s390/mm: Convert bootmem to memblock

The original bootmem allocator is getting replaced by memblock. To
cover the needs of the s390 kdump implementation the physical memory
list is used.
With this patch the bootmem allocator and its bitmaps are completely
removed from s390.

Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 44 insertions, 116 deletions

diff --git a/arch/s390/mm/mem_detect.c b/arch/s390/mm/mem_detect.c
index cca388253a3..5535cfe0ee1 100644
--- a/arch/s390/mm/mem_detect.c
+++ b/arch/s390/mm/mem_detect.c
@@ -6,130 +6,60 @@
 
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/memblock.h>
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
 #include <asm/ipl.h>
 #include <asm/sclp.h>
 #include <asm/setup.h>
 
 #define ADDR2G (1ULL << 31)
 
-static void find_memory_chunks(struct mem_chunk chunk[], unsigned long maxsize)
+#define CHUNK_READ_WRITE 0
+#define CHUNK_READ_ONLY  1
+
+static inline void memblock_physmem_add(phys_addr_t start, phys_addr_t size)
+{
+	memblock_add_range(&memblock.memory, start, size, 0, 0);
+	memblock_add_range(&memblock.physmem, start, size, 0, 0);
+}
+
+void __init detect_memory_memblock(void)
 {
 	unsigned long long memsize, rnmax, rzm;
-	unsigned long addr = 0, size;
-	int i = 0, type;
+	unsigned long addr, size;
+	int type;
 
 	rzm = sclp_get_rzm();
 	rnmax = sclp_get_rnmax();
 	memsize = rzm * rnmax;
 	if (!rzm)
 		rzm = 1ULL << 17;
-	if (sizeof(long) == 4) {
+	if (IS_ENABLED(CONFIG_32BIT)) {
 		rzm = min(ADDR2G, rzm);
-		memsize = memsize ? min(ADDR2G, memsize) : ADDR2G;
+		memsize = min(ADDR2G, memsize);
 	}
-	if (maxsize)
-		memsize = memsize ? min((unsigned long)memsize, maxsize) : maxsize;
+	max_physmem_end = memsize;
+	addr = 0;
+	/* keep memblock lists close to the kernel */
+	memblock_set_bottom_up(true);
 	do {
 		size = 0;
 		type = tprot(addr);
 		do {
 			size += rzm;
-			if (memsize && addr + size >= memsize)
+			if (max_physmem_end && addr + size >= max_physmem_end)
 				break;
 		} while (type == tprot(addr + size));
 		if (type == CHUNK_READ_WRITE || type == CHUNK_READ_ONLY) {
-			if (memsize && (addr + size > memsize))
-				size = memsize - addr;
-			chunk[i].addr = addr;
-			chunk[i].size = size;
-			chunk[i].type = type;
-			i++;
+			if (max_physmem_end && (addr + size > max_physmem_end))
+				size = max_physmem_end - addr;
+			memblock_physmem_add(addr, size);
 		}
 		addr += size;
-	} while (addr < memsize && i < MEMORY_CHUNKS);
-}
-
-/**
- * detect_memory_layout - fill mem_chunk array with memory layout data
- * @chunk: mem_chunk array to be filled
- * @maxsize: maximum address where memory detection should stop
- *
- * Fills the passed in memory chunk array with the memory layout of the
- * machine. The array must have a size of at least MEMORY_CHUNKS and will
- * be fully initialized afterwards.
- * If the maxsize paramater has a value > 0 memory detection will stop at
- * that address. It is guaranteed that all chunks have an ending address
- * that is smaller than maxsize.
- * If maxsize is 0 all memory will be detected.
- */
-void detect_memory_layout(struct mem_chunk chunk[], unsigned long maxsize)
-{
-	unsigned long flags, flags_dat, cr0;
-
-	memset(chunk, 0, MEMORY_CHUNKS * sizeof(struct mem_chunk));
-	/*
-	 * Disable IRQs, DAT and low address protection so tprot does the
-	 * right thing and we don't get scheduled away with low address
-	 * protection disabled.
-	 */
-	local_irq_save(flags);
-	flags_dat = __arch_local_irq_stnsm(0xfb);
-	/*
-	 * In case DAT was enabled, make sure chunk doesn't reside in vmalloc
-	 * space. We have disabled DAT and any access to vmalloc area will
-	 * cause an exception.
-	 * If DAT was disabled we are called from early ipl code.
-	 */
-	if (test_bit(5, &flags_dat)) {
-		if (WARN_ON_ONCE(is_vmalloc_or_module_addr(chunk)))
-			goto out;
-	}
-	__ctl_store(cr0, 0, 0);
-	__ctl_clear_bit(0, 28);
-	find_memory_chunks(chunk, maxsize);
-	__ctl_load(cr0, 0, 0);
-out:
-	__arch_local_irq_ssm(flags_dat);
-	local_irq_restore(flags);
-}
-EXPORT_SYMBOL(detect_memory_layout);
-
-/*
- * Create memory hole with given address and size.
- */
-void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr,
-		     unsigned long size)
-{
-	int i;
-
-	for (i = 0; i < MEMORY_CHUNKS; i++) {
-		struct mem_chunk *chunk = &mem_chunk[i];
-
-		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;
-
-			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)) {
-			memmove(chunk, chunk + 1, (MEMORY_CHUNKS-i-1) * sizeof(*chunk));
-			memset(&mem_chunk[MEMORY_CHUNKS-1], 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;
-		}
-	}
+	} while (addr < max_physmem_end);
+	memblock_set_bottom_up(false);
+	if (!max_physmem_end)
+		max_physmem_end = memblock_end_of_DRAM();
 }
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 72b04de1828..fe9012a49aa 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -10,6 +10,7 @@
 #include <linux/list.h>
 #include <linux/hugetlb.h>
 #include <linux/slab.h>
+#include <linux/memblock.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 #include <asm/setup.h>
@@ -66,7 +67,8 @@ static pte_t __ref *vmem_pte_alloc(unsigned long address)
 	if (slab_is_available())
 		pte = (pte_t *) page_table_alloc(&init_mm, address);
 	else
-		pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
+		pte = alloc_bootmem_align(PTRS_PER_PTE * sizeof(pte_t),
+					  PTRS_PER_PTE * sizeof(pte_t));
 	if (!pte)
 		return NULL;
 	clear_table((unsigned long *) pte, _PAGE_INVALID,
@@ -371,16 +373,14 @@ out:
 void __init vmem_map_init(void)
 {
 	unsigned long ro_start, ro_end;
-	unsigned long start, end;
-	int i;
+	struct memblock_region *reg;
+	phys_addr_t start, end;
 
