some kexec MIPS improvements

-  using simple   mips* ) in configure.ac to make it compilable on mips2
   and mips64
- remove kexec/arch/mips/mips-setup-simple.S which prepares cmdline for
  new kernel, it is better to move this work to kernel code. BTW this code was
  compilable only on o32 because of t4 is not defined on 64-64 or n32 MIPS ABIs.
- simple put cmdline as string, kernel code should catch cmdline like this

int board_kexec_prepare(struct kimage *image)
{
    int i;
    char *bootloader = "kexec";
    board_boot_desc_ptr->argc = 0;
    for(i=0;i<image->nr_segments;i++)
    {
        printk("segment %d
        if (!strncmp(bootloader, (char*)image->segment[i].buf,
                strlen(bootloader)))
        {
            /*
             * convert command line string to array
             * of parameters (as bootloader does).
             */
            int argc = 0, offt;
            char *str = (char *)image->segment[i].buf;
            char *ptr = strchr(str, ' ');
            while (ptr && (ARGV_MAX_ARGS > argc)) {
                *ptr = '\0';
                if (ptr[1] != ' ') {
                    offt = (int)(ptr - str + 1);
                    boot_desc_ptr->argv[argc] =
                        image->segment[i].mem + offt;
                    argc++;
                }
                ptr = strchr(ptr + 1, ' ');
            }
            boot_desc_ptr->argc = argc;
            break;
        }
    }
   Keep it as string make code simple and more readable.

- add crashdump support
- do not redefine syscalls numbers if they defined in system
  remove fixups for /proc/iomem. If your board provides wrong /proc/iomem please
  fix kernel, or at least you local version of kexec. No need to support it in
  main line. At least add option --fake-iomem
- some minor fixes

Signed-off-by: Maxim Uvarov <muvarov@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 377 insertions, 0 deletions

