2 * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL
);
29 #include <ipxe/umalloc.h>
30 #include <ipxe/efi/efi.h>
34 * iPXE user memory allocation API for EFI
38 /** Equivalent of NOWHERE for user pointers */
39 #define UNOWHERE ( ~UNULL )
42 * Reallocate external memory
44 * @v old_ptr Memory previously allocated by umalloc(), or UNULL
45 * @v new_size Requested size
46 * @ret new_ptr Allocated memory, or UNULL
48 * Calling realloc() with a new size of zero is a valid way to free a
51 static userptr_t
efi_urealloc ( userptr_t old_ptr
, size_t new_size
) {
52 EFI_BOOT_SERVICES
*bs
= efi_systab
->BootServices
;
53 EFI_PHYSICAL_ADDRESS phys_addr
;
54 unsigned int new_pages
, old_pages
;
55 userptr_t new_ptr
= UNOWHERE
;
60 /* Allocate new memory if necessary. If allocation fails,
61 * return without touching the old block.
64 new_pages
= ( EFI_SIZE_TO_PAGES ( new_size
) + 1 );
65 if ( ( efirc
= bs
->AllocatePages ( AllocateAnyPages
,
68 &phys_addr
) ) != 0 ) {
70 DBG ( "EFI could not allocate %d pages: %s\n",
71 new_pages
, strerror ( rc
) );
74 assert ( phys_addr
!= 0 );
75 new_ptr
= phys_to_user ( phys_addr
+ EFI_PAGE_SIZE
);
76 copy_to_user ( new_ptr
, -EFI_PAGE_SIZE
,
77 &new_size
, sizeof ( new_size
) );
78 DBG ( "EFI allocated %d pages at %llx\n",
79 new_pages
, phys_addr
);
82 /* Copy across relevant part of the old data region (if any),
83 * then free it. Note that at this point either (a) new_ptr
84 * is valid, or (b) new_size is 0; either way, the memcpy() is
87 if ( old_ptr
&& ( old_ptr
!= UNOWHERE
) ) {
88 copy_from_user ( &old_size
, old_ptr
, -EFI_PAGE_SIZE
,
89 sizeof ( old_size
) );
90 memcpy_user ( new_ptr
, 0, old_ptr
, 0,
91 ( (old_size
< new_size
) ? old_size
: new_size
));
92 old_pages
= ( EFI_SIZE_TO_PAGES ( old_size
) + 1 );
93 phys_addr
= user_to_phys ( old_ptr
, -EFI_PAGE_SIZE
);
94 if ( ( efirc
= bs
->FreePages ( phys_addr
, old_pages
) ) != 0 ){
96 DBG ( "EFI could not free %d pages at %llx: %s\n",
97 old_pages
, phys_addr
, strerror ( rc
) );
98 /* Not fatal; we have leaked memory but successfully
99 * allocated (if asked to do so).
102 DBG ( "EFI freed %d pages at %llx\n", old_pages
, phys_addr
);
108 PROVIDE_UMALLOC ( efi
, urealloc
, efi_urealloc
);