powerpc/fadump: make crash memory ranges array allocation generic

Make allocate_crash_memory_ranges() and free_crash_memory_ranges()
functions generic to reuse them for memory management of all types of
dynamic memory range arrays. This change helps in memory management
of reserved ranges array to be added later.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821369863.5656.4375667005352155892.stgit@hbathini.in.ibm.com

arch/powerpc/include/asm/fadump-internal.h

@@ -72,9 +72,18 @@ struct fadump_crash_info_header {
 	struct cpumask	online_mask;
 };
 
-struct fad_crash_memory_ranges {
-	unsigned long long	base;
-	unsigned long long	size;
+struct fadump_memory_range {
+	u64	base;
+	u64	size;
+};
+
+/* fadump memory ranges info */
+struct fadump_mrange_info {
+	char				name[16];
+	struct fadump_memory_range	*mem_ranges;
+	u32				mem_ranges_sz;
+	u32				mem_range_cnt;
+	u32				max_mem_ranges;
 };
 
 /* Platform specific callback functions */

arch/powerpc/kernel/fadump.c

@@ -35,10 +35,7 @@
 static struct fw_dump fw_dump;
 
 static DEFINE_MUTEX(fadump_mutex);
-struct fad_crash_memory_ranges *crash_memory_ranges;
-int crash_memory_ranges_size;
-int crash_mem_ranges;
-int max_crash_mem_ranges;
+struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0 };
 
 #ifdef CONFIG_CMA
 static struct cma *fadump_cma;
@@ -629,46 +626,48 @@ void fadump_free_cpu_notes_buf(void)
 	fw_dump.cpu_notes_buf_size = 0;
 }
 
-static void free_crash_memory_ranges(void)
+static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
 {
-	kfree(crash_memory_ranges);
-	crash_memory_ranges = NULL;
-	crash_memory_ranges_size = 0;
-	max_crash_mem_ranges = 0;
+	kfree(mrange_info->mem_ranges);
+	mrange_info->mem_ranges = NULL;
+	mrange_info->mem_ranges_sz = 0;
+	mrange_info->max_mem_ranges = 0;
 }
 
 /*
- * Allocate or reallocate crash memory ranges array in incremental units
+ * Allocate or reallocate mem_ranges array in incremental units
  * of PAGE_SIZE.
  */
-static int allocate_crash_memory_ranges(void)
+static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
 {
-	struct fad_crash_memory_ranges *new_array;
+	struct fadump_memory_range *new_array;
 	u64 new_size;
 
-	new_size = crash_memory_ranges_size + PAGE_SIZE;
-	pr_debug("Allocating %llu bytes of memory for crash memory ranges\n",
-		 new_size);
+	new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
+	pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
+		 new_size, mrange_info->name);
 
-	new_array = krealloc(crash_memory_ranges, new_size, GFP_KERNEL);
+	new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
 	if (new_array == NULL) {
-		pr_err("Insufficient memory for setting up crash memory ranges\n");
-		free_crash_memory_ranges();
+		pr_err("Insufficient memory for setting up %s memory ranges\n",
+		       mrange_info->name);
+		fadump_free_mem_ranges(mrange_info);
 		return -ENOMEM;
 	}
 
-	crash_memory_ranges = new_array;
-	crash_memory_ranges_size = new_size;
-	max_crash_mem_ranges = (new_size /
-				sizeof(struct fad_crash_memory_ranges));
+	mrange_info->mem_ranges = new_array;
+	mrange_info->mem_ranges_sz = new_size;
+	mrange_info->max_mem_ranges = (new_size /
+				       sizeof(struct fadump_memory_range));
 	return 0;
 }
 
-static inline int fadump_add_crash_memory(unsigned long long base,
-					  unsigned long long end)
+static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
+				       u64 base, u64 end)
 {
-	u64  start, size;
+	struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
 	bool is_adjacent = false;
+	u64 start, size;
 
 	if (base == end)
 		return 0;
@@ -677,38 +676,41 @@ static inline int fadump_add_crash_memory(unsigned long long base,
 	 * Fold adjacent memory ranges to bring down the memory ranges/
 	 * PT_LOAD segments count.
 	 */
-	if (crash_mem_ranges) {
-		start = crash_memory_ranges[crash_mem_ranges - 1].base;
-		size = crash_memory_ranges[crash_mem_ranges - 1].size;
+	if (mrange_info->mem_range_cnt) {
+		start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
+		size  = mem_ranges[mrange_info->mem_range_cnt - 1].size;
 
 		if ((start + size) == base)
 			is_adjacent = true;
 	}
 	if (!is_adjacent) {
 		/* resize the array on reaching the limit */
-		if (crash_mem_ranges == max_crash_mem_ranges) {
+		if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
 			int ret;
 
