linux/arch/arm/mach-tegra/headsmp.S
Peter De Schrijver 86e51a2ee4 ARM: tegra: support for secondary cores on Tegra30
Add support for bringing up secondary cores on Tegra30. On Tegra30 secondary
CPU cores are powergated, so we need to turn on the domains before we can bring
the CPU cores online. Bringing secondary cores online happens early during the
sytem boot, so we call powergating initialization from platform early_init
function.

Based on work by:

Scott Williams <scwilliams@nvidia.com>
Colin Cross <ccross@android.com>
Alex Frid <afrid@nvidia.com>

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
2012-02-26 14:44:46 -08:00

213 lines
5.2 KiB
ArmAsm

#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/cache.h>
#include <mach/iomap.h>
#include "flowctrl.h"
#include "reset.h"
#define APB_MISC_GP_HIDREV 0x804
#define PMC_SCRATCH41 0x140
#define RESET_DATA(x) ((TEGRA_RESET_##x)*4)
.macro mov32, reg, val
movw \reg, #:lower16:\val
movt \reg, #:upper16:\val
.endm
.section ".text.head", "ax"
__CPUINIT
/*
* Tegra specific entry point for secondary CPUs.
* The secondary kernel init calls v7_flush_dcache_all before it enables
* the L1; however, the L1 comes out of reset in an undefined state, so
* the clean + invalidate performed by v7_flush_dcache_all causes a bunch
* of cache lines with uninitialized data and uninitialized tags to get
* written out to memory, which does really unpleasant things to the main
* processor. We fix this by performing an invalidate, rather than a
* clean + invalidate, before jumping into the kernel.
*/
ENTRY(v7_invalidate_l1)
mov r0, #0
mcr p15, 2, r0, c0, c0, 0
mrc p15, 1, r0, c0, c0, 0
ldr r1, =0x7fff
and r2, r1, r0, lsr #13
ldr r1, =0x3ff
and r3, r1, r0, lsr #3 @ NumWays - 1
add r2, r2, #1 @ NumSets
and r0, r0, #0x7
add r0, r0, #4 @ SetShift
clz r1, r3 @ WayShift
add r4, r3, #1 @ NumWays
1: sub r2, r2, #1 @ NumSets--
mov r3, r4 @ Temp = NumWays
2: subs r3, r3, #1 @ Temp--
mov r5, r3, lsl r1
mov r6, r2, lsl r0
orr r5, r5, r6 @ Reg = (Temp<<WayShift)|(NumSets<<SetShift)
mcr p15, 0, r5, c7, c6, 2
bgt 2b
cmp r2, #0
bgt 1b
dsb
isb
mov pc, lr
ENDPROC(v7_invalidate_l1)
ENTRY(tegra_secondary_startup)
bl v7_invalidate_l1
/* Enable coresight */
mov32 r0, 0xC5ACCE55
mcr p14, 0, r0, c7, c12, 6
b secondary_startup
ENDPROC(tegra_secondary_startup)
.align L1_CACHE_SHIFT
ENTRY(__tegra_cpu_reset_handler_start)
/*
* __tegra_cpu_reset_handler:
*
* Common handler for all CPU reset events.
*
* Register usage within the reset handler:
*
* R7 = CPU present (to the OS) mask
* R8 = CPU in LP1 state mask
* R9 = CPU in LP2 state mask
* R10 = CPU number
* R11 = CPU mask
* R12 = pointer to reset handler data
*
* NOTE: This code is copied to IRAM. All code and data accesses
* must be position-independent.
*/
.align L1_CACHE_SHIFT
ENTRY(__tegra_cpu_reset_handler)
cpsid aif, 0x13 @ SVC mode, interrupts disabled
mrc p15, 0, r10, c0, c0, 5 @ MPIDR
and r10, r10, #0x3 @ R10 = CPU number
mov r11, #1
mov r11, r11, lsl r10 @ R11 = CPU mask
adr r12, __tegra_cpu_reset_handler_data
#ifdef CONFIG_SMP
/* Does the OS know about this CPU? */
ldr r7, [r12, #RESET_DATA(MASK_PRESENT)]
tst r7, r11 @ if !present
bleq __die @ CPU not present (to OS)
#endif
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
/* Are we on Tegra20? */
mov32 r6, TEGRA_APB_MISC_BASE
ldr r0, [r6, #APB_MISC_GP_HIDREV]
and r0, r0, #0xff00
cmp r0, #(0x20 << 8)
bne 1f
/* If not CPU0, don't let CPU0 reset CPU1 now that CPU1 is coming up. */
mov32 r6, TEGRA_PMC_BASE
mov r0, #0
cmp r10, #0
strne r0, [r6, #PMC_SCRATCH41]
1:
#endif
#ifdef CONFIG_SMP
/*
* Can only be secondary boot (initial or hotplug) but CPU 0
* cannot be here.
*/
cmp r10, #0
bleq __die @ CPU0 cannot be here
ldr lr, [r12, #RESET_DATA(STARTUP_SECONDARY)]
cmp lr, #0
bleq __die @ no secondary startup handler
bx lr
#endif
/*
* We don't know why the CPU reset. Just kill it.
* The LR register will contain the address we died at + 4.
*/
__die:
sub lr, lr, #4
mov32 r7, TEGRA_PMC_BASE
str lr, [r7, #PMC_SCRATCH41]
mov32 r7, TEGRA_CLK_RESET_BASE
/* Are we on Tegra20? */
mov32 r6, TEGRA_APB_MISC_BASE
ldr r0, [r6, #APB_MISC_GP_HIDREV]
and r0, r0, #0xff00
cmp r0, #(0x20 << 8)
bne 1f
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
mov32 r0, 0x1111
mov r1, r0, lsl r10
str r1, [r7, #0x340] @ CLK_RST_CPU_CMPLX_SET
#endif
1:
#ifdef CONFIG_ARCH_TEGRA_3x_SOC
mov32 r6, TEGRA_FLOW_CTRL_BASE
cmp r10, #0
moveq r1, #FLOW_CTRL_HALT_CPU0_EVENTS
moveq r2, #FLOW_CTRL_CPU0_CSR
movne r1, r10, lsl #3
addne r2, r1, #(FLOW_CTRL_CPU1_CSR-8)
addne r1, r1, #(FLOW_CTRL_HALT_CPU1_EVENTS-8)
/* Clear CPU "event" and "interrupt" flags and power gate
it when halting but not before it is in the "WFI" state. */
ldr r0, [r6, +r2]
orr r0, r0, #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
orr r0, r0, #FLOW_CTRL_CSR_ENABLE
str r0, [r6, +r2]
/* Unconditionally halt this CPU */
mov r0, #FLOW_CTRL_WAITEVENT
str r0, [r6, +r1]
ldr r0, [r6, +r1] @ memory barrier
dsb
isb
wfi @ CPU should be power gated here
/* If the CPU didn't power gate above just kill it's clock. */
mov r0, r11, lsl #8
str r0, [r7, #348] @ CLK_CPU_CMPLX_SET
#endif
/* If the CPU still isn't dead, just spin here. */
b .
ENDPROC(__tegra_cpu_reset_handler)
.align L1_CACHE_SHIFT
.type __tegra_cpu_reset_handler_data, %object
.globl __tegra_cpu_reset_handler_data
__tegra_cpu_reset_handler_data:
.rept TEGRA_RESET_DATA_SIZE
.long 0
.endr
.align L1_CACHE_SHIFT
ENTRY(__tegra_cpu_reset_handler_end)