 	ro_start = PFN_ALIGN((unsigned long)&_stext);
 	ro_end = (unsigned long)&_eshared & PAGE_MASK;
-	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;
+	for_each_memblock(memory, reg) {
+		start = reg->base;
+		end = reg->base + reg->size - 1;
 		if (start >= ro_end || end <= ro_start)
 			vmem_add_mem(start, end - start, 0);
 		else if (start >= ro_start && end <= ro_end)
@@ -400,23 +400,21 @@ void __init vmem_map_init(void)
 }
 
 /*
- * Convert memory chunk array to a memory segment list so there is a single
- * list that contains both r/w memory and shared memory segments.
+ * Convert memblock.memory  to a memory segment list so there is a single
+ * list that contains all memory segments.
  */
 static int __init vmem_convert_memory_chunk(void)
 {
+	struct memblock_region *reg;
 	struct memory_segment *seg;
-	int i;
 
 	mutex_lock(&vmem_mutex);
-	for (i = 0; i < MEMORY_CHUNKS; i++) {
-		if (!memory_chunk[i].size)
-			continue;
+	for_each_memblock(memory, reg) {
 		seg = kzalloc(sizeof(*seg), GFP_KERNEL);
 		if (!seg)
 			panic("Out of memory...\n");
-		seg->start = memory_chunk[i].addr;
-		seg->size = memory_chunk[i].size;
+		seg->start = reg->base;
+		seg->size = reg->size;
 		insert_memory_segment(seg);
 	}
 	mutex_unlock(&vmem_mutex);