UniPhier SoCs are not equipped with dedicated on-chip SRAM. Instead, locked outer cache is used as RAM area during the early boot stage where DRAM is not ready yet. This effectively means MMU must be always enabled while we are in SPL.
Currently, the SPL image for UniPhier SoCs contains the page table statically defined at compile time. It has been a burden because the 16KB page table occupies a quarter memory footprint of the 64KB SPL image.
Finally, there is no more room to implement new features in SPL. Setting aside the NOR boot mode, this issue can be solved by creating the page table onto RAM at run time.
Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com ---
arch/arm/mach-uniphier/Makefile | 1 - arch/arm/mach-uniphier/init_page_table.S | 29 --------- arch/arm/mach-uniphier/lowlevel_init.S | 103 ++++++++++++++++++++++++++++--- 3 files changed, 95 insertions(+), 38 deletions(-) delete mode 100644 arch/arm/mach-uniphier/init_page_table.S
diff --git a/arch/arm/mach-uniphier/Makefile b/arch/arm/mach-uniphier/Makefile index ea3ae54..491e78e 100644 --- a/arch/arm/mach-uniphier/Makefile +++ b/arch/arm/mach-uniphier/Makefile @@ -5,7 +5,6 @@ ifdef CONFIG_SPL_BUILD
obj-y += lowlevel_init.o -obj-y += init_page_table.o
obj-y += init/ bcu/ memconf/ pll/ early-clk/ early-pinctrl/ dram/ obj-$(CONFIG_MICRO_SUPPORT_CARD) += sbc/ diff --git a/arch/arm/mach-uniphier/init_page_table.S b/arch/arm/mach-uniphier/init_page_table.S deleted file mode 100644 index 4ed2656..0000000 --- a/arch/arm/mach-uniphier/init_page_table.S +++ /dev/null @@ -1,29 +0,0 @@ -/* - * Copyright (C) 2015 Masahiro Yamada yamada.masahiro@socionext.com - * - * SPDX-License-Identifier: GPL-2.0+ - */ - -#include <config.h> -#include <linux/linkage.h> - -/* page table */ -#define NR_SECTIONS 4096 -#define SECTION_SHIFT 20 -#define DEVICE 0x00002002 /* Non-shareable Device */ -#define NORMAL 0x0000000e /* Normal Memory Write-Back, No Write-Allocate */ - - .section ".rodata" - .align 14 -ENTRY(init_page_table) - section = 0 - .rept NR_SECTIONS - .if section == 0 || section == 1 - attr = NORMAL - .else - attr = DEVICE - .endif - .word (section << SECTION_SHIFT) | attr - section = section + 1 - .endr -END(init_page_table) diff --git a/arch/arm/mach-uniphier/lowlevel_init.S b/arch/arm/mach-uniphier/lowlevel_init.S index 2913370..c23e0d1 100644 --- a/arch/arm/mach-uniphier/lowlevel_init.S +++ b/arch/arm/mach-uniphier/lowlevel_init.S @@ -29,12 +29,16 @@ ENTRY(lowlevel_init) bl debug_ll_init #endif
+ bl setup_init_ram @ RAM area for stack and page talbe + /* * 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. + * Also, the access to the external bus is prohibited. What we need + * to do next is to create a page table and switch over to it. */ - ldr r3, =init_page_table @ page table must be 16KB aligned + bl create_page_table + bl v7_flush_dcache_all
/* Disable MMU and Dcache before switching Page Table */ mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Control Register) @@ -43,8 +47,6 @@ ENTRY(lowlevel_init)
bl enable_mmu
- 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) @@ -55,7 +57,7 @@ ENTRY(enable_mmu) orr r0, r0, #0x20 @ disable TTBR1 mcr p15, 0, r0, c2, c0, 2
- orr r0, r3, #0x8 @ Outer Cacheability for table walks: WBWA + orr r0, r12, #0x8 @ Outer Cacheability for table walks: WBWA mcr p15, 0, r0, c2, c0, 0 @ TTBR0
