s390/mem_detect: remove artificial kdump memory types

Simplify the memory detection code a bit by removing the CHUNK_OLDMEM
and CHUNK_CRASHK memory types.
They are not needed. Everything that is needed is a mechanism to
insert holes into the detected memory.

Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/setup.h

@@ -33,8 +33,6 @@
 
 #define CHUNK_READ_WRITE 0
 #define CHUNK_READ_ONLY  1
-#define CHUNK_OLDMEM	 4
-#define CHUNK_CRASHK	 5
 
 struct mem_chunk {
 	unsigned long addr;
@@ -47,8 +45,8 @@ extern int memory_end_set;
 extern unsigned long memory_end;
 
 void detect_memory_layout(struct mem_chunk chunk[], unsigned long maxsize);
-void create_mem_hole(struct mem_chunk memory_chunk[], unsigned long addr,
-		     unsigned long size, int type);
+void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr,
+		     unsigned long size);
 
 #define PRIMARY_SPACE_MODE	0
 #define ACCESS_REGISTER_MODE	1

arch/s390/kernel/crash_dump.c

@@ -89,7 +89,7 @@ static struct mem_chunk *get_memory_layout(void)
 
 	chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk));
 	detect_memory_layout(chunk_array, 0);
-	create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE, CHUNK_CRASHK);
+	create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE);
 	return chunk_array;
 }
 
@@ -344,7 +344,7 @@ static int loads_init(Elf64_Phdr *phdr, u64 loads_offset)
 	for (i = 0; i < MEMORY_CHUNKS; i++) {
 		mem_chunk = &chunk_array[i];
 		if (mem_chunk->size == 0)
-			break;
+			continue;
 		if (chunk_array[i].type != CHUNK_READ_WRITE &&
 		    chunk_array[i].type != CHUNK_READ_ONLY)
 			continue;

arch/s390/kernel/setup.c

@@ -463,14 +463,10 @@ static void __init setup_resources(void)
 	for (i = 0; i < MEMORY_CHUNKS; i++) {
 		if (!memory_chunk[i].size)
 			continue;
-		if (memory_chunk[i].type == CHUNK_OLDMEM ||
-		    memory_chunk[i].type == CHUNK_CRASHK)
-			continue;
 		res = alloc_bootmem_low(sizeof(*res));
 		res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
 		switch (memory_chunk[i].type) {
 		case CHUNK_READ_WRITE:
-		case CHUNK_CRASHK:
 			res->name = "System RAM";
 			break;
 		case CHUNK_READ_ONLY:
@@ -527,7 +523,7 @@ static void __init setup_memory_end(void)
 		unsigned long align;
 
 		chunk = &memory_chunk[i];
-		if (chunk->type == CHUNK_OLDMEM)
+		if (!chunk->size)
 			continue;
 		align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
 		start = (chunk->addr + align - 1) & ~(align - 1);
@@ -579,7 +575,7 @@ static void __init setup_memory_end(void)
 	for (i = 0; i < MEMORY_CHUNKS; i++) {
 		struct mem_chunk *chunk = &memory_chunk[i];
 
-		if (chunk->type == CHUNK_OLDMEM)
+		if (!chunk->size)
 			continue;
 		if (chunk->addr >= memory_end) {
 			memset(chunk, 0, sizeof(*chunk));
@@ -680,15 +676,6 @@ static int __init verify_crash_base(unsigned long crash_base,
 	return -EINVAL;
 }
 
-/*
- * Reserve kdump memory by creating a memory hole in the mem_chunk array
- */
-static void __init reserve_kdump_bootmem(unsigned long addr, unsigned long size,
-					 int type)
-{
-	create_mem_hole(memory_chunk, addr, size, type);
-}
-
 /*
  * When kdump is enabled, we have to ensure that no memory from
  * the area [0 - crashkernel memory size] and
@@ -730,8 +717,8 @@ static void reserve_oldmem(void)
 
 		real_size = max(real_size, chunk->addr + chunk->size);
 	}
-	reserve_kdump_bootmem(OLDMEM_BASE, OLDMEM_SIZE, CHUNK_OLDMEM);
-	reserve_kdump_bootmem(OLDMEM_SIZE, real_size - OLDMEM_SIZE, CHUNK_OLDMEM);
+	create_mem_hole(memory_chunk, OLDMEM_BASE, OLDMEM_SIZE);
+	create_mem_hole(memory_chunk, OLDMEM_SIZE, real_size - OLDMEM_SIZE);
 	if (OLDMEM_BASE + OLDMEM_SIZE == real_size)
 		saved_max_pfn = PFN_DOWN(OLDMEM_BASE) - 1;
 	else
@@ -774,7 +761,7 @@ static void __init reserve_crashkernel(void)
 	crashk_res.start = crash_base;
 	crashk_res.end = crash_base + crash_size - 1;
 	insert_resource(&iomem_resource, &crashk_res);
-	reserve_kdump_bootmem(crash_base, crash_size, CHUNK_CRASHK);
+	create_mem_hole(memory_chunk, crash_base, crash_size);
 	pr_info("Reserving %lluMB of memory at %lluMB "
 		"for crashkernel (System RAM: %luMB)\n",
 		crash_size >> 20, crash_base >> 20, memory_end >> 20);
@@ -846,11 +833,10 @@ static void __init setup_memory(void)
 	 * Register RAM areas with the bootmem allocator.
 	 */
 
-	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
+	for (i = 0; i < MEMORY_CHUNKS; i++) {
 		unsigned long start_chunk, end_chunk, pfn;
 
