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authorPaul Mundt <lethal@linux-sh.org>2012-06-14 14:46:36 +0900
committerPaul Mundt <lethal@linux-sh.org>2012-06-14 14:46:36 +0900
commit0375a73c6f1be69d5a9b439a7e95b92e54b3c09b (patch)
tree8b8c000fb330770940ab84dee8bf1487b75830a7 /arch/sh
parent5f857bce21cfd0531dc7d4daac74d976caf6166b (diff)
downloadop-kernel-dev-0375a73c6f1be69d5a9b439a7e95b92e54b3c09b.zip
op-kernel-dev-0375a73c6f1be69d5a9b439a7e95b92e54b3c09b.tar.gz
sh64: Attempt to make reserved insn trap handler resemble C.
This has been long overdue. No functional changes. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh')
-rw-r--r--arch/sh/kernel/traps_64.c386
1 files changed, 195 insertions, 191 deletions
diff --git a/arch/sh/kernel/traps_64.c b/arch/sh/kernel/traps_64.c
index 75bef61..f87d20d 100644
--- a/arch/sh/kernel/traps_64.c
+++ b/arch/sh/kernel/traps_64.c
@@ -32,195 +32,6 @@
#include <asm/pgtable.h>
#include <asm/fpu.h>
-static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
- unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk);
-
-#define DO_ERROR(trapnr, signr, str, name, tsk) \
-asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \
-{ \
- do_unhandled_exception(trapnr, signr, str, __stringify(name), error_code, regs, current); \
-}
-
-DO_ERROR(13, SIGILL, "illegal slot instruction", illegal_slot_inst, current)
-DO_ERROR(87, SIGSEGV, "address error (exec)", address_error_exec, current)
-
-
-/* Implement misaligned load/store handling for kernel (and optionally for user
- mode too). Limitation : only SHmedia mode code is handled - there is no
- handling at all for misaligned accesses occurring in SHcompact code yet. */
-
-static int misaligned_fixup(struct pt_regs *regs);
-
-asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs)
-{
- if (misaligned_fixup(regs) < 0) {
- do_unhandled_exception(7, SIGSEGV, "address error(load)",
- "do_address_error_load",
- error_code, regs, current);
- }
- return;
-}
-
-asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs)
-{
- if (misaligned_fixup(regs) < 0) {
- do_unhandled_exception(8, SIGSEGV, "address error(store)",
- "do_address_error_store",
- error_code, regs, current);
- }
- return;
-}
-
-#if defined(CONFIG_SH64_ID2815_WORKAROUND)
-
-#define OPCODE_INVALID 0
-#define OPCODE_USER_VALID 1
-#define OPCODE_PRIV_VALID 2
-
-/* getcon/putcon - requires checking which control register is referenced. */
-#define OPCODE_CTRL_REG 3
-
-/* Table of valid opcodes for SHmedia mode.
- Form a 10-bit value by concatenating the major/minor opcodes i.e.
- opcode[31:26,20:16]. The 6 MSBs of this value index into the following
- array. The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to
- LSBs==4'b0000 etc). */
-static unsigned long shmedia_opcode_table[64] = {
- 0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015,
- 0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000,
- 0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000,
- 0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000,
- 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
- 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
- 0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
- 0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000
-};
-
-void do_reserved_inst(unsigned long error_code, struct pt_regs *regs)
-{
- /* Workaround SH5-101 cut2 silicon defect #2815 :
- in some situations, inter-mode branches from SHcompact -> SHmedia
- which should take ITLBMISS or EXECPROT exceptions at the target
- falsely take RESINST at the target instead. */
-
- unsigned long opcode = 0x6ff4fff0; /* guaranteed reserved opcode */
- unsigned long pc, aligned_pc;
- int get_user_error;
- int trapnr = 12;
- int signr = SIGILL;
- char *exception_name = "reserved_instruction";
-
- pc = regs->pc;
- if ((pc & 3) == 1) {
- /* SHmedia : check for defect. This requires executable vmas
- to be readable too. */
- aligned_pc = pc & ~3;
- if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) {
- get_user_error = -EFAULT;
- } else {
- get_user_error = __get_user(opcode, (unsigned long *)aligned_pc);
- }
- if (get_user_error >= 0) {
- unsigned long index, shift;
- unsigned long major, minor, combined;
- unsigned long reserved_field;
- reserved_field = opcode & 0xf; /* These bits are currently reserved as zero in all valid opcodes */
- major = (opcode >> 26) & 0x3f;
- minor = (opcode >> 16) & 0xf;
- combined = (major << 4) | minor;
- index = major;
- shift = minor << 1;
- if (reserved_field == 0) {
- int opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3;
- switch (opcode_state) {
- case OPCODE_INVALID:
- /* Trap. */
- break;
- case OPCODE_USER_VALID:
- /* Restart the instruction : the branch to the instruction will now be from an RTE
- not from SHcompact so the silicon defect won't be triggered. */
- return;
- case OPCODE_PRIV_VALID:
- if (!user_mode(regs)) {
- /* Should only ever get here if a module has
- SHcompact code inside it. If so, the same fix up is needed. */
