diff options
| -rw-r--r-- | arch/arm/Kconfig | 13 | ||||
| -rw-r--r-- | arch/arm/include/asm/memory.h | 55 | ||||
| -rw-r--r-- | arch/arm/include/asm/module.h | 15 | ||||
| -rw-r--r-- | arch/arm/kernel/armksyms.c | 4 | ||||
| -rw-r--r-- | arch/arm/kernel/head.S | 68 | ||||
| -rw-r--r-- | arch/arm/kernel/module.c | 23 | ||||
| -rw-r--r-- | arch/arm/kernel/vmlinux.lds.S | 4 |
7 files changed, 167 insertions, 15 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 5cff165b7eb0..4147f76e7988 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -191,6 +191,19 @@ config VECTORS_BASE help The base address of exception vectors. +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 + the position of the kernel in system memory. + + This can only be used with non-XIP, non-Thumb2, MMU kernels where + the base of physical memory is at a 16MB boundary. + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 2efec578a62e..7197879e1cb7 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -24,8 +24,6 @@ */ #define UL(x) _AC(x, UL) -#define PHYS_OFFSET PLAT_PHYS_OFFSET - #ifdef CONFIG_MMU /* @@ -135,16 +133,6 @@ #endif /* - * Physical vs virtual RAM address space conversion. These are - * private definitions which should NOT be used outside memory.h - * files. Use virt_to_phys/phys_to_virt/__pa/__va instead. - */ -#ifndef __virt_to_phys -#define __virt_to_phys(x) ((x) - PAGE_OFFSET + PHYS_OFFSET) -#define __phys_to_virt(x) ((x) - PHYS_OFFSET + PAGE_OFFSET) -#endif - -/* * Convert a physical address to a Page Frame Number and back */ #define __phys_to_pfn(paddr) ((paddr) >> PAGE_SHIFT) @@ -159,6 +147,49 @@ #ifndef __ASSEMBLY__ /* + * Physical vs virtual RAM address space conversion. These are + * private definitions which should NOT be used outside memory.h + * files. Use virt_to_phys/phys_to_virt/__pa/__va instead. + */ +#ifndef __virt_to_phys +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT + +extern unsigned long __pv_phys_offset; +#define PHYS_OFFSET __pv_phys_offset + +#define __pv_stub(from,to,instr) \ + __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)) + +static inline unsigned long __virt_to_phys(unsigned long x) +{ + unsigned long t; + __pv_stub(x, t, "add"); + return t; +} + +static inline unsigned long __phys_to_virt(unsigned long x) +{ + unsigned long t; + __pv_stub(x, t, "sub"); + return t; +} +#else +#define __virt_to_phys(x) ((x) - PAGE_OFFSET + PHYS_OFFSET) +#define __phys_to_virt(x) ((x) - PHYS_OFFSET + PAGE_OFFSET) +#endif +#endif + +#ifndef PHYS_OFFSET +#define PHYS_OFFSET PLAT_PHYS_OFFSET +#endif + +/* * The DMA mask corresponding to the maximum bus address allocatable * using GFP_DMA. The default here places no restriction on DMA * allocations. This must be the smallest DMA mask in the system, diff --git a/arch/arm/include/asm/module.h b/arch/arm/include/asm/module.h index 12c8e680cbff..d072c21332ee 100644 --- a/arch/arm/include/asm/module.h +++ b/arch/arm/include/asm/module.h @@ -25,8 +25,19 @@ struct mod_arch_specific { }; /* - * Include the ARM architecture version. + * Add the ARM architecture version to the version magic string */ -#define MODULE_ARCH_VERMAGIC "ARMv" __stringify(__LINUX_ARM_ARCH__) " " +#define MODULE_ARCH_VERMAGIC_ARMVSN "ARMv" __stringify(__LINUX_ARM_ARCH__) " " + +/* Add __virt_to_phys patching state as well */ +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT +#define MODULE_ARCH_VERMAGIC_P2V "p2v8 " +#else +#define MODULE_ARCH_VERMAGIC_P2V "" +#endif + +#define MODULE_ARCH_VERMAGIC \ + MODULE_ARCH_VERMAGIC_ARMVSN \ + MODULE_ARCH_VERMAGIC_P2V #endif /* _ASM_ARM_MODULE_H */ diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index e5e1e5387678..9615423c37dd 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -170,3 +170,7 @@ EXPORT_SYMBOL(mcount); #endif EXPORT_SYMBOL(__gnu_mcount_nc); #endif + +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT +EXPORT_SYMBOL(__pv_phys_offset); +#endif diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 03a588b6e15c..1db8ead2e331 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -98,6 +98,9 @@ ENTRY(stext) #ifdef CONFIG_SMP_ON_UP bl __fixup_smp #endif +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT + bl __fixup_pv_table +#endif bl __create_page_tables /* @@ -438,4 +441,69 @@ smp_on_up: #endif +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT + +/* __fixup_pv_table - patch the stub instructions with the delta between + * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be 16MiB aligned and + * can be expressed by an immediate shifter operand. The stub instruction + * has a form of '(add|sub) rd, rn, #imm'. + */ + __HEAD +__fixup_pv_table: + adr r0, 1f + ldmia r0, {r3-r5, r7} + sub r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET + 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 + mov r6, r3, lsr #24 @ constant for add/sub instructions + teq r3, r6, lsl #24 @ must be 16MiB aligned + bne __error + str r6, [r7, #4] @ save to __pv_offset + b __fixup_a_pv_table +ENDPROC(__fixup_pv_table) + + .align +1: .long . + .long __pv_table_begin + .long __pv_table_end +2: .long __pv_phys_offset + + .text +__fixup_a_pv_table: + b 3f +2: ldr ip, [r7, r3] + bic ip, ip, #0x000000ff + orr ip, ip, r6 + str ip, [r7, r3] +3: cmp r4, r5 + ldrcc r7, [r4], #4 @ use branch for delay slot + bcc 2b + mov pc, lr +ENDPROC(__fixup_a_pv_table) + +ENTRY(fixup_pv_table) + stmfd sp!, {r4 - r7, lr} + ldr r2, 2f @ get address of __pv_phys_offset + mov r3, #0 @ no offset + mov r4, r0 @ r0 = table start + add r5, r0, r1 @ r1 = table size + ldr r6, [r2, #4] @ get __pv_offset + bl __fixup_a_pv_table + ldmfd sp!, {r4 - r7, pc} +ENDPROC(fixup_pv_table) + + .align +2: .long __pv_phys_offset + + .data + .globl __pv_phys_offset + .type __pv_phys_offset, %object +__pv_phys_offset: + .long 0 + .size __pv_phys_offset, . - __pv_phys_offset +__pv_offset: + .long 0 +#endif + #include "head-common.S" diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c index 2cfe8161b478..c5679f6d9f64 100644 --- a/arch/arm/kernel/module.c +++ b/arch/arm/kernel/module.c @@ -268,12 +268,28 @@ struct mod_unwind_map { const Elf_Shdr *txt_sec; }; +static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr, + const Elf_Shdr *sechdrs, const char *name) +{ + const Elf_Shdr *s, *se; + const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; + + for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) + if (strcmp(name, secstrs + s->sh_name) == 0) + return s; + + return NULL; +} + +extern void fixup_pv_table(const void *, unsigned long); + int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *mod) { + const Elf_Shdr *s = NULL; #ifdef CONFIG_ARM_UNWIND const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - const Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum; + const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum; struct mod_unwind_map maps[ARM_SEC_MAX]; int i; @@ -315,6 +331,11 @@ int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, maps[i].txt_sec->sh_addr, maps[i].txt_sec->sh_size); #endif +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT + s = find_mod_section(hdr, sechdrs, ".pv_table"); + if (s) + fixup_pv_table((void *)s->sh_addr, s->sh_size); +#endif return 0; } diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index 86b66f3f2031..45b5651777ee 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -57,6 +57,10 @@ SECTIONS __smpalt_end = .; #endif + __pv_table_begin = .; + *(.pv_table) + __pv_table_end = .; + INIT_SETUP(16) INIT_CALLS |