-			ret = allocate_crash_memory_ranges();
+			ret = fadump_alloc_mem_ranges(mrange_info);
 			if (ret)
 				return ret;
+
+			/* Update to the new resized array */
+			mem_ranges = mrange_info->mem_ranges;
 		}
 
 		start = base;
-		crash_memory_ranges[crash_mem_ranges].base = start;
-		crash_mem_ranges++;
+		mem_ranges[mrange_info->mem_range_cnt].base = start;
+		mrange_info->mem_range_cnt++;
 	}
 
-	crash_memory_ranges[crash_mem_ranges - 1].size = (end - start);
-	pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
-		(crash_mem_ranges - 1), start, end - 1, (end - start));
+	mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
+	pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
+		 mrange_info->name, (mrange_info->mem_range_cnt - 1),
+		 start, end - 1, (end - start));
 	return 0;
 }
 
-static int fadump_exclude_reserved_area(unsigned long long start,
-					unsigned long long end)
+static int fadump_exclude_reserved_area(u64 start, u64 end)
 {
-	unsigned long long ra_start, ra_end;
+	u64 ra_start, ra_end;
 	int ret = 0;
 
 	ra_start = fw_dump.reserve_dump_area_start;
@@ -716,18 +718,22 @@ static int fadump_exclude_reserved_area(unsigned long long start,
 
 	if ((ra_start < end) && (ra_end > start)) {
 		if ((start < ra_start) && (end > ra_end)) {
-			ret = fadump_add_crash_memory(start, ra_start);
+			ret = fadump_add_mem_range(&crash_mrange_info,
+						   start, ra_start);
 			if (ret)
 				return ret;
 
-			ret = fadump_add_crash_memory(ra_end, end);
+			ret = fadump_add_mem_range(&crash_mrange_info,
+						   ra_end, end);
 		} else if (start < ra_start) {
-			ret = fadump_add_crash_memory(start, ra_start);
+			ret = fadump_add_mem_range(&crash_mrange_info,
+						   start, ra_start);
 		} else if (ra_end < end) {
-			ret = fadump_add_crash_memory(ra_end, end);
+			ret = fadump_add_mem_range(&crash_mrange_info,
+						   ra_end, end);
 		}
 	} else
-		ret = fadump_add_crash_memory(start, end);
+		ret = fadump_add_mem_range(&crash_mrange_info, start, end);
 
 	return ret;
 }
@@ -772,11 +778,11 @@ static int fadump_init_elfcore_header(char *bufp)
 static int fadump_setup_crash_memory_ranges(void)
 {
 	struct memblock_region *reg;
-	unsigned long long start, end;
+	u64 start, end;
 	int ret;
 
 	pr_debug("Setup crash memory ranges.\n");
-	crash_mem_ranges = 0;
+	crash_mrange_info.mem_range_cnt = 0;
 
 	/*
 	 * add the first memory chunk (RMA_START through boot_memory_size) as
@@ -785,13 +791,14 @@ static int fadump_setup_crash_memory_ranges(void)
 	 * specified during fadump registration. We need to create a separate
 	 * program header for this chunk with the correct offset.
 	 */
-	ret = fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
+	ret = fadump_add_mem_range(&crash_mrange_info,
+				   RMA_START, fw_dump.boot_memory_size);
 	if (ret)
 		return ret;
 
 	for_each_memblock(memory, reg) {
-		start = (unsigned long long)reg->base;
-		end = start + (unsigned long long)reg->size;
+		start = (u64)reg->base;
+		end = start + (u64)reg->size;
 
 		/*
 		 * skip the first memory chunk that is already added (RMA_START
@@ -876,11 +883,11 @@ static int fadump_create_elfcore_headers(char *bufp)
 
 	/* setup PT_LOAD sections. */
 
-	for (i = 0; i < crash_mem_ranges; i++) {
-		unsigned long long mbase, msize;
-		mbase = crash_memory_ranges[i].base;
-		msize = crash_memory_ranges[i].size;
+	for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
+		u64 mbase, msize;
 
+		mbase = crash_mrange_info.mem_ranges[i].base;
+		msize = crash_mrange_info.mem_ranges[i].size;
 		if (!msize)
 			continue;
 
@@ -973,7 +980,7 @@ void fadump_cleanup(void)
 	} else if (fw_dump.dump_registered) {
 		/* Un-register Firmware-assisted dump if it was registered. */
 		fw_dump.ops->fadump_unregister(&fw_dump);
-		free_crash_memory_ranges();
+		fadump_free_mem_ranges(&crash_mrange_info);
 	}
 
 	if (fw_dump.ops->fadump_cleanup)