summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/machine_kexec_file_64.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/machine_kexec_file_64.c')
-rw-r--r--arch/powerpc/kernel/machine_kexec_file_64.c338
1 files changed, 338 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/machine_kexec_file_64.c b/arch/powerpc/kernel/machine_kexec_file_64.c
new file mode 100644
index 000000000000..7abc8a75ee48
--- /dev/null
+++ b/arch/powerpc/kernel/machine_kexec_file_64.c
@@ -0,0 +1,338 @@
+/*
+ * ppc64 code to implement the kexec_file_load syscall
+ *
+ * Copyright (C) 2004 Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004 IBM Corp.
+ * Copyright (C) 2004,2005 Milton D Miller II, IBM Corporation
+ * Copyright (C) 2005 R Sharada (sharada@in.ibm.com)
+ * Copyright (C) 2006 Mohan Kumar M (mohan@in.ibm.com)
+ * Copyright (C) 2016 IBM Corporation
+ *
+ * Based on kexec-tools' kexec-elf-ppc64.c, fs2dt.c.
+ * Heavily modified for the kernel by
+ * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
+ *
+ * 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 of the License).
+ *
+ * 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. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/slab.h>
+#include <linux/kexec.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+
+#define SLAVE_CODE_SIZE 256
+
+static struct kexec_file_ops *kexec_file_loaders[] = {
+ &kexec_elf64_ops,
+};
+
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+ unsigned long buf_len)
+{
+ int i, ret = -ENOEXEC;
+ struct kexec_file_ops *fops;
+
+ /* We don't support crash kernels yet. */
+ if (image->type == KEXEC_TYPE_CRASH)
+ return -ENOTSUPP;
+
+ for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
+ fops = kexec_file_loaders[i];
+ if (!fops || !fops->probe)
+ continue;
+
+ ret = fops->probe(buf, buf_len);
+ if (!ret) {
+ image->fops = fops;
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+void *arch_kexec_kernel_image_load(struct kimage *image)
+{
+ if (!image->fops || !image->fops->load)
+ return ERR_PTR(-ENOEXEC);
+
+ return image->fops->load(image, image->kernel_buf,
+ image->kernel_buf_len, image->initrd_buf,
+ image->initrd_buf_len, image->cmdline_buf,
+ image->cmdline_buf_len);
+}
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+ if (!image->fops || !image->fops->cleanup)
+ return 0;
+
+ return image->fops->cleanup(image->image_loader_data);
+}
+
+/**
+ * arch_kexec_walk_mem - call func(data) for each unreserved memory block
+ * @kbuf: Context info for the search. Also passed to @func.
+ * @func: Function to call for each memory block.
+ *
+ * This function is used by kexec_add_buffer and kexec_locate_mem_hole
+ * to find unreserved memory to load kexec segments into.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *))
+{
+ int ret = 0;
+ u64 i;
+ phys_addr_t mstart, mend;
+
+ if (kbuf->top_down) {
+ for_each_free_mem_range_reverse(i, NUMA_NO_NODE, 0,
+ &mstart, &mend, NULL) {
+ /*
+ * In memblock, end points to the first byte after the
+ * range while in kexec, end points to the last byte
+ * in the range.
+ */
+ ret = func(mstart, mend - 1, kbuf);
+ if (ret)
+ break;
+ }
+ } else {
+ for_each_free_mem_range(i, NUMA_NO_NODE, 0, &mstart, &mend,
+ NULL) {
+ /*
+ * In memblock, end points to the first byte after the
+ * range while in kexec, end points to the last byte
+ * in the range.
+ */
+ ret = func(mstart, mend - 1, kbuf);
+ if (ret)
+ break;
+ }
+ }
+
+ return ret;
+}
+
+/**
+ * setup_purgatory - initialize the purgatory's global variables
+ * @image: kexec image.
+ * @slave_code: Slave code for the purgatory.
+ * @fdt: Flattened device tree for the next kernel.
+ * @kernel_load_addr: Address where the kernel is loaded.
