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-rw-r--r--arch/powerpc/kexec/ranges.c729
1 files changed, 729 insertions, 0 deletions
diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c
new file mode 100644
index 000000000000..867135560e5c
--- /dev/null
+++ b/arch/powerpc/kexec/ranges.c
@@ -0,0 +1,729 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * powerpc 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) 2020 IBM Corporation
+ *
+ * Based on kexec-tools' kexec-ppc64.c, fs2dt.c.
+ * Heavily modified for the kernel by
+ * Hari Bathini, IBM Corporation.
+ */
+
+#define pr_fmt(fmt) "kexec ranges: " fmt
+
+#include <linux/sort.h>
+#include <linux/kexec.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/crash_core.h>
+#include <asm/sections.h>
+#include <asm/kexec_ranges.h>
+#include <asm/crashdump-ppc64.h>
+
+#if defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_DUMP)
+/**
+ * get_max_nr_ranges - Get the max no. of ranges crash_mem structure
+ * could hold, given the size allocated for it.
+ * @size: Allocation size of crash_mem structure.
+ *
+ * Returns the maximum no. of ranges.
+ */
+static inline unsigned int get_max_nr_ranges(size_t size)
+{
+ return ((size - sizeof(struct crash_mem)) /
+ sizeof(struct range));
+}
+
+/**
+ * get_mem_rngs_size - Get the allocated size of mem_rngs based on
+ * max_nr_ranges and chunk size.
+ * @mem_rngs: Memory ranges.
+ *
+ * Returns the maximum size of @mem_rngs.
+ */
+static inline size_t get_mem_rngs_size(struct crash_mem *mem_rngs)
+{
+ size_t size;
+
+ if (!mem_rngs)
+ return 0;
+
+ size = (sizeof(struct crash_mem) +
+ (mem_rngs->max_nr_ranges * sizeof(struct range)));
+
+ /*
+ * Memory is allocated in size multiple of MEM_RANGE_CHUNK_SZ.
+ * So, align to get the actual length.
+ */
+ return ALIGN(size, MEM_RANGE_CHUNK_SZ);
+}
+
+/**
+ * __add_mem_range - add a memory range to memory ranges list.
+ * @mem_ranges: Range list to add the memory range to.
+ * @base: Base address of the range to add.
+ * @size: Size of the memory range to add.
+ *
+ * (Re)allocates memory, if needed.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int __add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size)
+{
+ struct crash_mem *mem_rngs = *mem_ranges;
+
+ if (!mem_rngs || (mem_rngs->nr_ranges == mem_rngs->max_nr_ranges)) {
+ mem_rngs = realloc_mem_ranges(mem_ranges);
+ if (!mem_rngs)
+ return -ENOMEM;
+ }
+
+ mem_rngs->ranges[mem_rngs->nr_ranges].start = base;
+ mem_rngs->ranges[mem_rngs->nr_ranges].end = base + size - 1;
+ pr_debug("Added memory range [%#016llx - %#016llx] at index %d\n",
+ base, base + size - 1, mem_rngs->nr_ranges);
+ mem_rngs->nr_ranges++;
+ return 0;
+}
+
+/**
+ * __merge_memory_ranges - Merges the given memory ranges list.
+ * @mem_rngs: Range list to merge.
+ *
+ * Assumes a sorted range list.
+ *
+ * Returns nothing.
+ */
+static void __merge_memory_ranges(struct crash_mem *mem_rngs)
+{
+ struct range *ranges;
+ int i, idx;
+
+ if (!mem_rngs)
+ return;
+
+ idx = 0;
+ ranges = &(mem_rngs->ranges[0]);
+ for (i = 1; i < mem_rngs->nr_ranges; i++) {
+ if (ranges[i].start <= (ranges[i-1].end + 1))
+ ranges[idx].end = ranges[i].end;
+ else {
+ idx++;
+ if (i == idx)
+ continue;
+
+ ranges[idx] = ranges[i];
+ }
+ }
+ mem_rngs->nr_ranges = idx + 1;
+}
+
+/* cmp_func_t callback to sort ranges with sort() */
+static int rngcmp(const void *_x, const void *_y)
+{
+ const struct range *x = _x, *y = _y;
+
+ if (x->start > y->start)
+ return 1;
+ if (x->start < y->start)
+ return -1;
+ return 0;
+}
+
+/**
+ * sort_memory_ranges - Sorts the given memory ranges list.
