128 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
			
		
		
	
	
			128 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
| /* SPDX-License-Identifier: GPL-2.0+ */
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| /*
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|  * Copyright (C) 2013 Samsung Electronics
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|  * Akshay Saraswat <akshay.s@samsung.com>
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|  */
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| 
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| #include <config.h>
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| #include <asm/arch/cpu.h>
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| 
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| 	.globl relocate_wait_code
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| relocate_wait_code:
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| 	adr     r0, code_base		@ r0: source address (start)
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| 	adr     r1, code_end		@ r1: source address (end)
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| 	ldr     r2, =0x02073000		@ r2: target address
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| 1:
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| 	ldmia   r0!, {r3-r6}
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| 	stmia   r2!, {r3-r6}
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| 	cmp     r0, r1
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| 	blt     1b
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| 	b	code_end
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| 	.ltorg
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| /*
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|  * Secondary core waits here until Primary wake it up.
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|  * Below code is copied to (CFG_IRAM_TOP - 0x1000)
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|  * This is a workaround code which is supposed to act as a
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|  * substitute/supplement to the iROM code.
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|  *
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|  * This workaround code is relocated to the address 0x02073000
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|  * because that comes out to be the last 4KB of the iRAM
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|  * (Base Address - 0x02020000, Limit Address - 0x020740000).
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|  *
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|  * U-Boot and kernel are aware of this code and flags by the simple
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|  * fact that we are implementing a workaround in the last 4KB
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|  * of the iRAM and we have already defined these flag and address
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|  * values in both kernel and U-Boot for our use.
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|  */
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| code_base:
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| 	b	 1f
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| /*
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|  * These addresses are being used as flags in u-boot and kernel.
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|  *
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|  * Jump address for resume and flag to check for resume/reset:
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|  * Resume address - 0x2073008
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|  * Resume flag - 0x207300C
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|  *
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|  * Jump address for cluster switching:
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|  * Switch address - 0x2073018
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|  *
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|  * Jump address for core hotplug:
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|  * Hotplug address - 0x207301C
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|  *
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|  * Jump address for C2 state (Reserved for future not being used right now):
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|  * C2 address - 0x2073024
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|  *
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|  * Managed per core status for the active cluster:
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|  * CPU0 state - 0x2073028
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|  * CPU1 state - 0x207302C
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|  * CPU2 state - 0x2073030
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|  * CPU3 state - 0x2073034
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|  *
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|  * Managed per core GIC status for the active cluster:
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|  * CPU0 gic state - 0x2073038
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|  * CPU1 gic state - 0x207303C
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|  * CPU2 gic state - 0x2073040
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|  * CPU3 gic state - 0x2073044
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|  *
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|  * Logic of the code:
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|  * Step-1: Read current CPU status.
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|  * Step-2: If it's a resume then continue, else jump to step 4.
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|  * Step-3: Clear inform1 PMU register and jump to inform0 value.
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|  * Step-4: If it's a switch, C2 or reset, get the hotplug address.
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|  * Step-5: If address is not available, enter WFE.
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|  * Step-6: If address is available, jump to that address.
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|  */
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| 	nop			     @ for backward compatibility
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| 	.word   0x0		     @ REG0: RESUME_ADDR
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| 	.word   0x0		     @ REG1: RESUME_FLAG
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| 	.word   0x0		     @ REG2
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| 	.word   0x0		     @ REG3
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| _switch_addr:
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| 	.word   0x0		     @ REG4: SWITCH_ADDR
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| _hotplug_addr:
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| 	.word   0x0		     @ REG5: CPU1_BOOT_REG
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| 	.word   0x0		     @ REG6
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| _c2_addr:
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| 	.word   0x0		     @ REG7: REG_C2_ADDR
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| _cpu_state:
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| 	.word   0x1		     @ CPU0_STATE : RESET
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| 	.word   0x2		     @ CPU1_STATE : SECONDARY RESET
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| 	.word   0x2		     @ CPU2_STATE : SECONDARY RESET
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| 	.word   0x2		     @ CPU3_STATE : SECONDARY RESET
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| _gic_state:
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| 	.word   0x0		     @ CPU0 - GICD_IGROUPR0
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| 	.word   0x0		     @ CPU1 - GICD_IGROUPR0
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| 	.word   0x0		     @ CPU2 - GICD_IGROUPR0
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| 	.word   0x0		     @ CPU3 - GICD_IGROUPR0
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| 1:
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| 	adr     r0, _cpu_state
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| 	mrc     p15, 0, r7, c0, c0, 5   @ read MPIDR
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| 	and     r7, r7, #0xf	    @ r7 = cpu id
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| /* Read the current cpu state */
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| 	ldr     r10, [r0, r7, lsl #2]
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| svc_entry:
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| 	tst     r10, #(1 << 4)
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| 	adrne   r0, _switch_addr
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| 	bne     wait_for_addr
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| /* Clear INFORM1 */
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| 	ldr     r0, =(0x10040000 + 0x804)
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| 	ldr     r1, [r0]
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| 	cmp     r1, #0x0
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| 	movne   r1, #0x0
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| 	strne   r1, [r0]
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| /* Get INFORM0 */
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| 	ldrne   r1, =(0x10040000 + 0x800)
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| 	ldrne   pc, [r1]
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| 	tst     r10, #(1 << 0)
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| 	ldrne   pc, =0x23e00000
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| 	adr     r0, _hotplug_addr
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| wait_for_addr:
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| 	ldr     r1, [r0]
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| 	cmp     r1, #0x0
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| 	bxne    r1
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| 	wfe
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| 	b	 wait_for_addr
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| 	.ltorg
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| code_end:
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| 	mov	pc, lr
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