From 6c5c2a01fcfdb70f2e95e30e96ccf53b88e81023 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 4 Apr 2015 23:22:07 +0100 Subject: 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-macros.S | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'arch/arm/mm/proc-macros.S') 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 -- cgit v1.2.1