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ARM: proc-arm94*.S: fix setup function

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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 <broscutamaker@gmail.com>
Tested-by: Georg Hofstetter <g3gg0.de@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2015-04-04 23:22:07 +01:00
parent f6ac49ba29
commit 6c5c2a01fc
3 changed files with 38 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
arch/arm/mm/proc-arm940.S
View File

@ -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

22
arch/arm/mm/proc-arm946.S
View File

@ -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

24
arch/arm/mm/proc-macros.S
View File

@ -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