1 files changed, 113 insertions, 42 deletions

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 59e60a9a9f5c..78ab9a6ee6ac 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -40,8 +40,17 @@ struct kobject *fadump_kobj;
 
 #ifndef CONFIG_PRESERVE_FA_DUMP
 static DEFINE_MUTEX(fadump_mutex);
-struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0 };
-struct fadump_mrange_info reserved_mrange_info = { "reserved", NULL, 0, 0, 0 };
+struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false };
+
+#define RESERVED_RNGS_SZ	16384 /* 16K - 128 entries */
+#define RESERVED_RNGS_CNT	(RESERVED_RNGS_SZ / \
+				 sizeof(struct fadump_memory_range))
+static struct fadump_memory_range rngs[RESERVED_RNGS_CNT];
+struct fadump_mrange_info reserved_mrange_info = { "reserved", rngs,
+						   RESERVED_RNGS_SZ, 0,
+						   RESERVED_RNGS_CNT, true };
+
+static void __init early_init_dt_scan_reserved_ranges(unsigned long node);
 
 #ifdef CONFIG_CMA
 static struct cma *fadump_cma;
@@ -110,6 +119,11 @@ static int __init fadump_cma_init(void) { return 1; }
 int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
 				      int depth, void *data)
 {
+	if (depth == 0) {
+		early_init_dt_scan_reserved_ranges(node);
+		return 0;
+	}
+
 	if (depth != 1)
 		return 0;
 
@@ -431,10 +445,72 @@ static int __init fadump_get_boot_mem_regions(void)
 	return ret;
 }
 
+/*
+ * Returns true, if the given range overlaps with reserved memory ranges
+ * starting at idx. Also, updates idx to index of overlapping memory range
+ * with the given memory range.
+ * False, otherwise.
+ */
+static bool overlaps_reserved_ranges(u64 base, u64 end, int *idx)
+{
+	bool ret = false;
+	int i;
+
+	for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) {
+		u64 rbase = reserved_mrange_info.mem_ranges[i].base;
+		u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size;
+
+		if (end <= rbase)
+			break;
+
+		if ((end > rbase) &&  (base < rend)) {
+			*idx = i;
+			ret = true;
+			break;
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Locate a suitable memory area to reserve memory for FADump. While at it,
+ * lookup reserved-ranges & avoid overlap with them, as they are used by F/W.
+ */
+static u64 __init fadump_locate_reserve_mem(u64 base, u64 size)
+{
+	struct fadump_memory_range *mrngs;
+	phys_addr_t mstart, mend;
+	int idx = 0;
+	u64 i, ret = 0;
+
+	mrngs = reserved_mrange_info.mem_ranges;
+	for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
+				&mstart, &mend, NULL) {
+		pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n",
+			 i, mstart, mend, base);
+
+		if (mstart > base)
+			base = PAGE_ALIGN(mstart);
+
+		while ((mend > base) && ((mend - base) >= size)) {
+			if (!overlaps_reserved_ranges(base, base+size, &idx)) {
+				ret = base;
+				goto out;
+			}
+
+			base = mrngs[idx].base + mrngs[idx].size;
+			base = PAGE_ALIGN(base);
+		}
+	}
+
+out:
+	return ret;
+}
+
 int __init fadump_reserve_mem(void)
 {
-	u64 base, size, mem_boundary, bootmem_min, align = PAGE_SIZE;
-	bool is_memblock_bottom_up = memblock_bottom_up();
+	u64 base, size, mem_boundary, bootmem_min;
 	int ret = 1;
 
 	if (!fw_dump.fadump_enabled)
@@ -455,9 +531,9 @@ int __init fadump_reserve_mem(void)
 			PAGE_ALIGN(fadump_calculate_reserve_size());
 #ifdef CONFIG_CMA
 		if (!fw_dump.nocma) {
-			align = FADUMP_CMA_ALIGNMENT;
 			fw_dump.boot_memory_size =
-				ALIGN(fw_dump.boot_memory_size, align);
+				ALIGN(fw_dump.boot_memory_size,
+				      FADUMP_CMA_ALIGNMENT);
 		}
 #endif
 
