226 lines
		
	
	
		
			5.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			226 lines
		
	
	
		
			5.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0+ */
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| /*
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|  * code for switching cores into non-secure state and into HYP mode
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|  *
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|  * Copyright (c) 2013	Andre Przywara <andre.przywara@linaro.org>
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|  */
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| 
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| #include <config.h>
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| #include <linux/linkage.h>
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| #include <asm/gic.h>
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| #include <asm/armv7.h>
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| #include <asm/proc-armv/ptrace.h>
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| 
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| .arch_extension sec
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| .arch_extension virt
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| 
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| 	.pushsection ._secure.text, "ax"
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| 
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| 	.align	5
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| /* the vector table for secure state and HYP mode */
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| _monitor_vectors:
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| 	.word 0	/* reset */
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| 	.word 0 /* undef */
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| 	adr pc, _secure_monitor
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| 	.word 0
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| 	.word 0
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| 	.word 0
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| 	.word 0
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| 	.word 0
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| 
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| .macro is_cpu_virt_capable	tmp
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| 	mrc	p15, 0, \tmp, c0, c1, 1		@ read ID_PFR1
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| 	and	\tmp, \tmp, #CPUID_ARM_VIRT_MASK	@ mask virtualization bits
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| 	cmp	\tmp, #(1 << CPUID_ARM_VIRT_SHIFT)
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| .endm
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| 
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| /*
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|  * secure monitor handler
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|  * U-Boot calls this "software interrupt" in start.S
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|  * This is executed on a "smc" instruction, we use a "smc #0" to switch
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|  * to non-secure state.
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|  * r0, r1, r2: passed to the callee
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|  * ip: target PC
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|  */
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| _secure_monitor:
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| #ifdef CONFIG_ARMV7_PSCI
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| 	ldr	r5, =_psci_vectors		@ Switch to the next monitor
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| 	mcr	p15, 0, r5, c12, c0, 1
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| 	isb
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| 
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| 	@ Obtain a secure stack
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| 	bl	psci_stack_setup
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| 
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| 	@ Configure the PSCI backend
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| 	push	{r0, r1, r2, ip}
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| 	bl	psci_arch_init
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| 	pop	{r0, r1, r2, ip}
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| #endif
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| 
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| #ifdef CONFIG_ARM_ERRATA_773022
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| 	mrc	p15, 0, r5, c1, c0, 1
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| 	orr	r5, r5, #(1 << 1)
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| 	mcr	p15, 0, r5, c1, c0, 1
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| 	isb
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| #endif
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| 
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| #ifdef CONFIG_ARM_ERRATA_774769
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| 	mrc	p15, 0, r5, c1, c0, 1
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| 	orr	r5, r5, #(1 << 25)
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| 	mcr	p15, 0, r5, c1, c0, 1
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| 	isb
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| #endif
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| 
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| 	mrc	p15, 0, r5, c1, c1, 0		@ read SCR
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| 	bic	r5, r5, #0x4a			@ clear IRQ, EA, nET bits
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| 	orr	r5, r5, #0x31			@ enable NS, AW, FW bits
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| 						@ FIQ preserved for secure mode
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| 	mov	r6, #SVC_MODE			@ default mode is SVC
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| 	is_cpu_virt_capable r4
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| #ifdef CONFIG_ARMV7_VIRT
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| 	orreq	r5, r5, #0x100			@ allow HVC instruction
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| 	moveq	r6, #HYP_MODE			@ Enter the kernel as HYP
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| 	mrseq	r3, sp_svc
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| 	msreq	sp_hyp, r3			@ migrate SP
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| #endif
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| 
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| 	mcr	p15, 0, r5, c1, c1, 0		@ write SCR (with NS bit set)
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| 	isb
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| 
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| 	bne	1f
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| 
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| 	@ Reset CNTVOFF to 0 before leaving monitor mode
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| 	mrc	p15, 0, r4, c0, c1, 1		@ read ID_PFR1
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| 	ands	r4, r4, #CPUID_ARM_GENTIMER_MASK	@ test arch timer bits
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| 	movne	r4, #0
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| 	mcrrne	p15, 4, r4, r4, c14		@ Reset CNTVOFF to zero
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| 1:
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| 	mov	lr, ip
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| 	mov	ip, #(F_BIT | I_BIT | A_BIT)	@ Set A, I and F
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| 	tst	lr, #1				@ Check for Thumb PC
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| 	orrne	ip, ip, #T_BIT			@ Set T if Thumb
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| 	orr	ip, ip, r6			@ Slot target mode in
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| 	msr	spsr_cxfs, ip			@ Set full SPSR
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| 	movs	pc, lr				@ ERET to non-secure
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| 
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| ENTRY(_do_nonsec_entry)
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| 	mov	ip, r0
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| 	mov	r0, r1
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| 	mov	r1, r2
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| 	mov	r2, r3
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| 	smc	#0
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| ENDPROC(_do_nonsec_entry)
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| 
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| .macro get_cbar_addr	addr
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| #ifdef CONFIG_ARM_GIC_BASE_ADDRESS