-		if (memory_chunk[i].type != CHUNK_READ_WRITE &&
-		    memory_chunk[i].type != CHUNK_CRASHK)
+		if (!memory_chunk[i].size)
 			continue;
 		start_chunk = PFN_DOWN(memory_chunk[i].addr);
 		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);

arch/s390/mm/mem_detect.c

@@ -95,82 +95,40 @@ out:
 EXPORT_SYMBOL(detect_memory_layout);
 
 /*
- * Move memory chunks array from index "from" to index "to"
+ * Create memory hole with given address and size.
  */
-static void mem_chunk_move(struct mem_chunk chunk[], int to, int from)
+void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr,
+		     unsigned long size)
 {
-	int cnt = MEMORY_CHUNKS - to;
-
-	memmove(&chunk[to], &chunk[from], cnt * sizeof(struct mem_chunk));
-}
-
-/*
- * Initialize memory chunk
- */
-static void mem_chunk_init(struct mem_chunk *chunk, unsigned long addr,
-			   unsigned long size, int type)
-{
-	chunk->type = type;
-	chunk->addr = addr;
-	chunk->size = size;
-}
-
-/*
- * Create memory hole with given address, size, and type
- */
-void create_mem_hole(struct mem_chunk chunk[], unsigned long addr,
-		     unsigned long size, int type)
-{
-	unsigned long lh_start, lh_end, lh_size, ch_start, ch_end, ch_size;
-	int i, ch_type;
+	int i;
 
 	for (i = 0; i < MEMORY_CHUNKS; i++) {
-		if (chunk[i].size == 0)
-			continue;
-
-		/* Define chunk properties */
-		ch_start = chunk[i].addr;
-		ch_size = chunk[i].size;
-		ch_end = ch_start + ch_size - 1;
-		ch_type = chunk[i].type;
-
-		/* Is memory chunk hit by memory hole? */
-		if (addr + size <= ch_start)
-			continue; /* No: memory hole in front of chunk */
-		if (addr > ch_end)
-			continue; /* No: memory hole after chunk */
+		struct mem_chunk *chunk = &mem_chunk[i];
 
-		/* Yes: Define local hole properties */
-		lh_start = max(addr, chunk[i].addr);
-		lh_end = min(addr + size - 1, ch_end);
-		lh_size = lh_end - lh_start + 1;
+		if (chunk->size == 0)
+			continue;
+		if (addr > chunk->addr + chunk->size)
+			continue;
+		if (addr + size <= chunk->addr)
+			continue;
+		/* Split */
+		if ((addr > chunk->addr) &&
+		    (addr + size < chunk->addr + chunk->size)) {
+			struct mem_chunk *new = chunk + 1;
 
-		if (lh_start == ch_start && lh_end == ch_end) {
-			/* Hole covers complete memory chunk */
-			mem_chunk_init(&chunk[i], lh_start, lh_size, type);
-		} else if (lh_end == ch_end) {
-			/* Hole starts in memory chunk and convers chunk end */
-			mem_chunk_move(chunk, i + 1, i);
-			mem_chunk_init(&chunk[i], ch_start, ch_size - lh_size,
-				       ch_type);
-			mem_chunk_init(&chunk[i + 1], lh_start, lh_size, type);
-			i += 1;
-		} else if (lh_start == ch_start) {
-			/* Hole ends in memory chunk */
-			mem_chunk_move(chunk, i + 1, i);
-			mem_chunk_init(&chunk[i], lh_start, lh_size, type);
-			mem_chunk_init(&chunk[i + 1], lh_end + 1,
-				       ch_size - lh_size, ch_type);
-			break;
-		} else {
-			/* Hole splits memory chunk */
-			mem_chunk_move(chunk, i + 2, i);
-			mem_chunk_init(&chunk[i], ch_start,
-				       lh_start - ch_start, ch_type);
-			mem_chunk_init(&chunk[i + 1], lh_start, lh_size, type);
-			mem_chunk_init(&chunk[i + 2], lh_end + 1,
-				       ch_end - lh_end, ch_type);
-			break;
+			memmove(new, chunk, (MEMORY_CHUNKS-i-1) * sizeof(*new));
+			new->addr = addr + size;
+			new->size = chunk->addr + chunk->size - new->addr;
+			chunk->size = addr - chunk->addr;
+			continue;
+		} else if ((addr <= chunk->addr) &&
+			   (addr + size >= chunk->addr + chunk->size)) {
+			memset(chunk, 0 , sizeof(*chunk));
+		} else if (addr + size < chunk->addr + chunk->size) {
+			chunk->size =  chunk->addr + chunk->size - addr - size;
+			chunk->addr = addr + size;
+		} else if (addr > chunk->addr) {
+			chunk->size = addr - chunk->addr;
 		}
 	}
 }

arch/s390/mm/vmem.c

@@ -375,9 +375,8 @@ void __init vmem_map_init(void)
 
 	ro_start = PFN_ALIGN((unsigned long)&_stext);
 	ro_end = (unsigned long)&_eshared & PAGE_MASK;
-	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
-		if (memory_chunk[i].type == CHUNK_CRASHK ||
-		    memory_chunk[i].type == CHUNK_OLDMEM)
+	for (i = 0; i < MEMORY_CHUNKS; i++) {
+		if (!memory_chunk[i].size)
 			continue;
 		start = memory_chunk[i].addr;
 		end = memory_chunk[i].addr + memory_chunk[i].size;
@@ -412,9 +411,6 @@ static int __init vmem_convert_memory_chunk(void)
 	for (i = 0; i < MEMORY_CHUNKS; i++) {
 		if (!memory_chunk[i].size)
 			continue;
-		if (memory_chunk[i].type == CHUNK_CRASHK ||
-		    memory_chunk[i].type == CHUNK_OLDMEM)
-			continue;
 		seg = kzalloc(sizeof(*seg), GFP_KERNEL);
 		if (!seg)
 			panic("Out of memory...\n");