[PATCH v2 08/15] efi: Add get_dram_base() helper function

From: Leif Lindholm
Date: Thu Mar 13 2014 - 18:52:14 EST


From: Roy Franz <roy.franz@xxxxxxxxxx>

Add the get_dram_base() function, shared by arm/arm64.

Signed-off-by: Roy Franz <roy.franz@xxxxxxxxxx>
Signed-off-by: Leif Lindholm <leif.lindholm@xxxxxxxxxx>
---
drivers/firmware/efi/efi-stub-helper.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/efi-stub-helper.c
index 4c8ab86..4a9986b 100644
--- a/drivers/firmware/efi/efi-stub-helper.c
+++ b/drivers/firmware/efi/efi-stub-helper.c
@@ -11,6 +11,10 @@
*/
#define EFI_READ_CHUNK_SIZE (1024 * 1024)

+/* error code which can't be mistaken for valid address */
+#define EFI_ERROR (~0UL)
+
+
struct file_info {
efi_file_handle_t *handle;
u64 size;
@@ -92,6 +96,32 @@ fail:
return status;
}

+
+static unsigned long __init get_dram_base(efi_system_table_t *sys_table)
+{
+ efi_status_t status;
+ unsigned long map_size;
+ unsigned long membase = EFI_ERROR;
+ struct efi_memory_map map;
+ efi_memory_desc_t *md;
+
+ status = efi_get_memory_map(sys_table, (efi_memory_desc_t **)&map.map,
+ &map_size, &map.desc_size, NULL, NULL);
+ if (status != EFI_SUCCESS)
+ return membase;
+
+ map.map_end = map.map + map_size;
+
+ for_each_efi_memory_desc(&map, md)
+ if (md->attribute & EFI_MEMORY_WB)
+ if (membase > md->phys_addr)
+ membase = md->phys_addr;
+
+ efi_call_phys1(sys_table->boottime->free_pool, map.map);
+
+ return membase;
+}
+
/*
* Allocate at the highest possible address that is not above 'max'.
*/
--
1.7.10.4

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