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authorRichard Henderson <richard.henderson@linaro.org>2019-01-22 20:33:03 -0800
committerRichard Henderson <richard.henderson@linaro.org>2019-01-28 07:04:10 -0800
commitcd7d3cb7a26297c2ca28da68bbc7aacec0c04d25 (patch)
tree8706e8dd41d77a4535a56254da3c9798c1cf2b3a
parent41b70f220b8395ea1ceabb6bd4ee53a0eba195ef (diff)
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tcg/arm: enable dynamic TLB sizing
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
-rw-r--r--tcg/arm/tcg-target.h2
-rw-r--r--tcg/arm/tcg-target.inc.c139
2 files changed, 70 insertions, 71 deletions
diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
index c5a7064..679aaf0 100644
--- a/tcg/arm/tcg-target.h
+++ b/tcg/arm/tcg-target.h
@@ -60,7 +60,7 @@ extern int arm_arch;
#undef TCG_TARGET_STACK_GROWSUP
#define TCG_TARGET_INSN_UNIT_SIZE 4
#define TCG_TARGET_TLB_DISPLACEMENT_BITS 16
-#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0
+#define TCG_TARGET_IMPLEMENTS_DYN_TLB 1
typedef enum {
TCG_REG_R0 = 0,
diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c
index 49f57d6..2245a8a 100644
--- a/tcg/arm/tcg-target.inc.c
+++ b/tcg/arm/tcg-target.inc.c
@@ -500,6 +500,12 @@ static inline void tcg_out_ldrd_r(TCGContext *s, int cond, TCGReg rt,
tcg_out_memop_r(s, cond, INSN_LDRD_REG, rt, rn, rm, 1, 1, 0);
}
+static inline void tcg_out_ldrd_rwb(TCGContext *s, int cond, TCGReg rt,
+ TCGReg rn, TCGReg rm)
+{
+ tcg_out_memop_r(s, cond, INSN_LDRD_REG, rt, rn, rm, 1, 1, 1);
+}
+
static inline void tcg_out_strd_8(TCGContext *s, int cond, TCGReg rt,
TCGReg rn, int imm8)
{
@@ -1229,8 +1235,13 @@ static TCGReg tcg_out_arg_reg64(TCGContext *s, TCGReg argreg,
#define TLB_SHIFT (CPU_TLB_ENTRY_BITS + CPU_TLB_BITS)
-/* We're expecting to use an 8-bit immediate and to mask. */
-QEMU_BUILD_BUG_ON(CPU_TLB_BITS > 8);
+/* We expect tlb_mask to be before tlb_table. */
+QEMU_BUILD_BUG_ON(offsetof(CPUArchState, tlb_table) <
+ offsetof(CPUArchState, tlb_mask));
+
+/* We expect to use a 20-bit unsigned offset from ENV. */
+QEMU_BUILD_BUG_ON(offsetof(CPUArchState, tlb_table[NB_MMU_MODES - 1])
+ > 0xfffff);
/* Load and compare a TLB entry, leaving the flags set. Returns the register
containing the addend of the tlb entry. Clobbers R0, R1, R2, TMP. */
@@ -1238,84 +1249,72 @@ QEMU_BUILD_BUG_ON(CPU_TLB_BITS > 8);
static TCGReg tcg_out_tlb_read(TCGContext *s, TCGReg addrlo, TCGReg addrhi,
TCGMemOp opc, int mem_index, bool is_load)
{
- TCGReg base = TCG_AREG0;
- 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);
- int mask_off;
+ int cmp_off = (is_load ? offsetof(CPUTLBEntry, addr_read)
+ : offsetof(CPUTLBEntry, addr_write));
+ int mask_off = offsetof(CPUArchState, tlb_mask[mem_index]);
+ int table_off = offsetof(CPUArchState, tlb_table[mem_index]);
+ TCGReg mask_base = TCG_AREG0, table_base = TCG_AREG0;
unsigned s_bits = opc & MO_SIZE;
unsigned a_bits = get_alignment_bits(opc);
- /* V7 generates the following:
- * ubfx r0, addrlo, #TARGET_PAGE_BITS, #CPU_TLB_BITS
- * add r2, env, #high
- * add r2, r2, r0, lsl #CPU_TLB_ENTRY_BITS
- * ldr r0, [r2, #cmp]
- * ldr r2, [r2, #add]
- * movw tmp, #page_align_mask
- * bic tmp, addrlo, tmp
- * cmp r0, tmp
- *
- * Otherwise we generate:
- * shr tmp, addrlo, #TARGET_PAGE_BITS
- * add r2, env, #high
- * and r0, tmp, #(CPU_TLB_SIZE - 1)
- * add r2, r2, r0, lsl #CPU_TLB_ENTRY_BITS
- * ldr r0, [r2, #cmp]
- * ldr r2, [r2, #add]
- * tst addrlo, #s_mask
- * cmpeq r0, tmp, lsl #TARGET_PAGE_BITS
- */
- if (use_armv7_instructions) {
- tcg_out_extract(s, COND_AL, TCG_REG_R0, addrlo,
- TARGET_PAGE_BITS, CPU_TLB_BITS);
- } else {
- tcg_out_dat_reg(s, COND_AL, ARITH_MOV, TCG_REG_TMP,
- 0, addrlo, SHIFT_IMM_LSR(TARGET_PAGE_BITS));
- }
+ if (table_off > 0xfff) {
+ int mask_hi = mask_off & ~0xfff;
+ int table_hi = table_off & ~0xfff;
+ int rot;
+
+ table_base = TCG_REG_R2;
+ if (mask_hi == table_hi) {
+ mask_base = table_base;
+ } else if (mask_hi) {
+ mask_base = TCG_REG_TMP;
+ rot = encode_imm(mask_hi);
+ assert(rot >= 0);
+ tcg_out_dat_imm(s, COND_AL, ARITH_ADD, mask_base, TCG_AREG0,
+ rotl(mask_hi, rot) | (rot << 7));
+ }
+ rot = encode_imm(table_hi);
+ assert(rot >= 0);
+ tcg_out_dat_imm(s, COND_AL, ARITH_ADD, table_base, TCG_AREG0,
+ rotl(table_hi, rot) | (rot << 7));
- /* Add portions of the offset until the memory access is in range.
