Re: patch for kern/efi/mm.c (big memmap)

[Johan Rydberg <jrydberg@night.trouble.net>]

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Marco Gerards <mgerards@xs4all.nl> writes:

>> +  memory_map = grub_efi_allocate_pages
>> +    (0, 2 * BYTES_TO_PAGES (memory_map_size + 0x1000));
>>
>> I suppose you add 0x1000 to round it up.  Maybe we should change
>> the BYTES_TO_PAGES macro to do roundup.
>
> Agreed.  Can you make this change as well?

Done.  See attached patch.

>> Even through this patch is quite trivial and small, I believe we
>> need you to sign over the copyright for it to FSF.  Okuji, Marco,
>> what are your opinions?
>
> This patch is trivial enough to apply without the paperwork, I
> think.

OK.

I'll commit it after I get a few minutes over to test it.

~j


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Index: kern/efi/mm.c
===================================================================
RCS file: /sources/grub/grub2/kern/efi/mm.c,v
retrieving revision 1.3
diff -u -p -r1.3 mm.c
--- kern/efi/mm.c	28 May 2006 23:01:43 -0000	1.3
+++ kern/efi/mm.c	28 Sep 2006 13:57:30 -0000
@@ -27,13 +27,9 @@
 #define NEXT_MEMORY_DESCRIPTOR(desc, size)	\
   ((grub_efi_memory_descriptor_t *) ((char *) (desc) + (size)))
 
-#define BYTES_TO_PAGES(bytes)	((bytes) >> 12)
+#define BYTES_TO_PAGES(bytes)	(((bytes) + 4095) >> 12)
 #define PAGES_TO_BYTES(pages)	((pages) << 12)
 
-/* The size of a memory map obtained from the firmware. This must be
-   a multiplier of 4KB.  */
-#define MEMORY_MAP_SIZE	0x1000
-
 /* Maintain the list of allocated pages.  */
 struct allocated_page
 {
@@ -346,6 +342,8 @@ grub_efi_mm_init (void)
   grub_efi_uintn_t desc_size;
   grub_efi_uint64_t total_pages;
   grub_efi_uint64_t required_pages;
+  grub_efi_uintn_t memory_map_size;
+  int res;
 
   /* First of all, allocate pages to maintain allocations.  */
   allocated_pages
@@ -355,16 +353,23 @@ grub_efi_mm_init (void)
 
   grub_memset (allocated_pages, 0, ALLOCATED_PAGES_SIZE);
   
-  /* Prepare a memory region to store two memory maps.  */
-  memory_map = grub_efi_allocate_pages (0,
-					2 * BYTES_TO_PAGES (MEMORY_MAP_SIZE));
+  /* Prepare a memory region to store two memory maps.  Obtain size of
+     memory map by passing a NULL buffer and a buffer size of
+     zero.  */
+  memory_map_size = 0;
+  res = grub_efi_get_memory_map (&memory_map_size, NULL, 0, &desc_size, 0);
+  if (res != 0)
+    grub_fatal ("cannot get memory map size");
+
+  memory_map = grub_efi_allocate_pages
+    (0, 2 * BYTES_TO_PAGES (memory_map_size));
   if (! memory_map)
     grub_fatal ("cannot allocate memory");
 
-  filtered_memory_map = NEXT_MEMORY_DESCRIPTOR (memory_map, MEMORY_MAP_SIZE);
+  filtered_memory_map = NEXT_MEMORY_DESCRIPTOR (memory_map, memory_map_size);
 
   /* Obtain descriptors for available memory.  */
-  map_size = MEMORY_MAP_SIZE;
+  map_size = memory_map_size;
 
   if (grub_efi_get_memory_map (&map_size, memory_map, 0, &desc_size, 0) < 0)
     grub_fatal ("cannot get memory map");
@@ -393,7 +398,7 @@ grub_efi_mm_init (void)
 
 #if 0
   /* For debug.  */
-  map_size = MEMORY_MAP_SIZE;
+  map_size = memory_map_size;
 
   if (grub_efi_get_memory_map (&map_size, memory_map, 0, &desc_size, 0) < 0)
     grub_fatal ("cannot get memory map");
@@ -406,7 +411,7 @@ grub_efi_mm_init (void)
   
   /* Release the memory maps.  */
   grub_efi_free_pages ((grub_addr_t) memory_map,
-		       2 * BYTES_TO_PAGES (MEMORY_MAP_SIZE));
+		       2 * BYTES_TO_PAGES (memory_map_size));
 }
 
 void

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