[PATCH] i386: Preserve EFI run time regions with memmap parameter

When using memmap kernel parameter in EFI boot we should also add to memory map
memory regions of runtime services to enable their mapping later.

AK: merged and cleaned up the patch

Signed-off-by: Artiom Myaskouvskey <artiom.myaskouvskey@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 43 insertions, 17 deletions

diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
index b704790f796..2f7d0a92fd7 100644
--- a/arch/i386/kernel/e820.c
+++ b/arch/i386/kernel/e820.c
@@ -742,29 +742,55 @@ void __init print_memory_map(char *who)
 	}
 }
 
-void __init limit_regions(unsigned long long size)
+static __init __always_inline void efi_limit_regions(unsigned long long size)
 {
 	unsigned long long current_addr = 0;
+	efi_memory_desc_t *md, *next_md;
+	void *p, *p1;
+	int i, j;
+
+	j = 0;
+	p1 = memmap.map;
+	for (p = p1, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
+		md = p;
+		next_md = p1;
+		current_addr = md->phys_addr +
+			PFN_PHYS(md->num_pages);
+		if (is_available_memory(md)) {
+			if (md->phys_addr >= size) continue;
+			memcpy(next_md, md, memmap.desc_size);
+			if (current_addr >= size) {
+				next_md->num_pages -=
+					PFN_UP(current_addr-size);
+			}
+			p1 += memmap.desc_size;
+			next_md = p1;
+			j++;
+		} else if ((md->attribute & EFI_MEMORY_RUNTIME) ==
+			   EFI_MEMORY_RUNTIME) {
+			/* In order to make runtime services
+			 * available we have to include runtime
+			 * memory regions in memory map */
+			memcpy(next_md, md, memmap.desc_size);
+			p1 += memmap.desc_size;
+			next_md = p1;
+			j++;
+		}
+	}
+	memmap.nr_map = j;
+	memmap.map_end = memmap.map +
+		(memmap.nr_map * memmap.desc_size);
+}
+
+void __init limit_regions(unsigned long long size)
+{
+	unsigned long long current_addr;
 	int i;
 
 	print_memory_map("limit_regions start");
 	if (efi_enabled) {
-		efi_memory_desc_t *md;
-		void *p;
-
-		for (p = memmap.map, i = 0; p < memmap.map_end;
-			p += memmap.desc_size, i++) {
-			md = p;
-			current_addr = md->phys_addr + (md->num_pages << 12);
-			if (md->type == EFI_CONVENTIONAL_MEMORY) {
-				if (current_addr >= size) {
-					md->num_pages -=
-						(((current_addr-size) + PAGE_SIZE-1) >> PAGE_SHIFT);
-					memmap.nr_map = i + 1;
-					return;
-				}
-			}
-		}
+		efi_limit_regions(size);
+		return;
 	}
 	for (i = 0; i < e820.nr_map; i++) {
 		current_addr = e820.map[i].addr + e820.map[i].size;