--- /dev/null
+/*
+ * 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);
+}
Code Review / kvmfornfv.git / blobdiff