michael@0: /*
michael@0:  * Copyright 2008 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: /*
michael@0:  * Implementation of the user-space ashmem API for devices, which have our
michael@0:  * ashmem-enabled kernel. See ashmem-sim.c for the "fake" tmp-based version,
michael@0:  * used by the simulator.
michael@0:  */
michael@0: 
michael@0: #include <android/ashmem.h>
michael@0: 
michael@0: #include <unistd.h>
michael@0: #include <string.h>
michael@0: #include <sys/types.h>
michael@0: #include <sys/stat.h>
michael@0: #include <sys/ioctl.h>
michael@0: #include <fcntl.h>
michael@0: 
michael@0: #include <linux/ashmem.h>
michael@0: 
michael@0: #define ASHMEM_DEVICE   "/dev/ashmem"
michael@0: 
michael@0: /*
michael@0:  * ashmem_create_region - creates a new ashmem region and returns the file
michael@0:  * descriptor, or <0 on error
michael@0:  *
michael@0:  * `name' is an optional label to give the region (visible in /proc/pid/maps)
michael@0:  * `size' is the size of the region, in page-aligned bytes
michael@0:  */
michael@0: int ashmem_create_region(const char *name, size_t size)
michael@0: {
michael@0:     int fd, ret;
michael@0: 
michael@0:     fd = open(ASHMEM_DEVICE, O_RDWR);
michael@0:     if (fd < 0)
michael@0:         return fd;
michael@0: 
michael@0:     if (name) {
michael@0:         char buf[ASHMEM_NAME_LEN];
michael@0: 
michael@0:         strlcpy(buf, name, sizeof(buf));
michael@0:         ret = ioctl(fd, ASHMEM_SET_NAME, buf);
michael@0:         if (ret < 0)
michael@0:             goto error;
michael@0:     }
michael@0: 
michael@0:     ret = ioctl(fd, ASHMEM_SET_SIZE, size);
michael@0:     if (ret < 0)
michael@0:         goto error;
michael@0: 
michael@0:     return fd;
michael@0: 
michael@0: error:
michael@0:     close(fd);
michael@0:     return ret;
michael@0: }
michael@0: 
michael@0: int ashmem_set_prot_region(int fd, int prot)
michael@0: {
michael@0:     return ioctl(fd, ASHMEM_SET_PROT_MASK, prot);
michael@0: }
michael@0: 
michael@0: int ashmem_pin_region(int fd, size_t offset, size_t len)
michael@0: {
michael@0:     struct ashmem_pin pin = { offset, len };
michael@0:     return ioctl(fd, ASHMEM_PIN, &pin);
michael@0: }
michael@0: 
michael@0: int ashmem_unpin_region(int fd, size_t offset, size_t len)
michael@0: {
michael@0:     struct ashmem_pin pin = { offset, len };
michael@0:     return ioctl(fd, ASHMEM_UNPIN, &pin);
michael@0: }
michael@0: 
michael@0: int ashmem_get_size_region(int fd)
michael@0: {
michael@0:   return ioctl(fd, ASHMEM_GET_SIZE, NULL);
michael@0: }
michael@0: 
michael@0: int ashmem_purge_all_caches(int fd)
michael@0: {
michael@0:   return ioctl(fd, ASHMEM_PURGE_ALL_CACHES, NULL);
michael@0: }