/* * Common CPU TLB handling * * Copyright (c) 2003 Fabrice Bellard * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see <http://www.gnu.org/licenses/>. */ #include "config.h" #include "cpu.h" #include "exec/exec-all.h" #include "exec/memory.h" #include "exec/address-spaces.h" #include "exec/cputlb.h" #include "exec/memory-internal.h" //#define DEBUG_TLB //#define DEBUG_TLB_CHECK /* statistics */ int tlb_flush_count; static const CPUTLBEntry s_cputlb_empty_entry = { .addr_read = -1, .addr_write = -1, .addr_code = -1, .addend = -1, }; /* NOTE: * If flush_global is true (the usual case), flush all tlb entries. * If flush_global is false, flush (at least) all tlb entries not * marked global. * * Since QEMU doesn't currently implement a global/not-global flag * for tlb entries, at the moment tlb_flush() will also flush all * tlb entries in the flush_global == false case. This is OK because * CPU architectures generally permit an implementation to drop * entries from the TLB at any time, so flushing more entries than * required is only an efficiency issue, not a correctness issue. */ void tlb_flush(CPUArchState *env, int flush_global) { CPUState *cpu = ENV_GET_CPU(env); int i; #if defined(DEBUG_TLB) printf("tlb_flush:\n"); #endif /* must reset current TB so that interrupts cannot modify the links while we are modifying them */ cpu->current_tb = NULL; for (i = 0; i < CPU_TLB_SIZE; i++) { int mmu_idx; for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) { env->tlb_table[mmu_idx][i] = s_cputlb_empty_entry; } } memset(env->tb_jmp_cache, 0, TB_JMP_CACHE_SIZE * sizeof (void *)); env->tlb_flush_addr = -1; env->tlb_flush_mask = 0; tlb_flush_count++; } static inline void tlb_flush_entry(CPUTLBEntry *tlb_entry, target_ulong addr) { if (addr == (tlb_entry->addr_read & (TARGET_PAGE_MASK | TLB_INVALID_MASK)) || addr == (tlb_entry->addr_write & (TARGET_PAGE_MASK | TLB_INVALID_MASK)) || addr == (tlb_entry->addr_code & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) { *tlb_entry = s_cputlb_empty_entry; } } void tlb_flush_page(CPUArchState *env, target_ulong addr) { CPUState *cpu = ENV_GET_CPU(env); int i; int mmu_idx; #if defined(DEBUG_TLB) printf("tlb_flush_page: " TARGET_FMT_lx "\n", addr); #endif /* Check if we need to flush due to large pages. */ if ((addr & env->tlb_flush_mask) == env->tlb_flush_addr) { #if defined(DEBUG_TLB) printf("tlb_flush_page: forced full flush (" TARGET_FMT_lx "/" TARGET_FMT_lx ")\n", env->tlb_flush_addr, env->tlb_flush_mask); #endif tlb_flush(env, 1); return; } /* must reset current TB so that interrupts cannot modify the links while we are modifying them */ cpu->current_tb = NULL; addr &= TARGET_PAGE_MASK; i = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1); for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) { tlb_flush_entry(&env->tlb_table[mmu_idx][i], addr); } tb_flush_jmp_cache(env, addr); } /* update the TLBs so that writes to code in the virtual page 'addr' can be detected */ void tlb_protect_code(ram_addr_t ram_addr) { cpu_physical_memory_reset_dirty(ram_addr, ram_addr + TARGET_PAGE_SIZE, CODE_DIRTY_FLAG); } /* update the TLB so that writes in physical page 'phys_addr' are no longer tested for self modifying code */ void tlb_unprotect_code_phys(CPUArchState *env, ram_addr_t ram_addr, target_ulong vaddr) { cpu_physical_memory_set_dirty_flags(ram_addr, CODE_DIRTY_FLAG); } static bool tlb_is_dirty_ram(CPUTLBEntry *tlbe) { return (tlbe->addr_write & (TLB_INVALID_MASK|TLB_MMIO|TLB_NOTDIRTY)) == 0; } void tlb_reset_dirty_range(CPUTLBEntry *tlb_entry, uintptr_t start, uintptr_t length) { uintptr_t addr; if (tlb_is_dirty_ram(tlb_entry)) { addr = (tlb_entry->addr_write & TARGET_PAGE_MASK) + tlb_entry->addend; if ((addr - start) < length) { tlb_entry->addr_write |= TLB_NOTDIRTY; } } } static inline void tlb_update_dirty(CPUTLBEntry *tlb_entry) { ram_addr_t ram_addr; void *p; if (tlb_is_dirty_ram(tlb_entry)) { p = (void *)(uintptr_t)((tlb_entry->addr_write & TARGET_PAGE_MASK) + tlb_entry->addend); ram_addr = qemu_ram_addr_from_host_nofail(p); if (!cpu_physical_memory_is_dirty(ram_addr)) { tlb_entry->addr_write |= TLB_NOTDIRTY; } } } void cpu_tlb_reset_dirty_all(ram_addr_t start1, ram_addr_t length) { CPUArchState *env; for (env = first_cpu; env != NULL; env = env->next_cpu) { int mmu_idx; for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) { unsigned int i; for (i = 0; i < CPU_TLB_SIZE; i++) { tlb_reset_dirty_range(&env->tlb_table[mmu_idx][i], start1, length); } } } } static inline void tlb_set_dirty1(CPUTLBEntry *tlb_entry, target_ulong vaddr) { if (tlb_entry->addr_write == (vaddr | TLB_NOTDIRTY)) { tlb_entry->addr_write = vaddr; } } /* update the TLB corresponding to virtual page vaddr so that it is no longer dirty */ void tlb_set_dirty(CPUArchState *env, target_ulong vaddr) { int i; int mmu_idx; vaddr &= TARGET_PAGE_MASK; i = (vaddr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1); for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) { tlb_set_dirty1(&env->tlb_table[mmu_idx][i], vaddr); } } /* Our TLB does not support large pages, so remember the area covered by large pages and trigger a full TLB flush if these are invalidated. */ static void tlb_add_large_page(CPUArchState *env, target_ulong vaddr, target_ulong size) { target_ulong mask = ~(size - 1); if (env->tlb_flush_addr == (target_ulong)-1) { env->tlb_flush_addr = vaddr & mask; env->tlb_flush_mask = mask; return; } /* Extend the existing region to include the new page. This is a compromise between unnecessary flushes and the cost of maintaining a full variable size TLB. */ mask &= env->tlb_flush_mask; while (((env->tlb_flush_addr ^ vaddr) & mask) != 0) { mask <<= 1; } env->tlb_flush_addr &= mask; env->tlb_flush_mask = mask; } /* Add a new TLB entry. At most one entry for a given virtual address is permitted. Only a single TARGET_PAGE_SIZE region is mapped, the supplied size is only used by tlb_flush_page. */ void tlb_set_page(CPUArchState *env, target_ulong vaddr, hwaddr paddr, int prot, int mmu_idx, target_ulong size) { MemoryRegionSection *section; unsigned int index; target_ulong address; target_ulong code_address; uintptr_t addend; CPUTLBEntry *te; hwaddr iotlb, xlat, sz; assert(size >= TARGET_PAGE_SIZE); if (size != TARGET_PAGE_SIZE) { tlb_add_large_page(env, vaddr, size); } sz = size; section = address_space_translate(&address_space_memory, paddr, &xlat, &sz, false); assert(sz >= TARGET_PAGE_SIZE); #if defined(DEBUG_TLB) printf("tlb_set_page: vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx " prot=%x idx=%d pd=0x%08lx\n", vaddr, paddr, prot, mmu_idx, pd); #endif address = vaddr; if (!memory_region_is_ram(section->mr) && !memory_region_is_romd(section->mr)) { /* IO memory case */ address |= TLB_MMIO; addend = 0; } else { /* TLB_MMIO for rom/romd handled below */ addend = (uintptr_t)memory_region_get_ram_ptr(section->mr) + xlat; } code_address = address; iotlb = memory_region_section_get_iotlb(env, section, vaddr, paddr, xlat, prot, &address); index = (vaddr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1); env->iotlb[mmu_idx][index] = iotlb - vaddr; te = &env->tlb_table[mmu_idx][index]; te->addend = addend - vaddr; if (prot & PAGE_READ) { te->addr_read = address; } else { te->addr_read = -1; } if (prot & PAGE_EXEC) { te->addr_code = code_address; } else { te->addr_code = -1; } if (prot & PAGE_WRITE) { if ((memory_region_is_ram(section->mr) && section->readonly) || memory_region_is_romd(section->mr)) { /* Write access calls the I/O callback. */ te->addr_write = address | TLB_MMIO; } else if (memory_region_is_ram(section->mr) && !cpu_physical_memory_is_dirty(section->mr->ram_addr + xlat)) { te->addr_write = address | TLB_NOTDIRTY; } else { te->addr_write = address; } } else { te->addr_write = -1; } } /* NOTE: this function can trigger an exception */ /* NOTE2: the returned address is not exactly the physical address: it * is actually a ram_addr_t (in system mode; the user mode emulation * version of this function returns a guest virtual address). */ tb_page_addr_t get_page_addr_code(CPUArchState *env1, target_ulong addr) { int mmu_idx, page_index, pd; void *p; MemoryRegion *mr; page_index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1); mmu_idx = cpu_mmu_index(env1); if (unlikely(env1->tlb_table[mmu_idx][page_index].addr_code != (addr & TARGET_PAGE_MASK))) { cpu_ldub_code(env1, addr); } pd = env1->iotlb[mmu_idx][page_index] & ~TARGET_PAGE_MASK; mr = iotlb_to_region(pd); if (memory_region_is_unassigned(mr)) { #if defined(TARGET_ALPHA) || defined(TARGET_MIPS) || defined(TARGET_SPARC) cpu_unassigned_access(env1, addr, 0, 1, 0, 4); #else cpu_abort(env1, "Trying to execute code outside RAM or ROM at 0x" TARGET_FMT_lx "\n", addr); #endif } p = (void *)((uintptr_t)addr + env1->tlb_table[mmu_idx][page_index].addend); return qemu_ram_addr_from_host_nofail(p); } #define MMUSUFFIX _cmmu #undef GETPC #define GETPC() ((uintptr_t)0) #define SOFTMMU_CODE_ACCESS #define SHIFT 0 #include "exec/softmmu_template.h" #define SHIFT 1 #include "exec/softmmu_template.h" #define SHIFT 2 #include "exec/softmmu_template.h" #define SHIFT 3 #include "exec/softmmu_template.h" #undef env