ppsspp/Common/MemArenaAndroid.cpp
2017-01-26 08:51:48 +01:00

120 lines
3.2 KiB
C++

// Copyright (C) 2003 Dolphin Project.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0 or later versions.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License 2.0 for more details.
// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/
// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/
#include "ppsspp_config.h"
#ifdef __ANDROID__
#include "MemoryUtil.h"
#include "MemArena.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <cerrno>
#include <sys/ioctl.h>
#include <linux/ashmem.h>
// Hopefully this ABI will never change...
#define ASHMEM_DEVICE "/dev/ashmem"
bool MemArena::NeedsProbing() {
return false;
}
// ashmem_create_region - creates a new ashmem region and returns the file
// descriptor, or <0 on error
// `name' is an optional label to give the region (visible in /proc/pid/maps)
// `size' is the size of the region, in page-aligned bytes
static int ashmem_create_region(const char *name, size_t size) {
int fd = open(ASHMEM_DEVICE, O_RDWR);
if (fd < 0)
return fd;
int ret;
if (name) {
char buf[ASHMEM_NAME_LEN];
strncpy(buf, name, sizeof(buf));
ret = ioctl(fd, ASHMEM_SET_NAME, buf);
if (ret < 0)
goto error;
}
ret = ioctl(fd, ASHMEM_SET_SIZE, size);
if (ret < 0)
goto error;
return fd;
error:
ERROR_LOG(MEMMAP, "NASTY ASHMEM ERROR: ret = %08x", ret);
close(fd);
return ret;
}
// Windows mappings need to be on 64K boundaries, due to Alpha legacy.
size_t MemArena::roundup(size_t x) {
return x;
}
void MemArena::GrabLowMemSpace(size_t size) {
// Use ashmem so we don't have to allocate a file on disk!
fd = ashmem_create_region("PPSSPP_RAM", size);
// Note that it appears that ashmem is pinned by default, so no need to pin.
if (fd < 0) {
ERROR_LOG(MEMMAP, "Failed to grab ashmem space of size: %08x errno: %d", (int)size, (int)(errno));
return;
}
}
void MemArena::ReleaseSpace() {
close(fd);
}
void *MemArena::CreateView(s64 offset, size_t size, void *base) {
void *retval = mmap(base, size, PROT_READ | PROT_WRITE, MAP_SHARED | ((base == 0) ? 0 : MAP_FIXED), fd, offset);
if (retval == MAP_FAILED) {
NOTICE_LOG(MEMMAP, "mmap on ashmem (fd: %d) failed", (int)fd);
return 0;
}
return retval;
}
void MemArena::ReleaseView(void* view, size_t size) {
munmap(view, size);
}
u8* MemArena::Find4GBBase() {
#if PPSSPP_ARCH(64BIT)
// Just grab some random 4GB...
return reinterpret_cast<u8*>(0x2300000000ULL);
#else
// Address masking is used in 32-bit mode, so we can get away with less memory.
void* base = mmap(0, 0x10000000, PROT_READ | PROT_WRITE,
MAP_ANON | MAP_SHARED, -1, 0);
if (base == MAP_FAILED) {
PanicAlert("Failed to map 256 MB of memory space: %s", strerror(errno));
return 0;
}
munmap(base, 0x10000000);
return static_cast<u8*>(base);
#endif
}
#endif // __ANDROID__