diff options
Diffstat (limited to 'arch/tile/kernel/machine_kexec.c')
| -rw-r--r-- | arch/tile/kernel/machine_kexec.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/arch/tile/kernel/machine_kexec.c b/arch/tile/kernel/machine_kexec.c new file mode 100644 index 000000000..008aa2fae --- /dev/null +++ b/arch/tile/kernel/machine_kexec.c @@ -0,0 +1,298 @@ +/* + * 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. + * + * based on machine_kexec.c from other architectures in linux-2.6.18 + */ + +#include <linux/mm.h> +#include <linux/kexec.h> +#include <linux/delay.h> +#include <linux/reboot.h> +#include <linux/errno.h> +#include <linux/vmalloc.h> +#include <linux/cpumask.h> +#include <linux/kernel.h> +#include <linux/elf.h> +#include <linux/highmem.h> +#include <linux/mmu_context.h> +#include <linux/io.h> +#include <linux/timex.h> +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/cacheflush.h> +#include <asm/checksum.h> +#include <asm/tlbflush.h> +#include <asm/homecache.h> +#include <hv/hypervisor.h> + + +/* + * This stuff is not in elf.h and is not in any other kernel include. + * This stuff is needed below in the little boot notes parser to + * extract the command line so we can pass it to the hypervisor. + */ +struct Elf32_Bhdr { + Elf32_Word b_signature; + Elf32_Word b_size; + Elf32_Half b_checksum; + Elf32_Half b_records; +}; +#define ELF_BOOT_MAGIC 0x0E1FB007 +#define EBN_COMMAND_LINE 0x00000004 +#define roundupsz(X) (((X) + 3) & ~3) + +/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ + + +void machine_shutdown(void) +{ + /* + * Normally we would stop all the other processors here, but + * the check in machine_kexec_prepare below ensures we'll only + * get this far if we've been booted with "nosmp" on the + * command line or without CONFIG_SMP so there's nothing to do + * here (for now). + */ +} + +void machine_crash_shutdown(struct pt_regs *regs) +{ + /* + * Cannot happen. This type of kexec is disabled on this + * architecture (and enforced in machine_kexec_prepare below). + */ +} + + +int machine_kexec_prepare(struct kimage *image) +{ + if (num_online_cpus() > 1) { + pr_warn("%s: detected attempt to kexec with num_online_cpus() > 1\n", + __func__); + return -ENOSYS; + } + if (image->type != KEXEC_TYPE_DEFAULT) { + pr_warn("%s: detected attempt to kexec with unsupported type: %d\n", + __func__, image->type); + return -ENOSYS; + } + return 0; +} + +void machine_kexec_cleanup(struct kimage *image) +{ + /* + * We did nothing in machine_kexec_prepare, + * so we have nothing to do here. + */ +} + +/* + * If we can find elf boot notes on this page, return the command + * line. Otherwise, silently return null. Somewhat kludgy, but no + * good way to do this without significantly rearchitecting the + * architecture-independent kexec code. + */ + +static unsigned char *kexec_bn2cl(void *pg) +{ + struct Elf32_Bhdr *bhdrp; + Elf32_Nhdr *nhdrp; + unsigned char *desc; + unsigned char *command_line; + __sum16 csum; + + bhdrp = (struct Elf32_Bhdr *) pg; + + /* + * This routine is invoked for every source page, so make + * sure to quietly ignore every impossible page. + */ + if (bhdrp->b_signature != ELF_BOOT_MAGIC || + bhdrp->b_size > PAGE_SIZE) + return 0; + + /* + * If we get a checksum mismatch, warn with the checksum + * so we can diagnose better. + */ + csum = ip_compute_csum(pg, bhdrp->b_size); + if (csum != 0) { + pr_warn("%s: bad checksum %#x (size %d)\n", + __func__, csum, bhdrp->b_size); + return 0; + } + + nhdrp = (Elf32_Nhdr *) (bhdrp + 1); + + while (nhdrp->n_type != EBN_COMMAND_LINE) { + + desc = (unsigned char *) (nhdrp + 1); + desc += roundupsz(nhdrp->n_descsz); + + nhdrp = (Elf32_Nhdr *) desc; + + /* still in bounds? */ + if ((unsigned char *) (nhdrp + 1) > + ((unsigned char *) pg) + bhdrp->b_size) { + + pr_info("%s: out of bounds\n", __func__); + return 0; + } + } + + command_line = (unsigned char *) (nhdrp + 1); + desc = command_line; + + while (*desc != '\0') { + desc++; + if (((unsigned long)desc & PAGE_MASK) != (unsigned long)pg) { + pr_info("%s: ran off end of page\n", __func__); + return 0; + } + } + + return command_line; +} + +static void kexec_find_and_set_command_line(struct kimage *image) +{ + kimage_entry_t *ptr, entry; + + unsigned char *command_line = 0; + unsigned char *r; + HV_Errno hverr; + + for (ptr = &image->head; + (entry = *ptr) && !