arm64: entry.S: move SError handling into a C function for future expansion

Today SError is taken using the inv_entry macro that ends up in
bad_mode.

SError can be used by the RAS Extensions to notify either the OS or
firmware of CPU problems, some of which may have been corrected.

To allow this handling to be added, add a do_serror() C function
that just panic()s. Add the entry.S boiler plate to save/restore the
CPU registers and unmask debug exceptions. Future patches may change
do_serror() to return if the SError Interrupt was notification of a
corrected error.

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Wang Xiongfeng <wangxiongfengi2@huawei.com>
[Split out of a bigger patch, added compat path, renamed, enabled debug
 exceptions]
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 55d0807..bfa4bd0 100644 (file)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -375,18 +375,18 @@ ENTRY(vectors)
        kernel_ventry   el1_sync                        // Synchronous EL1h
        kernel_ventry   el1_irq                         // IRQ EL1h
        kernel_ventry   el1_fiq_invalid                 // FIQ EL1h
-       kernel_ventry   el1_error_invalid               // Error EL1h
+       kernel_ventry   el1_error                       // Error EL1h
 
        kernel_ventry   el0_sync                        // Synchronous 64-bit EL0
        kernel_ventry   el0_irq                         // IRQ 64-bit EL0
        kernel_ventry   el0_fiq_invalid                 // FIQ 64-bit EL0
-       kernel_ventry   el0_error_invalid               // Error 64-bit EL0
+       kernel_ventry   el0_error                       // Error 64-bit EL0
 
 #ifdef CONFIG_COMPAT
        kernel_ventry   el0_sync_compat                 // Synchronous 32-bit EL0
        kernel_ventry   el0_irq_compat                  // IRQ 32-bit EL0
        kernel_ventry   el0_fiq_invalid_compat          // FIQ 32-bit EL0
-       kernel_ventry   el0_error_invalid_compat        // Error 32-bit EL0
+       kernel_ventry   el0_error_compat                // Error 32-bit EL0
 #else
        kernel_ventry   el0_sync_invalid                // Synchronous 32-bit EL0
        kernel_ventry   el0_irq_invalid                 // IRQ 32-bit EL0
@@ -455,10 +455,6 @@ ENDPROC(el0_error_invalid)
 el0_fiq_invalid_compat:
        inv_entry 0, BAD_FIQ, 32
 ENDPROC(el0_fiq_invalid_compat)
-
-el0_error_invalid_compat:
-       inv_entry 0, BAD_ERROR, 32
-ENDPROC(el0_error_invalid_compat)
 #endif
 
 el1_sync_invalid:
@@ -663,6 +659,10 @@ el0_svc_compat:
 el0_irq_compat:
        kernel_entry 0, 32
        b       el0_irq_naked
+
+el0_error_compat:
+       kernel_entry 0, 32
+       b       el0_error_naked
 #endif
 
 el0_da:
@@ -780,6 +780,28 @@ el0_irq_naked:
        b       ret_to_user
 ENDPROC(el0_irq)
 
+el1_error:
+       kernel_entry 1
+       mrs     x1, esr_el1
+       enable_dbg
+       mov     x0, sp
+       bl      do_serror
+       kernel_exit 1
+ENDPROC(el1_error)
+
+el0_error:
+       kernel_entry 0
+el0_error_naked:
+       mrs     x1, esr_el1
+       enable_dbg
+       mov     x0, sp
+       bl      do_serror
+       enable_daif
+       ct_user_exit
+       b       ret_to_user
+ENDPROC(el0_error)
+
+
 /*
  * This is the fast syscall return path.  We do as little as possible here,
  * and this includes saving x0 back into the kernel stack.

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index fa52aef..c3a8d98 100644 (file)
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -661,6 +661,19 @@ asmlinkage void handle_bad_stack(struct pt_regs *regs)
 }
 #endif
 
+asmlinkage void do_serror(struct pt_regs *regs, unsigned int esr)
+{
+       nmi_enter();
+
+       console_verbose();
+
+       pr_crit("SError Interrupt on CPU%d, code 0x%08x -- %s\n",
+               smp_processor_id(), esr, esr_get_class_string(esr));
+       __show_regs(regs);
+
+       panic("Asynchronous SError Interrupt");
+}
+
 void __pte_error(const char *file, int line, unsigned long val)
 {
        pr_err("%s:%d: bad pte %016lx.\n", file, line, val);