On 01/08/2018 03:10 PM, Laurent Vivier wrote:
> +static int get_physical_address(CPUM68KState *env, hwaddr *physical,
> + int *prot, target_ulong address,
> + int access_type, target_ulong *page_size)
> +{
> + M68kCPU *cpu = m68k_env_get_cpu(env);
> + CPUState *cs = CPU(cpu);
> + uint32_t page_offset;
> + uint32_t entry;
> + uint32_t next;
> +
> + /* Page Table Root Pointer */
> + *prot = PAGE_READ | PAGE_WRITE;
> + if (access_type & ACCESS_CODE) {
> + *prot |= PAGE_EXEC;
> + }
> + if (access_type & ACCESS_SUPER) {
> + next = env->mmu.srp;
> + } else {
> + next = env->mmu.urp;
> + }
> +
> + /* Root Index */
> + entry = M68K_POINTER_BASE(next) | M68K_ROOT_INDEX(address);
> +
> + next = ldl_phys(cs->as, entry);
> + if (!M68K_UDT_VALID(next)) {
> + return -1;
> + }
> + if (!(next & M68K_DESC_USED)) {
> + stl_phys(cs->as, entry, next | M68K_DESC_USED);
> + }
You may want to add ACCESS_DEBUG or some such so that probes from gdb and the
monitor interface do not alter the cpu state.
> + if (env->mmu.tcr & M68K_TCR_PAGE_8K) {
> + *page_size = 8192;
> + page_offset = address & 0x1fff;
> + *physical = (next & ~0x1fff) + page_offset;
> + } else {
> + *page_size = 4096;
> + page_offset = address & 0x0fff;
> + *physical = (next & ~0x0fff) + page_offset;
> + }
So...
> + if (ret == 0) {
> + tlb_set_page(cs, address & TARGET_PAGE_MASK,
> + physical & TARGET_PAGE_MASK,
> + prot, mmu_idx, page_size);
... this is going to go through the tlb_add_large_page path every time, since
both 4K and 8K are larger than the default 1K page size.
Using the large page path by default means that any single-page tlb flush will
quickly devolve to flushing the entire tlb.
Also, using page_size and TARGET_PAGE_MASK looks wrong. I think you would have
needed address & -page_size.
That said, you may want to compare the performance of passing page_size vs
TARGET_PAGE_SIZE to tlb_set_page.
> +++ b/target/m68k/op_helper.c
> @@ -360,7 +360,50 @@ static void m68k_interrupt_all(CPUM68KState *env, int
> is_hw)
> sp = env->aregs[7];
>
> sp &= ~1;
> - if (cs->exception_index == EXCP_ADDRESS) {
> + if (cs->exception_index == EXCP_ACCESS) {
> + static int mmu_fault;
> + if (mmu_fault) {
> + cpu_abort(cs, "DOUBLE MMU FAULT\n");
> + }
> + mmu_fault = 1;
This variable shouldn't be static -- it should be in CPUM68KState or M68kCPU.
r~
