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accel/tcg: Introduce tlb_read_idx 
Instead of playing with offsetof in various places, use
MMUAccessType to index an array.  This is easily defined
instead of the previous dummy padding array in the union.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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@rth7680
rth7680 committed May 11, 2023
1 parent 9877ea0 commit 0b3c75a
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Showing 3 changed files with 57 additions and 76 deletions.
104 changes: 33 additions & 71 deletions accel/tcg/cputlb.c
View file
Expand Up @@ -1441,34 +1441,17 @@ static void io_writex(CPUArchState *env, CPUTLBEntryFull *full,
}
}

static inline target_ulong tlb_read_ofs(CPUTLBEntry *entry, size_t ofs)
{
#if TCG_OVERSIZED_GUEST
return *(target_ulong *)((uintptr_t)entry + ofs);
#else
/* ofs might correspond to .addr_write, so use qatomic_read */
return qatomic_read((target_ulong *)((uintptr_t)entry + ofs));
#endif
}

/* Return true if ADDR is present in the victim tlb, and has been copied
back to the main tlb. */
static bool victim_tlb_hit(CPUArchState *env, size_t mmu_idx, size_t index,
size_t elt_ofs, target_ulong page)
MMUAccessType access_type, target_ulong page)
{
size_t vidx;

assert_cpu_is_self(env_cpu(env));
for (vidx = 0; vidx < CPU_VTLB_SIZE; ++vidx) {
CPUTLBEntry *vtlb = &env_tlb(env)->d[mmu_idx].vtable[vidx];
target_ulong cmp;

/* elt_ofs might correspond to .addr_write, so use qatomic_read */
#if TCG_OVERSIZED_GUEST
cmp = *(target_ulong *)((uintptr_t)vtlb + elt_ofs);
#else
cmp = qatomic_read((target_ulong *)((uintptr_t)vtlb + elt_ofs));
#endif
target_ulong cmp = tlb_read_idx(vtlb, access_type);

if (cmp == page) {
/* Found entry in victim tlb, swap tlb and iotlb. */
Expand All @@ -1490,11 +1473,6 @@ static bool victim_tlb_hit(CPUArchState *env, size_t mmu_idx, size_t index,
return false;
}

/* Macro to call the above, with local variables from the use context. */
#define VICTIM_TLB_HIT(TY, ADDR) \
victim_tlb_hit(env, mmu_idx, index, offsetof(CPUTLBEntry, TY), \
(ADDR) & TARGET_PAGE_MASK)

static void notdirty_write(CPUState *cpu, vaddr mem_vaddr, unsigned size,
CPUTLBEntryFull *full, uintptr_t retaddr)
{
Expand Down Expand Up @@ -1527,29 +1505,12 @@ static int probe_access_internal(CPUArchState *env, target_ulong addr,
{
uintptr_t index = tlb_index(env, mmu_idx, addr);
CPUTLBEntry *entry = tlb_entry(env, mmu_idx, addr);
target_ulong tlb_addr, page_addr;
size_t elt_ofs;
int flags;

switch (access_type) {
case MMU_DATA_LOAD:
elt_ofs = offsetof(CPUTLBEntry, addr_read);
break;
case MMU_DATA_STORE:
elt_ofs = offsetof(CPUTLBEntry, addr_write);
break;
case MMU_INST_FETCH:
elt_ofs = offsetof(CPUTLBEntry, addr_code);
break;
default:
g_assert_not_reached();
}
tlb_addr = tlb_read_ofs(entry, elt_ofs);
target_ulong tlb_addr = tlb_read_idx(entry, access_type);
target_ulong page_addr = addr & TARGET_PAGE_MASK;
int flags = TLB_FLAGS_MASK;

flags = TLB_FLAGS_MASK;
page_addr = addr & TARGET_PAGE_MASK;
if (!tlb_hit_page(tlb_addr, page_addr)) {
if (!victim_tlb_hit(env, mmu_idx, index, elt_ofs, page_addr)) {
if (!victim_tlb_hit(env, mmu_idx, index, access_type, page_addr)) {
CPUState *cs = env_cpu(env);

if (!cs->cc->tcg_ops->tlb_fill(cs, addr, fault_size, access_type,
Expand All @@ -1571,7 +1532,7 @@ static int probe_access_internal(CPUArchState *env, target_ulong addr,
*/
flags &= ~TLB_INVALID_MASK;
}
tlb_addr = tlb_read_ofs(entry, elt_ofs);
tlb_addr = tlb_read_idx(entry, access_type);
}
flags &= tlb_addr;

