dolphin/Source/Core/Common/MemArena.cpp
magumagu d557310371 Support for dynamic BAT modification (dynamic-bat).
Fundamentally, all this does is enforce the invariant that we always
translate effective addresses based on the current BAT registers and
page table before we do anything else with them.

This change can be logically divided into three parts.  The first part is
creating a table to represent the current BAT state, and keeping it up to
date (PowerPC::IBATUpdated, PowerPC::DBATUpdated, etc.).  This does
nothing by itself, but it's necessary for the other parts.

The second part (mostly in MMU.cpp) is simply removing all the hardcoded
checks for specific untranslated addresses, and consistently translating
addresses using the current BAT configuration. Very straightforward, but a
lot of code changes because we hardcoded assumptions all over the place.

The third part (mostly in Memmap.cpp) is making the fastmem arena reflect
the current BAT configuration.  We do this by redoing the mapping (calling
memmap()) based on the BAT table whenever it changes.

One additional minor change is that translation can fail in two ways:
either the segment is a direct store segment, or page table lookup failed.
The difference doesn't usually matter, but the difference affects cache
instructions, like dcbz.
2016-09-06 08:43:22 +02:00

160 lines
3.6 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include <cstddef>
#include <cstdlib>
#include <set>
#include <string>
#include "Common/CommonTypes.h"
#include "Common/Logging/Log.h"
#include "Common/MemArena.h"
#include "Common/MsgHandler.h"
#include "Common/StringUtil.h"
#ifdef _WIN32
#include <windows.h>
#else
#include <cerrno>
#include <cstring>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#ifdef ANDROID
#include <linux/ashmem.h>
#include <sys/ioctl.h>
#endif
#endif
#ifdef ANDROID
#define ASHMEM_DEVICE "/dev/ashmem"
static int AshmemCreateFileMapping(const char* name, size_t size)
{
int fd, ret;
fd = open(ASHMEM_DEVICE, O_RDWR);
if (fd < 0)
return fd;
// We don't really care if we can't set the name, it is optional
ioctl(fd, ASHMEM_SET_NAME, name);
ret = ioctl(fd, ASHMEM_SET_SIZE, size);
if (ret < 0)
{
close(fd);
NOTICE_LOG(MEMMAP, "Ashmem returned error: 0x%08x", ret);
return ret;
}
return fd;
}
#endif
void MemArena::GrabSHMSegment(size_t size)
{
#ifdef _WIN32
hMemoryMapping =
CreateFileMapping(INVALID_HANDLE_VALUE, nullptr, PAGE_READWRITE, 0, (DWORD)(size), nullptr);
#elif defined(ANDROID)
fd = AshmemCreateFileMapping("Dolphin-emu", size);
if (fd < 0)
{
NOTICE_LOG(MEMMAP, "Ashmem allocation failed");
return;
}
#else
for (int i = 0; i < 10000; i++)
{
std::string file_name = StringFromFormat("/dolphinmem.%d", i);
fd = shm_open(file_name.c_str(), O_RDWR | O_CREAT | O_EXCL, 0600);
if (fd != -1)
{
shm_unlink(file_name.c_str());
break;
}
else if (errno != EEXIST)
{
ERROR_LOG(MEMMAP, "shm_open failed: %s", strerror(errno));
return;
}
}
if (ftruncate(fd, size) < 0)
ERROR_LOG(MEMMAP, "Failed to allocate low memory space");
#endif
}
void MemArena::ReleaseSHMSegment()
{
#ifdef _WIN32
CloseHandle(hMemoryMapping);
hMemoryMapping = 0;
#else
close(fd);
#endif
}
void* MemArena::CreateView(s64 offset, size_t size, void* base)
{
#ifdef _WIN32
return MapViewOfFileEx(hMemoryMapping, FILE_MAP_ALL_ACCESS, 0, (DWORD)((u64)offset), size, base);
#else
void* retval = mmap(base, size, PROT_READ | PROT_WRITE,
MAP_SHARED | ((base == nullptr) ? 0 : MAP_FIXED), fd, offset);
if (retval == MAP_FAILED)
{
NOTICE_LOG(MEMMAP, "mmap failed");
return nullptr;
}
else
{
return retval;
}
#endif
}
void MemArena::ReleaseView(void* view, size_t size)
{
#ifdef _WIN32
UnmapViewOfFile(view);
#else
munmap(view, size);
#endif
}
u8* MemArena::FindMemoryBase()
{
#if _ARCH_64
#ifdef _WIN32
// 64 bit
u8* base = (u8*)VirtualAlloc(0, 0x400000000, MEM_RESERVE, PAGE_READWRITE);
VirtualFree(base, 0, MEM_RELEASE);
return base;
#else
// Very precarious - mmap cannot return an error when trying to map already used pages.
// This makes the Windows approach above unusable on Linux, so we will simply pray...
return reinterpret_cast<u8*>(0x2300000000ULL);
#endif
#else // 32 bit
#ifdef ANDROID
// Android 4.3 changed how mmap works.
// if we map it private and then munmap it, we can't use the base returned.
// This may be due to changes in them support a full SELinux implementation.
const int flags = MAP_ANON | MAP_SHARED;
#else
const int flags = MAP_ANON | MAP_PRIVATE;
#endif
const u32 MemSize = 0x31000000;
void* base = mmap(0, MemSize, PROT_NONE, flags, -1, 0);
if (base == MAP_FAILED)
{
PanicAlert("Failed to map 1 GB of memory space: %s", strerror(errno));
return 0;
}
munmap(base, MemSize);
return static_cast<u8*>(base);
#endif
}