diff options
Diffstat (limited to 'arch/tile/kernel/head_64.S')
| -rw-r--r-- | arch/tile/kernel/head_64.S | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/arch/tile/kernel/head_64.S b/arch/tile/kernel/head_64.S new file mode 100644 index 0000000..6bc3a93 --- /dev/null +++ b/arch/tile/kernel/head_64.S @@ -0,0 +1,269 @@ +/* + * Copyright 2011 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 + jal hv_init + } + /* Get a reasonable default ASID in r0 */ + { + move r0, zero + jal hv_inquire_asid + } + + /* + * Install the default page table. The relocation required to + * statically define the table is a bit too complex, so we have + * to plug in the pointer from the L0 to the L1 table by hand. + * We only do this on the first cpu to boot, though, since the + * other CPUs should see a properly-constructed page table. + */ + { + v4int_l r2, zero, r0 /* ASID for hv_install_context */ + moveli r4, hw1_last(swapper_pgprot - PAGE_OFFSET) + } + { + shl16insli r4, r4, hw0(swapper_pgprot - PAGE_OFFSET) + } + { + ld r1, r4 /* access_pte for hv_install_context */ + } + { + moveli r0, hw1_last(.Lsv_data_pmd - PAGE_OFFSET) + moveli r6, hw1_last(temp_data_pmd - PAGE_OFFSET) + } + { + /* After initializing swapper_pgprot, HV_PTE_GLOBAL is set. */ + bfextu r7, r1, HV_PTE_INDEX_GLOBAL, HV_PTE_INDEX_GLOBAL + inv r4 + } + bnez r7, .Lno_write + { + shl16insli r0, r0, hw0(.Lsv_data_pmd - PAGE_OFFSET) + shl16insli r6, r6, hw0(temp_data_pmd - PAGE_OFFSET) + } + { + /* Cut off the low bits of the PT address. */ + shrui r6, r6, HV_LOG2_PAGE_TABLE_ALIGN + /* Start with our access pte. */ + move r5, r1 + } + { + /* Stuff the address into the page table pointer slot of the PTE. */ + bfins r5, r6, HV_PTE_INDEX_PTFN, \ + HV_PTE_INDEX_PTFN + HV_PTE_PTFN_BITS - 1 + } + { + /* Store the L0 data PTE. */ + st r0, r5 + addli r6, r6, (temp_code_pmd - temp_data_pmd) >> \ + HV_LOG2_PAGE_TABLE_ALIGN + } + { + addli r0, r0, .Lsv_code_pmd - .Lsv_data_pmd + bfins r5, r6, HV_PTE_INDEX_PTFN, \ + HV_PTE_INDEX_PTFN + HV_PTE_PTFN_BITS - 1 + } + /* Store the L0 code PTE. */ + st r0, r5 + +.Lno_write: + moveli lr, hw2_last(1f) + { + shl16insli lr, lr, hw1(1f) + moveli r0, hw1_last(swapper_pg_dir - PAGE_OFFSET) + } + { + shl16insli lr, lr, hw0(1f) + shl16insli r0, r0, hw0(swapper_pg_dir - PAGE_OFFSET) + } + { + move r3, zero + j hv_install_context + } +1: + + /* Install the interrupt base. */ + moveli r0, hw2_last(MEM_SV_START) + shl16insli r0, r0, hw1(MEM_SV_START) + shl16insli r0, r0, hw0(MEM_SV_START) + mtspr SPR_INTERRUPT_VECTOR_BASE_K, r0 + + /* + * Get our processor number and save it away in SAVE_K_0. + * Extract stuff from the topology structure: r4 = y, r6 = x, + * r5 = width. FIXME: consider whether we want to just make these + * 64-bit values (and if so fix smp_topology write below, too). + */ + jal hv_inquire_topology + { + v4int_l r5, zero, r1 /* r5 = width */ + shrui r4, r0, 32 /* r4 = y */ + } + { + v4int_l r6, zero, r0 /* r6 = x */ + mul_lu_lu r4, r4, r5 + } + { + add r4, r4, r6 /* 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 with init_stack + THREAD_SIZE. + * 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, hw2_last(__per_cpu_offset) + shl16insli r5, r5, hw1(__per_cpu_offset) + shl16insli r5, r5, hw0(__per_cpu_offset) + shl3add r5, r4, r5 + ld r5, r5 + bnez r5, 1f + + /* + * Save the width and height to the smp_topology variable + * for later use. + */ + moveli r0, hw2_last(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET) + shl16insli r0, r0, hw1(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET) + shl16insli r0, r0, hw0(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET) + st r0, r1 +1: +#else + move r5, zero +#endif + + /* Load and go with the correct pc and sp. */ + { + moveli r1, hw2_last(boot_sp) + moveli r0, hw2_last(boot_pc) + } + { + shl16insli r1, r1, hw1(boot_sp) + shl16insli r0, r0, hw1(boot_pc) + } + { + shl16insli r1, r1, hw0(boot_sp) + shl16insli r0, r0, hw0(boot_pc) + } + { + add r1, r1, r5 + add r0, r0, r5 + } + ld r0, r0 + ld sp, r1 + or r4, sp, r4 + mtspr SPR_SYSTEM_SAVE_K_0, r4 /* save ksp0 + cpu */ + addi sp, sp, -STACK_TOP_DELTA + { + 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 cpa, bits1 + .quad HV_PTE_PAGE | HV_PTE_DIRTY | HV_PTE_PRESENT | HV_PTE_ACCESSED |\ + HV_PTE_GLOBAL | (HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE) |\ + (\bits1) | (HV_CPA_TO_PFN(\cpa) << HV_PTE_INDEX_PFN) + .endm + +__PAGE_ALIGNED_DATA + .align PAGE_SIZE +ENTRY(swapper_pg_dir) + .org swapper_pg_dir + HV_L0_INDEX(PAGE_OFFSET) * HV_PTE_SIZE +.Lsv_data_pmd: + .quad 0 /* PTE temp_data_pmd - PAGE_OFFSET, 0 */ + .org swapper_pg_dir + HV_L0_INDEX(MEM_SV_START) * HV_PTE_SIZE +.Lsv_code_pmd: + .quad 0 /* PTE temp_code_pmd - PAGE_OFFSET, 0 */ + .org swapper_pg_dir + HV_L0_SIZE + END(swapper_pg_dir) + + .align HV_PAGE_TABLE_ALIGN +ENTRY(temp_data_pmd) + /* + * We fill the PAGE_OFFSET pmd with huge pages with + * VA = PA + PAGE_OFFSET. We remap things with more precise access + * permissions later. + */ + .set addr, 0 + .rept HV_L1_ENTRIES + PTE addr, HV_PTE_READABLE | HV_PTE_WRITABLE + .set addr, addr + HV_PAGE_SIZE_LARGE + .endr + .org temp_data_pmd + HV_L1_SIZE + END(temp_data_pmd) + + .align HV_PAGE_TABLE_ALIGN +ENTRY(temp_code_pmd) + /* + * We fill the MEM_SV_START pmd with huge pages with + * VA = PA + PAGE_OFFSET. We remap things with more precise access + * permissions later. + */ + .set addr, 0 + .rept HV_L1_ENTRIES + PTE addr, HV_PTE_READABLE | HV_PTE_EXECUTABLE + .set addr, addr + HV_PAGE_SIZE_LARGE + .endr + .org temp_code_pmd + HV_L1_SIZE + END(temp_code_pmd) + + /* + * 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) + .quad HV_PTE_PRESENT | (HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE) + .align CHIP_L2_LINE_SIZE() + END(swapper_pgprot) |