u-boot/arch/arm/mach-uniphier/lowlevel_init.S
Masahiro Yamada e6eecca54f ARM: uniphier: unify low-level debug init code
Move init code of low-level debug into a single file.
This is helpful to create an image that runs on multiple SoCs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-09-25 00:27:53 +09:00

175 lines
4.8 KiB
ArmAsm

/*
* Copyright (C) 2012-2015 Masahiro Yamada <yamada.masahiro@socionext.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <linux/linkage.h>
#include <linux/sizes.h>
#include <asm/system.h>
#include <mach/arm-mpcore.h>
#include <mach/sbc-regs.h>
#include <mach/ssc-regs.h>
ENTRY(lowlevel_init)
mov r8, lr @ persevere link reg across call
/*
* The UniPhier Boot ROM loads SPL code to the L2 cache.
* But CPUs can only do instruction fetch now because start.S has
* cleared C and M bits.
* First we need to turn on MMU and Dcache again to get back
* data access to L2.
*/
mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Control Register)
orr r0, r0, #(CR_C | CR_M) @ enable MMU and Dcache
mcr p15, 0, r0, c1, c0, 0
#ifdef CONFIG_DEBUG_LL
bl debug_ll_init
#endif
/*
* Now we are using the page table embedded in the Boot ROM.
* It is not handy since it is not a straight mapped table for sLD3.
* What we need to do next is to switch over to the page table in SPL.
*/
ldr r3, =init_page_table @ page table must be 16KB aligned
/* Disable MMU and Dcache before switching Page Table */
mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Control Register)
bic r0, r0, #(CR_C | CR_M) @ disable MMU and Dcache
mcr p15, 0, r0, c1, c0, 0
bl enable_mmu
#ifdef CONFIG_UNIPHIER_SMP
secondary_startup:
/*
* Entry point for secondary CPUs
*
* The Boot ROM has already enabled MMU for the secondary CPUs as well
* as for the primary one. The MMU table embedded in the Boot ROM
* prohibits the DRAM access, so it is impossible to bring the
* secondary CPUs into DRAM directly. They must jump here into SPL,
* which is run on L2 cache.
*
* Boot Sequence
* [primary CPU] [secondary CPUs]
* start from Boot ROM start from Boot ROM
* jump to SPL sleep in Boot ROM
* kick secondaries ---(sev)---> jump to SPL
* jump to U-Boot main sleep in SPL
* jump to Linux
* kick secondaries ---(sev)---> jump to Linux
*/
/* branch by CPU ID */
mrc p15, 0, r0, c0, c0, 5 @ MPIDR (Multiprocessor Affinity Register)
and r0, r0, #0x3
cmp r0, #0x0
beq primary_cpu
/* only for secondary CPUs */
ldr r1, =ROM_BOOT_ROMRSV2 @ The last data access to L2 cache
mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Control Register)
orr r0, r0, #CR_I @ Enable ICache
bic r0, r0, #(CR_C | CR_M) @ MMU and Dcache must be disabled
mcr p15, 0, r0, c1, c0, 0 @ before jumping to Linux
mov r0, #0
str r0, [r1]
b 1f
/*
* L2 cache is shared among all the CPUs and it might be disabled by
* the primary one. Before that, the following 5 lines must be cached
* on the Icaches of the secondary CPUs.
*/
0: wfe @ kicked by Linux
1: ldr r0, [r1]
cmp r0, #0
bxne r0 @ r0: Linux entry for secondary CPUs
b 0b
primary_cpu:
ldr r1, =ROM_BOOT_ROMRSV2
ldr r0, =secondary_startup
str r0, [r1]
ldr r0, [r1] @ make sure str is complete before sev
sev @ kick the secondary CPU
#endif
bl setup_init_ram @ RAM area for temporary stack pointer
mov lr, r8 @ restore link
mov pc, lr @ back to my caller
ENDPROC(lowlevel_init)
ENTRY(enable_mmu)
mrc p15, 0, r0, c2, c0, 2 @ TTBCR (Translation Table Base Control Register)
bic r0, r0, #0x37
orr r0, r0, #0x20 @ disable TTBR1
mcr p15, 0, r0, c2, c0, 2
orr r0, r3, #0x8 @ Outer Cacheability for table walks: WBWA
mcr p15, 0, r0, c2, c0, 0 @ TTBR0
mov r0, #0
mcr p15, 0, r0, c8, c7, 0 @ invalidate TLBs
mov r0, #-1 @ manager for all domains (No permission check)
mcr p15, 0, r0, c3, c0, 0 @ DACR (Domain Access Control Register)
dsb
isb
/*
* MMU on:
* TLBs was already invalidated in "../start.S"
* So, we don't need to invalidate it here.
*/
mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Control Register)
orr r0, r0, #(CR_C | CR_M) @ MMU and Dcache enable
mcr p15, 0, r0, c1, c0, 0
mov pc, lr
ENDPROC(enable_mmu)
/*
* For PH1-Pro4 or older SoCs, the size of WAY is 32KB.
* It is large enough for tmp RAM.
*/
#define BOOT_RAM_SIZE (SZ_32K)
#define BOOT_WAY_BITS (0x00000100) /* way 8 */
ENTRY(setup_init_ram)
/*
* Touch to zero for the boot way
*/
0:
/*
* set SSCOQM, SSCOQAD, SSCOQSZ, SSCOQWN in this order
*/
ldr r0, = 0x00408006 @ touch to zero with address range
ldr r1, = SSCOQM
str r0, [r1]
ldr r0, = (CONFIG_SPL_STACK - BOOT_RAM_SIZE) @ base address
ldr r1, = SSCOQAD
str r0, [r1]
ldr r0, = BOOT_RAM_SIZE
ldr r1, = SSCOQSZ
str r0, [r1]
ldr r0, = BOOT_WAY_BITS
ldr r1, = SSCOQWN
str r0, [r1]
ldr r1, = SSCOPPQSEF
ldr r0, [r1]
cmp r0, #0 @ check if the command is successfully set
bne 0b @ try again if an error occurs
ldr r1, = SSCOLPQS
1:
ldr r0, [r1]
cmp r0, #0x4
bne 1b @ wait until the operation is completed
str r0, [r1] @ clear the complete notification flag
mov pc, lr
ENDPROC(setup_init_ram)