(entry & IND_DONE); + ptr = (entry & IND_INDIRECTION) ? + phys_to_virt((entry & PAGE_MASK)) : ptr + 1) { + + if ((entry & IND_SOURCE)) { + void *va = + kmap_atomic_pfn(entry >> PAGE_SHIFT); + r = kexec_bn2cl(va); + if (r) { + command_line = r; + break; + } + kunmap_atomic(va); + } + } + + if (command_line != 0) { + pr_info("setting new command line to \"%s\"\n", command_line); + + hverr = hv_set_command_line( + (HV_VirtAddr) command_line, strlen(command_line)); + kunmap_atomic(command_line); + } else { + pr_info("%s: no command line found; making empty\n", __func__); + hverr = hv_set_command_line((HV_VirtAddr) command_line, 0); + } + if (hverr) + pr_warn("%s: hv_set_command_line returned error: %d\n", + __func__, hverr); +} + +/* + * The kexec code range-checks all its PAs, so to avoid having it run + * amok and allocate memory and then sequester it from every other + * controller, we force it to come from controller zero. We also + * disable the oom-killer since if we do end up running out of memory, + * that almost certainly won't help. + */ +struct page *kimage_alloc_pages_arch(gfp_t gfp_mask, unsigned int order) +{ + gfp_mask |= __GFP_THISNODE | __GFP_NORETRY; + return alloc_pages_node(0, gfp_mask, order); +} + +/* + * Address range in which pa=va mapping is set in setup_quasi_va_is_pa(). + * For tilepro, PAGE_OFFSET is used since this is the largest possbile value + * for tilepro, while for tilegx, we limit it to entire middle level page + * table which we assume has been allocated and is undoubtedly large enough. + */ +#ifndef __tilegx__ +#define QUASI_VA_IS_PA_ADDR_RANGE PAGE_OFFSET +#else +#define QUASI_VA_IS_PA_ADDR_RANGE PGDIR_SIZE +#endif + +static void setup_quasi_va_is_pa(void) +{ + HV_PTE pte; + unsigned long i; + + /* + * Flush our TLB to prevent conflicts between the previous contents + * and the new stuff we're about to add. + */ + local_flush_tlb_all(); + + /* + * setup VA is PA, at least up to QUASI_VA_IS_PA_ADDR_RANGE. + * Note here we assume that level-1 page table is defined by + * HPAGE_SIZE. + */ + pte = hv_pte(_PAGE_KERNEL | _PAGE_HUGE_PAGE); + pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_NO_L3); + for (i = 0; i < (QUASI_VA_IS_PA_ADDR_RANGE >> HPAGE_SHIFT); i++) { + unsigned long vaddr = i << HPAGE_SHIFT; + pgd_t *pgd = pgd_offset(current->mm, vaddr); + pud_t *pud = pud_offset(pgd, vaddr); + pte_t *ptep = (pte_t *) pmd_offset(pud, vaddr); + unsigned long pfn = i << (HPAGE_SHIFT - PAGE_SHIFT); + + if (pfn_valid(pfn)) + __set_pte(ptep, pfn_pte(pfn, pte)); + } +} + + +void machine_kexec(struct kimage *image) +{ + void *reboot_code_buffer; + pte_t *ptep; + void (*rnk)(unsigned long, void *, unsigned long) + __noreturn; + + /* Mask all interrupts before starting to reboot. */ + interrupt_mask_set_mask(~0ULL); + + kexec_find_and_set_command_line(image); + + /* + * Adjust the home caching of the control page to be cached on + * this cpu, and copy the assembly helper into the control + * code page, which we map in the vmalloc area. + */ + homecache_change_page_home(image->control_code_page, 0, + smp_processor_id()); + reboot_code_buffer = page_address(image->control_code_page); + BUG_ON(reboot_code_buffer == NULL); + ptep = virt_to_pte(NULL, (unsigned long)reboot_code_buffer); + __set_pte(ptep, pte_mkexec(*ptep)); + memcpy(reboot_code_buffer, relocate_new_kernel, + relocate_new_kernel_size); + __flush_icache_range( + (unsigned long) reboot_code_buffer, + (unsigned long) reboot_code_buffer + relocate_new_kernel_size); + + setup_quasi_va_is_pa(); + + /* now call it */ + rnk = reboot_code_buffer; + (*rnk)(image->head, reboot_code_buffer, image->start); +} |