- return; /* same reason */
- }
- /* Otherwise, user mode trying to execute a privileged instruction -
- fall through to trap. */
- break;
- case OPCODE_CTRL_REG:
- /* If in privileged mode, return as above. */
- if (!user_mode(regs)) return;
- /* In user mode ... */
- if (combined == 0x9f) { /* GETCON */
- unsigned long regno = (opcode >> 20) & 0x3f;
- if (regno >= 62) {
- return;
- }
- /* Otherwise, reserved or privileged control register, => trap */
- } else if (combined == 0x1bf) { /* PUTCON */
- unsigned long regno = (opcode >> 4) & 0x3f;
- if (regno >= 62) {
- return;
- }
- /* Otherwise, reserved or privileged control register, => trap */
- } else {
- /* Trap */
- }
- break;
- default:
- /* Fall through to trap. */
- break;
- }
- }
- /* fall through to normal resinst processing */
- } else {
- /* Error trying to read opcode. This typically means a
- real fault, not a RESINST any more. So change the
- codes. */
- trapnr = 87;
- exception_name = "address error (exec)";
- signr = SIGSEGV;
- }
- }
-
- do_unhandled_exception(trapnr, signr, exception_name, "do_reserved_inst", error_code, regs, current);
-}
-
-#else /* CONFIG_SH64_ID2815_WORKAROUND */
-
-/* If the workaround isn't needed, this is just a straightforward reserved
- instruction */
-DO_ERROR(12, SIGILL, "reserved instruction", reserved_inst, current)
-
-#endif /* CONFIG_SH64_ID2815_WORKAROUND */
-
-/* Called with interrupts disabled */
-asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs)
-{
- die_if_kernel("exception", regs, ex);
-}
-
-int do_unknown_trapa(unsigned long scId, struct pt_regs *regs)
-{
- /* Syscall debug */
- printk("System call ID error: [0x1#args:8 #syscall:16 0x%lx]\n", scId);
-
- die_if_kernel("unknown trapa", regs, scId);
-
- return -ENOSYS;
-}
-
-static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
- unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk)
-{
- if (user_mode(regs))
- force_sig(signr, tsk);
-
- die_if_no_fixup(str, regs, error_code);
-}
-
static int read_opcode(reg_size_t pc, insn_size_t *result_opcode, int from_user_mode)
{
int get_user_error;
@@ -784,7 +595,201 @@ static int misaligned_fixup(struct pt_regs *regs)
regs->pc += 4; /* Skip the instruction that's just been emulated */
return 0;
}
+}
+
+static void do_unhandled_exception(int signr, char *str, unsigned long error,
+ struct pt_regs *regs)
+{
+ if (user_mode(regs))
+ force_sig(signr, current);
+
+ die_if_no_fixup(str, regs, error);
+}
+
+#define DO_ERROR(signr, str, name) \
+asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \
+{ \
+ do_unhandled_exception(signr, str, error_code, regs); \
+}
+
+DO_ERROR(SIGILL, "illegal slot instruction", illegal_slot_inst)
+DO_ERROR(SIGSEGV, "address error (exec)", address_error_exec)
+
+#if defined(CONFIG_SH64_ID2815_WORKAROUND)
+
+#define OPCODE_INVALID 0
+#define OPCODE_USER_VALID 1
+#define OPCODE_PRIV_VALID 2
+
+/* getcon/putcon - requires checking which control register is referenced. */
+#define OPCODE_CTRL_REG 3
+
+/* Table of valid opcodes for SHmedia mode.
+ Form a 10-bit value by concatenating the major/minor opcodes i.e.
+ opcode[31:26,20:16]. The 6 MSBs of this value index into the following
+ array. The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to
+ LSBs==4'b0000 etc). */
+static unsigned long shmedia_opcode_table[64] = {
+ 0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015,
+ 0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000,
+ 0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000,
+ 0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000,
+ 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
+ 0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
+ 0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
+ 0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000
+};
+
+/* Workaround SH5-101 cut2 silicon defect #2815 :
+ in some situations, inter-mode branches from SHcompact -> SHmedia
+ which should take ITLBMISS or EXECPROT exceptions at the target
+ falsely take RESINST at the target instead. */
+void do_reserved_inst(unsigned long error_code, struct pt_regs *regs)
+{
+ insn_size_t opcode = 0x6ff4fff0; /* guaranteed reserved opcode */
+ unsigned long pc, aligned_pc;
+ unsigned long index, shift;
+ unsigned long major, minor, combined;
+ unsigned long reserved_field;
+ int opcode_state;
+ int get_user_error;
+ int signr = SIGILL;
+ char *exception_name = "reserved_instruction";
+
+ pc = regs->pc;
+
+ /* SHcompact is not handled */
+ if (unlikely((pc & 3) == 0))
+ goto out;
+
+ /* SHmedia : check for defect. This requires executable vmas
+ to be readable too. */
+ aligned_pc = pc & ~3;
+ if (!access_ok(VERIFY_READ, aligned_pc, sizeof(insn_size_t)))
+ get_user_error = -EFAULT;
+ else
+ get_user_error = __get_user(opcode, (insn_size_t *)aligned_pc);
+
+ if (get_user_error < 0) {
+ /*
+ * Error trying to read opcode. This typically means a
+ * real fault, not a RESINST any more. So change the
+ * codes.
