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-rw-r--r--arch/mips/math-emu/cp1emu.c169
1 files changed, 158 insertions, 11 deletions
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 9dfcd7fc1bc3..b30bf65c7d7d 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -48,6 +48,7 @@
#include <asm/processor.h>
#include <asm/fpu_emulator.h>
#include <asm/fpu.h>
+#include <asm/mips-r2-to-r6-emul.h>
#include "ieee754.h"
@@ -68,7 +69,7 @@ static int fpux_emu(struct pt_regs *,
#define modeindex(v) ((v) & FPU_CSR_RM)
/* convert condition code register number to csr bit */
-static const unsigned int fpucondbit[8] = {
+const unsigned int fpucondbit[8] = {
FPU_CSR_COND0,
FPU_CSR_COND1,
FPU_CSR_COND2,
@@ -448,6 +449,9 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
dec_insn.next_pc_inc;
/* Fall through */
case jr_op:
+ /* For R6, JR already emulated in jalr_op */
+ if (NO_R6EMU && insn.r_format.opcode == jr_op)
+ break;
*contpc = regs->regs[insn.r_format.rs];
return 1;
}
@@ -456,12 +460,18 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
switch (insn.i_format.rt) {
case bltzal_op:
case bltzall_op:
+ if (NO_R6EMU && (insn.i_format.rs ||
+ insn.i_format.rt == bltzall_op))
+ break;
+
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
/* Fall through */
- case bltz_op:
case bltzl_op:
+ if (NO_R6EMU)
+ break;
+ case bltz_op:
if ((long)regs->regs[insn.i_format.rs] < 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
@@ -473,12 +483,18 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
return 1;
case bgezal_op:
case bgezall_op:
+ if (NO_R6EMU && (insn.i_format.rs ||
+ insn.i_format.rt == bgezall_op))
+ break;
+
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
/* Fall through */
- case bgez_op:
case bgezl_op:
+ if (NO_R6EMU)
+ break;
+ case bgez_op:
if ((long)regs->regs[insn.i_format.rs] >= 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
@@ -505,8 +521,10 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
/* Set microMIPS mode bit: XOR for jalx. */
*contpc ^= bit;
return 1;
- case beq_op:
case beql_op:
+ if (NO_R6EMU)
+ break;
+ case beq_op:
if (regs->regs[insn.i_format.rs] ==
regs->regs[insn.i_format.rt])
*contpc = regs->cp0_epc +
@@ -517,8 +535,10 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
- case bne_op:
case bnel_op:
+ if (NO_R6EMU)
+ break;
+ case bne_op:
if (regs->regs[insn.i_format.rs] !=
regs->regs[insn.i_format.rt])
*contpc = regs->cp0_epc +
@@ -529,8 +549,34 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
- case blez_op:
case blezl_op:
+ if (NO_R6EMU)
+ break;
+ case blez_op:
+
+ /*
+ * Compact branches for R6 for the
+ * blez and blezl opcodes.
+ * BLEZ | rs = 0 | rt != 0 == BLEZALC
+ * BLEZ | rs = rt != 0 == BGEZALC
+ * BLEZ | rs != 0 | rt != 0 == BGEUC
+ * BLEZL | rs = 0 | rt != 0 == BLEZC
+ * BLEZL | rs = rt != 0 == BGEZC
+ * BLEZL | rs != 0 | rt != 0 == BGEC
+ *
+ * For real BLEZ{,L}, rt is always 0.
+ */
+ if (cpu_has_mips_r6 && insn.i_format.rt) {
+ if ((insn.i_format.opcode == blez_op) &&
+ ((!insn.i_format.rs && insn.i_format.rt) ||
+ (insn.i_format.rs == insn.i_format.rt)))
+ regs->regs[31] = regs->cp0_epc +
+ dec_insn.pc_inc;
+ *contpc = regs->cp0_epc + dec_insn.pc_inc +
+ dec_insn.next_pc_inc;
+
+ return 1;
+ }
if ((long)regs->regs[insn.i_format.rs] <= 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
@@ -540,8 +586,35 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
- case bgtz_op:
case bgtzl_op:
+ if (NO_R6EMU)
+ break;
+ case bgtz_op:
+ /*
+ * Compact branches for R6 for the
+ * bgtz and bgtzl opcodes.
+ * BGTZ | rs = 0 | rt != 0 == BGTZALC
+ * BGTZ | rs = rt != 0 == BLTZALC
+ * BGTZ | rs != 0 | rt != 0 == BLTUC
+ * BGTZL | rs = 0 | rt != 0 == BGTZC
+ * BGTZL | rs = rt != 0 == BLTZC
+ * BGTZL | rs != 0 | rt != 0 == BLTC
+ *
+ * *ZALC varint for BGTZ &&& rt != 0
+ * For real GTZ{,L}, rt is always 0.
