[PATCH v5 22/31] powerpc/fadump: make crash memory ranges array allocation generic

[Hari Bathini <hbathini@linux.ibm.com>]

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>
---
 arch/powerpc/kernel/fadump-common.h |   11 ++++
 arch/powerpc/kernel/fadump.c        |   99 +++++++++++++++++++----------------
 2 files changed, 64 insertions(+), 46 deletions(-)

diff --git a/arch/powerpc/kernel/fadump-common.h b/arch/powerpc/kernel/fadump-common.h
index fc408b0..d1ff5b2 100644
--- a/arch/powerpc/kernel/fadump-common.h
+++ b/arch/powerpc/kernel/fadump-common.h
@@ -83,11 +83,20 @@ struct fadump_crash_info_header {
 	struct cpumask	online_mask;
 };
 
-struct fad_crash_memory_ranges {
+struct fadump_memory_range {
 	unsigned long long	base;
 	unsigned long long	size;
 };
 
+/* fadump memory ranges info */
+struct fadump_mrange_info {
+	char				name[16];
+	struct fadump_memory_range	*mem_ranges;
+	int				mem_ranges_sz;
+	int				mem_range_cnt;
+	int				max_mem_ranges;
+};
+
 /* Platform specific callback functions */
 struct fadump_ops;
 
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 8dd2dcc..2dd4621 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -36,10 +36,7 @@
 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;
@@ -487,46 +484,49 @@ void crash_fadump(struct pt_regs *regs, const char *str)
 	fw_dump.ops->fadump_trigger(fdh, str);
 }
 
-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,
+				       unsigned long long base,
+				       unsigned long long end)
 {
 	u64  start, size;
 	bool is_adjacent = false;
+	struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
 
 	if (base == end)
 		return 0;
@@ -535,31 +535,35 @@ 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;
 }
 
@@ -574,18 +578,22 @@ 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;
 }
@@ -634,7 +642,7 @@ static int fadump_setup_crash_memory_ranges(void)
 	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
@@ -643,7 +651,8 @@ 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;
 
@@ -734,10 +743,10 @@ static int fadump_create_elfcore_headers(char *bufp)
 
 	/* setup PT_LOAD sections. */
 
-	for (i = 0; i < crash_mem_ranges; i++) {
+	for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
 		unsigned long long mbase, msize;
-		mbase = crash_memory_ranges[i].base;
-		msize = crash_memory_ranges[i].size;
+		mbase = crash_mrange_info.mem_ranges[i].base;
+		msize = crash_mrange_info.mem_ranges[i].size;
 
 		if (!msize)
 			continue;
@@ -828,7 +837,7 @@ 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);
 	}
 
 	fw_dump.ops->fadump_cleanup(&fw_dump);