+ */
+ exception_name = "address error (exec)";
+ signr = SIGSEGV;
+ goto out;
+ }
+
+ /* These bits are currently reserved as zero in all valid opcodes */
+ reserved_field = opcode & 0xf;
+ if (unlikely(reserved_field))
+ goto out; /* invalid opcode */
+
+ major = (opcode >> 26) & 0x3f;
+ minor = (opcode >> 16) & 0xf;
+ combined = (major << 4) | minor;
+ index = major;
+ shift = minor << 1;
+ opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3;
+ switch (opcode_state) {
+ case OPCODE_INVALID:
+ /* Trap. */
+ break;
+ case OPCODE_USER_VALID:
+ /*
+ * Restart the instruction: the branch to the instruction
+ * will now be from an RTE not from SHcompact so the
+ * silicon defect won't be triggered.
+ */
+ return;
+ case OPCODE_PRIV_VALID:
+ if (!user_mode(regs)) {
+ /*
+ * Should only ever get here if a module has
+ * SHcompact code inside it. If so, the same fix
+ * up is needed.
+ */
+ return; /* same reason */
+ }
+
+ /*
+ * Otherwise, user mode trying to execute a privileged
+ * instruction - fall through to trap.
+ */
+ break;
+ case OPCODE_CTRL_REG:
+ /* If in privileged mode, return as above. */
+ if (!user_mode(regs))
+ return;
+
+ /* In user mode ... */
+ if (combined == 0x9f) { /* GETCON */
+ unsigned long regno = (opcode >> 20) & 0x3f;
+
+ if (regno >= 62)
+ return;
+
+ /* reserved/privileged control register => trap */
+ } else if (combined == 0x1bf) { /* PUTCON */
+ unsigned long regno = (opcode >> 4) & 0x3f;
+
+ if (regno >= 62)
+ return;
+
+ /* reserved/privileged control register => trap */
+ }
+
+ break;
+ default:
+ /* Fall through to trap. */
+ break;
+ }
+out:
+ do_unhandled_exception(signr, exception_name, error_code, regs);
+}
+
+#else /* CONFIG_SH64_ID2815_WORKAROUND */
+
+/* If the workaround isn't needed, this is just a straightforward reserved
+ instruction */
+DO_ERROR(SIGILL, "reserved instruction", reserved_inst)
+
+#endif /* CONFIG_SH64_ID2815_WORKAROUND */
+
+/* Called with interrupts disabled */
+asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs)
+{
+ die_if_kernel("exception", regs, ex);
+}
+
+asmlinkage int do_unknown_trapa(unsigned long scId, struct pt_regs *regs)
+{
+ /* Syscall debug */
+ printk("System call ID error: [0x1#args:8 #syscall:16 0x%lx]\n", scId);
+
+ die_if_kernel("unknown trapa", regs, scId);
+
+ return -ENOSYS;
+}
+
+/* Implement misaligned load/store handling for kernel (and optionally for user
+ mode too). Limitation : only SHmedia mode code is handled - there is no
+ handling at all for misaligned accesses occurring in SHcompact code yet. */
+
+asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs)
+{
+ if (misaligned_fixup(regs) < 0)
+ do_unhandled_exception(SIGSEGV, "address error(load)",
+ error_code, regs);
+}
+
+asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs)
+{
+ if (misaligned_fixup(regs) < 0)
+ do_unhandled_exception(SIGSEGV, "address error(store)",
+ error_code, regs);
}
asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs)
@@ -797,10 +802,9 @@ asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs)
of access we make to them - just go direct to their physical
addresses. */
exp_cause = peek_real_address_q(DM_EXP_CAUSE_PHY);
- if (exp_cause & ~4) {
+ if (exp_cause & ~4)
printk("DM.EXP_CAUSE had unexpected bits set (=%08lx)\n",
(unsigned long)(exp_cause & 0xffffffff));
- }
show_state();
/* Clear all DEBUGINT causes */
poke_real_address_q(DM_EXP_CAUSE_PHY, 0x0);
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