+ * @mem_rngs: Range list to sort.
+ * @merge: If true, merge the list after sorting.
+ *
+ * Returns nothing.
+ */
+void sort_memory_ranges(struct crash_mem *mem_rngs, bool merge)
+{
+ int i;
+
+ if (!mem_rngs)
+ return;
+
+ /* Sort the ranges in-place */
+ sort(&(mem_rngs->ranges[0]), mem_rngs->nr_ranges,
+ sizeof(mem_rngs->ranges[0]), rngcmp, NULL);
+
+ if (merge)
+ __merge_memory_ranges(mem_rngs);
+
+ /* For debugging purpose */
+ pr_debug("Memory ranges:\n");
+ for (i = 0; i < mem_rngs->nr_ranges; i++) {
+ pr_debug("\t[%03d][%#016llx - %#016llx]\n", i,
+ mem_rngs->ranges[i].start,
+ mem_rngs->ranges[i].end);
+ }
+}
+
+/**
+ * realloc_mem_ranges - reallocate mem_ranges with size incremented
+ * by MEM_RANGE_CHUNK_SZ. Frees up the old memory,
+ * if memory allocation fails.
+ * @mem_ranges: Memory ranges to reallocate.
+ *
+ * Returns pointer to reallocated memory on success, NULL otherwise.
+ */
+struct crash_mem *realloc_mem_ranges(struct crash_mem **mem_ranges)
+{
+ struct crash_mem *mem_rngs = *mem_ranges;
+ unsigned int nr_ranges;
+ size_t size;
+
+ size = get_mem_rngs_size(mem_rngs);
+ nr_ranges = mem_rngs ? mem_rngs->nr_ranges : 0;
+
+ size += MEM_RANGE_CHUNK_SZ;
+ mem_rngs = krealloc(*mem_ranges, size, GFP_KERNEL);
+ if (!mem_rngs) {
+ kfree(*mem_ranges);
+ *mem_ranges = NULL;
+ return NULL;
+ }
+
+ mem_rngs->nr_ranges = nr_ranges;
+ mem_rngs->max_nr_ranges = get_max_nr_ranges(size);
+ *mem_ranges = mem_rngs;
+
+ return mem_rngs;
+}
+
+/**
+ * add_mem_range - Updates existing memory range, if there is an overlap.
+ * Else, adds a new memory range.
+ * @mem_ranges: Range list to add the memory range to.
+ * @base: Base address of the range to add.
+ * @size: Size of the memory range to add.
+ *
+ * (Re)allocates memory, if needed.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size)
+{
+ struct crash_mem *mem_rngs = *mem_ranges;
+ u64 mstart, mend, end;
+ unsigned int i;
+
+ if (!size)
+ return 0;
+
+ end = base + size - 1;
+
+ if (!mem_rngs || !(mem_rngs->nr_ranges))
+ return __add_mem_range(mem_ranges, base, size);
+
+ for (i = 0; i < mem_rngs->nr_ranges; i++) {
+ mstart = mem_rngs->ranges[i].start;
+ mend = mem_rngs->ranges[i].end;
+ if (base < mend && end > mstart) {
+ if (base < mstart)
+ mem_rngs->ranges[i].start = base;
+ if (end > mend)
+ mem_rngs->ranges[i].end = end;
+ return 0;
+ }
+ }
+
+ return __add_mem_range(mem_ranges, base, size);
+}
+
+#endif /* CONFIG_KEXEC_FILE || CONFIG_CRASH_DUMP */
+
+#ifdef CONFIG_KEXEC_FILE
+/**
+ * add_tce_mem_ranges - Adds tce-table range to the given memory ranges list.
+ * @mem_ranges: Range list to add the memory range(s) to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_tce_mem_ranges(struct crash_mem **mem_ranges)
+{
+ struct device_node *dn = NULL;
+ int ret = 0;
+
+ for_each_node_by_type(dn, "pci") {
+ u64 base;
+ u32 size;
+
+ ret = of_property_read_u64(dn, "linux,tce-base", &base);
+ ret |= of_property_read_u32(dn, "linux,tce-size", &size);
+ if (ret) {
+ /*
+ * It is ok to have pci nodes without tce. So, ignore
+ * property does not exist error.
