1 files changed, 279 insertions, 0 deletions
diff --git a/arch/tile/kernel/machine_kexec.c b/arch/tile/kernel/machine_kexec.c
new file mode 100644
index 00000000000..ba7a265d617
--- /dev/null
+++ b/arch/tile/kernel/machine_kexec.c
@@ -0,0 +1,279 @@
+/*
+ * 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 <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_warning("%s: detected attempt to kexec "
+		       "with num_online_cpus() > 1\n",
+		       __func__);
+		return -ENOSYS;
+	}
+	if (image->type != KEXEC_TYPE_DEFAULT) {
+		pr_warning("%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_warning("%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, KM_USER0);
+			r = kexec_bn2cl(va);
+			if (r) {
+				command_line = r;
+				break;
+			}
+			kunmap_atomic(va, KM_USER0);
+		}
+	}
+
+	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, KM_USER0);
+	} 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_warning("%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);
+}
+
+static void setup_quasi_va_is_pa(void)
+{
+	HV_PTE *pgtable;
+	HV_PTE pte;
+	int 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 PAGE_OFFSET */
+
+	pgtable = (HV_PTE *)current->mm->pgd;
+	pte = hv_pte(_PAGE_KERNEL | _PAGE_HUGE_PAGE);
+	pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_NO_L3);
+
+	for (i = 0; i < pgd_index(PAGE_OFFSET); i++)
+		pgtable[i] = pfn_pte(i << (HPAGE_SHIFT - PAGE_SHIFT), pte);
+}
+
+
+NORET_TYPE void machine_kexec(struct kimage *image)
+{
+	void *reboot_code_buffer;
+	NORET_TYPE void (*rnk)(unsigned long, void *, unsigned long)
+		ATTRIB_NORET;
+
+	/* 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 = vmap(&image->control_code_page, 1, 0,
+				  __pgprot(_PAGE_KERNEL | _PAGE_EXECUTABLE));
+	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);
+}