diff options
Diffstat (limited to 'arch/arm64/kernel/head.S')
| -rw-r--r-- | arch/arm64/kernel/head.S | 218 |
1 files changed, 178 insertions, 40 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 0b281fffda51..e28eaef0568f 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -22,10 +22,12 @@ #include <linux/linkage.h> #include <linux/init.h> +#include <linux/irqchip/arm-gic-v3.h> #include <asm/assembler.h> #include <asm/ptrace.h> #include <asm/asm-offsets.h> +#include <asm/cache.h> #include <asm/cputype.h> #include <asm/memory.h> #include <asm/thread_info.h> @@ -34,29 +36,17 @@ #include <asm/page.h> #include <asm/virt.h> -/* - * swapper_pg_dir is the virtual address of the initial page table. We place - * the page tables 3 * PAGE_SIZE below KERNEL_RAM_VADDR. The idmap_pg_dir has - * 2 pages and is placed below swapper_pg_dir. - */ #define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET) #if (KERNEL_RAM_VADDR & 0xfffff) != 0x80000 #error KERNEL_RAM_VADDR must start at 0xXXX80000 #endif -#define SWAPPER_DIR_SIZE (3 * PAGE_SIZE) -#define IDMAP_DIR_SIZE (2 * PAGE_SIZE) - - .globl swapper_pg_dir - .equ swapper_pg_dir, KERNEL_RAM_VADDR - SWAPPER_DIR_SIZE - - .globl idmap_pg_dir - .equ idmap_pg_dir, swapper_pg_dir - IDMAP_DIR_SIZE - - .macro pgtbl, ttb0, ttb1, phys - add \ttb1, \phys, #TEXT_OFFSET - SWAPPER_DIR_SIZE - sub \ttb0, \ttb1, #IDMAP_DIR_SIZE + .macro pgtbl, ttb0, ttb1, virt_to_phys + ldr \ttb1, =swapper_pg_dir + ldr \ttb0, =idmap_pg_dir + add \ttb1, \ttb1, \virt_to_phys + add \ttb0, \ttb0, \virt_to_phys .endm #ifdef CONFIG_ARM64_64K_PAGES @@ -107,8 +97,18 @@ /* * DO NOT MODIFY. Image header expected by Linux boot-loaders. */ +#ifdef CONFIG_EFI +efi_head: + /* + * This add instruction has no meaningful effect except that + * its opcode forms the magic "MZ" signature required by UEFI. + */ + add x13, x18, #0x16 + b stext +#else b stext // branch to kernel start, magic .long 0 // reserved +#endif .quad TEXT_OFFSET // Image load offset from start of RAM .quad 0 // reserved .quad 0 // reserved @@ -119,7 +119,109 @@ .byte 0x52 .byte 0x4d .byte 0x64 +#ifdef CONFIG_EFI + .long pe_header - efi_head // Offset to the PE header. +#else .word 0 // reserved +#endif + +#ifdef CONFIG_EFI + .align 3 +pe_header: + .ascii "PE" + .short 0 +coff_header: + .short 0xaa64 // AArch64 + .short 2 // nr_sections + .long 0 // TimeDateStamp + .long 0 // PointerToSymbolTable + .long 1 // NumberOfSymbols + .short section_table - optional_header // SizeOfOptionalHeader + .short 0x206 // Characteristics. + // IMAGE_FILE_DEBUG_STRIPPED | + // IMAGE_FILE_EXECUTABLE_IMAGE | + // IMAGE_FILE_LINE_NUMS_STRIPPED +optional_header: + .short 0x20b // PE32+ format + .byte 0x02 // MajorLinkerVersion + .byte 0x14 // MinorLinkerVersion + .long _edata - stext // SizeOfCode + .long 0 // SizeOfInitializedData + .long 0 // SizeOfUninitializedData + .long efi_stub_entry - efi_head // AddressOfEntryPoint + .long stext - efi_head // BaseOfCode + +extra_header_fields: + .quad 0 // ImageBase + .long 0x20 // SectionAlignment + .long 0x8 // FileAlignment + .short 0 // MajorOperatingSystemVersion + .short 0 // MinorOperatingSystemVersion + .short 0 // MajorImageVersion + .short 0 // MinorImageVersion + .short 0 // MajorSubsystemVersion + .short 0 // MinorSubsystemVersion + .long 0 // Win32VersionValue + + .long _edata - efi_head // SizeOfImage + + // Everything before the kernel image is considered part of