tcg/riscv: enable dynamic TLB sizing

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2018-12-26 17:01:48 +11:00
parent 4f47e338f6
commit 41b70f220b
2 changed files with 56 additions and 72 deletions

View File

@ -33,7 +33,7 @@
#define TCG_TARGET_INSN_UNIT_SIZE 4
#define TCG_TARGET_TLB_DISPLACEMENT_BITS 20
#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0
#define TCG_TARGET_IMPLEMENTS_DYN_TLB 1
#define TCG_TARGET_NB_REGS 32
typedef enum {

View File

@ -958,6 +958,17 @@ static void * const qemu_st_helpers[16] = {
[MO_BEQ] = helper_be_stq_mmu,
};
/* We don't support oversize guests */
QEMU_BUILD_BUG_ON(TCG_TARGET_REG_BITS < TARGET_LONG_BITS);
/* We expect tlb_mask to be before tlb_table. */
QEMU_BUILD_BUG_ON(offsetof(CPUArchState, tlb_table) <
offsetof(CPUArchState, tlb_mask));
/* We expect tlb_mask to be "near" tlb_table. */
QEMU_BUILD_BUG_ON(offsetof(CPUArchState, tlb_table) -
offsetof(CPUArchState, tlb_mask) >= 0x800);
static void tcg_out_tlb_load(TCGContext *s, TCGReg addrl,
TCGReg addrh, TCGMemOpIdx oi,
tcg_insn_unit **label_ptr, bool is_load)
@ -965,94 +976,67 @@ static void tcg_out_tlb_load(TCGContext *s, TCGReg addrl,
TCGMemOp opc = get_memop(oi);
unsigned s_bits = opc & MO_SIZE;
unsigned a_bits = get_alignment_bits(opc);
target_ulong mask;
tcg_target_long compare_mask;
int mem_index = get_mmuidx(oi);
int cmp_off
= (is_load
? offsetof(CPUArchState, tlb_table[mem_index][0].addr_read)
: offsetof(CPUArchState, tlb_table[mem_index][0].addr_write));
int add_off = offsetof(CPUArchState, tlb_table[mem_index][0].addend);
RISCVInsn load_cmp_op = (TARGET_LONG_BITS == 64 ? OPC_LD :
TCG_TARGET_REG_BITS == 64 ? OPC_LWU : OPC_LW);
RISCVInsn load_add_op = TCG_TARGET_REG_BITS == 64 ? OPC_LD : OPC_LW;
TCGReg base = TCG_AREG0;
int mask_off, table_off;
TCGReg mask_base = TCG_AREG0, table_base = TCG_AREG0;
/* We don't support oversize guests */
if (TCG_TARGET_REG_BITS < TARGET_LONG_BITS) {
g_assert_not_reached();
mask_off = offsetof(CPUArchState, tlb_mask[mem_index]);
table_off = offsetof(CPUArchState, tlb_table[mem_index]);
if (table_off > 0x7ff) {
int mask_hi = mask_off - sextreg(mask_off, 0, 12);
int table_hi = table_off - sextreg(table_off, 0, 12);
if (likely(mask_hi == table_hi)) {
mask_base = table_base = TCG_REG_TMP1;
tcg_out_opc_upper(s, OPC_LUI, mask_base, mask_hi);
tcg_out_opc_reg(s, OPC_ADD, mask_base, mask_base, TCG_AREG0);
mask_off -= mask_hi;
table_off -= mask_hi;
} else {
mask_base = TCG_REG_TMP0;
table_base = TCG_REG_TMP1;
tcg_out_opc_upper(s, OPC_LUI, mask_base, mask_hi);
tcg_out_opc_reg(s, OPC_ADD, mask_base, mask_base, TCG_AREG0);
table_off -= mask_off;
mask_off -= mask_hi;
tcg_out_opc_imm(s, OPC_ADDI, table_base, mask_base, mask_off);
}
}
tcg_out_ld(s, TCG_TYPE_PTR, TCG_REG_TMP0, mask_base, mask_off);
tcg_out_ld(s, TCG_TYPE_PTR, TCG_REG_TMP1, table_base, table_off);
tcg_out_opc_imm(s, OPC_SRLI, TCG_REG_TMP2, addrl,
TARGET_PAGE_BITS - CPU_TLB_ENTRY_BITS);
tcg_out_opc_reg(s, OPC_AND, TCG_REG_TMP2, TCG_REG_TMP2, TCG_REG_TMP0);
