[PATCH 2/4] x86: Store memory ranges globally used for crash kernel to boot into

[WANG Chao <chaowang@redhat.com>]

Use these two variables to store the memory ranges and the number of
memory ranges for crash kernel to boot into:

struct memory_range crash_memory_range;
int crash_memory_range;

crash_memory_range also will store RANGE_RESERVED ranges which is
discarded previously, but will be filtered out when exactmap case.

These two variables are not static now, so can be used in other file
later.

Signed-off-by: WANG Chao <chaowang@redhat.com>
---
 kexec/arch/i386/crashdump-x86.c | 136 ++++++++++++++++++++++------------------
 kexec/arch/i386/crashdump-x86.h |   5 +-
 2 files changed, 79 insertions(+), 62 deletions(-)

diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
index 979c2bd..b2c2442 100644
--- a/kexec/arch/i386/crashdump-x86.c
+++ b/kexec/arch/i386/crashdump-x86.c
@@ -179,7 +179,8 @@ static int exclude_region(int *nr_ranges, uint64_t start, uint64_t end);
 
 /* 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];
+struct memory_range crash_memory_range[CRASH_MAX_MEMORY_RANGES];
+int crash_memory_ranges;
 
 /* Memory region reserved for storing panic kernel and other data. */
 #define CRASH_RESERVED_MEM_NR	8
@@ -201,7 +202,7 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
 				   int kexec_flags, unsigned long lowmem_limit)
 {
 	const char *iomem = proc_iomem();
-	int memory_ranges = 0, gart = 0, i;
+	int gart = 0, i;
 	char line[MAX_LINE];
 	FILE *fp;
 	unsigned long long start, end;
@@ -218,7 +219,7 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
 		char *str;
 		int type, consumed, count;
 
-		if (memory_ranges >= CRASH_MAX_MEMORY_RANGES)
+		if (crash_memory_ranges >= CRASH_MAX_MEMORY_RANGES)
 			break;
 		count = sscanf(line, "%Lx-%Lx : %n",
 			&start, &end, &consumed);
@@ -230,6 +231,8 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
 		/* Only Dumping memory of type System RAM. */
 		if (memcmp(str, "System RAM\n", 11) == 0) {
 			type = RANGE_RAM;
+		} else if (memcmp(str, "reserved\n", 9) == 0) {
+			type = RANGE_RESERVED;
 		} else if (memcmp(str, "ACPI Tables\n", 12) == 0) {
 			/*
 			 * ACPI Tables area need to be passed to new
@@ -250,17 +253,17 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
 			continue;
 		}
 
-		crash_memory_range[memory_ranges].start = start;
-		crash_memory_range[memory_ranges].end = end;
-		crash_memory_range[memory_ranges].type = type;
+		crash_memory_range[crash_memory_ranges].start = start;
+		crash_memory_range[crash_memory_ranges].end = end;
+		crash_memory_range[crash_memory_ranges].type = type;
 
-		segregate_lowmem_region(&memory_ranges, lowmem_limit);
+		segregate_lowmem_region(&crash_memory_ranges, lowmem_limit);
 
-		memory_ranges++;
+		crash_memory_ranges++;
 	}
 	fclose(fp);
 	if (kexec_flags & KEXEC_PRESERVE_CONTEXT) {
-		for (i = 0; i < memory_ranges; i++) {
+		for (i = 0; i < crash_memory_ranges; i++) {
 			if (crash_memory_range[i].end > 0x0009ffff) {
 				crash_reserved_mem[0].start = \
 					crash_memory_range[i].start;
@@ -278,17 +281,17 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
 	}
 
 	for (i = 0; i < crash_reserved_mem_nr; i++)
-		if (exclude_region(&memory_ranges, crash_reserved_mem[i].start,
+		if (exclude_region(&crash_memory_ranges, crash_reserved_mem[i].start,
 				crash_reserved_mem[i].end) < 0)
 			return -1;
 
 	if (gart) {
 		/* exclude GART region if the system has one */
-		if (exclude_region(&memory_ranges, gart_start, gart_end) < 0)
+		if (exclude_region(&crash_memory_ranges, gart_start, gart_end) < 0)
 			return -1;
 	}
 	*range = crash_memory_range;
-	*ranges = memory_ranges;
+	*ranges = crash_memory_ranges;
 
 	return 0;
 }
@@ -324,7 +327,7 @@ static int get_crash_memory_ranges_xen(struct memory_range **range,
 	}
 
 	*range = crash_memory_range;
-	*ranges = j;
+	*ranges = crash_memory_ranges = j;
 
 	qsort(*range, *ranges, sizeof(struct memory_range), compare_ranges);
 
@@ -417,8 +420,8 @@ static int exclude_region(int *nr_ranges, uint64_t start, uint64_t end)
 