diff --git a/kexec/arch/mips/crashdump-mips.c b/kexec/arch/mips/crashdump-mips.c
new file mode 100644
index 0000000..17cf52d
--- /dev/null
+++ b/kexec/arch/mips/crashdump-mips.c
@@ -0,0 +1,377 @@
+/*
+ * kexec: Linux boots Linux
+ *
+ * 2005 (C) IBM Corporation.
+ * 2008 (C) MontaVista Software, Inc.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <limits.h>
+#include <elf.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include "../../kexec.h"
+#include "../../kexec-elf.h"
+#include "../../kexec-syscall.h"
+#include "../../crashdump.h"
+#include "kexec-mips.h"
+#include "crashdump-mips.h"
+#include "unused.h"
+
+/* Stores a sorted list of RAM memory ranges for which to create elf headers.
+ * A separate program header is created for backup region */
+static struct memory_range crash_memory_range[CRASH_MAX_MEMORY_RANGES];
+
+/* Memory region reserved for storing panic kernel and other data. */
+static struct memory_range crash_reserved_mem;
+
+/*
+ * To store the memory size of the first kernel and this value will be
+ * passed to the second kernel as command line (savemaxmem=xM).
+ * The second kernel will be calculated saved_max_pfn based on this
+ * variable.
+ */
+unsigned long long saved_max_mem;
+
+/* Removes crash reserve region from list of memory chunks for whom elf program
+ * headers have to be created. Assuming crash reserve region to be a single
+ * continuous area fully contained inside one of the memory chunks */
+static int exclude_crash_reserve_region(int *nr_ranges)
+{
+	int i, j, tidx = -1;
+	unsigned long long cstart, cend;
+	struct memory_range temp_region = {
+		.start = 0,
+		.end = 0
+	};
+
+	/* Crash reserved region. */
+	cstart = crash_reserved_mem.start;
+	cend = crash_reserved_mem.end;
+
+	for (i = 0; i < (*nr_ranges); i++) {
+		unsigned long long mstart, mend;
+		mstart = crash_memory_range[i].start;
+		mend = crash_memory_range[i].end;
+		if (cstart < mend && cend > mstart) {
+			if (cstart != mstart && cend != mend) {
+				/* Split memory region */
+				crash_memory_range[i].end = cstart - 1;
+				temp_region.start = cend + 1;
+				temp_region.end = mend;
+				temp_region.type = RANGE_RAM;
+				tidx = i+1;
+			} else if (cstart != mstart)
+				crash_memory_range[i].end = cstart - 1;
+			else
+				crash_memory_range[i].start = cend + 1;
+		}
+	}
+	/* Insert split memory region, if any. */
+	if (tidx >= 0) {
+		if (*nr_ranges == CRASH_MAX_MEMORY_RANGES) {
+			/* No space to insert another element. */
+			fprintf(stderr, "Error: Number of crash memory ranges"
+					" excedeed the max limit\n");
+			return -1;
+		}
+		for (j = (*nr_ranges - 1); j >= tidx; j--)
+			crash_memory_range[j+1] = crash_memory_range[j];
+		crash_memory_range[tidx].start = temp_region.start;
+		crash_memory_range[tidx].end = temp_region.end;
+		crash_memory_range[tidx].type = temp_region.type;
+		(*nr_ranges)++;
+	}
+	return 0;
+}
+/* Reads the appropriate file and retrieves the SYSTEM RAM regions for whom to
+ * create Elf headers. Keeping it separate from get_memory_ranges() as
+ * requirements are different in the case of normal kexec and crashdumps.
+ *
+ * Normal kexec needs to look at all of available physical memory irrespective
+ * of the fact how much of it is being used by currently running kernel.
+ * Crashdumps need to have access to memory regions actually being used by
+ * running  kernel. Expecting a different file/data structure than /proc/iomem
+ * to look into down the line. May be something like /proc/kernelmem or may
+ * be zone data structures exported from kernel.
+ */
+static int get_crash_memory_ranges(struct memory_range **range, int *ranges)
+{
+	const char iomem[] = "/proc/iomem";
+	int i, memory_ranges = 0;
+	char line[MAX_LINE];
+	FILE *fp;
+	unsigned long long start, end;
+
+	fp = fopen(iomem, "r");
+	if (!fp) {
+		fprintf(stderr, "Cannot open %s: %s\n",
+			iomem, strerror(errno));
+		return -1;
+	}
+	/* Separate segment for backup region */
+	crash_memory_range[0].start = BACKUP_SRC_START;
+	crash_memory_range[0].end = BACKUP_SRC_END;
+	crash_memory_range[0].type = RANGE_RAM;
+	memory_ranges++;
+
+	while (fgets(line, sizeof(line), fp) != 0) {
+		char *str;
+		int type, consumed, count;
+		if (memory_ranges >= CRASH_MAX_MEMORY_RANGES)
+			break;
+		count = sscanf(line, "%Lx-%Lx : %n",
+			&start, &end, &consumed);
+		if (count != 2)
+			continue;
+		str = line + consumed;
+
+		/* Only Dumping memory of type System RAM. */
+		if (memcmp(str, "System RAM\n", 11) == 0) {
+			type = RANGE_RAM;
+		} else if (memcmp(str, "Crash kernel\n", 13) == 0) {
+				/* Reserved memory region. New kernel can
+				 * use this region to boot into. */
+				crash_reserved_mem.start = start;
+				crash_reserved_mem.end = end;
+				crash_reserved_mem.type = RANGE_RAM;
+				continue;
+		} else
+			continue;
+
+		if (start == BACKUP_SRC_START && end >= (BACKUP_SRC_END + 1))
+			start = BACKUP_SRC_END + 1;
+
+		crash_memory_range[memory_ranges].start = start;
+		crash_memory_range[memory_ranges].end = end;
+		crash_memory_range[memory_ranges].type = type;
+		memory_ranges++;
+
+		/* Segregate linearly mapped region. */
+		if ((MAXMEM - 1) >= start && (MAXMEM - 1) <= end) {
+			crash_memory_range[memory_ranges - 1].end = MAXMEM - 1;
+
+			/* Add segregated region. */
+			crash_memory_range[memory_ranges].start = MAXMEM;
