[IA64] Recovery from user-mode memory error

This is the latest/Updated OS_MCA handler which try to do recovery
from multibit-ECC/poisoned memory-read error on user-land.
(Thank you very much for comments, Keith and Grant!)

I'd still appreciate it if anyone having good test environment
could apply my patch and could report how it works.
(especially reports on non-Tiger/non-Intel platform are welcome.)
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/Kconfig

@@ -280,6 +280,9 @@ config COMPAT
 	depends on IA32_SUPPORT
 	default y
 
+config IA64_MCA_RECOVERY
+	tristate "MCA recovery from errors other than TLB."
+
 config PERFMON
 	bool "Performance monitor support"
 	help

arch/ia64/kernel/Makefile

@@ -17,6 +17,8 @@ obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_SMP)		+= smp.o smpboot.o
 obj-$(CONFIG_PERFMON)		+= perfmon_default_smpl.o
 obj-$(CONFIG_IA64_CYCLONE)	+= cyclone.o
+obj-$(CONFIG_IA64_MCA_RECOVERY)	+= mca_recovery.o
+mca_recovery-y			+= mca_drv.o mca_drv_asm.o
 
 # The gate DSO image is built using a special linker script.
 targets += gate.so gate-syms.o

arch/ia64/kernel/mca.c

@@ -82,11 +82,6 @@
 # define IA64_MCA_DEBUG(fmt...)
 #endif
 
-typedef struct ia64_fptr {
-	unsigned long fp;
-	unsigned long gp;
-} ia64_fptr_t;
-
 /* Used by mca_asm.S */
 ia64_mca_sal_to_os_state_t	ia64_sal_to_os_handoff_state;
 ia64_mca_os_to_sal_state_t	ia64_os_to_sal_handoff_state;
@@ -831,6 +826,31 @@ ia64_return_to_sal_check(int recover)
 
 }
 
+/* Function pointer for extra MCA recovery */
+int (*ia64_mca_ucmc_extension)
+	(void*,ia64_mca_sal_to_os_state_t*,ia64_mca_os_to_sal_state_t*)
+	= NULL;
+
+int
+ia64_reg_MCA_extension(void *fn)
+{
+	if (ia64_mca_ucmc_extension)
+		return 1;
+
+	ia64_mca_ucmc_extension = fn;
+	return 0;
+}
+
+void
+ia64_unreg_MCA_extension(void)
+{
+	if (ia64_mca_ucmc_extension)
+		ia64_mca_ucmc_extension = NULL;
+}
+
+EXPORT_SYMBOL(ia64_reg_MCA_extension);
+EXPORT_SYMBOL(ia64_unreg_MCA_extension);
+
 /*
  * ia64_mca_ucmc_handler
  *
@@ -852,11 +872,20 @@ ia64_mca_ucmc_handler(void)
 {
 	pal_processor_state_info_t *psp = (pal_processor_state_info_t *)
 		&ia64_sal_to_os_handoff_state.proc_state_param;
-	int recover = psp->tc && !(psp->cc || psp->bc || psp->rc || psp->uc);
+	int recover; 
 
 	/* Get the MCA error record and log it */
 	ia64_mca_log_sal_error_record(SAL_INFO_TYPE_MCA);
 
+	/* TLB error is only exist in this SAL error record */
+	recover = (psp->tc && !(psp->cc || psp->bc || psp->rc || psp->uc))
+	/* other error recovery */
+	   || (ia64_mca_ucmc_extension 
+		&& ia64_mca_ucmc_extension(
+			IA64_LOG_CURR_BUFFER(SAL_INFO_TYPE_MCA),
+			&ia64_sal_to_os_handoff_state,
+			&ia64_os_to_sal_handoff_state)); 
+
 	/*
 	 *  Wakeup all the processors which are spinning in the rendezvous
 	 *  loop.

