diff options
Diffstat (limited to 'arch/arm/kernel/head.S')
| -rw-r--r-- | arch/arm/kernel/head.S | 184 |
1 files changed, 159 insertions, 25 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 60fe2795f4a3..c9173cfbbc74 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -26,14 +26,6 @@ #include <mach/debug-macro.S> #endif -#if (PHYS_OFFSET & 0x001fffff) -#error "PHYS_OFFSET must be at an even 2MiB boundary!" -#endif - -#define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET) -#define KERNEL_RAM_PADDR (PHYS_OFFSET + TEXT_OFFSET) - - /* * swapper_pg_dir is the virtual address of the initial page table. * We place the page tables 16K below KERNEL_RAM_VADDR. Therefore, we must @@ -41,6 +33,7 @@ * the least significant 16 bits to be 0x8000, but we could probably * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000. */ +#define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET) #if (KERNEL_RAM_VADDR & 0xffff) != 0x8000 #error KERNEL_RAM_VADDR must start at 0xXXXX8000 #endif @@ -48,8 +41,8 @@ .globl swapper_pg_dir .equ swapper_pg_dir, KERNEL_RAM_VADDR - 0x4000 - .macro pgtbl, rd - ldr \rd, =(KERNEL_RAM_PADDR - 0x4000) + .macro pgtbl, rd, phys + add \rd, \phys, #TEXT_OFFSET - 0x4000 .endm #ifdef CONFIG_XIP_KERNEL @@ -88,14 +81,26 @@ ENTRY(stext) THUMB( it eq ) @ force fixup-able long branch encoding beq __error_p @ yes, error 'p' +#ifndef CONFIG_XIP_KERNEL + adr r3, 2f + ldmia r3, {r4, r8} + sub r4, r3, r4 @ (PHYS_OFFSET - PAGE_OFFSET) + add r8, r8, r4 @ PHYS_OFFSET +#else + ldr r8, =PLAT_PHYS_OFFSET +#endif + /* * r1 = machine no, r2 = atags, - * r9 = cpuid, r10 = procinfo + * r8 = phys_offset, r9 = cpuid, r10 = procinfo */ bl __vet_atags #ifdef CONFIG_SMP_ON_UP bl __fixup_smp #endif +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT + bl __fixup_pv_table +#endif bl __create_page_tables /* @@ -114,21 +119,24 @@ ENTRY(stext) 1: b __enable_mmu ENDPROC(stext) .ltorg +#ifndef CONFIG_XIP_KERNEL +2: .long . + .long PAGE_OFFSET +#endif /* * Setup the initial page tables. We only setup the barest * amount which are required to get the kernel running, which * generally means mapping in the kernel code. * - * r9 = cpuid - * r10 = procinfo + * r8 = phys_offset, r9 = cpuid, r10 = procinfo * * Returns: * r0, r3, r5-r7 corrupted * r4 = physical page table address */ __create_page_tables: - pgtbl r4 @ page table address + pgtbl r4, r8 @ page table address /* * Clear the 16K level 1 swapper page table @@ -184,10 +192,8 @@ __create_page_tables: /* * Map some ram to cover our .data and .bss areas. */ - orr r3, r7, #(KERNEL_RAM_PADDR & 0xff000000) - .if (KERNEL_RAM_PADDR & 0x00f00000) - orr r3, r3, #(KERNEL_RAM_PADDR & 0x00f00000) - .endif + add r3, r8, #TEXT_OFFSET + orr r3, r3, r7 add r0, r4, #(KERNEL_RAM_VADDR & 0xff000000) >> 18 str r3, [r0, #(KERNEL_RAM_VADDR & 0x00f00000) >> 18]! ldr r6, =(_end - 1) @@ -200,14 +206,17 @@ __create_page_tables: #endif /* - * Then map first 1MB of ram in case it contains our boot params. + * Then map boot params address in r2 or + * the first 1MB of ram if boot params address is not specified. */ - add r0, r4, #PAGE_OFFSET >> 18 - orr r6, r7, #(PHYS_OFFSET & 0xff000000) - .if (PHYS_OFFSET & 0x00f00000) - orr r6, r6, #(PHYS_OFFSET & 0x00f00000) - .endif - str r6, [r0] + mov r0, r2, lsr #20 + movs r0, r0, lsl #20 + moveq r0, r8 + sub r3, r0, r8 + add r3, r3, #PAGE_OFFSET + add r3, r4, r3, lsr #18 + orr r6, r7, r0 + str r6, [r3] #ifdef CONFIG_DEBUG_LL #ifndef CONFIG_DEBUG_ICEDCC @@ -452,4 +461,129 @@ ENTRY(fixup_smp) ldmfd sp!, {r4 - r6, pc} ENDPROC(fixup_smp) +#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 + add r7, r7, r3 @ adjust __pv_phys_offset address + str r8, [r7] @ 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 +THUMB( it ne @ cross section branch ) + 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: +#ifdef CONFIG_THUMB2_KERNEL +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT + lsls r0, r6, #24 + lsr r6, #8 + beq 1f + clz r7, r0 + lsr r0, #24 + lsl r0, r7 + bic r0, 0x0080 + lsrs r7, #1 + orrcs r0, #0x0080 + orr r0, r0, r7, lsl #12 +#endif +1: lsls r6, #24 + beq 4f + clz r7, r6 + lsr r6, #24 + lsl r6, r7 + bic r6, #0x0080 + lsrs r7, #1 + orrcs r6, #0x0080 + orr r6, r6, r7, lsl #12 + orr r6, #0x4000 + b 4f +2: @ at this point the C flag is always clear + add r7, r3 +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT + ldrh ip, [r7] + tst ip, 0x0400 @ the i bit tells us LS or MS byte + beq 3f + cmp r0, #0 @ set C flag, and ... + biceq ip, 0x0400 @ immediate zero value has a special encoding + streqh ip, [r7] @ that requires the i bit cleared +#endif +3: ldrh ip, [r7, #2] + and ip, 0x8f00 + orrcc ip, r6 @ mask in offset bits 31-24 + orrcs ip, r0 @ mask in offset bits 23-16 + strh ip, [r7, #2] +4: cmp r4, r5 + ldrcc r7, [r4], #4 @ use branch for delay slot + bcc 2b + bx lr +#else +#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 + 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 + bcc 2b + mov pc, lr +#endif +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" |