From: Roy Franz <roy.franz@linaro.org>
Date: Tue, 28 Jan 2014 18:41:28 +0000 (-0800)
Subject: efi: Add get_dram_base() helper function
X-Git-Tag: firefly_0821_release~3680^2~36^2~41^2~25
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f2b145dc4ff8efdeb37b10e88b5058d1086b1fe0;p=firefly-linux-kernel-4.4.55.git

efi: Add get_dram_base() helper function

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

Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
(cherry picked from commit 9bb40191e88d23563fd0467ac195debf5f6daaf9)
Signed-off-by: Mark Brown <broonie@linaro.org>
---

diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/efi-stub-helper.c
index 1bf439be9138..a168dd20511f 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;
@@ -83,6 +87,32 @@ fail:
 	return status;
 }
 
+
+static unsigned long __init get_dram_base(efi_system_table_t *sys_table_arg)
+{
+	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_arg, (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_early(free_pool, map.map);
+
+	return membase;
+}
+
 /*
  * Allocate at the highest possible address that is not above 'max'.
  */