the header + .long stext - efi_head // SizeOfHeaders + .long 0 // CheckSum + .short 0xa // Subsystem (EFI application) + .short 0 // DllCharacteristics + .quad 0 // SizeOfStackReserve + .quad 0 // SizeOfStackCommit + .quad 0 // SizeOfHeapReserve + .quad 0 // SizeOfHeapCommit + .long 0 // LoaderFlags + .long 0x6 // NumberOfRvaAndSizes + + .quad 0 // ExportTable + .quad 0 // ImportTable + .quad 0 // ResourceTable + .quad 0 // ExceptionTable + .quad 0 // CertificationTable + .quad 0 // BaseRelocationTable + + // Section table +section_table: + + /* + * The EFI application loader requires a relocation section + * because EFI applications must be relocatable. This is a + * dummy section as far as we are concerned. + */ + .ascii ".reloc" + .byte 0 + .byte 0 // end of 0 padding of section name + .long 0 + .long 0 + .long 0 // SizeOfRawData + .long 0 // PointerToRawData + .long 0 // PointerToRelocations + .long 0 // PointerToLineNumbers + .short 0 // NumberOfRelocations + .short 0 // NumberOfLineNumbers + .long 0x42100040 // Characteristics (section flags) + + + .ascii ".text" + .byte 0 + .byte 0 + .byte 0 // end of 0 padding of section name + .long _edata - stext // VirtualSize + .long stext - efi_head // VirtualAddress + .long _edata - stext // SizeOfRawData + .long stext - efi_head // PointerToRawData + + .long 0 // PointerToRelocations (0 for executables) + .long 0 // PointerToLineNumbers (0 for executables) + .short 0 // NumberOfRelocations (0 for executables) + .short 0 // NumberOfLineNumbers (0 for executables) + .long 0xe0500020 // Characteristics (section flags) + .align 5 +#endif ENTRY(stext) mov x21, x0 // x21=FDT @@ -183,6 +285,23 @@ CPU_LE( bic x0, x0, #(3 << 24) ) // Clear the EE and E0E bits for EL1 msr cnthctl_el2, x0 msr cntvoff_el2, xzr // Clear virtual offset +#ifdef CONFIG_ARM_GIC_V3 + /* GICv3 system register access */ + mrs x0, id_aa64pfr0_el1 + ubfx x0, x0, #24, #4 + cmp x0, #1 + b.ne 3f + + mrs_s x0, ICC_SRE_EL2 + orr x0, x0, #ICC_SRE_EL2_SRE // Set ICC_SRE_EL2.SRE==1 + orr x0, x0, #ICC_SRE_EL2_ENABLE // Set ICC_SRE_EL2.Enable==1 + msr_s ICC_SRE_EL2, x0 + isb // Make sure SRE is now set + msr_s ICH_HCR_EL2, xzr // Reset ICC_HCR_EL2 to defaults + +3: +#endif + /* Populate ID registers. */ mrs x0, midr_el1 mrs x1, mpidr_el1 @@ -240,8 +359,9 @@ ENDPROC(set_cpu_boot_mode_flag) * This is not in .bss, because we set it sufficiently early that the boot-time * zeroing of .bss would clobber it. */ - .pushsection .data + .pushsection .data..cacheline_aligned ENTRY(__boot_cpu_mode) + .align L1_CACHE_SHIFT .long BOOT_CPU_MODE_EL2 .long 0 .popsection @@ -298,7 +418,7 @@ ENTRY(secondary_startup) mov x23, x0 // x23=current cpu_table cbz x23, __error_p // invalid processor (x23=0)? - pgtbl x25, x26, x24 // x25=TTBR0, x26=TTBR1 + pgtbl x25, x26, x28 // x25=TTBR0, x26=TTBR1 ldr x12, [x23, #CPU_INFO_SETUP] add x12, x12, x28 // __virt_to_phys blr x12 // initialise processor @@ -340,8 +460,13 @@ ENDPROC(__enable_mmu) * x27 = *virtual* address to jump to upon completion * * other registers depend on the function called upon completion + * + * We align the entire function to the smallest power of two larger than it to + * ensure it fits within a single block map entry. Otherwise were PHYS_OFFSET + * close to the end of a 512MB or 1GB block we might require an additional + * table to map the entire function. */ - .align 6 + .align 4 __turn_mmu_on: msr sctlr_el1, x0 isb @@ -384,26 +509,18 @@ ENDPROC(__calc_phys_offset) * Preserves: tbl, flags * Corrupts: phys, start, end, pstate */ - .macro create_block_map, tbl, flags, phys, start, end, idmap=0 + .macro create_block_map, tbl, flags, phys, start, end lsr \phys, \phys, #BLOCK_SHIFT - .if \idmap - and \start, \phys, #PTRS_PER_PTE - 1 // table index - .else lsr \start, \start, #BLOCK_SHIFT and \start, \start, #PTRS_PER_PTE - 1 // table index - .endif orr \phys, \flags, \phys, lsl #BLOCK_SHIFT // table entry - .ifnc \start,\end lsr \end, \end, #BLOCK_SHIFT and \end, \end, #PTRS_PER_PTE - 1 // table end index - .endif 9999: str \phys, [\tbl, \start, lsl #3] // store the entry - .ifnc \start,\end add \start, \start, #1 // next entry add \phys, \phys, #BLOCK_SIZE // next block cmp \start, \end b.ls 9999b - .endif .endm /* @@ -412,10 +529,19 @@ ENDPROC(__calc_phys_offset) * - identity mapping to enable the MMU (low address, TTBR0) * - first few MB of the kernel linear mapping to jump to once the MMU has * been enabled, including the FDT blob (TTBR1) - * - UART mapping if CONFIG_EARLY_PRINTK is enabled (TTBR1) + * - pgd entry for fixed mappings (TTBR1) */ __create_page_tables: - pgtbl x25, x26, x24 // idmap_pg_dir and swapper_pg_dir addresses + pgtbl x25, x26, x28 // idmap_pg_dir and swapper_pg_dir addresses + mov x27, lr + + /* + * Invalidate the idmap and swapper page tables to avoid potential + * dirty cache lines being evicted. + */ + mov x0, x25 + add x1, x26, #SWAPPER_DIR_SIZE + bl __inval_cache_range /* * Clear the idmap and swapper page tables. @@ -435,9 +561,13 @@ __create_page_tables: * Create the identity mapping. */ add x0, x25, #PAGE_SIZE // section table address - adr x3, __turn_mmu_on // virtual/physical address + ldr x3, =KERNEL_START + add x3, x3, x28 // __pa(KERNEL_START) create_pgd_entry x25, x0, x3, x5, x6 - create_block_map x0, x7, x3, x5, x5, idmap=1 + ldr x6, =KERNEL_END + mov x5, x3 // __pa(KERNEL_START) + add x6, x6, x28 // __pa(KERNEL_END) + create_block_map x0, x7, x3, x5, x6 /* * Map the kernel image (starting with PHYS_OFFSET). @@ -445,7 +575,7 @@ __create_page_tables: add x0, x26, #PAGE_SIZE // section table address mov x5, #PAGE_OFFSET create_pgd_entry x26, x0, x5, x3, x6 - ldr x6, =KERNEL_END - 1 + ldr x6, =KERNEL_END mov x3, x24 // phys offset create_block_map x0, x7, x3, x5, x6 @@ -465,15 +595,23 @@ __create_page_tables: sub x6, x6, #1 // inclusive range create_block_map x0, x7, x3, x5, x6 1: -#ifdef CONFIG_EARLY_PRINTK /* - * Create the pgd entry for the UART mapping. The full mapping is done - * later based earlyprintk kernel parameter. + * Create the pgd entry for the fixed mappings. */ - ldr x5, =EARLYCON_IOBASE // UART virtual address + ldr x5, =FIXADDR_TOP // Fixed mapping virtual address add x0, x26, #2 * PAGE_SIZE // section table address create_pgd_entry x26, x0, x5, x6, x7 -#endif + + /* + * Since the page tables have been populated with non-cacheable + * accesses (MMU disabled), invalidate the idmap and swapper page + * tables again to remove any speculatively loaded cache lines. + */ + mov x0, x25 + add x1, x26, #SWAPPER_DIR_SIZE + bl __inval_cache_range + + mov lr, x27 ret ENDPROC(__create_page_tables) .ltorg @@ -483,7 +621,7 @@ ENDPROC(__create_page_tables) __switch_data: .quad __mmap_switched .quad __bss_start // x6 - .quad _end // x7 + .quad __bss_stop // x7 .quad processor_id // x4 .quad __fdt_pointer // x5 .quad memstart_addr // x6 |