Expand Down Expand Up @@ -1802,7 +1763,8 @@ static void *atomic_mmu_lookup(CPUArchState *env, target_ulong addr,
if (prot & PAGE_WRITE) {
tlb_addr = tlb_addr_write(tlbe);
if (!tlb_hit(tlb_addr, addr)) {
if (!VICTIM_TLB_HIT(addr_write, addr)) {
if (!victim_tlb_hit(env, mmu_idx, index, MMU_DATA_STORE,
addr & TARGET_PAGE_MASK)) {
tlb_fill(env_cpu(env), addr, size,
MMU_DATA_STORE, mmu_idx, retaddr);
index = tlb_index(env, mmu_idx, addr);
Expand Down Expand Up @@ -1835,7 +1797,8 @@ static void *atomic_mmu_lookup(CPUArchState *env, target_ulong addr,
} else /* if (prot & PAGE_READ) */ {
tlb_addr = tlbe->addr_read;
if (!tlb_hit(tlb_addr, addr)) {
if (!VICTIM_TLB_HIT(addr_read, addr)) {
if (!victim_tlb_hit(env, mmu_idx, index, MMU_DATA_LOAD,
addr & TARGET_PAGE_MASK)) {
tlb_fill(env_cpu(env), addr, size,
MMU_DATA_LOAD, mmu_idx, retaddr);
index = tlb_index(env, mmu_idx, addr);
Expand Down Expand Up @@ -1929,13 +1892,9 @@ load_memop(const void *haddr, MemOp op)

static inline uint64_t QEMU_ALWAYS_INLINE
load_helper(CPUArchState *env, target_ulong addr, MemOpIdx oi,
uintptr_t retaddr, MemOp op, bool code_read,
uintptr_t retaddr, MemOp op, MMUAccessType access_type,
FullLoadHelper *full_load)
{
const size_t tlb_off = code_read ?
offsetof(CPUTLBEntry, addr_code) : offsetof(CPUTLBEntry, addr_read);
const MMUAccessType access_type =
code_read ? MMU_INST_FETCH : MMU_DATA_LOAD;
const unsigned a_bits = get_alignment_bits(get_memop(oi));
const size_t size = memop_size(op);
uintptr_t mmu_idx = get_mmuidx(oi);
Expand All @@ -1955,18 +1914,18 @@ load_helper(CPUArchState *env, target_ulong addr, MemOpIdx oi,

index = tlb_index(env, mmu_idx, addr);
entry = tlb_entry(env, mmu_idx, addr);
tlb_addr = code_read ? entry->addr_code : entry->addr_read;
tlb_addr = tlb_read_idx(entry, access_type);

/* If the TLB entry is for a different page, reload and try again. */
if (!tlb_hit(tlb_addr, addr)) {
if (!victim_tlb_hit(env, mmu_idx, index, tlb_off,
if (!victim_tlb_hit(env, mmu_idx, index, access_type,
addr & TARGET_PAGE_MASK)) {
tlb_fill(env_cpu(env), addr, size,
access_type, mmu_idx, retaddr);
index = tlb_index(env, mmu_idx, addr);
entry = tlb_entry(env, mmu_idx, addr);
}
tlb_addr = code_read ? entry->addr_code : entry->addr_read;
tlb_addr = tlb_read_idx(entry, access_type);
tlb_addr &= ~TLB_INVALID_MASK;
}

Expand Down Expand Up @@ -2052,7 +2011,8 @@ static uint64_t full_ldub_mmu(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
validate_memop(oi, MO_UB);
return load_helper(env, addr, oi, retaddr, MO_UB, false, full_ldub_mmu);
return load_helper(env, addr, oi, retaddr, MO_UB, MMU_DATA_LOAD,
full_ldub_mmu);
}

tcg_target_ulong helper_ret_ldub_mmu(CPUArchState *env, target_ulong addr,
Expand All @@ -2065,7 +2025,7 @@ static uint64_t full_le_lduw_mmu(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
validate_memop(oi, MO_LEUW);
return load_helper(env, addr, oi, retaddr, MO_LEUW, false,
return load_helper(env, addr, oi, retaddr, MO_LEUW, MMU_DATA_LOAD,
full_le_lduw_mmu);
}