- * If we plan on using ldrd, reduce to an 8-bit offset; otherwise
- * we can use a 12-bit offset. */
- if (use_armv6_instructions && TARGET_LONG_BITS == 64) {
- mask_off = 0xff;
- } else {
- mask_off = 0xfff;
- }
- while (cmp_off > mask_off) {
- int shift = ctz32(cmp_off & ~mask_off) & ~1;
- int rot = ((32 - shift) << 7) & 0xf00;
- int addend = cmp_off & (0xff << shift);
- tcg_out_dat_imm(s, COND_AL, ARITH_ADD, TCG_REG_R2, base,
- rot | ((cmp_off >> shift) & 0xff));
- base = TCG_REG_R2;
- add_off -= addend;
- cmp_off -= addend;
+ mask_off -= mask_hi;
+ table_off -= table_hi;
}
- if (!use_armv7_instructions) {
- tcg_out_dat_imm(s, COND_AL, ARITH_AND,
- TCG_REG_R0, TCG_REG_TMP, CPU_TLB_SIZE - 1);
- }
- tcg_out_dat_reg(s, COND_AL, ARITH_ADD, TCG_REG_R2, base,
- TCG_REG_R0, SHIFT_IMM_LSL(CPU_TLB_ENTRY_BITS));
-
- /* Load the tlb comparator. Use ldrd if needed and available,
- but due to how the pointer needs setting up, ldm isn't useful.
- Base arm5 doesn't have ldrd, but armv5te does. */
- if (use_armv6_instructions && TARGET_LONG_BITS == 64) {
- tcg_out_ldrd_8(s, COND_AL, TCG_REG_R0, TCG_REG_R2, cmp_off);
- } else {
- tcg_out_ld32_12(s, COND_AL, TCG_REG_R0, TCG_REG_R2, cmp_off);
- if (TARGET_LONG_BITS == 64) {
- tcg_out_ld32_12(s, COND_AL, TCG_REG_R1, TCG_REG_R2, cmp_off + 4);
+ /* Load tlb_mask[mmu_idx] and tlb_table[mmu_idx]. */
+ tcg_out_ld(s, TCG_TYPE_I32, TCG_REG_TMP, mask_base, mask_off);
+ tcg_out_ld(s, TCG_TYPE_I32, TCG_REG_R2, table_base, table_off);
+
+ /* Extract the tlb index from the address into TMP. */
+ tcg_out_dat_reg(s, COND_AL, ARITH_AND, TCG_REG_TMP, TCG_REG_TMP, addrlo,
+ SHIFT_IMM_LSR(TARGET_PAGE_BITS - CPU_TLB_ENTRY_BITS));
+
+ /*
+ * Add the tlb_table pointer, creating the CPUTLBEntry address in R2.
+ * Load the tlb comparator into R0/R1 and the fast path addend into R2.
+ */
+ if (cmp_off == 0) {
+ if (use_armv6_instructions && TARGET_LONG_BITS == 64) {
+ tcg_out_ldrd_rwb(s, COND_AL, TCG_REG_R0, TCG_REG_R2, TCG_REG_TMP);
+ } else {
+ tcg_out_ld32_rwb(s, COND_AL, TCG_REG_R0, TCG_REG_R2, TCG_REG_TMP);
}
+ } else {
+ tcg_out_dat_reg(s, COND_AL, ARITH_ADD,
+ TCG_REG_R2, TCG_REG_R2, TCG_REG_TMP, 0);
+ if (use_armv6_instructions && TARGET_LONG_BITS == 64) {
+ tcg_out_ldrd_8(s, COND_AL, TCG_REG_R0, TCG_REG_R2, cmp_off);
+ } else {
+ tcg_out_ld32_12(s, COND_AL, TCG_REG_R0, TCG_REG_R2, cmp_off);
+ }
+ }
+ if (!use_armv6_instructions && TARGET_LONG_BITS == 64) {
+ tcg_out_ld32_12(s, COND_AL, TCG_REG_R1, TCG_REG_R2, cmp_off + 4);
}
/* Load the tlb addend. */
- tcg_out_ld32_12(s, COND_AL, TCG_REG_R2, TCG_REG_R2, add_off);
+ tcg_out_ld32_12(s, COND_AL, TCG_REG_R2, TCG_REG_R2,
+ offsetof(CPUTLBEntry, addend));
/* Check alignment. We don't support inline unaligned acceses,
but we can easily support overalignment checks. */