Introduce flags for reserve_bootmem()

This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.

This patch:

Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past.  This is to avoid conflicts.

Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 19 insertions, 11 deletions

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index c0ad7c0fbae0..ec00f26bffa4 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -239,7 +239,7 @@ bootmem_init_node(int node, int initrd_node, struct meminfo *mi)
          * Reserve the bootmem bitmap for this node.
          */
         reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT,
-                             boot_pages << PAGE_SHIFT);
+                             boot_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
 
 #ifdef CONFIG_BLK_DEV_INITRD
         /*
@@ -247,7 +247,7 @@ bootmem_init_node(int node, int initrd_node, struct meminfo *mi)
          */
         if (node == initrd_node) {
                 reserve_bootmem_node(pgdat, phys_initrd_start,
-                                     phys_initrd_size);
+                                     phys_initrd_size, BOOTMEM_DEFAULT);
                 initrd_start = __phys_to_virt(phys_initrd_start);
                 initrd_end = initrd_start + phys_initrd_size;
         }
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index e5d61ee3d4a1..d41a75ed3dce 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -605,9 +605,11 @@ void __init reserve_node_zero(pg_data_t *pgdat)
          * Note that this can only be in node 0.
          */
 #ifdef CONFIG_XIP_KERNEL
-        reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);
+        reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start,
+                        BOOTMEM_DEFAULT);
 #else
-        reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
+        reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext,
+                        BOOTMEM_DEFAULT);
 #endif
 
         /*
@@ -615,7 +617,7 @@ void __init reserve_node_zero(pg_data_t *pgdat)
          * and can only be in node 0.
          */
         reserve_bootmem_node(pgdat, __pa(swapper_pg_dir),
-                             PTRS_PER_PGD * sizeof(pgd_t));
+                             PTRS_PER_PGD * sizeof(pgd_t), BOOTMEM_DEFAULT);
 
         /*
          * Hmm... This should go elsewhere, but we really really need to
@@ -638,8 +640,10 @@ void __init reserve_node_zero(pg_data_t *pgdat)
         /* H1940 and RX3715 need to reserve this for suspend */
 
         if (machine_is_h1940() || machine_is_rx3715()) {
-                reserve_bootmem_node(pgdat, 0x30003000, 0x1000);
-                reserve_bootmem_node(pgdat, 0x30081000, 0x1000);
+                reserve_bootmem_node(pgdat, 0x30003000, 0x1000,
+                                BOOTMEM_DEFAULT);
+                reserve_bootmem_node(pgdat, 0x30081000, 0x1000,
+                                BOOTMEM_DEFAULT);
         }
 
 #ifdef CONFIG_SA1111
@@ -650,7 +654,8 @@ void __init reserve_node_zero(pg_data_t *pgdat)
         res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
 #endif
         if (res_size)
-                reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size);
+                reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size,
+                                BOOTMEM_DEFAULT);
 }
 
 /*
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index 8cd3a60954f0..63c62fdea521 100644
--- a/arch/arm/mm/nommu.c
+++ b/arch/arm/mm/nommu.c
@@ -27,9 +27,11 @@ void __init reserve_node_zero(pg_data_t *pgdat)
          * Note that this can only be in node 0.
          */
 #ifdef CONFIG_XIP_KERNEL
-        reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);
+        reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start,
+                        BOOTMEM_DEFAULT);
 #else
-        reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
+        reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext,
+                        BOOTMEM_DEFAULT);
 #endif
 
         /*
@@ -37,7 +39,8 @@ void __init reserve_node_zero(pg_data_t *pgdat)
          * some architectures which the DRAM is the exception vector to trap,
          * alloc_page breaks with error, although it is not NULL, but "0."
          */
-        reserve_bootmem_node(pgdat, CONFIG_VECTORS_BASE, PAGE_SIZE);
+        reserve_bootmem_node(pgdat, CONFIG_VECTORS_BASE, PAGE_SIZE,
+                        BOOTMEM_DEFAULT);
 }
 
 /*