1 files changed, 220 insertions, 0 deletions
diff --git a/kexec/arch/loongarch/crashdump-loongarch.c b/kexec/arch/loongarch/crashdump-loongarch.c
new file mode 100644
index 0000000..81250e4
--- /dev/null
+++ b/kexec/arch/loongarch/crashdump-loongarch.c
@@ -0,0 +1,220 @@
+/*
+ * LoongArch crashdump.
+ *
+ * Copyright (C) 2022 Loongson Technology Corporation Limited.
+ *   Youling Tang <tangyouling@loongson.cn>
+ *
+ * derived from crashdump-arm64.c
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <linux/elf.h>
+
+#include "kexec.h"
+#include "crashdump.h"
+#include "crashdump-loongarch.h"
+#include "iomem.h"
+#include "kexec-loongarch.h"
+#include "kexec-elf.h"
+#include "mem_regions.h"
+
+/* memory ranges of crashed kernel */
+static struct memory_ranges system_memory_rgns;
+
+/* memory range reserved for crashkernel */
+struct memory_range crash_reserved_mem[CRASH_MAX_RESERVED_RANGES];
+struct memory_ranges usablemem_rgns = {
+	.size = 0,
+	.max_size = CRASH_MAX_RESERVED_RANGES,
+	.ranges = crash_reserved_mem,
+};
+
+struct memory_range elfcorehdr_mem;
+
+static struct crash_elf_info elf_info64 = {
+	.class		= ELFCLASS64,
+	.data		= ELFDATA2LSB,
+	.machine	= EM_LOONGARCH,
+	.page_offset	= PAGE_OFFSET,
+};
+
+/*
+ * iomem_range_callback() - callback called for each iomem region
+ * @data: not used
+ * @nr: not used
+ * @str: name of the memory region
+ * @base: start address of the memory region
+ * @length: size of the memory region
+ *
+ * This function is called once for each memory region found in /proc/iomem.
+ * It locates system RAM and crashkernel reserved memory and places these to
+ * variables, respectively, system_memory_rgns and usablemem_rgns.
+ */
+
+static int iomem_range_callback(void *UNUSED(data), int UNUSED(nr),
+				char *str, unsigned long long base,
+				unsigned long long length)
+{
+	if (strncmp(str, CRASH_KERNEL, strlen(CRASH_KERNEL)) == 0)
+		return mem_regions_alloc_and_add(&usablemem_rgns,
+						base, length, RANGE_RAM);
+	else if (strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM)) == 0)
+		return mem_regions_alloc_and_add(&system_memory_rgns,
+						base, length, RANGE_RAM);
+	else if (strncmp(str, KERNEL_CODE, strlen(KERNEL_CODE)) == 0)
+		elf_info64.kern_paddr_start = base;
+	else if (strncmp(str, KERNEL_DATA, strlen(KERNEL_DATA)) == 0)
+		elf_info64.kern_size = base + length - elf_info64.kern_paddr_start;
+
+	return 0;
+}
+
+int is_crashkernel_mem_reserved(void)
+{
+	if (!usablemem_rgns.size)
+		kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL);
+
+	return usablemem_rgns.size;
+}
+
+/*
+ * crash_get_memory_ranges() - read system physical memory
+ *
+ * Function reads through system physical memory and stores found memory
+ * regions in system_memory_ranges.
+ * Regions are sorted in ascending order.
+ *
+ * Returns 0 in case of success and a negative value otherwise.
+ */
+static int crash_get_memory_ranges(void)
+{
+	int i;
+
+	/*
+	 * First read all memory regions that can be considered as
+	 * system memory including the crash area.
+	 */
+	if (!usablemem_rgns.size)
+		kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL);
+
+	/* allow one or two regions for crash dump kernel */
+	if (!usablemem_rgns.size)
+		return -EINVAL;
+
+	dbgprint_mem_range("Reserved memory range",
+			usablemem_rgns.ranges, usablemem_rgns.size);
+
+	for (i = 0; i < usablemem_rgns.size; i++) {
+		if (mem_regions_alloc_and_exclude(&system_memory_rgns,
+					&crash_reserved_mem[i])) {
+			fprintf(stderr, "Cannot allocate memory for ranges\n");
+			return -ENOMEM;
+		}
+	}
+
+	/*
+	 * Make sure that the memory regions are sorted.
+	 */
+	mem_regions_sort(&system_memory_rgns);
+
+	dbgprint_mem_range("Coredump memory ranges",
+			   system_memory_rgns.ranges, system_memory_rgns.size);
+
+	/*
+	 * For additional kernel code/data segment.
+	 * kern_paddr_start/kern_size are determined in iomem_range_callback
+	 */
+	elf_info64.kern_vaddr_start = get_kernel_sym("_text");
+	if (!elf_info64.kern_vaddr_start)
+		elf_info64.kern_vaddr_start = UINT64_MAX;
+
+	return 0;
+}
+
+/*
+ * load_crashdump_segments() - load the elf core header
+ * @info: kexec info structure
+ *
+ * This function creates and loads an additional segment of elf core header
+ : which is used to construct /proc/vmcore on crash dump kernel.
+ *
+ * Return 0 in case of success and -1 in case of error.
+ */
+
+int load_crashdump_segments(struct kexec_info *info)
+{
+	unsigned long elfcorehdr;
+	unsigned long bufsz;
+	void *buf;
+	int err;
+
+	/*
+	 * First fetch all the memory (RAM) ranges that we are going to
+	 * pass to the crash dump kernel during panic.
+	 */
+
+	err = crash_get_memory_ranges();
+
+	if (err)
+		return EFAILED;
+
+	err = crash_create_elf64_headers(info, &elf_info64,
+			system_memory_rgns.ranges, system_memory_rgns.size,
+			&buf, &bufsz, ELF_CORE_HEADER_ALIGN);
+
+	if (err)
+		return EFAILED;
+
+	elfcorehdr = add_buffer(info, buf, bufsz, bufsz, 1024,
+		crash_reserved_mem[usablemem_rgns.size - 1].start,
+		crash_reserved_mem[usablemem_rgns.size - 1].end, -1);
+
+	elfcorehdr_mem.start = elfcorehdr;
+	elfcorehdr_mem.end = elfcorehdr + bufsz - 1;
+
+	dbgprintf("%s: elfcorehdr 0x%llx-0x%llx\n", __func__,
+			elfcorehdr_mem.start, elfcorehdr_mem.end);
+
+	return 0;
+}
+
+/*
+ * e_entry and p_paddr are actually in virtual address space.
+ * Those values will be translated to physcal addresses by using
+ * virt_to_phys() in add_segment().
+ * So let's fix up those values for later use so the memory base will be
+ * correctly replaced with crash_reserved_mem[usablemem_rgns.size - 1].start.
+ */
+void fixup_elf_addrs(struct mem_ehdr *ehdr)
+{
+	struct mem_phdr *phdr;
+	int i;
+
+	ehdr->e_entry += crash_reserved_mem[usablemem_rgns.size - 1].start;
+
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		phdr = &ehdr->e_phdr[i];
+		if (phdr->p_type != PT_LOAD)
+			continue;
+		phdr->p_paddr += crash_reserved_mem[usablemem_rgns.size - 1].start;
+	}
+}
+
+int get_crash_kernel_load_range(uint64_t *start, uint64_t *end)
+{
+	if (!usablemem_rgns.size)
+		kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL);
+
+	if (!usablemem_rgns.size)
+		return -1;
+
+	*start = crash_reserved_mem[usablemem_rgns.size - 1].start;
+	*end = crash_reserved_mem[usablemem_rgns.size - 1].end;
+
+	return 0;
+}