diff options
Diffstat (limited to 'arch/arm/mm/pv-fixup-asm.S')
| -rw-r--r-- | arch/arm/mm/pv-fixup-asm.S | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/arm/mm/pv-fixup-asm.S b/arch/arm/mm/pv-fixup-asm.S new file mode 100644 index 000000000..1867f3e43 --- /dev/null +++ b/arch/arm/mm/pv-fixup-asm.S @@ -0,0 +1,88 @@ +/* + * Copyright (C) 2015 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This assembly is required to safely remap the physical address space + * for Keystone 2 + */ +#include <linux/linkage.h> +#include <asm/asm-offsets.h> +#include <asm/cp15.h> +#include <asm/memory.h> +#include <asm/pgtable.h> + + .section ".idmap.text", "ax" + +#define L1_ORDER 3 +#define L2_ORDER 3 + +ENTRY(lpae_pgtables_remap_asm) + stmfd sp!, {r4-r8, lr} + + mrc p15, 0, r8, c1, c0, 0 @ read control reg + bic ip, r8, #CR_M @ disable caches and MMU + mcr p15, 0, ip, c1, c0, 0 + dsb + isb + + /* Update level 2 entries covering the kernel */ + ldr r6, =(_end - 1) + add r7, r2, #0x1000 + add r6, r7, r6, lsr #SECTION_SHIFT - L2_ORDER + add r7, r7, #PAGE_OFFSET >> (SECTION_SHIFT - L2_ORDER) +1: ldrd r4, [r7] + adds r4, r4, r0 + adc r5, r5, r1 + strd r4, [r7], #1 << L2_ORDER + cmp r7, r6 + bls 1b + + /* Update level 2 entries for the boot data */ + add r7, r2, #0x1000 + add r7, r7, r3, lsr #SECTION_SHIFT - L2_ORDER + bic r7, r7, #(1 << L2_ORDER) - 1 + ldrd r4, [r7] + adds r4, r4, r0 + adc r5, r5, r1 + strd r4, [r7], #1 << L2_ORDER + ldrd r4, [r7] + adds r4, r4, r0 + adc r5, r5, r1 + strd r4, [r7] + + /* Update level 1 entries */ + mov r6, #4 + mov r7, r2 +2: ldrd r4, [r7] + adds r4, r4, r0 + adc r5, r5, r1 + strd r4, [r7], #1 << L1_ORDER + subs r6, r6, #1 + bne 2b + + mrrc p15, 0, r4, r5, c2 @ read TTBR0 + adds r4, r4, r0 @ update physical address + adc r5, r5, r1 + mcrr p15, 0, r4, r5, c2 @ write back TTBR0 + mrrc p15, 1, r4, r5, c2 @ read TTBR1 + adds r4, r4, r0 @ update physical address + adc r5, r5, r1 + mcrr p15, 1, r4, r5, c2 @ write back TTBR1 + + dsb + + mov ip, #0 + mcr p15, 0, ip, c7, c5, 0 @ I+BTB cache invalidate + mcr p15, 0, ip, c8, c7, 0 @ local_flush_tlb_all() + dsb + isb + + mcr p15, 0, r8, c1, c0, 0 @ re-enable MMU + dsb + isb + + ldmfd sp!, {r4-r8, pc} +ENDPROC(lpae_pgtables_remap_asm) |