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| 	ldr	\addr, =CONFIG_ARM_GIC_BASE_ADDRESS
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| #else
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| 	mrc	p15, 4, \addr, c15, c0, 0	@ read CBAR
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| 	bfc	\addr, #0, #15			@ clear reserved bits
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| #endif
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| .endm
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| 
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| .macro get_gicd_addr	addr
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| 	get_cbar_addr	\addr
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| 	add	\addr, \addr, #GIC_DIST_OFFSET	@ GIC dist i/f offset
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| .endm
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| 
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| .macro get_gicc_addr	addr, tmp
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| 	get_cbar_addr	\addr
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| 	is_cpu_virt_capable \tmp
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| 	movne	\tmp, #GIC_CPU_OFFSET_A9	@ GIC CPU offset for A9
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| 	moveq	\tmp, #GIC_CPU_OFFSET_A15	@ GIC CPU offset for A15/A7
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| 	add	\addr, \addr, \tmp
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| .endm
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| 
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| #ifndef CONFIG_ARMV7_PSCI
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| /*
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|  * Secondary CPUs start here and call the code for the core specific parts
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|  * of the non-secure and HYP mode transition. The GIC distributor specific
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|  * code has already been executed by a C function before.
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|  * Then they go back to wfi and wait to be woken up by the kernel again.
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|  */
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| ENTRY(_smp_pen)
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| 	cpsid	i
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| 	cpsid	f
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| 
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| 	bl	_nonsec_init
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| 
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| 	adr	r0, _smp_pen			@ do not use this address again
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| 	b	smp_waitloop			@ wait for IPIs, board specific
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| ENDPROC(_smp_pen)
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| #endif
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| 
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| /*
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|  * Switch a core to non-secure state.
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|  *
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|  *  1. initialize the GIC per-core interface
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|  *  2. allow coprocessor access in non-secure modes
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|  *
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|  * Called from smp_pen by secondary cores and directly by the BSP.
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|  * Do not assume that the stack is available and only use registers
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|  * r0-r3 and r12.
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|  *
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|  * PERIPHBASE is used to get the GIC address. This could be 40 bits long,
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|  * though, but we check this in C before calling this function.
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|  */
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| ENTRY(_nonsec_init)
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| 	get_gicd_addr	r3
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| 
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| 	mvn	r1, #0				@ all bits to 1
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| 	str	r1, [r3, #GICD_IGROUPRn]	@ allow private interrupts
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| 
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| 	get_gicc_addr	r3, r1
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| 
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| 	mov	r1, #3				@ Enable both groups
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| 	str	r1, [r3, #GICC_CTLR]		@ and clear all other bits
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| 	mov	r1, #0xff
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| 	str	r1, [r3, #GICC_PMR]		@ set priority mask register
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| 
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| 	mrc	p15, 0, r0, c1, c1, 2
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| 	movw	r1, #0x3fff
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| 	movt	r1, #0x0004
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| 	orr	r0, r0, r1
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| 	mcr	p15, 0, r0, c1, c1, 2		@ NSACR = all copros to non-sec
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| 
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| /* The CNTFRQ register of the generic timer needs to be
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|  * programmed in secure state. Some primary bootloaders / firmware
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|  * omit this, so if the frequency is provided in the configuration,
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|  * we do this here instead.
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|  * But first check if we have the generic timer.
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|  */
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| #ifdef COUNTER_FREQUENCY
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| 	mrc	p15, 0, r0, c0, c1, 1		@ read ID_PFR1
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| 	and	r0, r0, #CPUID_ARM_GENTIMER_MASK	@ mask arch timer bits
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| 	cmp	r0, #(1 << CPUID_ARM_GENTIMER_SHIFT)
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| 	ldreq	r1, =COUNTER_FREQUENCY
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| 	mcreq	p15, 0, r1, c14, c0, 0		@ write CNTFRQ
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| #endif
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| 
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| 	adr	r1, _monitor_vectors
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| 	mcr	p15, 0, r1, c12, c0, 1		@ set MVBAR to secure vectors
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| 	isb
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| 
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| 	mov	r0, r3				@ return GICC address
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| 	bx	lr
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| ENDPROC(_nonsec_init)
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| 
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| #ifdef CONFIG_SMP_PEN_ADDR
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| /* void __weak smp_waitloop(unsigned previous_address); */
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| ENTRY(smp_waitloop)
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| 	wfi
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| 	ldr	r1, =CONFIG_SMP_PEN_ADDR	@ load start address
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| 	ldr	r1, [r1]
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| #ifdef CONFIG_PEN_ADDR_BIG_ENDIAN
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| 	rev	r1, r1
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| #endif
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| 	cmp	r0, r1			@ make sure we dont execute this code
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| 	beq	smp_waitloop		@ again (due to a spurious wakeup)
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| 	mov	r0, r1
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| 	b	_do_nonsec_entry
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| ENDPROC(smp_waitloop)
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| .weak smp_waitloop
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| #endif
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| 
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| 	.popsection
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