Expand All @@ -2079,7 +2039,7 @@ static uint64_t full_be_lduw_mmu(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
validate_memop(oi, MO_BEUW);
return load_helper(env, addr, oi, retaddr, MO_BEUW, false,
return load_helper(env, addr, oi, retaddr, MO_BEUW, MMU_DATA_LOAD,
full_be_lduw_mmu);
}

Expand All @@ -2093,7 +2053,7 @@ static uint64_t full_le_ldul_mmu(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
validate_memop(oi, MO_LEUL);
return load_helper(env, addr, oi, retaddr, MO_LEUL, false,
return load_helper(env, addr, oi, retaddr, MO_LEUL, MMU_DATA_LOAD,
full_le_ldul_mmu);
}

Expand All @@ -2107,7 +2067,7 @@ static uint64_t full_be_ldul_mmu(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
validate_memop(oi, MO_BEUL);
return load_helper(env, addr, oi, retaddr, MO_BEUL, false,
return load_helper(env, addr, oi, retaddr, MO_BEUL, MMU_DATA_LOAD,
full_be_ldul_mmu);
}

Expand All @@ -2121,15 +2081,15 @@ uint64_t helper_le_ldq_mmu(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
validate_memop(oi, MO_LEUQ);
return load_helper(env, addr, oi, retaddr, MO_LEUQ, false,
return load_helper(env, addr, oi, retaddr, MO_LEUQ, MMU_DATA_LOAD,
helper_le_ldq_mmu);
}

uint64_t helper_be_ldq_mmu(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
validate_memop(oi, MO_BEUQ);
return load_helper(env, addr, oi, retaddr, MO_BEUQ, false,
return load_helper(env, addr, oi, retaddr, MO_BEUQ, MMU_DATA_LOAD,
helper_be_ldq_mmu);
}

Expand Down Expand Up @@ -2325,7 +2285,6 @@ store_helper_unaligned(CPUArchState *env, target_ulong addr, uint64_t val,
uintptr_t retaddr, size_t size, uintptr_t mmu_idx,
bool big_endian)
{
const size_t tlb_off = offsetof(CPUTLBEntry, addr_write);
uintptr_t index, index2;
CPUTLBEntry *entry, *entry2;
target_ulong page1, page2, tlb_addr, tlb_addr2;
Expand All @@ -2347,7 +2306,7 @@ store_helper_unaligned(CPUArchState *env, target_ulong addr, uint64_t val,

tlb_addr2 = tlb_addr_write(entry2);
if (page1 != page2 && !tlb_hit_page(tlb_addr2, page2)) {
if (!victim_tlb_hit(env, mmu_idx, index2, tlb_off, page2)) {
if (!victim_tlb_hit(env, mmu_idx, index2, MMU_DATA_STORE, page2)) {
tlb_fill(env_cpu(env), page2, size2, MMU_DATA_STORE,
mmu_idx, retaddr);
index2 = tlb_index(env, mmu_idx, page2);
Expand Down Expand Up @@ -2400,7 +2359,6 @@ static inline void QEMU_ALWAYS_INLINE
store_helper(CPUArchState *env, target_ulong addr, uint64_t val,
MemOpIdx oi, uintptr_t retaddr, MemOp op)
{
const size_t tlb_off = offsetof(CPUTLBEntry, addr_write);
const unsigned a_bits = get_alignment_bits(get_memop(oi));
const size_t size = memop_size(op);
uintptr_t mmu_idx = get_mmuidx(oi);
Expand All @@ -2423,7 +2381,7 @@ store_helper(CPUArchState *env, target_ulong addr, uint64_t val,