+ */
+ if (ret == -EINVAL) {
+ ret = 0;
+ continue;
+ }
+ break;
+ }
+
+ ret = add_mem_range(mem_ranges, base, size);
+ if (ret)
+ break;
+ }
+
+ of_node_put(dn);
+ return ret;
+}
+
+/**
+ * add_initrd_mem_range - Adds initrd range to the given memory ranges list,
+ * if the initrd was retained.
+ * @mem_ranges: Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_initrd_mem_range(struct crash_mem **mem_ranges)
+{
+ u64 base, end;
+ int ret;
+
+ /* This range means something, only if initrd was retained */
+ if (!strstr(saved_command_line, "retain_initrd"))
+ return 0;
+
+ ret = of_property_read_u64(of_chosen, "linux,initrd-start", &base);
+ ret |= of_property_read_u64(of_chosen, "linux,initrd-end", &end);
+ if (!ret)
+ ret = add_mem_range(mem_ranges, base, end - base + 1);
+
+ return ret;
+}
+
+/**
+ * add_htab_mem_range - Adds htab range to the given memory ranges list,
+ * if it exists
+ * @mem_ranges: Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_htab_mem_range(struct crash_mem **mem_ranges)
+{
+
+#ifdef CONFIG_PPC_64S_HASH_MMU
+ if (!htab_address)
+ return 0;
+
+ return add_mem_range(mem_ranges, __pa(htab_address), htab_size_bytes);
+#else
+ return 0;
+#endif
+}
+
+/**
+ * add_kernel_mem_range - Adds kernel text region to the given
+ * memory ranges list.
+ * @mem_ranges: Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_kernel_mem_range(struct crash_mem **mem_ranges)
+{
+ return add_mem_range(mem_ranges, 0, __pa(_end));
+}
+#endif /* CONFIG_KEXEC_FILE */
+
+#if defined(CONFIG_KEXEC_FILE) || defined(CONFIG_CRASH_DUMP)
+/**
+ * add_rtas_mem_range - Adds RTAS region to the given memory ranges list.
+ * @mem_ranges: Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_rtas_mem_range(struct crash_mem **mem_ranges)
+{
+ struct device_node *dn;
+ u32 base, size;
+ int ret = 0;
+
+ dn = of_find_node_by_path("/rtas");
+ if (!dn)
+ return 0;
+
+ ret = of_property_read_u32(dn, "linux,rtas-base", &base);
+ ret |= of_property_read_u32(dn, "rtas-size", &size);
+ if (!ret)
+ ret = add_mem_range(mem_ranges, base, size);
+
+ of_node_put(dn);
+ return ret;
+}
+
+/**
+ * add_opal_mem_range - Adds OPAL region to the given memory ranges list.
+ * @mem_ranges: Range list to add the memory range to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_opal_mem_range(struct crash_mem **mem_ranges)
+{
+ struct device_node *dn;
+ u64 base, size;
+ int ret;
+
+ dn = of_find_node_by_path("/ibm,opal");
+ if (!dn)
+ return 0;
+
+ ret = of_property_read_u64(dn, "opal-base-address", &base);
+ ret |= of_property_read_u64(dn, "opal-runtime-size", &size);
+ if (!ret)
+ ret = add_mem_range(mem_ranges, base, size);
+
+ of_node_put(dn);
+ return ret;
+}
+#endif /* CONFIG_KEXEC_FILE || CONFIG_CRASH_DUMP */
+
+#ifdef CONFIG_KEXEC_FILE
+/**
+ * add_reserved_mem_ranges - Adds "/reserved-ranges" regions exported by f/w
+ * to the given memory ranges list.
+ * @mem_ranges: Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+static int add_reserved_mem_ranges(struct crash_mem **mem_ranges)
+{
+ int n_mem_addr_cells, n_mem_size_cells, i, len, cells, ret = 0;
+ struct device_node *root = of_find_node_by_path("/");
+ const __be32 *prop;
+
+ prop = of_get_property(root, "reserved-ranges", &len);
+ n_mem_addr_cells = of_n_addr_cells(root);
+ n_mem_size_cells = of_n_size_cells(root);
+ of_node_put(root);
+ if (!prop)
+ return 0;
+
+ cells = n_mem_addr_cells + n_mem_size_cells;
+
+ /* Each reserved range is an (address,size) pair */
+ for (i = 0; i < (len / (sizeof(u32) * cells)); i++) {
+ u64 base, size;
+
+ base = of_read_number(prop + (i * cells), n_mem_addr_cells);
+ size = of_read_number(prop + (i * cells) + n_mem_addr_cells,
+ n_mem_size_cells);
+
+ ret = add_mem_range(mem_ranges, base, size);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+/**
+ * get_reserved_memory_ranges - Get reserve memory ranges. This list includes
+ * memory regions that should be added to the
+ * memory reserve map to ensure the region is
+ * protected from any mischief.
