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Annotation of qemu/roms/ipxe/src/interface/efi/efi_umalloc.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Copyright (C) 2008 Michael Brown <[email protected]>.
                      3:  *
                      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.
                      8:  *
                      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.
                     13:  *
                     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., 675 Mass Ave, Cambridge, MA 02139, USA.
                     17:  */
                     18: 
                     19: FILE_LICENCE ( GPL2_OR_LATER );
                     20: 
                     21: #include <assert.h>
                     22: #include <ipxe/umalloc.h>
                     23: #include <ipxe/efi/efi.h>
                     24: 
                     25: /** @file
                     26:  *
                     27:  * iPXE user memory allocation API for EFI
                     28:  *
                     29:  */
                     30: 
                     31: /** Equivalent of NOWHERE for user pointers */
                     32: #define UNOWHERE ( ~UNULL )
                     33: 
                     34: /**
                     35:  * Reallocate external memory
                     36:  *
                     37:  * @v old_ptr          Memory previously allocated by umalloc(), or UNULL
                     38:  * @v new_size         Requested size
                     39:  * @ret new_ptr                Allocated memory, or UNULL
                     40:  *
                     41:  * Calling realloc() with a new size of zero is a valid way to free a
                     42:  * memory block.
                     43:  */
                     44: static userptr_t efi_urealloc ( userptr_t old_ptr, size_t new_size ) {
                     45:        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
                     46:        EFI_PHYSICAL_ADDRESS phys_addr;
                     47:        unsigned int new_pages, old_pages;
                     48:        userptr_t new_ptr = UNOWHERE;
                     49:        size_t old_size;
                     50:        EFI_STATUS efirc;
                     51: 
                     52:        /* Allocate new memory if necessary.  If allocation fails,
                     53:         * return without touching the old block.
                     54:         */
                     55:        if ( new_size ) {
                     56:                new_pages = ( EFI_SIZE_TO_PAGES ( new_size ) + 1 );
                     57:                if ( ( efirc = bs->AllocatePages ( AllocateAnyPages,
                     58:                                                   EfiBootServicesData,
                     59:                                                   new_pages,
                     60:                                                   &phys_addr ) ) != 0 ) {
                     61:                        DBG ( "EFI could not allocate %d pages: %s\n",
                     62:                              new_pages, efi_strerror ( efirc ) );
                     63:                        return UNULL;
                     64:                }
                     65:                assert ( phys_addr != 0 );
                     66:                new_ptr = phys_to_user ( phys_addr + EFI_PAGE_SIZE );
                     67:                copy_to_user ( new_ptr, -EFI_PAGE_SIZE,
                     68:                               &new_size, sizeof ( new_size ) );
                     69:                DBG ( "EFI allocated %d pages at %llx\n",
                     70:                      new_pages, phys_addr );
                     71:        }
                     72: 
                     73:        /* Copy across relevant part of the old data region (if any),
                     74:         * then free it.  Note that at this point either (a) new_ptr
                     75:         * is valid, or (b) new_size is 0; either way, the memcpy() is
                     76:         * valid.
                     77:         */
                     78:        if ( old_ptr && ( old_ptr != UNOWHERE ) ) {
                     79:                copy_from_user ( &old_size, old_ptr, -EFI_PAGE_SIZE,
                     80:                                 sizeof ( old_size ) );
                     81:                memcpy_user ( new_ptr, 0, old_ptr, 0,
                     82:                              ( (old_size < new_size) ? old_size : new_size ));
                     83:                old_pages = ( EFI_SIZE_TO_PAGES ( old_size ) + 1 );
                     84:                phys_addr = user_to_phys ( old_ptr, -EFI_PAGE_SIZE );
                     85:                if ( ( efirc = bs->FreePages ( phys_addr, old_pages ) ) != 0 ){
                     86:                        DBG ( "EFI could not free %d pages at %llx: %s\n",
                     87:                              old_pages, phys_addr, efi_strerror ( efirc ) );
                     88:                        /* Not fatal; we have leaked memory but successfully
                     89:                         * allocated (if asked to do so).
                     90:                         */
                     91:                }
                     92:                DBG ( "EFI freed %d pages at %llx\n", old_pages, phys_addr );
                     93:        }
                     94: 
                     95:        return new_ptr;
                     96: }
                     97: 
                     98: PROVIDE_UMALLOC ( efi, urealloc, efi_urealloc );

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