MIPS: MIPS16e: Add unaligned access support.
Add logic needed to handle unaligned accesses in MIPS16e mode.
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c
index 0213906..203d885 100644
--- a/arch/mips/kernel/unaligned.c
+++ b/arch/mips/kernel/unaligned.c
@@ -1304,6 +1304,250 @@
force_sig(SIGILL, current);
}
+static void emulate_load_store_MIPS16e(struct pt_regs *regs, void __user * addr)
+{
+ unsigned long value;
+ unsigned int res;
+ int reg;
+ unsigned long orig31;
+ u16 __user *pc16;
+ unsigned long origpc;
+ union mips16e_instruction mips16inst, oldinst;
+
+ origpc = regs->cp0_epc;
+ orig31 = regs->regs[31];
+ pc16 = (unsigned short __user *)msk_isa16_mode(origpc);
+ /*
+ * This load never faults.
+ */
+ __get_user(mips16inst.full, pc16);
+ oldinst = mips16inst;
+
+ /* skip EXTEND instruction */
+ if (mips16inst.ri.opcode == MIPS16e_extend_op) {
+ pc16++;
+ __get_user(mips16inst.full, pc16);
+ } else if (delay_slot(regs)) {
+ /* skip jump instructions */
+ /* JAL/JALX are 32 bits but have OPCODE in first short int */
+ if (mips16inst.ri.opcode == MIPS16e_jal_op)
+ pc16++;
+ pc16++;
+ if (get_user(mips16inst.full, pc16))
+ goto sigbus;
+ }
+
+ switch (mips16inst.ri.opcode) {
+ case MIPS16e_i64_op: /* I64 or RI64 instruction */
+ switch (mips16inst.i64.func) { /* I64/RI64 func field check */
+ case MIPS16e_ldpc_func:
+ case MIPS16e_ldsp_func:
+ reg = reg16to32[mips16inst.ri64.ry];
+ goto loadDW;
+
+ case MIPS16e_sdsp_func:
+ reg = reg16to32[mips16inst.ri64.ry];
+ goto writeDW;
+
+ case MIPS16e_sdrasp_func:
+ reg = 29; /* GPRSP */
+ goto writeDW;
+ }
+
+ goto sigbus;
+
+ case MIPS16e_swsp_op:
+ case MIPS16e_lwpc_op:
+ case MIPS16e_lwsp_op:
+ reg = reg16to32[mips16inst.ri.rx];
+ break;
+
+ case MIPS16e_i8_op:
+ if (mips16inst.i8.func != MIPS16e_swrasp_func)
+ goto sigbus;
+ reg = 29; /* GPRSP */
+ break;
+
+ default:
+ reg = reg16to32[mips16inst.rri.ry];
+ break;
+ }
+
+ switch (mips16inst.ri.opcode) {
+
+ case MIPS16e_lb_op:
+ case MIPS16e_lbu_op:
+ case MIPS16e_sb_op:
+ goto sigbus;
+
+ case MIPS16e_lh_op:
+ if (!access_ok(VERIFY_READ, addr, 2))
+ goto sigbus;
+
+ LoadHW(addr, value, res);
+ if (res)
+ goto fault;
+ MIPS16e_compute_return_epc(regs, &oldinst);
+ regs->regs[reg] = value;
+ break;
+
+ case MIPS16e_lhu_op:
+ if (!access_ok(VERIFY_READ, addr, 2))
+ goto sigbus;
+
+ LoadHWU(addr, value, res);
+ if (res)
+ goto fault;
+ MIPS16e_compute_return_epc(regs, &oldinst);
+ regs->regs[reg] = value;
+ break;
+
+ case MIPS16e_lw_op:
+ case MIPS16e_lwpc_op:
+ case MIPS16e_lwsp_op:
+ if (!access_ok(VERIFY_READ, addr, 4))
+ goto sigbus;
+
+ LoadW(addr, value, res);
+ if (res)
+ goto fault;
+ MIPS16e_compute_return_epc(regs, &oldinst);
+ regs->regs[reg] = value;
+ break;
+
+ case MIPS16e_lwu_op:
+#ifdef CONFIG_64BIT
+ /*
+ * A 32-bit kernel might be running on a 64-bit processor. But
+ * if we're on a 32-bit processor and an i-cache incoherency
+ * or race makes us see a 64-bit instruction here the sdl/sdr
+ * would blow up, so for now we don't handle unaligned 64-bit
+ * instructions on 32-bit kernels.
+ */
+ if (!access_ok(VERIFY_READ, addr, 4))
+ goto sigbus;
+
+ LoadWU(addr, value, res);
+ if (res)
+ goto fault;
+ MIPS16e_compute_return_epc(regs, &oldinst);
+ regs->regs[reg] = value;
+ break;
+#endif /* CONFIG_64BIT */
+
+ /* Cannot handle 64-bit instructions in 32-bit kernel */
+ goto sigill;
+
+ case MIPS16e_ld_op:
+loadDW:
+#ifdef CONFIG_64BIT
+ /*
+ * A 32-bit kernel might be running on a 64-bit processor. But
+ * if we're on a 32-bit processor and an i-cache incoherency
+ * or race makes us see a 64-bit instruction here the sdl/sdr
+ * would blow up, so for now we don't handle unaligned 64-bit
+ * instructions on 32-bit kernels.
+ */
+ if (!access_ok(VERIFY_READ, addr, 8))
+ goto sigbus;
+
+ LoadDW(addr, value, res);
+ if (res)
+ goto fault;
+ MIPS16e_compute_return_epc(regs, &oldinst);
+ regs->regs[reg] = value;
+ break;
+#endif /* CONFIG_64BIT */
+
+ /* Cannot handle 64-bit instructions in 32-bit kernel */
+ goto sigill;
+
+ case MIPS16e_sh_op:
+ if (!access_ok(VERIFY_WRITE, addr, 2))
+ goto sigbus;
+
+ MIPS16e_compute_return_epc(regs, &oldinst);
+ value = regs->regs[reg];
+ StoreHW(addr, value, res);
+ if (res)
+ goto fault;
+ break;
+
+ case MIPS16e_sw_op:
+ case MIPS16e_swsp_op:
+ case MIPS16e_i8_op: /* actually - MIPS16e_swrasp_func */
+ if (!access_ok(VERIFY_WRITE, addr, 4))
+ goto sigbus;
+
+ MIPS16e_compute_return_epc(regs, &oldinst);
+ value = regs->regs[reg];
+ StoreW(addr, value, res);
+ if (res)
+ goto fault;
+ break;
+
+ case MIPS16e_sd_op:
+writeDW:
+#ifdef CONFIG_64BIT
+ /*
+ * A 32-bit kernel might be running on a 64-bit processor. But
+ * if we're on a 32-bit processor and an i-cache incoherency
+ * or race makes us see a 64-bit instruction here the sdl/sdr
+ * would blow up, so for now we don't handle unaligned 64-bit
+ * instructions on 32-bit kernels.
+ */
+ if (!access_ok(VERIFY_WRITE, addr, 8))
+ goto sigbus;
+
+ MIPS16e_compute_return_epc(regs, &oldinst);
+ value = regs->regs[reg];
+ StoreDW(addr, value, res);
+ if (res)
+ goto fault;
+ break;
+#endif /* CONFIG_64BIT */
+
+ /* Cannot handle 64-bit instructions in 32-bit kernel */
+ goto sigill;
+
+ default:
+ /*
+ * Pheeee... We encountered an yet unknown instruction or
+ * cache coherence problem. Die sucker, die ...
+ */
+ goto sigill;
+ }
+
+#ifdef CONFIG_DEBUG_FS
+ unaligned_instructions++;
+#endif
+
+ return;
+
+fault:
+ /* roll back jump/branch */
+ regs->cp0_epc = origpc;
+ regs->regs[31] = orig31;
+ /* Did we have an exception handler installed? */
+ if (fixup_exception(regs))
+ return;
+
+ die_if_kernel("Unhandled kernel unaligned access", regs);
+ force_sig(SIGSEGV, current);
+
+ return;
+
+sigbus:
+ die_if_kernel("Unhandled kernel unaligned access", regs);
+ force_sig(SIGBUS, current);
+
+ return;
+
+sigill:
+ die_if_kernel
+ ("Unhandled kernel unaligned access or invalid instruction", regs);
+ force_sig(SIGILL, current);
+}
asmlinkage void do_ade(struct pt_regs *regs)
{
unsigned int __user *pc;
@@ -1351,6 +1595,17 @@
return;
}
+ if (cpu_has_mips16) {
+ seg = get_fs();
+ if (!user_mode(regs))
+ set_fs(KERNEL_DS);
+ emulate_load_store_MIPS16e(regs,
+ (void __user *)regs->cp0_badvaddr);
+ set_fs(seg);
+
+ return;
+ }
+
goto sigbus;
}