mov r0, #0 @@ -82,8 +84,9 @@ 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 */ +#define BOOT_RAM_SIZE (SZ_32K) +#define BOOT_RAM_BASE ((CONFIG_SPL_STACK) - (BOOT_RAM_SIZE)) +#define BOOT_WAY_BITS (0x00000100) /* way 8 */
ENTRY(setup_init_ram) /* @@ -96,7 +99,7 @@ ENTRY(setup_init_ram) 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 r0, = BOOT_RAM_BASE ldr r1, = SSCOQAD str r0, [r1] ldr r0, = BOOT_RAM_SIZE @@ -119,3 +122,87 @@ ENTRY(setup_init_ram)
mov pc, lr ENDPROC(setup_init_ram) + +/* page table */ +#define DEVICE 0x00002002 /* Non-shareable Device */ +#define NORMAL 0x0000000e /* Normal Memory Write-Back, No Write-Allocate */ + +ENTRY(create_page_table) + ldr r0, = DEVICE + ldr r1, = BOOT_RAM_BASE + mov r12, r1 @ r12 is preserved during D-cache flush +0: str r0, [r1], #4 @ specify all the sections as Device + adds r0, r0, #0x00100000 + bcc 0b + + ldr r0, = NORMAL + str r0, [r12] @ mark the first section as Normal + add r0, r0, #0x00100000 + str r0, [r12, #4] @ mark the second section as Normal + mov pc, lr +ENDPROC(create_page_table) + +/* We don't use Thumb instructions for now */ +#define ARM(x...) x +#define THUMB(x...) + +/* + * v7_flush_dcache_all() + * + * Flush the whole D-cache. + * + * Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode) + * + * - mm - mm_struct describing address space + * + * Note: copied from arch/arm/mm/cache-v7.S of Linux 4.4 + */ +ENTRY(v7_flush_dcache_all) + dmb @ ensure ordering with previous memory accesses + mrc p15, 1, r0, c0, c0, 1 @ read clidr + mov r3, r0, lsr #23 @ move LoC into position + ands r3, r3, #7 << 1 @ extract LoC*2 from clidr + beq finished @ if loc is 0, then no need to clean +start_flush_levels: + mov r10, #0 @ start clean at cache level 0 +flush_levels: + add r2, r10, r10, lsr #1 @ work out 3x current cache level + mov r1, r0, lsr r2 @ extract cache type bits from clidr + and r1, r1, #7 @ mask of the bits for current cache only + cmp r1, #2 @ see what cache we have at this level + blt skip @ skip if no cache, or just i-cache + mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr + isb @ isb to sych the new cssr&csidr + mrc p15, 1, r1, c0, c0, 0 @ read the new csidr + and r2, r1, #7 @ extract the length of the cache lines + add r2, r2, #4 @ add 4 (line length offset) + movw r4, #0x3ff + ands r4, r4, r1, lsr #3 @ find maximum number on the way size + clz r5, r4 @ find bit position of way size increment + movw r7, #0x7fff + ands r7, r7, r1, lsr #13 @ extract max number of the index size +loop1: + mov r9, r7 @ create working copy of max index +loop2: + ARM( orr r11, r10, r4, lsl r5 ) @ factor way and cache number into r11 + THUMB( lsl r6, r4, r5 ) + THUMB( orr r11, r10, r6 ) @ factor way and cache number into r11 + ARM( orr r11, r11, r9, lsl r2 ) @ factor index number into r11 + THUMB( lsl r6, r9, r2 ) + THUMB( orr r11, r11, r6 ) @ factor index number into r11 + mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way + subs r9, r9, #1 @ decrement the index + bge loop2 + subs r4, r4, #1 @ decrement the way + bge loop1 +skip: + add r10, r10, #2 @ increment cache number + cmp r3, r10 + bgt flush_levels +finished: + mov r10, #0 @ swith back to cache level 0 + mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr + dsb st + isb + mov pc, lr +ENDPROC(v7_flush_dcache_all)