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MMU: implement misaligned cross-page accesses.

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This commit is contained in:
Maxim Poliakovski 2020-11-29 00:23:30 +01:00
parent 2be8e7b542
commit a775007d3a
1 changed files with 47 additions and 7 deletions
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54
cpu/ppc/ppcmmu.cpp
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@ -55,6 +55,8 @@ AddressMapEntry last_ptab_area = {0xFFFFFFFF, 0xFFFFFFFF};
AddressMapEntry last_dma_area = {0xFFFFFFFF, 0xFFFFFFFF}; AddressMapEntry last_dma_area = {0xFFFFFFFF, 0xFFFFFFFF};
#define WRITE_BYTE(addr, val) (*(addr) = val)
/* macro for generating code reading from physical memory */ /* macro for generating code reading from physical memory */
#define READ_PHYS_MEM(ENTRY, ADDR, OP, SIZE, UNVAL) \ #define READ_PHYS_MEM(ENTRY, ADDR, OP, SIZE, UNVAL) \
{ \ { \
@ -371,13 +373,32 @@ static uint32_t ppc_mmu_addr_translate(uint32_t la, int is_write) {
} }
static void mem_write_unaligned(uint32_t addr, uint32_t value, uint32_t size) { static void mem_write_unaligned(uint32_t addr, uint32_t value, uint32_t size) {
#ifdef MMU_DEBUG
LOG_F(WARNING, "Attempt to write unaligned %d bytes to 0x%08X\n", size, addr); LOG_F(WARNING, "Attempt to write unaligned %d bytes to 0x%08X\n", size, addr);
#endif
if (((addr & 0xFFF) + size) > 0x1000) { if (((addr & 0xFFF) + size) > 0x1000) {
LOG_F(ERROR, "SOS! Cross-page unaligned write, addr=%08X, size=%d\n", addr, size); // Special case: unaligned cross-page writes
exit(-1); // FIXME! LOG_F(WARNING, "Cross-page unaligned write, addr=%08X, size=%d\n",
addr, size);
uint32_t phys_addr;
uint32_t shift = (size - 1) * 8;
// Break misaligned memory accesses into multiple, smaller accesses
// and retranslate on page boundary.
// Because such accesses suffer a performance penalty, they will be
// presumably very rare so don't care much about performance.
for (int i = 0; i < size; shift -= 8, addr++, phys_addr++, i++) {
if ((ppc_state.msr & 0x10) && (!i || !(addr & 0xFFF))) {
phys_addr = ppc_mmu_addr_translate(addr, 0);
}
WRITE_PHYS_MEM(last_write_area, phys_addr, WRITE_BYTE,
(value >> shift) & 0xFF, 1);
}
} else { } else {
/* data address translation if enabled */ // data address translation if enabled
if (ppc_state.msr & 0x10) { if (ppc_state.msr & 0x10) {
addr = ppc_mmu_addr_translate(addr, 0); addr = ppc_mmu_addr_translate(addr, 0);
} }
@ -396,8 +417,6 @@ void mem_write_byte(uint32_t addr, uint8_t value) {
addr = ppc_mmu_addr_translate(addr, 1); addr = ppc_mmu_addr_translate(addr, 1);
} }
#define WRITE_BYTE(addr, val) (*(addr) = val)
WRITE_PHYS_MEM(last_write_area, addr, WRITE_BYTE, value, 1); WRITE_PHYS_MEM(last_write_area, addr, WRITE_BYTE, value, 1);
} }
@ -444,11 +463,32 @@ void mem_write_qword(uint32_t addr, uint64_t value) {
static uint32_t mem_grab_unaligned(uint32_t addr, uint32_t size) { static uint32_t mem_grab_unaligned(uint32_t addr, uint32_t size) {
uint32_t ret = 0; uint32_t ret = 0;
#ifdef MMU_DEBUG
LOG_F(WARNING, "Attempt to read unaligned %d bytes from 0x%08X\n", size, addr); LOG_F(WARNING, "Attempt to read unaligned %d bytes from 0x%08X\n", size, addr);
#endif
if (((addr & 0xFFF) + size) > 0x1000) { if (((addr & 0xFFF) + size) > 0x1000) {
LOG_F(ERROR, "SOS! Cross-page unaligned read, addr=%08X, size=%d\n", addr, size); // Special case: misaligned cross-page reads
exit(-1); // FIXME! LOG_F(WARNING, "Cross-page unaligned read, addr=%08X, size=%d\n",
addr, size);
uint32_t phys_addr;
uint32_t res = 0;
// Break misaligned memory accesses into multiple, smaller accesses
// and retranslate on page boundary.
// Because such accesses suffer a performance penalty, they will be
// presumably very rare so don't care much about performance.
for (int i = 0; i < size; addr++, phys_addr++, i++) {
if ((ppc_state.msr & 0x10) && (!i || !(addr & 0xFFF))) {
phys_addr = ppc_mmu_addr_translate(addr, 0);
}
READ_PHYS_MEM(last_read_area, phys_addr, *, 1, 0xFFU);
res = (res << 8) | ret;
}
return res;
} else { } else {
/* data address translation if enabled */ /* data address translation if enabled */
if (ppc_state.msr & 0x10) { if (ppc_state.msr & 0x10) {