From a7fbc0d62a4d46e642af889e7288fede5078bc46 Mon Sep 17 00:00:00 2001 From: Cyril Chemparathy Date: Sat, 21 Jul 2012 19:47:52 -0400 Subject: [PATCH] ARM: LPAE: factor out T1SZ and TTBR1 computations This patch moves the TTBR1 offset calculation and the T1SZ calculation out of the TTB setup assembly code. This should not affect functionality in any way, but improves code readability as well as readability of subsequent patches in this series. Signed-off-by: Cyril Chemparathy Signed-off-by: Vitaly Andrianov Acked-by: Nicolas Pitre Tested-by: Santosh Shilimkar Tested-by: Subash Patel Signed-off-by: Will Deacon --- arch/arm/include/asm/pgtable-3level-hwdef.h | 20 ++++++++++++++ arch/arm/mm/proc-v7-3level.S | 29 ++++++--------------- 2 files changed, 28 insertions(+), 21 deletions(-) diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h index 18f5cef82ad5..c6c6e6df22f3 100644 --- a/arch/arm/include/asm/pgtable-3level-hwdef.h +++ b/arch/arm/include/asm/pgtable-3level-hwdef.h @@ -79,4 +79,24 @@ #define PHYS_MASK_SHIFT (40) #define PHYS_MASK ((1ULL << PHYS_MASK_SHIFT) - 1) +/* + * TTBR0/TTBR1 split (PAGE_OFFSET): + * 0x40000000: T0SZ = 2, T1SZ = 0 (not used) + * 0x80000000: T0SZ = 0, T1SZ = 1 + * 0xc0000000: T0SZ = 0, T1SZ = 2 + * + * Only use this feature if PHYS_OFFSET <= PAGE_OFFSET, otherwise + * booting secondary CPUs would end up using TTBR1 for the identity + * mapping set up in TTBR0. + */ +#if defined CONFIG_VMSPLIT_2G +#define TTBR1_OFFSET 16 /* skip two L1 entries */ +#elif defined CONFIG_VMSPLIT_3G +#define TTBR1_OFFSET (4096 * (1 + 3)) /* only L2, skip pgd + 3*pmd */ +#else +#define TTBR1_OFFSET 0 +#endif + +#define TTBR1_SIZE (((PAGE_OFFSET >> 30) - 1) << 16) + #endif diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S index 995857d3b530..58ab7477bb61 100644 --- a/arch/arm/mm/proc-v7-3level.S +++ b/arch/arm/mm/proc-v7-3level.S @@ -114,7 +114,7 @@ ENDPROC(cpu_v7_set_pte_ext) */ .macro v7_ttb_setup, zero, ttbr0, ttbr1, tmp ldr \tmp, =swapper_pg_dir @ swapper_pg_dir virtual address - cmp \ttbr1, \tmp @ PHYS_OFFSET > PAGE_OFFSET? (branch below) + cmp \ttbr1, \tmp @ PHYS_OFFSET > PAGE_OFFSET? mrc p15, 0, \tmp, c2, c0, 2 @ TTB control register orr \tmp, \tmp, #TTB_EAE ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP) @@ -122,27 +122,14 @@ ENDPROC(cpu_v7_set_pte_ext) ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP << 16) ALT_UP(orr \tmp, \tmp, #TTB_FLAGS_UP << 16) /* - * TTBR0/TTBR1 split (PAGE_OFFSET): - * 0x40000000: T0SZ = 2, T1SZ = 0 (not used) - * 0x80000000: T0SZ = 0, T1SZ = 1 - * 0xc0000000: T0SZ = 0, T1SZ = 2 - * - * Only use this feature if PHYS_OFFSET <= PAGE_OFFSET, otherwise - * booting secondary CPUs would end up using TTBR1 for the identity - * mapping set up in TTBR0. + * Only use split TTBRs if PHYS_OFFSET <= PAGE_OFFSET (cmp above), + * otherwise booting secondary CPUs would end up using TTBR1 for the + * identity mapping set up in TTBR0. */ - bhi 9001f @ PHYS_OFFSET > PAGE_OFFSET? - orr \tmp, \tmp, #(((PAGE_OFFSET >> 30) - 1) << 16) @ TTBCR.T1SZ -#if defined CONFIG_VMSPLIT_2G - /* PAGE_OFFSET == 0x80000000, T1SZ == 1 */ - add \ttbr1, \ttbr1, #1 << 4 @ skip two L1 entries -#elif defined CONFIG_VMSPLIT_3G - /* PAGE_OFFSET == 0xc0000000, T1SZ == 2 */ - add \ttbr1, \ttbr1, #4096 * (1 + 3) @ only L2 used, skip pgd+3*pmd -#endif - /* CONFIG_VMSPLIT_1G does not need TTBR1 adjustment */ -9001: mcr p15, 0, \tmp, c2, c0, 2 @ TTB control register - mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1 + orrls \tmp, \tmp, #TTBR1_SIZE @ TTBCR.T1SZ + mcr p15, 0, \tmp, c2, c0, 2 @ TTBCR + addls \ttbr1, \ttbr1, #TTBR1_OFFSET + mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1 .endm __CPUINIT -- 2.39.5