 /* Adds a segment from list of memory regions which new kernel can use to
  * boot. Segment start and end should be aligned to 1K boundary. */
-static int add_memmap(struct memory_range *memmap_p, unsigned long long addr,
-								size_t size)
+static int add_memmap(struct memory_range *memmap_p, int *nr_range,
+					unsigned long long addr, size_t size)
 {
 	int i, j, nr_entries = 0, tidx = 0, align = 1024;
 	unsigned long long mstart, mend;
@@ -450,29 +453,23 @@ static int add_memmap(struct memory_range *memmap_p, unsigned long long addr,
 		else if (addr > mend)
 			tidx = i+1;
 	}
-		/* Insert the memory region. */
-		for (j = nr_entries-1; j >= tidx; j--)
-			memmap_p[j+1] = memmap_p[j];
-		memmap_p[tidx].start = addr;
-		memmap_p[tidx].end = addr + size - 1;
+	/* Insert the memory region. */
+	for (j = nr_entries-1; j >= tidx; j--)
+		memmap_p[j+1] = memmap_p[j];
+	memmap_p[tidx].start = addr;
+	memmap_p[tidx].end = addr + size - 1;
+	memmap_p[tidx].type = RANGE_RAM;
+	*nr_range = nr_entries + 1;
 
-	dbgprintf("Memmap after adding segment\n");
-	for (i = 0; i < CRASH_MAX_MEMMAP_NR;  i++) {
-		mstart = memmap_p[i].start;
-		mend = memmap_p[i].end;
-		if (mstart == 0 && mend == 0)
-			break;
-		dbgprintf("%016llx - %016llx\n",
-			mstart, mend);
-	}
+	dbgprint_mem_range("Memmap after adding segment", memmap_p, *nr_range);
 
 	return 0;
 }
 
 /* Removes a segment from list of memory regions which new kernel can use to
  * boot. Segment start and end should be aligned to 1K boundary. */
-static int delete_memmap(struct memory_range *memmap_p, unsigned long long addr,
-								size_t size)
+static int delete_memmap(struct memory_range *memmap_p, int *nr_range,
+					unsigned long long addr, size_t size)
 {
 	int i, j, nr_entries = 0, tidx = -1, operation = 0, align = 1024;
 	unsigned long long mstart, mend;
@@ -534,24 +531,17 @@ static int delete_memmap(struct memory_range *memmap_p, unsigned long long addr,
 		for (j = nr_entries-1; j > tidx; j--)
 			memmap_p[j+1] = memmap_p[j];
 		memmap_p[tidx+1] = temp_region;
+		*nr_range = nr_entries + 1;
 	}
 	if ((operation == -1) && tidx >=0) {
 		/* Delete the exact match memory region. */
 		for (j = i+1; j < CRASH_MAX_MEMMAP_NR; j++)
 			memmap_p[j-1] = memmap_p[j];
 		memmap_p[j-1].start = memmap_p[j-1].end = 0;
+		*nr_range = nr_entries - 1;
 	}
 
-	dbgprintf("Memmap after deleting segment\n");
-	for (i = 0; i < CRASH_MAX_MEMMAP_NR;  i++) {
-		mstart = memmap_p[i].start;
-		mend = memmap_p[i].end;
-		if (mstart == 0 && mend == 0) {
-			break;
-		}
-		dbgprintf("%016llx - %016llx\n",
-			mstart, mend);
-	}
+	dbgprint_mem_range("Memmap after deleting segment", memmap_p, *nr_range);
 
 	return 0;
 }
@@ -626,6 +616,9 @@ static int cmdline_add_memmap(char *cmdline, struct memory_range *memmap_p)
 			/* All regions traversed. */
 			break;
 
+		if (memmap_p[i].type != RANGE_RAM)
+			continue;
+
 		/* A region is not worth adding if region size < 100K. It eats
 		 * up precious command line length. */
 		if ((endk - startk) < min_sizek)
@@ -797,6 +790,25 @@ static void get_backup_area(struct kexec_info *info,
 	info->backup_src_size = BACKUP_SRC_END - BACKUP_SRC_START + 1;
 }
 
+static void exclude_ram(struct memory_range *mr, int *nr_mr)
+{
+	int ranges, i, j, m;
+
+	ranges = *nr_mr;
+	for (i = 0, j = 0; i < ranges; i++) {
+		if (mr[j].type == RANGE_RAM) {
+			dbgprintf("Remove RAM %016llx-%016llxx: (%d)\n", mr[j].start, mr[j].end, mr[j].type);
+			for (m = j; m < *nr_mr; m++)
+				mr[m] = mr[m+1];
+			(*nr_mr)--;
+		} else {
+			j++;
+		}
+	}
+
+	dbgprint_mem_range("After remove RAM", mr, *nr_mr);
+}
+
 /* 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.
@@ -807,7 +819,7 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 	void *tmp;
 	unsigned long sz, bufsz, memsz, elfcorehdr;
 	int nr_ranges = 0, align = 1024, i;
-	struct memory_range *mem_range, *memmap_p;
+	struct memory_range *mem_range;
 	struct crash_elf_info elf_info;
 	unsigned kexec_arch;
 
@@ -850,10 +862,7 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 
 	get_backup_area(info, mem_range, nr_ranges);
 
-	dbgprintf("CRASH MEMORY RANGES\n");
-
-	for(i = 0; i < nr_ranges; ++i)
-		dbgprintf("%016Lx-%016Lx\n", mem_range[i].start, mem_range[i].end);
+	dbgprint_mem_range("CRASH MEMORY RANGES", mem_range, nr_ranges);
 
 	/*
 	 * if the core type has not been set on command line, set it here
@@ -878,17 +887,6 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 	if (get_kernel_vaddr_and_size(info, &elf_info))
 		return -1;
 
-	/* Memory regions which panic kernel can safely use to boot into */
-	sz = (sizeof(struct memory_range) * CRASH_MAX_MEMMAP_NR);
-	memmap_p = xmalloc(sz);
-	memset(memmap_p, 0, sz);
-	add_memmap(memmap_p, info->backup_src_start, info->backup_src_size);
-	for (i = 0; i < crash_reserved_mem_nr; i++) {
-		sz = crash_reserved_mem[i].end - crash_reserved_mem[i].start +1;
-		if (add_memmap(memmap_p, crash_reserved_mem[i].start, sz) < 0)
-			return ENOCRASHKERNEL;
-	}
-
 	/* Create a backup region segment to store backup data*/
 	if (!(info->kexec_flags & KEXEC_PRESERVE_CONTEXT)) {
 		sz = _ALIGN(info->backup_src_size, align);
@@ -898,8 +896,6 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 						0, max_addr, -1);
 		dbgprintf("Created backup segment at 0x%lx\n",
 			  info->backup_start);
-		if (delete_memmap(memmap_p, info->backup_start, sz) < 0)
-			return EFAILED;
 	}
 
 	/* Create elf header segment and store crash image data. */
@@ -915,6 +911,23 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 						ELF_CORE_HEADER_ALIGN) < 0)
 			return EFAILED;
 	}
+
+	/* Memory regions which panic kernel can safely use to boot into */
+	exclude_ram(crash_memory_range, &crash_memory_ranges);
+
+	add_memmap(crash_memory_range, &crash_memory_ranges, info->backup_src_start, info->backup_src_size);
+	for (i = 0; i < crash_reserved_mem_nr; i++) {
+		sz = crash_reserved_mem[i].end - crash_reserved_mem[i].start +1;
+		if (add_memmap(crash_memory_range, &crash_memory_ranges, crash_reserved_mem[i].start, sz) < 0)
+			return ENOCRASHKERNEL;
+	}
+
+	/* exclude backup region from crash dump memory range */
+	sz = _ALIGN(info->backup_src_size, align);
+	if (delete_memmap(crash_memory_range, &crash_memory_ranges, info->backup_start, sz) < 0) {
+		return EFAILED;
+	}
+
 	/* the size of the elf headers allocated is returned in 'bufsz' */
 
 	/* Hack: With some ld versions (GNU ld version 2.14.90.0.4 20030523),
@@ -934,9 +947,9 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 	elfcorehdr = add_buffer(info, tmp, bufsz, memsz, align, min_base,
 							max_addr, -1);
 	dbgprintf("Created elf header segment at 0x%lx\n", elfcorehdr);
-	if (delete_memmap(memmap_p, elfcorehdr, memsz) < 0)
+	if (delete_memmap(crash_memory_range, &crash_memory_ranges, elfcorehdr, memsz) < 0)
 		return -1;
-	cmdline_add_memmap(mod_cmdline, memmap_p);
+	cmdline_add_memmap(mod_cmdline, crash_memory_range);
 	if (!bzImage_support_efi_boot)
 		cmdline_add_efi(mod_cmdline);
 	cmdline_add_elfcorehdr(mod_cmdline, elfcorehdr);
@@ -951,6 +964,7 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 		end = mem_range[i].end;
 		cmdline_add_memmap_acpi(mod_cmdline, start, end);
 	}
+
 	return 0;
 }
 
diff --git a/kexec/arch/i386/crashdump-x86.h b/kexec/arch/i386/crashdump-x86.h
index b61cf0a..633ee0e 100644
--- a/kexec/arch/i386/crashdump-x86.h
+++ b/kexec/arch/i386/crashdump-x86.h
@@ -20,7 +20,7 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
 /* Kernel text size */
 #define X86_64_KERNEL_TEXT_SIZE  (512UL*1024*1024)
 
-#define CRASH_MAX_MEMMAP_NR	(KEXEC_MAX_SEGMENTS + 1)
+#define CRASH_MAX_MEMMAP_NR	CRASH_MAX_MEMORY_RANGES
 #define CRASH_MAX_MEMORY_RANGES	(MAX_MEMORY_RANGES + 2)
 
 /* Backup Region, First 640K of System RAM. */
@@ -28,4 +28,7 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
 #define BACKUP_SRC_END		0x0009ffff
 #define BACKUP_SRC_SIZE	(BACKUP_SRC_END - BACKUP_SRC_START + 1)
 
+extern struct memory_range crash_memory_range[CRASH_MAX_MEMORY_RANGES];
+extern int crash_memory_ranges;
+
 #endif /* CRASHDUMP_X86_H */
-- 
1.8.5.3


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