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Merge pull request #1176 from FioraAeterna/pagecrossings

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MMU: support loads/stores that cross page boundaries
This commit is contained in:
skidau 2014-10-01 13:22:52 +10:00
commit 19fbefd9bd
1 changed files with 73 additions and 11 deletions
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84
Source/Core/Core/HW/MemmapFunctions.cpp
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@ -34,6 +34,8 @@
namespace Memory
{
#define HW_PAGE_SIZE 4096
// EFB RE
/*
GXPeekZ
@ -123,17 +125,51 @@ inline void ReadFromHardware(T &_var, const u32 em_address, const u32 effective_
else
{
// MMU
u32 tlb_addr = TranslateAddress(em_address, flag);
if (tlb_addr == 0)
// Handle loads that cross page boundaries (ewwww)
if (sizeof(T) > 1 && (em_address & (HW_PAGE_SIZE - 1)) > HW_PAGE_SIZE - sizeof(T))
{
if (flag == FLAG_READ)
_var = 0;
// This could be unaligned down to the byte level... hopefully this is rare, so doing it this
// way isn't too terrible.
// TODO: floats on non-word-aligned boundaries should technically cause alignment exceptions.
// Note that "word" means 32-bit, so paired singles or doubles might still be 32-bit aligned!
u32 tlb_addr = TranslateAddress(em_address, flag);
for (u32 addr = em_address; addr < em_address + sizeof(T); addr++, tlb_addr++)
{
GenerateDSIException(em_address, false);
// Start of the new page... translate the address again!
if (!(addr & (HW_PAGE_SIZE-1)))
tlb_addr = TranslateAddress(addr, flag);
// Important: we need to generate the DSI on the first store that caused the fault, NOT
// the address of the start of the load.
if (tlb_addr == 0)
{
if (flag == FLAG_READ)
{
GenerateDSIException(addr, false);
break;
}
}
else
{
_var <<= 8;
_var |= m_pRAM[tlb_addr & RAM_MASK];
}
}
}
else
{
_var = bswap((*(const T*)&m_pRAM[tlb_addr & RAM_MASK]));
u32 tlb_addr = TranslateAddress(em_address, flag);
if (tlb_addr == 0)
{
if (flag == FLAG_READ)
{
GenerateDSIException(em_address, false);
}
}
else
{
_var = bswap((*(const T*)&m_pRAM[tlb_addr & RAM_MASK]));
}
}
}
}
@ -208,17 +244,44 @@ inline void WriteToHardware(u32 em_address, const T data, u32 effective_address,
else
{
// MMU
u32 tlb_addr = TranslateAddress(em_address, flag);
if (tlb_addr == 0)
// Handle stores that cross page boundaries (ewwww)
if (sizeof(T) > 1 && (em_address & (HW_PAGE_SIZE-1)) > HW_PAGE_SIZE - sizeof(T))
{
if (flag == FLAG_WRITE)
T val = bswap(data);
u32 tlb_addr = TranslateAddress(em_address, flag);
for (u32 addr = em_address; addr < em_address + sizeof(T); addr++, tlb_addr++)
{
GenerateDSIException(em_address, true);
if (!(addr & (HW_PAGE_SIZE-1)))
tlb_addr = TranslateAddress(addr, flag);
if (tlb_addr == 0)
{
if (flag == FLAG_WRITE)
{
GenerateDSIException(addr, true);
break;
}
}
else
{
m_pRAM[tlb_addr & RAM_MASK] = (u8)val;
val >>= 8;
}
}
}
else
{
*(T*)&m_pRAM[tlb_addr & RAM_MASK] = bswap(data);
u32 tlb_addr = TranslateAddress(em_address, flag);
if (tlb_addr == 0)
{
if (flag == FLAG_WRITE)
{
GenerateDSIException(em_address, true);
}
}
else
{
*(T*)&m_pRAM[tlb_addr & RAM_MASK] = bswap(data);
}
}
}
}
@ -607,7 +670,6 @@ void SDRUpdated()
#define TLB_WAYS 2
#define NUM_TLBS 2
#define HW_PAGE_SIZE 4096
#define HW_PAGE_INDEX_SHIFT 12
#define HW_PAGE_INDEX_MASK 0x3f
#define HW_PAGE_TAG_SHIFT 18