+ * @mem_ranges: Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int get_reserved_memory_ranges(struct crash_mem **mem_ranges)
+{
+ int ret;
+
+ ret = add_rtas_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_tce_mem_ranges(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_reserved_mem_ranges(mem_ranges);
+out:
+ if (ret)
+ pr_err("Failed to setup reserved memory ranges\n");
+ return ret;
+}
+
+/**
+ * get_exclude_memory_ranges - Get exclude memory ranges. This list includes
+ * regions like opal/rtas, tce-table, initrd,
+ * kernel, htab which should be avoided while
+ * setting up kexec load segments.
+ * @mem_ranges: Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int get_exclude_memory_ranges(struct crash_mem **mem_ranges)
+{
+ int ret;
+
+ ret = add_tce_mem_ranges(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_initrd_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_htab_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_kernel_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_rtas_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_opal_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_reserved_mem_ranges(mem_ranges);
+ if (ret)
+ goto out;
+
+ /* exclude memory ranges should be sorted for easy lookup */
+ sort_memory_ranges(*mem_ranges, true);
+out:
+ if (ret)
+ pr_err("Failed to setup exclude memory ranges\n");
+ return ret;
+}
+
+#ifdef CONFIG_CRASH_DUMP
+/**
+ * get_usable_memory_ranges - Get usable memory ranges. This list includes
+ * regions like crashkernel, opal/rtas & tce-table,
+ * that kdump kernel could use.
+ * @mem_ranges: Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int get_usable_memory_ranges(struct crash_mem **mem_ranges)
+{
+ int ret, i;
+
+ /*
+ * Early boot failure observed on guests when low memory (first memory
+ * block?) is not added to usable memory. So, add [0, crashk_res.end]
+ * instead of [crashk_res.start, crashk_res.end] to workaround it.
+ * Also, crashed kernel's memory must be added to reserve map to
+ * avoid kdump kernel from using it.
+ */
+ ret = add_mem_range(mem_ranges, 0, crashk_res.end + 1);
+ if (ret)
+ goto out;
+
+ for (i = 0; i < crashk_cma_cnt; i++) {
+ ret = add_mem_range(mem_ranges, crashk_cma_ranges[i].start,
+ crashk_cma_ranges[i].end - crashk_cma_ranges[i].start + 1);
+ if (ret)
+ goto out;
+ }
+
+ ret = add_rtas_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_opal_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_tce_mem_ranges(mem_ranges);
+out:
+ if (ret)
+ pr_err("Failed to setup usable memory ranges\n");
+ return ret;
+}
+#endif /* CONFIG_CRASH_DUMP */
+#endif /* CONFIG_KEXEC_FILE */
+
+#ifdef CONFIG_CRASH_DUMP
+static int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
+ unsigned long long mstart,
+ unsigned long long mend)
+{
+ struct crash_mem *tmem = *mem_ranges;
+
+ /* Reallocate memory ranges if there is no space to split ranges */
+ if (tmem && (tmem->nr_ranges == tmem->max_nr_ranges)) {
+ tmem = realloc_mem_ranges(mem_ranges);
+ if (!tmem)
+ return -ENOMEM;
+ }
+
+ return crash_exclude_mem_range(tmem, mstart, mend);
+}
+
+/**
+ * get_crash_memory_ranges - Get crash memory ranges. This list includes
+ * first/crashing kernel's memory regions that
+ * would be exported via an elfcore.
