From 6c5c2a01fcfdb70f2e95e30e96ccf53b88e81023 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 4 Apr 2015 23:22:07 +0100 Subject: [PATCH] ARM: proc-arm94*.S: fix setup function Both ARM946 and ARM940 setup functions were corrupting r1 and r2, which is not permissible - these are used to carry the machine ID and boot data into the kernel, and must be preserved. The code responsible for this was the same in both files: they were using the registers to generate a protection region register value. Fix this by turning this process into a macro, and using that macro in both these files with an alternative register allocation. r0, r3 and r7 can be used for temporary values here. Reported-by: Alex Dumitrache Tested-by: Georg Hofstetter Signed-off-by: Russell King --- arch/arm/mm/proc-arm940.S | 26 ++++++++------------------ arch/arm/mm/proc-arm946.S | 22 ++++++---------------- arch/arm/mm/proc-macros.S | 24 ++++++++++++++++++++++++ 3 files changed, 38 insertions(+), 34 deletions(-) diff --git a/arch/arm/mm/proc-arm940.S b/arch/arm/mm/proc-arm940.S index e5212d489377..c42cdd3b44bc 100644 --- a/arch/arm/mm/proc-arm940.S +++ b/arch/arm/mm/proc-arm940.S @@ -297,26 +297,16 @@ __arm940_setup: mcr p15, 0, r0, c6, c0, 1 ldr r0, =(CONFIG_DRAM_BASE & 0xFFFFF000) @ base[31:12] of RAM - ldr r1, =(CONFIG_DRAM_SIZE >> 12) @ size of RAM (must be >= 4KB) - mov r2, #10 @ 11 is the minimum (4KB) -1: add r2, r2, #1 @ area size *= 2 - mov r1, r1, lsr #1 - bne 1b @ count not zero r-shift - orr r0, r0, r2, lsl #1 @ the area register value - orr r0, r0, #1 @ set enable bit - mcr p15, 0, r0, c6, c1, 0 @ set area 1, RAM - mcr p15, 0, r0, c6, c1, 1 + ldr r7, =CONFIG_DRAM_SIZE >> 12 @ size of RAM (must be >= 4KB) + pr_val r3, r0, r7, #1 + mcr p15, 0, r3, c6, c1, 0 @ set area 1, RAM + mcr p15, 0, r3, c6, c1, 1 ldr r0, =(CONFIG_FLASH_MEM_BASE & 0xFFFFF000) @ base[31:12] of FLASH - ldr r1, =(CONFIG_FLASH_SIZE >> 12) @ size of FLASH (must be >= 4KB) - mov r2, #10 @ 11 is the minimum (4KB) -1: add r2, r2, #1 @ area size *= 2 - mov r1, r1, lsr #1 - bne 1b @ count not zero r-shift - orr r0, r0, r2, lsl #1 @ the area register value - orr r0, r0, #1 @ set enable bit - mcr p15, 0, r0, c6, c2, 0 @ set area 2, ROM/FLASH - mcr p15, 0, r0, c6, c2, 1 + ldr r7, =CONFIG_FLASH_SIZE @ size of FLASH (must be >= 4KB) + pr_val r3, r0, r6, #1 + mcr p15, 0, r3, c6, c2, 0 @ set area 2, ROM/FLASH + mcr p15, 0, r3, c6, c2, 1 mov r0, #0x06 mcr p15, 0, r0, c2, c0, 0 @ Region 1&2 cacheable diff --git a/arch/arm/mm/proc-arm946.S b/arch/arm/mm/proc-arm946.S index b3dd9b2d0b8e..17a8c2075c62 100644 --- a/arch/arm/mm/proc-arm946.S +++ b/arch/arm/mm/proc-arm946.S @@ -343,24 +343,14 @@ __arm946_setup: mcr p15, 0, r0, c6, c0, 0 @ set region 0, default ldr r0, =(CONFIG_DRAM_BASE & 0xFFFFF000) @ base[31:12] of RAM - ldr r1, =(CONFIG_DRAM_SIZE >> 12) @ size of RAM (must be >= 4KB) - mov r2, #10 @ 11 is the minimum (4KB) -1: add r2, r2, #1 @ area size *= 2 - mov r1, r1, lsr #1 - bne 1b @ count not zero r-shift - orr r0, r0, r2, lsl #1 @ the region register value - orr r0, r0, #1 @ set enable bit - mcr p15, 0, r0, c6, c1, 0 @ set region 1, RAM + ldr r7, =CONFIG_DRAM_SIZE @ size of RAM (must be >= 4KB) + pr_val r3, r0, r7, #1 + mcr p15, 0, r3, c6, c1, 0 ldr r0, =(CONFIG_FLASH_MEM_BASE & 0xFFFFF000) @ base[31:12] of FLASH - ldr r1, =(CONFIG_FLASH_SIZE >> 12) @ size of FLASH (must be >= 4KB) - mov r2, #10 @ 11 is the minimum (4KB) -1: add r2, r2, #1 @ area size *= 2 - mov r1, r1, lsr #1 - bne 1b @ count not zero r-shift - orr r0, r0, r2, lsl #1 @ the region register value - orr r0, r0, #1 @ set enable bit - mcr p15, 0, r0, c6, c2, 0 @ set region 2, ROM/FLASH + ldr r7, =CONFIG_FLASH_SIZE @ size of FLASH (must be >= 4KB) + pr_val r3, r0, r7, #1 + mcr p15, 0, r3, c6, c2, 0 mov r0, #0x06 mcr p15, 0, r0, c2, c0, 0 @ region 1,2 d-cacheable diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S index 082b9f2f7e90..d081c9d9420d 100644 --- a/arch/arm/mm/proc-macros.S +++ b/arch/arm/mm/proc-macros.S @@ -331,3 +331,27 @@ ENTRY(\name\()_tlb_fns) .globl \x .equ \x, \y .endm + + /* + * Macro to calculate the log2 size for the protection region + * registers. This calculates rd = log2(size) - 1. tmp must + * not be the same register as rd. + */ +.macro pr_sz, rd, size, tmp + mov \tmp, \size, lsr #12 + mov \rd, #11 +1: movs \tmp, \tmp, lsr #1 + addne \rd, \rd, #1 + bne 1b +.endm + + /* + * Macro to generate a protection region register value + * given a pre-masked address, size, and enable bit. + * Corrupts size. + */ +.macro pr_val, dest, addr, size, enable + pr_sz \dest, \size, \size @ calculate log2(size) - 1 + orr \dest, \addr, \dest, lsl #1 @ mask in the region size + orr \dest, \dest, \enable +.endm -- 2.34.1