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>

5 files changed, 41 insertions, 103 deletions

diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index 2765e40d8739..59880dbaf360 100644
--- a/arch/s390/include/asm/setup.h
+++ b/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
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 30b7f63aa4e8..f703d91bf720 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/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;
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index cdd9ec0a6fc0..0a49095104c9 100644
--- a/arch/s390/kernel/setup.c
+++ b/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));
@@ -681,15 +677,6 @@ static int __init verify_crash_base(unsigned long crash_base,
 }
 
 /*
- * 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
  * [crashk_res.start - crashk_res.end] is set offline.
@@ -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);
diff --git a/arch/s390/mm/mem_detect.c b/arch/s390/mm/mem_detect.c
index ec00576bf8d5..3cbd3b8bf311 100644
--- a/arch/s390/mm/mem_detect.c
+++ b/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;
                 }
         }
 }
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 35837054f734..8b268fcc4612 100644
--- a/arch/s390/mm/vmem.c
+++ b/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");