+ * @mem_ranges: Range list to add the memory ranges to.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int get_crash_memory_ranges(struct crash_mem **mem_ranges)
+{
+ phys_addr_t base, end;
+ u64 i;
+ int ret;
+
+ for_each_mem_range(i, &base, &end) {
+ u64 size = end - base;
+
+ /* Skip backup memory region, which needs a separate entry */
+ if (base == BACKUP_SRC_START) {
+ if (size > BACKUP_SRC_SIZE) {
+ base = BACKUP_SRC_END + 1;
+ size -= BACKUP_SRC_SIZE;
+ } else
+ continue;
+ }
+
+ ret = add_mem_range(mem_ranges, base, size);
+ if (ret)
+ goto out;
+
+ /* Try merging adjacent ranges before reallocation attempt */
+ if ((*mem_ranges)->nr_ranges == (*mem_ranges)->max_nr_ranges)
+ sort_memory_ranges(*mem_ranges, true);
+ }
+
+ /* Exclude crashkernel region */
+ ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_res.start, crashk_res.end);
+ if (ret)
+ goto out;
+
+ for (i = 0; i < crashk_cma_cnt; ++i) {
+ ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_cma_ranges[i].start,
+ crashk_cma_ranges[i].end);
+ if (ret)
+ goto out;
+ }
+
+ /*
+ * FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL
+ * regions are exported to save their context at the time of
+ * crash, they should actually be backed up just like the
+ * first 64K bytes of memory.
+ */
+ ret = add_rtas_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ ret = add_opal_mem_range(mem_ranges);
+ if (ret)
+ goto out;
+
+ /* create a separate program header for the backup region */
+ ret = add_mem_range(mem_ranges, BACKUP_SRC_START, BACKUP_SRC_SIZE);
+ if (ret)
+ goto out;
+
+ sort_memory_ranges(*mem_ranges, false);
+out:
+ if (ret)
+ pr_err("Failed to setup crash memory ranges\n");
+ return ret;
+}
+
+/**
+ * remove_mem_range - Removes the given memory range from the range list.
+ * @mem_ranges: Range list to remove the memory range to.
+ * @base: Base address of the range to remove.
+ * @size: Size of the memory range to remove.
+ *
+ * (Re)allocates memory, if needed.
+ *
+ * Returns 0 on success, negative errno on error.
+ */
+int remove_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size)
+{
+ u64 end;
+ int ret = 0;
+ unsigned int i;
+ u64 mstart, mend;
+ struct crash_mem *mem_rngs = *mem_ranges;
+
+ if (!size)
+ return 0;
+
+ /*
+ * Memory range are stored as start and end address, use
+ * the same format to do remove operation.
+ */
+ end = base + size - 1;
+
+ for (i = 0; i < mem_rngs->nr_ranges; i++) {
+ mstart = mem_rngs->ranges[i].start;
+ mend = mem_rngs->ranges[i].end;
+
+ /*
+ * Memory range to remove is not part of this range entry
+ * in the memory range list
+ */
+ if (!(base >= mstart && end <= mend))
+ continue;
+
+ /*
+ * Memory range to remove is equivalent to this entry in the
+ * memory range list. Remove the range entry from the list.
+ */
+ if (base == mstart && end == mend) {
+ for (; i < mem_rngs->nr_ranges - 1; i++) {
+ mem_rngs->ranges[i].start = mem_rngs->ranges[i+1].start;
+ mem_rngs->ranges[i].end = mem_rngs->ranges[i+1].end;
+ }
+ mem_rngs->nr_ranges--;
+ goto out;
+ }
+ /*
+ * Start address of the memory range to remove and the
+ * current memory range entry in the list is same. Just
+ * move the start address of the current memory range
+ * entry in the list to end + 1.
+ */
+ else if (base == mstart) {
+ mem_rngs->ranges[i].start = end + 1;
+ goto out;
+ }
+ /*
+ * End address of the memory range to remove and the
+ * current memory range entry in the list is same.
+ * Just move the end address of the current memory
+ * range entry in the list to base - 1.
+ */
+ else if (end == mend) {
+ mem_rngs->ranges[i].end = base - 1;
+ goto out;
+ }
+ /*
+ * Memory range to remove is not at the edge of current
+ * memory range entry. Split the current memory entry into
+ * two half.
+ */
+ else {
+ size = mem_rngs->ranges[i].end - end + 1;
+ mem_rngs->ranges[i].end = base - 1;
+ ret = add_mem_range(mem_ranges, end + 1, size);
+ }
+ }
+out:
+ return ret;
+}
+#endif /* CONFIG_CRASH_DUMP */
generated by cgit (git 2.34.1) at 2025-12-24 23:10:59 +0000