+ * @fdt_load_addr: Address where the flattened device tree is loaded.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int setup_purgatory(struct kimage *image, const void *slave_code,
+ const void *fdt, unsigned long kernel_load_addr,
+ unsigned long fdt_load_addr)
+{
+ unsigned int *slave_code_buf, master_entry;
+ int ret;
+
+ slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
+ if (!slave_code_buf)
+ return -ENOMEM;
+
+ /* Get the slave code from the new kernel and put it in purgatory. */
+ ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+ slave_code_buf, SLAVE_CODE_SIZE,
+ true);
+ if (ret) {
+ kfree(slave_code_buf);
+ return ret;
+ }
+
+ master_entry = slave_code_buf[0];
+ memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
+ slave_code_buf[0] = master_entry;
+ ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+ slave_code_buf, SLAVE_CODE_SIZE,
+ false);
+ kfree(slave_code_buf);
+
+ ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
+ sizeof(kernel_load_addr), false);
+ if (ret)
+ return ret;
+ ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
+ sizeof(fdt_load_addr), false);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+/**
+ * delete_fdt_mem_rsv - delete memory reservation with given address and size
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
+{
+ int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
+
+ for (i = 0; i < num_rsvs; i++) {
+ uint64_t rsv_start, rsv_size;
+
+ ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+ if (ret) {
+ pr_err("Malformed device tree.\n");
+ return -EINVAL;
+ }
+
+ if (rsv_start == start && rsv_size == size) {
+ ret = fdt_del_mem_rsv(fdt, i);
+ if (ret) {
+ pr_err("Error deleting device tree reservation.\n");
+ return -EINVAL;
+ }
+
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+
+/*
+ * setup_new_fdt - modify /chosen and memory reservation for the next kernel
+ * @fdt: Flattened device tree for the next kernel.
+ * @initrd_load_addr: Address where the next initrd will be loaded.
+ * @initrd_len: Size of the next initrd, or 0 if there will be none.
+ * @cmdline: Command line for the next kernel, or NULL if there will
+ * be none.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
+ unsigned long initrd_len, const char *cmdline)
+{
+ int ret, chosen_node;
+ const void *prop;
+
+ /* Remove memory reservation for the current device tree. */
+ ret = delete_fdt_mem_rsv(fdt, __pa(initial_boot_params),
+ fdt_totalsize(initial_boot_params));
+ if (ret == 0)
+ pr_debug("Removed old device tree reservation.\n");
+ else if (ret != -ENOENT)
+ return ret;
+
+ chosen_node = fdt_path_offset(fdt, "/chosen");
+ if (chosen_node == -FDT_ERR_NOTFOUND) {
+ chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
+ "chosen");
+ if (chosen_node < 0) {
+ pr_err("Error creating /chosen.\n");
+ return -EINVAL;
+ }
+ } else if (chosen_node < 0) {
+ pr_err("Malformed device tree: error reading /chosen.\n");
+ return -EINVAL;
+ }
+
+ /* Did we boot using an initrd? */
+ prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
+ if (prop) {
+ uint64_t tmp_start, tmp_end, tmp_size;
+
+ tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+ prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
+ if (!prop) {
+ pr_err("Malformed device tree.\n");
+ return -EINVAL;
+ }
+ tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+ /*
+ * kexec reserves exact initrd size, while firmware may
+ * reserve a multiple of PAGE_SIZE, so check for both.
+ */
+ tmp_size = tmp_end - tmp_start;
+ ret = delete_fdt_mem_rsv(fdt, tmp_start, tmp_size);
+ if (ret == -ENOENT)
+ ret = delete_fdt_mem_rsv(fdt, tmp_start,
+ round_up(tmp_size, PAGE_SIZE));
+ if (ret == 0)
+ pr_debug("Removed old initrd reservation.\n");
+ else if (ret != -ENOENT)
+ return ret;
+
+ /* If there's no new initrd, delete the old initrd's info. */
+ if (initrd_len == 0) {
+ ret = fdt_delprop(fdt, chosen_node,
+ "linux,initrd-start");
+ if (ret) {
+ pr_err("Error deleting linux,initrd-start.\n");
+ return -EINVAL;
+ }
+
+ ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
+ if (ret) {
+ pr_err("Error deleting linux,initrd-end.\n");
+ return -EINVAL;
+ }
+ }
+ }
+
+ if (initrd_len) {
+ ret = fdt_setprop_u64(fdt, chosen_node,
+ "linux,initrd-start",
+ initrd_load_addr);
+ if (ret < 0) {
+ pr_err("Error setting up the new device tree.\n");
+ return -EINVAL;
+ }
+
+ /* initrd-end is the first address after the initrd image. */
+ ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
+ initrd_load_addr + initrd_len);
+ if (ret < 0) {
+ pr_err("Error setting up the new device tree.\n");
+ return -EINVAL;
+ }
+
+ ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
+ if (ret) {
+ pr_err("Error reserving initrd memory: %s\n",
+ fdt_strerror(ret));
+ return -EINVAL;
+ }
+ }
+
+ if (cmdline != NULL) {
+ ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
+ if (ret < 0) {
+ pr_err("Error setting up the new device tree.\n");
+ return -EINVAL;
+ }
+ } else {
+ ret = fdt_delprop(fdt, chosen_node, "bootargs");
+ if (ret && ret != -FDT_ERR_NOTFOUND) {
+ pr_err("Error deleting bootargs.\n");
+ return -EINVAL;
+ }
+ }
+
+ ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+ if (ret) {
+ pr_err("Error setting up the new device tree.\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
OpenPOWER on IntegriCloud