linux/arch/arm/mm/l2c-l2x0-resume.S
Russell King de7e75326c ARM: l2c: provide common PL310 early resume code
Provide a common assembly implementation for PL310 resume code.  Certain
platforms need to re-initialise the L2C cache early as it may preserve
data across a S2RAM cycle, and therefore must be enabled along with the
L1 cache and MMU.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-05-30 00:49:01 +01:00

59 lines
1.4 KiB
ArmAsm

/*
* L2C-310 early resume code. This can be used by platforms to restore
* the settings of their L2 cache controller before restoring the
* processor state.
*
* This code can only be used to if you are running in the secure world.
*/
#include <linux/linkage.h>
#include <asm/hardware/cache-l2x0.h>
.text
ENTRY(l2c310_early_resume)
adr r0, 1f
ldr r2, [r0]
add r0, r2, r0
ldmia r0, {r1, r2, r3, r4, r5, r6, r7, r8}
@ r1 = phys address of L2C-310 controller
@ r2 = aux_ctrl
@ r3 = tag_latency
@ r4 = data_latency
@ r5 = filter_start
@ r6 = filter_end
@ r7 = prefetch_ctrl
@ r8 = pwr_ctrl
@ Check that the address has been initialised
teq r1, #0
moveq pc, lr
@ The prefetch and power control registers are revision dependent
@ and can be written whether or not the L2 cache is enabled
ldr r0, [r1, #L2X0_CACHE_ID]
and r0, r0, #L2X0_CACHE_ID_RTL_MASK
cmp r0, #L310_CACHE_ID_RTL_R2P0
strcs r7, [r1, #L310_PREFETCH_CTRL]
cmp r0, #L310_CACHE_ID_RTL_R3P0
strcs r8, [r1, #L310_POWER_CTRL]
@ Don't setup the L2 cache if it is already enabled
ldr r0, [r1, #L2X0_CTRL]
tst r0, #L2X0_CTRL_EN
movne pc, lr
str r3, [r1, #L310_TAG_LATENCY_CTRL]
str r4, [r1, #L310_DATA_LATENCY_CTRL]
str r6, [r1, #L310_ADDR_FILTER_END]
str r5, [r1, #L310_ADDR_FILTER_START]
str r2, [r1, #L2X0_AUX_CTRL]
mov r9, #L2X0_CTRL_EN
str r9, [r1, #L2X0_CTRL]
mov pc, lr
ENDPROC(l2c310_early_resume)
.align
1: .long l2x0_saved_regs - .