+			crash_memory_range[memory_ranges].end = end;
+			crash_memory_range[memory_ranges].type = type;
+			memory_ranges++;
+		}
+	}
+	fclose(fp);
+
+	if (exclude_crash_reserve_region(&memory_ranges) < 0)
+		return -1;
+
+	for (i = 0; i < memory_ranges; i++)
+		if (saved_max_mem < crash_memory_range[i].end)
+			saved_max_mem = crash_memory_range[i].end + 1;
+
+	*range = crash_memory_range;
+	*ranges = memory_ranges;
+	return 0;
+}
+
+/* Converts unsigned long to ascii string. */
+static void ultoa(unsigned long i, char *str)
+{
+	int j = 0, k;
+	char tmp;
+
+	do {
+		str[j++] = i % 10 + '0';
+	} while ((i /= 10) > 0);
+	str[j] = '\0';
+
+	/* Reverse the string. */
+	for (j = 0, k = strlen(str) - 1; j < k; j++, k--) {
+		tmp = str[k];
+		str[k] = str[j];
+		str[j] = tmp;
+	}
+}
+
+/* Adds the appropriate mem= options to command line, indicating the
+ * memory region the new kernel can use to boot into. */
+static int cmdline_add_mem(char *cmdline, unsigned long addr,
+		unsigned long size)
+{
+	int cmdlen, len;
+	char str[50], *ptr;
+
+	addr = addr/1024;
+	size = size/1024;
+	ptr = str;
+	strcpy(str, " mem=");
+	ptr += strlen(str);
+	ultoa(size, ptr);
+	strcat(str, "K@");
+	ptr = str + strlen(str);
+	ultoa(addr, ptr);
+	strcat(str, "K");
+	len = strlen(str);
+	cmdlen = strlen(cmdline) + len;
+	if (cmdlen > (COMMAND_LINE_SIZE - 1))
+		die("Command line overflow\n");
+	strcat(cmdline, str);
+
+	return 0;
+}
+
+/* Adds the elfcorehdr= command line parameter to command line. */
+static int cmdline_add_elfcorehdr(char *cmdline, unsigned long addr)
+{
+	int cmdlen, len, align = 1024;
+	char str[30], *ptr;
+
+	/* Passing in elfcorehdr=xxxK format. Saves space required in cmdline.
+	 * Ensure 1K alignment*/
+	if (addr%align)
+		return -1;
+	addr = addr/align;
+	ptr = str;
+	strcpy(str, " elfcorehdr=");
+	ptr += strlen(str);
+	ultoa(addr, ptr);
+	strcat(str, "K");
+	len = strlen(str);
+	cmdlen = strlen(cmdline) + len;
+	if (cmdlen > (COMMAND_LINE_SIZE - 1))
+		die("Command line overflow\n");
+	strcat(cmdline, str);
+	return 0;
+}
+
+/* Adds the savemaxmem= command line parameter to command line. */
+static int cmdline_add_savemaxmem(char *cmdline, unsigned long long addr)
+{
+	int cmdlen, len, align = 1024;
+	char str[30], *ptr;
+
+	/* Passing in savemaxmem=xxxM format. Saves space required in cmdline.*/
+	addr = addr/(align*align);
+	ptr = str;
+	strcpy(str, " savemaxmem=");
+	ptr += strlen(str);
+	ultoa(addr, ptr);
+	strcat(str, "M");
+	len = strlen(str);
+	cmdlen = strlen(cmdline) + len;
+	if (cmdlen > (COMMAND_LINE_SIZE - 1))
+		die("Command line overflow\n");
+	strcat(cmdline, str);
+	return 0;
+}
+
+#ifdef __mips64
+static struct crash_elf_info elf_info64 = {
+	class: ELFCLASS64,
+	data : ELFDATA2MSB,
+	machine : EM_MIPS,
+	backup_src_start : BACKUP_SRC_START,
+	backup_src_end : BACKUP_SRC_END,
+	page_offset : PAGE_OFFSET,
+	lowmem_limit : MAXMEM,
+};
+#endif
+static struct crash_elf_info elf_info32 = {
+	class: ELFCLASS32,
+	data : ELFDATA2MSB,
+	machine : EM_MIPS,
+	backup_src_start : BACKUP_SRC_START,
+	backup_src_end : BACKUP_SRC_END,
+	page_offset : PAGE_OFFSET,
+	lowmem_limit : MAXMEM,
+};
+
+/* Loads additional segments in case of a panic kernel is being loaded.
+ * One segment for backup region, another segment for storing elf headers
+ * for crash memory image.
+ */
+int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
+				unsigned long UNUSED(max_addr),
+				unsigned long UNUSED(min_base))
+{
+	void *tmp;
+	unsigned long sz, elfcorehdr;
+	int nr_ranges, align = 1024;
+	struct memory_range *mem_range;
+
+	if (get_crash_memory_ranges(&mem_range, &nr_ranges) < 0)
+		return -1;
+
+	/* Create a backup region segment to store backup data*/
+	sz = (BACKUP_SRC_SIZE + align - 1) & ~(align - 1);
+	tmp = xmalloc(sz);
+	memset(tmp, 0, sz);
+	info->backup_start = add_buffer(info, tmp, sz, sz, align,
+				crash_reserved_mem.start,
+				crash_reserved_mem.end, -1);
+
+#ifdef __mips64
+	/* Create elf header segment and store crash image data. */
+	if (arch_options.core_header_type == CORE_TYPE_ELF64) {
+		if (crash_create_elf64_headers(info, &elf_info64,
+			crash_memory_range, nr_ranges,
+			&tmp, &sz,
+			ELF_CORE_HEADER_ALIGN) < 0)
+			return -1;
+	} else {
+		if (crash_create_elf32_headers(info, &elf_info32,
+			crash_memory_range, nr_ranges,
+			&tmp, &sz,
+			ELF_CORE_HEADER_ALIGN) < 0)
+			return -1;
+	}
+#else
+	if (crash_create_elf32_headers(info, &elf_info32,
+		crash_memory_range, nr_ranges,
+		&tmp, &sz,
+		ELF_CORE_HEADER_ALIGN) < 0)
+		return -1;
+#endif
+	elfcorehdr = add_buffer(info, tmp, sz, sz, align,
+		crash_reserved_mem.start,
+		crash_reserved_mem.end, -1);
+
+	/*
+	 * backup segment is after elfcorehdr, so use elfcorehdr as top of
+	 * kernel's available memory
+	 */
+	cmdline_add_mem(mod_cmdline, crash_reserved_mem.start,
+		elfcorehdr - crash_reserved_mem.start);
+	cmdline_add_elfcorehdr(mod_cmdline, elfcorehdr);
+	cmdline_add_savemaxmem(mod_cmdline, saved_max_mem);
+
+#ifdef DEBUG
+	printf("CRASH MEMORY RANGES:\n");
+	printf("%016Lx-%016Lx\n", crash_reserved_mem.start,
+			crash_reserved_mem.end);
+#endif
+	return 0;
+}
+
+int is_crashkernel_mem_reserved(void)
+{
+	uint64_t start, end;
+
+	return parse_iomem_single("Crash kernel\n", &start, &end) == 0 ?
+		(start != end) : 0;
+}
+