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>

4 files changed, 9 insertions, 6 deletions

diff --git a/arch/x86/mm/discontig_32.c b/arch/x86/mm/discontig_32.c
index 04b1d20e2613..c394ca0720b8 100644
--- a/arch/x86/mm/discontig_32.c
+++ b/arch/x86/mm/discontig_32.c
@@ -391,7 +391,8 @@ unsigned long __init setup_memory(void)
 void __init numa_kva_reserve(void)
 {
         if (kva_pages)
-                reserve_bootmem(PFN_PHYS(kva_start_pfn), PFN_PHYS(kva_pages));
+                reserve_bootmem(PFN_PHYS(kva_start_pfn), PFN_PHYS(kva_pages),
+                                BOOTMEM_DEFAULT);
 }
 
 void __init zone_sizes_init(void)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 9b61c75a2355..5fe880fc305d 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -644,9 +644,9 @@ void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
 
         /* Should check here against the e820 map to avoid double free */
 #ifdef CONFIG_NUMA
-        reserve_bootmem_node(NODE_DATA(nid), phys, len);
+        reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
 #else
-        reserve_bootmem(phys, len);
+        reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
 #endif
         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
                 dma_reserve += len / PAGE_SIZE;
diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 5a02bf4c91ec..1aecc658cd7d 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -238,9 +238,10 @@ void __init setup_node_bootmem(int nodeid, unsigned long start,
 
         free_bootmem_with_active_regions(nodeid, end);
 
-        reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys, pgdat_size);
+        reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys, pgdat_size,
+                        BOOTMEM_DEFAULT);
         reserve_bootmem_node(NODE_DATA(nodeid), bootmap_start,
-                             bootmap_pages<<PAGE_SHIFT);
+                        bootmap_pages<<PAGE_SHIFT, BOOTMEM_DEFAULT);
 #ifdef CONFIG_ACPI_NUMA
         srat_reserve_add_area(nodeid);
 #endif
diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c
index 65416f843e59..ecd91ea8a8ae 100644
--- a/arch/x86/mm/srat_64.c
+++ b/arch/x86/mm/srat_64.c
@@ -488,7 +488,8 @@ void __init srat_reserve_add_area(int nodeid)
                 printk(KERN_INFO "SRAT: This will cost you %Lu MB of "
                                 "pre-allocated memory.\n", (unsigned long long)total_mb);
                 reserve_bootmem_node(NODE_DATA(nodeid), nodes_add[nodeid].start,
-                               nodes_add[nodeid].end - nodes_add[nodeid].start);
+                               nodes_add[nodeid].end - nodes_add[nodeid].start,
+                               BOOTMEM_DEFAULT);
         }
 }