_CPUS_PER_CLUSTER



	.type	mcpm_power_up_setup_phys, #object

ENTRY(mcpm_power_up_setup_phys)

	.space  4		@ set by mcpm_sync_init()

arch/arm/include/asm/mcpm.h

+8 −0
Original line number Diff line number Diff line
@@ -41,6 +41,14 @@ extern void mcpm_entry_point(void); 
 */

void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr);



/*

 * This sets an early poke i.e a value to be poked into some address

 * from very early assembly code before the CPU is ungated.  The

 * address must be physical, and if 0 then nothing will happen.

 */

void mcpm_set_early_poke(unsigned cpu, unsigned cluster,

			 unsigned long poke_phys_addr, unsigned long poke_val);



/*

 * CPU/cluster power operations API for higher subsystems to use.

 */