xref: /openbmc/linux/arch/arm/mach-tegra/reset-handler.S (revision a2faac39)

/* 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

.arch armv7-a

#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)