+ */
+ if (cpu_has_mips_r6 && insn.i_format.rt) {
+ if ((insn.i_format.opcode == blez_op) &&
+ ((!insn.i_format.rs && insn.i_format.rt) ||
+ (insn.i_format.rs == insn.i_format.rt)))
+ regs->regs[31] = regs->cp0_epc +
+ dec_insn.pc_inc;
+ *contpc = regs->cp0_epc + dec_insn.pc_inc +
+ dec_insn.next_pc_inc;
+
+ return 1;
+ }
+
if ((long)regs->regs[insn.i_format.rs] > 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
@@ -551,6 +624,16 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
+ case cbcond0_op:
+ case cbcond1_op:
+ if (!cpu_has_mips_r6)
+ break;
+ if (insn.i_format.rt && !insn.i_format.rs)
+ regs->regs[31] = regs->cp0_epc + 4;
+ *contpc = regs->cp0_epc + dec_insn.pc_inc +
+ dec_insn.next_pc_inc;
+
+ return 1;
#ifdef CONFIG_CPU_CAVIUM_OCTEON
case lwc2_op: /* This is bbit0 on Octeon */
if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
@@ -576,9 +659,73 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
else
*contpc = regs->cp0_epc + 8;
return 1;
+#else
+ case bc6_op:
+ /*
+ * Only valid for MIPS R6 but we can still end up
+ * here from a broken userland so just tell emulator
+ * this is not a branch and let it break later on.
+ */
+ if (!cpu_has_mips_r6)
+ break;
+ *contpc = regs->cp0_epc + dec_insn.pc_inc +
+ dec_insn.next_pc_inc;
+
+ return 1;
+ case balc6_op:
+ if (!cpu_has_mips_r6)
+ break;
+ regs->regs[31] = regs->cp0_epc + 4;
+ *contpc = regs->cp0_epc + dec_insn.pc_inc +
+ dec_insn.next_pc_inc;
+
+ return 1;
+ case beqzcjic_op:
+ if (!cpu_has_mips_r6)
+ break;
+ *contpc = regs->cp0_epc + dec_insn.pc_inc +
+ dec_insn.next_pc_inc;
+
+ return 1;
+ case bnezcjialc_op:
+ if (!cpu_has_mips_r6)
+ break;
+ if (!insn.i_format.rs)
+ regs->regs[31] = regs->cp0_epc + 4;
+ *contpc = regs->cp0_epc + dec_insn.pc_inc +
+ dec_insn.next_pc_inc;
+
+ return 1;
#endif
case cop0_op:
case cop1_op:
+ /* Need to check for R6 bc1nez and bc1eqz branches */
+ if (cpu_has_mips_r6 &&
+ ((insn.i_format.rs == bc1eqz_op) ||
+ (insn.i_format.rs == bc1nez_op))) {
+ bit = 0;
+ switch (insn.i_format.rs) {
+ case bc1eqz_op:
+ if (get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1)
+ bit = 1;
+ break;
+ case bc1nez_op:
+ if (!(get_fpr32(&current->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1))
+ bit = 1;
+ break;
+ }
+ if (bit)
+ *contpc = regs->cp0_epc +
+ dec_insn.pc_inc +
+ (insn.i_format.simmediate << 2);
+ else
+ *contpc = regs->cp0_epc +
+ dec_insn.pc_inc +
+ dec_insn.next_pc_inc;
+
+ return 1;
+ }
+ /* R2/R6 compatible cop1 instruction. Fall through */
case cop2_op:
case cop1x_op:
if (insn.i_format.rs == bc_op) {
@@ -1414,14 +1561,14 @@ static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
* achieve full IEEE-754 accuracy - however this emulator does.
*/
case frsqrt_op:
- if (!cpu_has_mips_4_5_r2)
+ if (!cpu_has_mips_4_5_r2_r6)
return SIGILL;
handler.u = fpemu_sp_rsqrt;
goto scopuop;
case frecip_op:
- if (!cpu_has_mips_4_5_r2)
+ if (!cpu_has_mips_4_5_r2_r6)
return SIGILL;
handler.u = fpemu_sp_recip;
@@ -1616,13 +1763,13 @@ copcsr:
* achieve full IEEE-754 accuracy - however this emulator does.
*/
case frsqrt_op:
- if (!cpu_has_mips_4_5_r2)
+ if (!cpu_has_mips_4_5_r2_r6)
return SIGILL;
handler.u = fpemu_dp_rsqrt;
goto dcopuop;
case frecip_op:
- if (!cpu_has_mips_4_5_r2)
+ if (!cpu_has_mips_4_5_r2_r6)
return SIGILL;
handler.u = fpemu_dp_recip;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.