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linux-stable/arch/arm/mach-tegra/reset-handler.S
Dmitry Osipenko 36dc3b1a7e ARM: tegra: Initialize r0 register for firmware wake-up 
Downstream kernel of ASUS TF300T sets r0 to #3. There is no explanation in
downstream code whether this is really needed and some of T30 downstream
kernels have and explicit comment telling that all arguments are ignored
by firmware. Let's take a safe side by replicating behavior of the TF300T
downstream kernel. This change works fine on Ouya and Nexus 7 devices.

Tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Jasper Korten <jja2000@gmail.com>
Tested-by: David Heidelberg <david@ixit.cz>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-05-06 18:29:04 +02:00

301 lines
6.9 KiB
ArmAsm
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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2012, NVIDIA Corporation. All rights reserved.
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <soc/tegra/flowctrl.h>
#include <soc/tegra/fuse.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
#include <asm/cache.h>
#include "iomap.h"
#include "reset.h"
#include "sleep.h"
#define PMC_SCRATCH41 0x140
#ifdef CONFIG_PM_SLEEP
/*
* tegra_resume
*
* CPU boot vector when restarting the a CPU following
* an LP2 transition. Also branched to by LP0 and LP1 resume after
* re-enabling sdram.
*
* r6: SoC ID
* r8: CPU part number
*/
ENTRY(tegra_resume)
check_cpu_part_num 0xc09, r8, r9
bleq v7_invalidate_l1
cpu_id r0
cmp r0, #0 @ CPU0?
THUMB( it ne )
bne cpu_resume @ no
tegra_get_soc_id TEGRA_APB_MISC_BASE, r6
/* Are we on Tegra20? */
cmp r6, #TEGRA20
beq 1f @ Yes
/* Clear the flow controller flags for this CPU. */
cpu_to_csr_reg r3, r0
mov32 r2, TEGRA_FLOW_CTRL_BASE
ldr r1, [r2, r3]
/* Clear event & intr flag */
orr r1, r1, \
#FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
movw r0, #0x3FFD @ enable, cluster_switch, immed, bitmaps
@ & ext flags for CPU power mgnt
bic r1, r1, r0
str r1, [r2, r3]
1:
mov32 r9, 0xc09
cmp r8, r9
bne end_ca9_scu_l2_resume
#ifdef CONFIG_HAVE_ARM_SCU
/* enable SCU */
mov32 r0, TEGRA_ARM_PERIF_BASE
ldr r1, [r0]
orr r1, r1, #1
str r1, [r0]
#endif
bl tegra_resume_trusted_foundations
#ifdef CONFIG_CACHE_L2X0
/* L2 cache resume & re-enable */
bl l2c310_early_resume
#endif
end_ca9_scu_l2_resume:
mov32 r9, 0xc0f
cmp r8, r9
bleq tegra_init_l2_for_a15
b cpu_resume
ENDPROC(tegra_resume)
/*
* tegra_resume_trusted_foundations
*
* Trusted Foundations firmware initialization.
*
* Doesn't return if firmware presents.
* Corrupted registers: r1, r2
*/
ENTRY(tegra_resume_trusted_foundations)
/* Check whether Trusted Foundations firmware presents. */
mov32 r2, TEGRA_IRAM_BASE + TEGRA_IRAM_RESET_HANDLER_OFFSET
ldr r1, =__tegra_cpu_reset_handler_data_offset + \
RESET_DATA(TF_PRESENT)
ldr r1, [r2, r1]
cmp r1, #0
reteq lr
.arch_extension sec
/*
* First call after suspend wakes firmware. No arguments required
* for some firmware versions. Downstream kernel of ASUS TF300T uses
* r0=3 for the wake-up notification.
*/
mov r0, #3
smc #0
b cpu_resume
ENDPROC(tegra_resume_trusted_foundations)
#endif
.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:
*
* Others: scratch
* R6 = SoC ID
* 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.
*/
.arm
.align L1_CACHE_SHIFT
ENTRY(__tegra_cpu_reset_handler)
cpsid aif, 0x13 @ SVC mode, interrupts disabled
tegra_get_soc_id TEGRA_APB_MISC_BASE, r6
adr r12, __tegra_cpu_reset_handler_data
ldr r5, [r12, #RESET_DATA(TF_PRESENT)]
cmp r5, #0
bne after_errata
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
t20_check:
cmp r6, #TEGRA20
bne after_t20_check
t20_errata:
# Tegra20 is a Cortex-A9 r1p1
mrc p15, 0, r0, c1, c0, 0 @ read system control register
orr r0, r0, #1 << 14 @ erratum 716044
mcr p15, 0, r0, c1, c0, 0 @ write system control register
mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register
orr r0, r0, #1 << 4 @ erratum 742230
orr r0, r0, #1 << 11 @ erratum 751472
mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
b after_errata
after_t20_check:
#endif
#ifdef CONFIG_ARCH_TEGRA_3x_SOC
t30_check:
cmp r6, #TEGRA30
bne after_t30_check
t30_errata:
# Tegra30 is a Cortex-A9 r2p9
mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register
orr r0, r0, #1 << 6 @ erratum 743622
orr r0, r0, #1 << 11 @ erratum 751472
mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register
b after_errata
after_t30_check:
#endif
after_errata:
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
#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
/* Waking up from LP1? */
ldr r8, [r12, #RESET_DATA(MASK_LP1)]
tst r8, r11 @ if in_lp1
beq __is_not_lp1
cmp r10, #0
bne __die @ only CPU0 can be here
ldr lr, [r12, #RESET_DATA(STARTUP_LP1)]
cmp lr, #0
bleq __die @ no LP1 startup handler
THUMB( add lr, lr, #1 ) @ switch to Thumb mode
bx lr
__is_not_lp1:
/* Waking up from LP2? */
ldr r9, [r12, #RESET_DATA(MASK_LP2)]
tst r9, r11 @ if in_lp2
beq __is_not_lp2
ldr lr, [r12, #RESET_DATA(STARTUP_LP2)]
cmp lr, #0
bleq __die @ no LP2 startup handler
bx lr
__is_not_lp2:
#ifdef CONFIG_SMP
/*
* Can only be secondary boot (initial or hotplug)
* CPU0 can't be here for Tegra20/30
*/
cmp r6, #TEGRA114
beq __no_cpu0_chk
cmp r10, #0
bleq __die @ CPU0 cannot be here
__no_cpu0_chk:
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? */
cmp r6, #TEGRA20
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
.globl __tegra_cpu_reset_handler_data_offset
.equ __tegra_cpu_reset_handler_data_offset, \
. - __tegra_cpu_reset_handler_start
__tegra_cpu_reset_handler_data:
.rept TEGRA_RESET_DATA_SIZE
.long 0
.endr
.align L1_CACHE_SHIFT
ENTRY(__tegra_cpu_reset_handler_end)
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