tcg/arm: Support tlb offsets larger than 64k

AArch64 with SVE has an offset of 80k to the 8th TLB.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2018-01-11 12:25:49 -08:00
parent 7170ac3313
commit 71f9cee9d0

View file

@ -1247,12 +1247,6 @@ static TCGReg tcg_out_arg_reg64(TCGContext *s, TCGReg argreg,
/* We're expecting to use an 8-bit immediate and to mask. */
QEMU_BUILD_BUG_ON(CPU_TLB_BITS > 8);
/* We're expecting to use an 8-bit immediate add + 8-bit ldrd offset.
Using the offset of the second entry in the last tlb table ensures
that we can index all of the elements of the first entry. */
QEMU_BUILD_BUG_ON(offsetof(CPUArchState, tlb_table[NB_MMU_MODES - 1][1])
> 0xffff);
/* 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. */
@ -1265,6 +1259,7 @@ static TCGReg tcg_out_tlb_read(TCGContext *s, TCGReg addrlo, TCGReg addrhi,
? 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;
unsigned s_bits = opc & MO_SIZE;
unsigned a_bits = get_alignment_bits(opc);
@ -1296,16 +1291,25 @@ static TCGReg tcg_out_tlb_read(TCGContext *s, TCGReg addrlo, TCGReg addrhi,
0, addrlo, SHIFT_IMM_LSR(TARGET_PAGE_BITS));
}
/* We checked that the offset is contained within 16 bits above. */
if (add_off > 0xfff
|| (use_armv6_instructions && TARGET_LONG_BITS == 64
&& cmp_off > 0xff)) {
tcg_out_dat_imm(s, COND_AL, ARITH_ADD, TCG_REG_R2, base,
(24 << 7) | (cmp_off >> 8));
base = TCG_REG_R2;
add_off -= cmp_off & 0xff00;
cmp_off &= 0xff;
/* 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;
}
if (!use_armv7_instructions) {
tcg_out_dat_imm(s, COND_AL, ARITH_AND,
TCG_REG_R0, TCG_REG_TMP, CPU_TLB_SIZE - 1);