diff options
Diffstat (limited to 'arch/tile/kernel/head_32.S')
| -rw-r--r-- | arch/tile/kernel/head_32.S | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/tile/kernel/head_32.S b/arch/tile/kernel/head_32.S new file mode 100644 index 000000000..8d5b40ff2 --- /dev/null +++ b/arch/tile/kernel/head_32.S @@ -0,0 +1,183 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + * + * TILE startup code. + */ + +#include <linux/linkage.h> +#include <linux/init.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/thread_info.h> +#include <asm/processor.h> +#include <asm/asm-offsets.h> +#include <hv/hypervisor.h> +#include <arch/chip.h> +#include <arch/spr_def.h> + +/* + * This module contains the entry code for kernel images. It performs the + * minimal setup needed to call the generic C routines. + */ + + __HEAD +ENTRY(_start) + /* Notify the hypervisor of what version of the API we want */ + { + movei r1, TILE_CHIP + movei r2, TILE_CHIP_REV + } + { + moveli r0, _HV_VERSION_OLD_HV_INIT + jal _hv_init + } + /* Get a reasonable default ASID in r0 */ + { + move r0, zero + jal _hv_inquire_asid + } + /* Install the default page table */ + { + moveli r6, lo16(swapper_pgprot - PAGE_OFFSET) + move r4, r0 /* use starting ASID of range for this page table */ + } + { + moveli r0, lo16(swapper_pg_dir - PAGE_OFFSET) + auli r6, r6, ha16(swapper_pgprot - PAGE_OFFSET) + } + { + lw r2, r6 + addi r6, r6, 4 + } + { + lw r3, r6 + auli r0, r0, ha16(swapper_pg_dir - PAGE_OFFSET) + } + { + finv r6 + move r1, zero /* high 32 bits of CPA is zero */ + } + { + moveli lr, lo16(1f) + moveli r5, CTX_PAGE_FLAG + } + { + auli lr, lr, ha16(1f) + j _hv_install_context + } +1: + + /* Get our processor number and save it away in SAVE_K_0. */ + jal _hv_inquire_topology + mulll_uu r4, r1, r2 /* r1 == y, r2 == width */ + add r4, r4, r0 /* r0 == x, so r4 == cpu == y*width + x */ + +#ifdef CONFIG_SMP + /* + * Load up our per-cpu offset. When the first (master) tile + * boots, this value is still zero, so we will load boot_pc + * with start_kernel, and boot_sp at the top of init_stack. + * The master tile initializes the per-cpu offset array, so that + * when subsequent (secondary) tiles boot, they will instead load + * from their per-cpu versions of boot_sp and boot_pc. + */ + moveli r5, lo16(__per_cpu_offset) + auli r5, r5, ha16(__per_cpu_offset) + s2a r5, r4, r5 + lw r5, r5 + bnz r5, 1f + + /* + * Save the width and height to the smp_topology variable + * for later use. + */ + moveli r0, lo16(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET) + auli r0, r0, ha16(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET) + { + sw r0, r2 + addi r0, r0, (HV_TOPOLOGY_HEIGHT_OFFSET - HV_TOPOLOGY_WIDTH_OFFSET) + } + sw r0, r3 +1: +#else + move r5, zero +#endif + + /* Load and go with the correct pc and sp. */ + { + addli r1, r5, lo16(boot_sp) + addli r0, r5, lo16(boot_pc) + } + { + auli r1, r1, ha16(boot_sp) + auli r0, r0, ha16(boot_pc) + } + lw r0, r0 + lw sp, r1 + or r4, sp, r4 + mtspr SPR_SYSTEM_SAVE_K_0, r4 /* save ksp0 + cpu */ + { + move lr, zero /* stop backtraces in the called function */ + jr r0 + } + ENDPROC(_start) + +__PAGE_ALIGNED_BSS + .align PAGE_SIZE +ENTRY(empty_zero_page) + .fill PAGE_SIZE,1,0 + END(empty_zero_page) + + .macro PTE va, cpa, bits1, no_org=0 + .ifeq \no_org + .org swapper_pg_dir + PGD_INDEX(\va) * HV_PTE_SIZE + .endif + .word HV_PTE_PAGE | HV_PTE_DIRTY | HV_PTE_PRESENT | HV_PTE_ACCESSED | \ + (HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE) + .word (\bits1) | (HV_CPA_TO_PTFN(\cpa) << (HV_PTE_INDEX_PTFN - 32)) + .endm + +__PAGE_ALIGNED_DATA + .align PAGE_SIZE +ENTRY(swapper_pg_dir) + /* + * All data pages from PAGE_OFFSET to MEM_USER_INTRPT are mapped as + * VA = PA + PAGE_OFFSET. We remap things with more precise access + * permissions and more respect for size of RAM later. + */ + .set addr, 0 + .rept (MEM_USER_INTRPT - PAGE_OFFSET) >> PGDIR_SHIFT + PTE addr + PAGE_OFFSET, addr, (1 << (HV_PTE_INDEX_READABLE - 32)) | \ + (1 << (HV_PTE_INDEX_WRITABLE - 32)) + .set addr, addr + PGDIR_SIZE + .endr + + /* The true text VAs are mapped as VA = PA + MEM_SV_START */ + PTE MEM_SV_START, 0, (1 << (HV_PTE_INDEX_READABLE - 32)) | \ + (1 << (HV_PTE_INDEX_EXECUTABLE - 32)) + .org swapper_pg_dir + PGDIR_SIZE + END(swapper_pg_dir) + + /* + * Isolate swapper_pgprot to its own cache line, since each cpu + * starting up will read it using VA-is-PA and local homing. + * This would otherwise likely conflict with other data on the cache + * line, once we have set its permanent home in the page tables. + */ + __INITDATA + .align CHIP_L2_LINE_SIZE() +ENTRY(swapper_pgprot) + PTE 0, 0, (1 << (HV_PTE_INDEX_READABLE - 32)) | \ + (1 << (HV_PTE_INDEX_WRITABLE - 32)), 1 + .align CHIP_L2_LINE_SIZE() + END(swapper_pgprot) |