/* If the TLB entry is for a different page, reload and try again. */
if (!tlb_hit(tlb_addr, addr)) {
if (!victim_tlb_hit(env, mmu_idx, index, tlb_off,
if (!victim_tlb_hit(env, mmu_idx, index, MMU_DATA_STORE,
addr & TARGET_PAGE_MASK)) {
tlb_fill(env_cpu(env), addr, size, MMU_DATA_STORE,
mmu_idx, retaddr);
Expand Down Expand Up @@ -2729,7 +2687,8 @@ void cpu_st16_le_mmu(CPUArchState *env, abi_ptr addr, Int128 val,
static uint64_t full_ldub_code(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
return load_helper(env, addr, oi, retaddr, MO_8, true, full_ldub_code);
return load_helper(env, addr, oi, retaddr, MO_8,
MMU_INST_FETCH, full_ldub_code);
}

uint32_t cpu_ldub_code(CPUArchState *env, abi_ptr addr)
Expand All @@ -2741,7 +2700,8 @@ uint32_t cpu_ldub_code(CPUArchState *env, abi_ptr addr)
static uint64_t full_lduw_code(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
return load_helper(env, addr, oi, retaddr, MO_TEUW, true, full_lduw_code);
return load_helper(env, addr, oi, retaddr, MO_TEUW,
MMU_INST_FETCH, full_lduw_code);
}

uint32_t cpu_lduw_code(CPUArchState *env, abi_ptr addr)
Expand All @@ -2753,7 +2713,8 @@ uint32_t cpu_lduw_code(CPUArchState *env, abi_ptr addr)
static uint64_t full_ldl_code(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
return load_helper(env, addr, oi, retaddr, MO_TEUL, true, full_ldl_code);
return load_helper(env, addr, oi, retaddr, MO_TEUL,
MMU_INST_FETCH, full_ldl_code);
}

uint32_t cpu_ldl_code(CPUArchState *env, abi_ptr addr)
Expand All @@ -2765,7 +2726,8 @@ uint32_t cpu_ldl_code(CPUArchState *env, abi_ptr addr)
static uint64_t full_ldq_code(CPUArchState *env, target_ulong addr,
MemOpIdx oi, uintptr_t retaddr)
{
return load_helper(env, addr, oi, retaddr, MO_TEUQ, true, full_ldq_code);
return load_helper(env, addr, oi, retaddr, MO_TEUQ,
MMU_INST_FETCH, full_ldq_code);
}

uint64_t cpu_ldq_code(CPUArchState *env, abi_ptr addr)
Expand Down
7 changes: 5 additions & 2 deletions include/exec/cpu-defs.h
View file
Expand Up @@ -111,8 +111,11 @@ typedef struct CPUTLBEntry {
use the corresponding iotlb value. */
uintptr_t addend;
};
/* padding to get a power of two size */
uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
/*
* Padding to get a power of two size, as well as index
* access to addr_{read,write,code}.
*/
target_ulong addr_idx[(1 << CPU_TLB_ENTRY_BITS) / TARGET_LONG_SIZE];
};
} CPUTLBEntry;

Expand Down
22 changes: 19 additions & 3 deletions include/exec/cpu_ldst.h
View file
Expand Up @@ -360,15 +360,31 @@ static inline void clear_helper_retaddr(void)
/* Needed for TCG_OVERSIZED_GUEST */
#include "tcg/tcg.h"

static inline target_ulong tlb_addr_write(const CPUTLBEntry *entry)
static inline target_ulong tlb_read_idx(const CPUTLBEntry *entry,
MMUAccessType access_type)
{
/* Do not rearrange the CPUTLBEntry structure members. */
QEMU_BUILD_BUG_ON(offsetof(CPUTLBEntry, addr_read) !=
MMU_DATA_LOAD * TARGET_LONG_SIZE);
QEMU_BUILD_BUG_ON(offsetof(CPUTLBEntry, addr_write) !=
MMU_DATA_STORE * TARGET_LONG_SIZE);
QEMU_BUILD_BUG_ON(offsetof(CPUTLBEntry, addr_code) !=
MMU_INST_FETCH * TARGET_LONG_SIZE);

const target_ulong *ptr = &entry->addr_idx[access_type];
#if TCG_OVERSIZED_GUEST
return entry->addr_write;
return *ptr;
#else
return qatomic_read(&entry->addr_write);
/* ofs might correspond to .addr_write, so use qatomic_read */
return qatomic_read(ptr);
#endif
}

static inline target_ulong tlb_addr_write(const CPUTLBEntry *entry)
{
return tlb_read_idx(entry, MMU_DATA_STORE);
}

/* Find the TLB index corresponding to the mmu_idx + address pair. */
static inline uintptr_t tlb_index(CPUArchState *env, uintptr_t mmu_idx,
target_ulong addr)
Expand Down

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