[PATCH] memblock: add memblock_start_of_DRAM()

[Sam Ravnborg <sam@ravnborg.org>]

SPARC32 require access to the start address.
Add a new helper memblock_start_of_DRAM() to give
access to the address of the first memblock - which
contains the lowest address.

The ackward name was chosen to match the already present
memblock_end_of_DRAM().

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Yinghai Lu <yinghai@kernel.org>
---
Hi Tejun.

I have started to replace bootmem with memblock for sparc32.
This is so far the only general functionality missing.

But conversion is not finished yet - more may come.

This is on top of the memblock branch of your misc tree

	Sam

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 7c59804..a6bb102 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -157,6 +157,7 @@ phys_addr_t memblock_alloc_base(phys_addr_t size, phys_addr_t align,
 phys_addr_t __memblock_alloc_base(phys_addr_t size, phys_addr_t align,
 				  phys_addr_t max_addr);
 phys_addr_t memblock_phys_mem_size(void);
+phys_addr_t memblock_start_of_DRAM(void);
 phys_addr_t memblock_end_of_DRAM(void);
 void memblock_enforce_memory_limit(phys_addr_t memory_limit);
 int memblock_is_memory(phys_addr_t addr);
diff --git a/mm/memblock.c b/mm/memblock.c
index 07cb3ae..2f55f19 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -782,6 +782,12 @@ phys_addr_t __init memblock_phys_mem_size(void)
 	return memblock.memory.total_size;
 }
 
+/* lowest address */
+phys_addr_t __init_memblock memblock_start_of_DRAM(void)
+{
+	return memblock.memory.regions[0].base;
+}
+
 phys_addr_t __init_memblock memblock_end_of_DRAM(void)
 {
 	int idx = memblock.memory.cnt - 1;