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- /*
- * 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);
- }
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