@@ -525,13 +601,9 @@ int __init fadump_reserve_mem(void)
 		 * Reserve memory at an offset closer to bottom of the RAM to
 		 * minimize the impact of memory hot-remove operation.
 		 */
-		memblock_set_bottom_up(true);
-		base = memblock_find_in_range(base, mem_boundary, size, align);
+		base = fadump_locate_reserve_mem(base, size);
 
-		/* Restore the previous allocation mode */
-		memblock_set_bottom_up(is_memblock_bottom_up);
-
-		if (!base) {
+		if (!base || (base + size > mem_boundary)) {
 			pr_err("Failed to find memory chunk for reservation!\n");
 			goto error_out;
 		}
@@ -728,10 +800,14 @@ void fadump_free_cpu_notes_buf(void)
 
 static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
 {
+	if (mrange_info->is_static) {
+		mrange_info->mem_range_cnt = 0;
+		return;
+	}
+
 	kfree(mrange_info->mem_ranges);
-	mrange_info->mem_ranges = NULL;
-	mrange_info->mem_ranges_sz = 0;
-	mrange_info->max_mem_ranges = 0;
+	memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0,
+	       (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ));
 }
 
 /*
@@ -788,6 +864,12 @@ static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
 		if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
 			int ret;
 
+			if (mrange_info->is_static) {
+				pr_err("Reached array size limit for %s memory ranges\n",
+				       mrange_info->name);
+				return -ENOSPC;
+			}
+
 			ret = fadump_alloc_mem_ranges(mrange_info);
 			if (ret)
 				return ret;
@@ -1204,20 +1286,19 @@ static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
  * Scan reserved-ranges to consider them while reserving/releasing
  * memory for FADump.
  */
-static inline int fadump_scan_reserved_mem_ranges(void)
+static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
 {
-	struct device_node *root;
 	const __be32 *prop;
 	int len, ret = -1;
 	unsigned long i;
 
-	root = of_find_node_by_path("/");
-	if (!root)
-		return ret;
+	/* reserved-ranges already scanned */
+	if (reserved_mrange_info.mem_range_cnt != 0)
+		return;
 
-	prop = of_get_property(root, "reserved-ranges", &len);
+	prop = of_get_flat_dt_prop(node, "reserved-ranges", &len);
 	if (!prop)
-		return ret;
+		return;
 
 	/*
 	 * Each reserved range is an (address,size) pair, 2 cells each,
@@ -1239,7 +1320,8 @@ static inline int fadump_scan_reserved_mem_ranges(void)
 		}
 	}
 
-	return ret;
+	/* Compact reserved ranges */
+	sort_and_merge_mem_ranges(&reserved_mrange_info);
 }
 
 /*
@@ -1253,32 +1335,21 @@ static void fadump_release_memory(u64 begin, u64 end)
 	u64 ra_start, ra_end, tstart;
 	int i, ret;
 
-	fadump_scan_reserved_mem_ranges();
-
 	ra_start = fw_dump.reserve_dump_area_start;
 	ra_end = ra_start + fw_dump.reserve_dump_area_size;
 
 	/*
-	 * Add reserved dump area to reserved ranges list
-	 * and exclude all these ranges while releasing memory.
+	 * If reserved ranges array limit is hit, overwrite the last reserved
+	 * memory range with reserved dump area to ensure it is excluded from
+	 * the memory being released (reused for next FADump registration).
 	 */
-	ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
-	if (ret != 0) {
-		/*
-		 * Not enough memory to setup reserved ranges but the system is
-		 * running shortage of memory. So, release all the memory except
-		 * Reserved dump area (reused for next fadump registration).
-		 */
-		if (begin < ra_end && end > ra_start) {
-			if (begin < ra_start)
-				fadump_release_reserved_area(begin, ra_start);
-			if (end > ra_end)
-				fadump_release_reserved_area(ra_end, end);
-		} else
-			fadump_release_reserved_area(begin, end);
+	if (reserved_mrange_info.mem_range_cnt ==
+	    reserved_mrange_info.max_mem_ranges)
+		reserved_mrange_info.mem_range_cnt--;
 
+	ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
+	if (ret != 0)
 		return;
-	}
 
 	/* Get the reserved ranges list in order first. */
 	sort_and_merge_mem_ranges(&reserved_mrange_info);