tcg_out_opc_reg(s, OPC_ADD, TCG_REG_TMP2, TCG_REG_TMP2, TCG_REG_TMP1);
/* Load the tlb comparator and the addend. */
tcg_out_ld(s, TCG_TYPE_TL, TCG_REG_TMP0, TCG_REG_TMP2,
is_load ? offsetof(CPUTLBEntry, addr_read)
: offsetof(CPUTLBEntry, addr_write));
tcg_out_ld(s, TCG_TYPE_PTR, TCG_REG_TMP2, TCG_REG_TMP2,
offsetof(CPUTLBEntry, addend));
/* We don't support unaligned accesses. */
if (a_bits < s_bits) {
a_bits = s_bits;
}
mask = (target_ulong)TARGET_PAGE_MASK | ((1 << a_bits) - 1);
/* Compensate for very large offsets. */
if (add_off >= 0x1000) {
int adj;
base = TCG_REG_TMP2;
if (cmp_off <= 2 * 0xfff) {
adj = 0xfff;
tcg_out_opc_imm(s, OPC_ADDI, base, TCG_AREG0, adj);
} else {
adj = cmp_off - sextreg(cmp_off, 0, 12);
tcg_debug_assert(add_off - adj >= -0x1000
&& add_off - adj < 0x1000);
tcg_out_opc_upper(s, OPC_LUI, base, adj);
tcg_out_opc_reg(s, OPC_ADD, base, base, TCG_AREG0);
}
add_off -= adj;
cmp_off -= adj;
}
/* Extract the page index. */
if (CPU_TLB_BITS + CPU_TLB_ENTRY_BITS < 12) {
tcg_out_opc_imm(s, OPC_SRLI, TCG_REG_TMP0, addrl,
TARGET_PAGE_BITS - CPU_TLB_ENTRY_BITS);
tcg_out_opc_imm(s, OPC_ANDI, TCG_REG_TMP0, TCG_REG_TMP0,
MAKE_64BIT_MASK(CPU_TLB_ENTRY_BITS, CPU_TLB_BITS));
} else if (TARGET_PAGE_BITS >= 12) {
tcg_out_opc_upper(s, OPC_LUI, TCG_REG_TMP0,
MAKE_64BIT_MASK(TARGET_PAGE_BITS, CPU_TLB_BITS));
tcg_out_opc_reg(s, OPC_AND, TCG_REG_TMP0, TCG_REG_TMP0, addrl);
tcg_out_opc_imm(s, OPC_SRLI, TCG_REG_TMP0, TCG_REG_TMP0,
CPU_TLB_BITS - CPU_TLB_ENTRY_BITS);
} else {
tcg_out_opc_imm(s, OPC_SRLI, TCG_REG_TMP0, addrl, TARGET_PAGE_BITS);
tcg_out_opc_imm(s, OPC_ANDI, TCG_REG_TMP0, TCG_REG_TMP0,
MAKE_64BIT_MASK(0, CPU_TLB_BITS));
tcg_out_opc_imm(s, OPC_SLLI, TCG_REG_TMP0, TCG_REG_TMP0,
CPU_TLB_ENTRY_BITS);
}
/* Add that to the base address to index the tlb. */
tcg_out_opc_reg(s, OPC_ADD, TCG_REG_TMP2, base, TCG_REG_TMP0);
base = TCG_REG_TMP2;
/* Load the tlb comparator and the addend. */
tcg_out_ldst(s, load_cmp_op, TCG_REG_TMP0, base, cmp_off);
tcg_out_ldst(s, load_add_op, TCG_REG_TMP2, base, add_off);
/* Clear the non-page, non-alignment bits from the address. */
if (mask == sextreg(mask, 0, 12)) {
tcg_out_opc_imm(s, OPC_ANDI, TCG_REG_TMP1, addrl, mask);
compare_mask = (tcg_target_long)TARGET_PAGE_MASK | ((1 << a_bits) - 1);
if (compare_mask == sextreg(compare_mask, 0, 12)) {
tcg_out_opc_imm(s, OPC_ANDI, TCG_REG_TMP1, addrl, compare_mask);
} else {
tcg_out_movi(s, TCG_TYPE_REG, TCG_REG_TMP1, mask);
tcg_out_movi(s, TCG_TYPE_TL, TCG_REG_TMP1, compare_mask);
tcg_out_opc_reg(s, OPC_AND, TCG_REG_TMP1, TCG_REG_TMP1, addrl);
}
}
/* Compare masked address with the TLB entry. */
label_ptr[0] = s->code_ptr;
tcg_out_opc_branch(s, OPC_BNE, TCG_REG_TMP0, TCG_REG_TMP1, 0);
/* NOP to allow patching later */
tcg_out_opc_imm(s, OPC_ADDI, TCG_REG_ZERO, TCG_REG_ZERO, 0);
/* TODO: Move this out of line
* see:
* https://lists.nongnu.org/archive/html/qemu-devel/2018-11/msg02234.html
*/
/* TLB Hit - translate address using addend. */
if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {