From cada3c0841e1deaec4c0f92654610b028dc683ff Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 4 Jan 2011 19:39:29 +0000 Subject: [PATCH] ARM: P2V: extend to 16-bit translation offsets MSM's memory is aligned to 2MB, which is more than we can do with our existing method as we're limited to the upper 8 bits. Extend this by using two instructions to 16 bits, automatically selected when MSM is enabled. Acked-by: Tony Lindgren Reviewed-by: Nicolas Pitre Tested-by: Nicolas Pitre Signed-off-by: Russell King --- arch/arm/Kconfig | 5 ++++- arch/arm/include/asm/memory.h | 21 +++++++++++++++++---- arch/arm/include/asm/module.h | 4 ++++ arch/arm/kernel/head.S | 15 ++++++++++++++- 4 files changed, 39 insertions(+), 6 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4147f76e7988..b357c29e7dfc 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -195,7 +195,6 @@ config ARM_PATCH_PHYS_VIRT bool "Patch physical to virtual translations at runtime (EXPERIMENTAL)" depends on EXPERIMENTAL depends on !XIP_KERNEL && !THUMB2_KERNEL && MMU - depends on !ARCH_MSM depends on !ARCH_REALVIEW || !SPARSEMEM help Patch phys-to-virt translation functions at runtime according to @@ -204,6 +203,10 @@ config ARM_PATCH_PHYS_VIRT This can only be used with non-XIP, non-Thumb2, MMU kernels where the base of physical memory is at a 16MB boundary. +config ARM_PATCH_PHYS_VIRT_16BIT + def_bool y + depends on ARM_PATCH_PHYS_VIRT && ARCH_MSM + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 7197879e1cb7..2398b3fc0268 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -154,29 +154,42 @@ #ifndef __virt_to_phys #ifdef CONFIG_ARM_PATCH_PHYS_VIRT +/* + * Constants used to force the right instruction encodings and shifts + * so that all we need to do is modify the 8-bit constant field. + */ +#define __PV_BITS_31_24 0x81000000 +#define __PV_BITS_23_16 0x00810000 + extern unsigned long __pv_phys_offset; #define PHYS_OFFSET __pv_phys_offset -#define __pv_stub(from,to,instr) \ +#define __pv_stub(from,to,instr,type) \ __asm__("@ __pv_stub\n" \ "1: " instr " %0, %1, %2\n" \ " .pushsection .pv_table,\"a\"\n" \ " .long 1b\n" \ " .popsection\n" \ : "=r" (to) \ - : "r" (from), "I" (0x81000000)) + : "r" (from), "I" (type)) static inline unsigned long __virt_to_phys(unsigned long x) { unsigned long t; - __pv_stub(x, t, "add"); + __pv_stub(x, t, "add", __PV_BITS_31_24); +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT + __pv_stub(t, t, "add", __PV_BITS_23_16); +#endif return t; } static inline unsigned long __phys_to_virt(unsigned long x) { unsigned long t; - __pv_stub(x, t, "sub"); + __pv_stub(x, t, "sub", __PV_BITS_31_24); +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT + __pv_stub(t, t, "sub", __PV_BITS_23_16); +#endif return t; } #else diff --git a/arch/arm/include/asm/module.h b/arch/arm/include/asm/module.h index d072c21332ee..a2b775b81cfa 100644 --- a/arch/arm/include/asm/module.h +++ b/arch/arm/include/asm/module.h @@ -31,7 +31,11 @@ struct mod_arch_specific { /* Add __virt_to_phys patching state as well */ #ifdef CONFIG_ARM_PATCH_PHYS_VIRT +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT +#define MODULE_ARCH_VERMAGIC_P2V "p2v16 " +#else #define MODULE_ARCH_VERMAGIC_P2V "p2v8 " +#endif #else #define MODULE_ARCH_VERMAGIC_P2V "" #endif diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 1db8ead2e331..a94dd99d54c3 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -456,8 +456,13 @@ __fixup_pv_table: add r4, r4, r3 @ adjust table start address add r5, r5, r3 @ adjust table end address str r8, [r7, r3]! @ save computed PHYS_OFFSET to __pv_phys_offset +#ifndef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT mov r6, r3, lsr #24 @ constant for add/sub instructions teq r3, r6, lsl #24 @ must be 16MiB aligned +#else + mov r6, r3, lsr #16 @ constant for add/sub instructions + teq r3, r6, lsl #16 @ must be 64kiB aligned +#endif bne __error str r6, [r7, #4] @ save to __pv_offset b __fixup_a_pv_table @@ -471,10 +476,18 @@ ENDPROC(__fixup_pv_table) .text __fixup_a_pv_table: +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT + and r0, r6, #255 @ offset bits 23-16 + mov r6, r6, lsr #8 @ offset bits 31-24 +#else + mov r0, #0 @ just in case... +#endif b 3f 2: ldr ip, [r7, r3] bic ip, ip, #0x000000ff - orr ip, ip, r6 + tst ip, #0x400 @ rotate shift tells us LS or MS byte + orrne ip, ip, r6 @ mask in offset bits 31-24 + orreq ip, ip, r0 @ mask in offset bits 23-16 str ip, [r7, r3] 3: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot