[PATCH v4 10/21] arm64: entry.S: move SError handling into a C function for future expansion

James Morse
2017-10-19T14:59:23Z

From: Xie XiuQi <xiexiuqi@huawei.com>

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>
---
arch/arm64/Kconfig | 2 +-
arch/arm64/kernel/entry.S | 36 +++++++++++++++++++++++++++++-------
arch/arm64/kernel/traps.c | 13 +++++++++++++
3 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 0df64a6a56d4..70dfe4e9ccc5 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -98,7 +98,7 @@ config ARM64
select HAVE_IRQ_TIME_ACCOUNTING
select HAVE_MEMBLOCK
select HAVE_MEMBLOCK_NODE_MAP if NUMA
- select HAVE_NMI if ACPI_APEI_SEA
+ select HAVE_NMI
select HAVE_PATA_PLATFORM
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index df085ec003b0..e147c1d00b41 100644
--- 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 1808be65d22f..773aae69c376 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -709,6 +709,19 @@ 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);
--
2.13.3