arch/ia64/kernel/mca_drv.h

+/*
+ * File:	mca_drv.h
+ * Purpose:	Define helpers for Generic MCA handling
+ *
+ * Copyright (C) 2004 FUJITSU LIMITED
+ * Copyright (C) Hidetoshi Seto (seto.hidetoshi@jp.fujitsu.com)
+ */
+/*
+ * Processor error section: 
+ *
+ *  +-sal_log_processor_info_t *info-------------+
+ *  | sal_log_section_hdr_t header;              |
+ *  | ...                                        |
+ *  | sal_log_mod_error_info_t info[0];          |
+ *  +-+----------------+-------------------------+
+ *    | CACHE_CHECK    |  ^ num_cache_check v
+ *    +----------------+
+ *    | TLB_CHECK      |  ^ num_tlb_check v
+ *    +----------------+
+ *    | BUS_CHECK      |  ^ num_bus_check v
+ *    +----------------+
+ *    | REG_FILE_CHECK |  ^ num_reg_file_check v
+ *    +----------------+
+ *    | MS_CHECK       |  ^ num_ms_check v
+ *  +-struct cpuid_info *id----------------------+
+ *  | regs[5];                                   |
+ *  | reserved;                                  |
+ *  +-sal_processor_static_info_t *regs----------+
+ *  | valid;                                     |
+ *  | ...                                        |
+ *  | fr[128];                                   |
+ *  +--------------------------------------------+
+ */
+
+/* peidx: index of processor error section */
+typedef struct peidx_table {
+	sal_log_processor_info_t        *info;
+	struct sal_cpuid_info           *id;
+	sal_processor_static_info_t     *regs;
+} peidx_table_t;
+
+#define peidx_head(p)   (((p)->info))
+#define peidx_mid(p)    (((p)->id))
+#define peidx_bottom(p) (((p)->regs))
+
+#define peidx_psp(p)           (&(peidx_head(p)->proc_state_parameter))
+#define peidx_field_valid(p)   (&(peidx_head(p)->valid))
+#define peidx_minstate_area(p) (&(peidx_bottom(p)->min_state_area))
+
+#define peidx_cache_check_num(p)    (peidx_head(p)->valid.num_cache_check)
+#define peidx_tlb_check_num(p)      (peidx_head(p)->valid.num_tlb_check)
+#define peidx_bus_check_num(p)      (peidx_head(p)->valid.num_bus_check)
+#define peidx_reg_file_check_num(p) (peidx_head(p)->valid.num_reg_file_check)
+#define peidx_ms_check_num(p)       (peidx_head(p)->valid.num_ms_check)
+
+#define peidx_cache_check_idx(p, n)    (n)
+#define peidx_tlb_check_idx(p, n)      (peidx_cache_check_idx(p, peidx_cache_check_num(p)) + n)
+#define peidx_bus_check_idx(p, n)      (peidx_tlb_check_idx(p, peidx_tlb_check_num(p)) + n)
+#define peidx_reg_file_check_idx(p, n) (peidx_bus_check_idx(p, peidx_bus_check_num(p)) + n)
+#define peidx_ms_check_idx(p, n)       (peidx_reg_file_check_idx(p, peidx_reg_file_check_num(p)) + n)
+
+#define peidx_mod_error_info(p, name, n) \
+({	int __idx = peidx_##name##_idx(p, n); \
+	sal_log_mod_error_info_t *__ret = NULL; \
+	if (peidx_##name##_num(p) > n) /*BUG*/ \
+		__ret = &(peidx_head(p)->info[__idx]); \
+	__ret; })
+
+#define peidx_cache_check(p, n)    peidx_mod_error_info(p, cache_check, n)
+#define peidx_tlb_check(p, n)      peidx_mod_error_info(p, tlb_check, n)
+#define peidx_bus_check(p, n)      peidx_mod_error_info(p, bus_check, n)
+#define peidx_reg_file_check(p, n) peidx_mod_error_info(p, reg_file_check, n)
+#define peidx_ms_check(p, n)       peidx_mod_error_info(p, ms_check, n)
+
+#define peidx_check_info(proc, name, n) \
+({ \
+	sal_log_mod_error_info_t *__info = peidx_mod_error_info(proc, name, n);\
+	u64 __temp = __info && __info->valid.check_info \
+		? __info->check_info : 0; \
+	__temp; })
+
+/* slidx: index of SAL log error record */
+
+typedef struct slidx_list {
+	struct list_head list;
+	sal_log_section_hdr_t *hdr;
+} slidx_list_t;
+
+typedef struct slidx_table {
+	sal_log_record_header_t *header;
+	int n_sections;			/* # of section headers */
+	struct list_head proc_err;
+	struct list_head mem_dev_err;
+	struct list_head sel_dev_err;
+	struct list_head pci_bus_err;
+	struct list_head smbios_dev_err;
+	struct list_head pci_comp_err;
+	struct list_head plat_specific_err;
+	struct list_head host_ctlr_err;
+	struct list_head plat_bus_err;
+	struct list_head unsupported;	/* list of unsupported sections */
+} slidx_table_t;
+
+#define slidx_foreach_entry(pos, head) \
+	list_for_each_entry(pos, head, list)
+#define slidx_first_entry(head) \
+	(((head)->next != (head)) ? list_entry((head)->next, typeof(slidx_list_t), list) : NULL)
+#define slidx_count(slidx, sec) \
+({	int __count = 0; \
+	slidx_list_t *__pos; \
+	slidx_foreach_entry(__pos, &((slidx)->sec)) { __count++; }\
+	__count; })
+

arch/ia64/kernel/mca_drv_asm.S

+/*
+ * File:        mca_drv_asm.S
+ * Purpose:     Assembly portion of Generic MCA handling
+ *
+ * Copyright (C) 2004 FUJITSU LIMITED
+ * Copyright (C) Hidetoshi Seto (seto.hidetoshi@jp.fujitsu.com)
+ */
+#include <linux/config.h>
+#include <linux/threads.h>
+
+#include <asm/asmmacro.h>
+#include <asm/processor.h>
+
+GLOBAL_ENTRY(mca_handler_bhhook)
+	invala						// clear RSE ?
+	;;						//
+	cover						// 
+	;;						//
+	clrrrb						//
+	;;						
+	alloc		r16=ar.pfs,0,2,1,0		// make a new frame
+	;;
+	mov		r13=IA64_KR(CURRENT)		// current task pointer
+	;;
+	adds		r12=IA64_TASK_THREAD_KSP_OFFSET,r13
+	;;
+	ld8		r12=[r12]			// stack pointer
+	;;
+	mov		loc0=r16
+	movl		loc1=mca_handler_bh		// recovery C function
+	;;
+	mov		out0=r8				// poisoned address
+	mov		b6=loc1
+	;;
+	mov		loc1=rp
+	;;
+	br.call.sptk.many    rp=b6			// not return ...
+	;;
+	mov		ar.pfs=loc0
+	mov 		rp=loc1
+	;;
+	mov		r8=r0
+	br.ret.sptk.many rp
+	;;
+END(mca_handler_bhhook)

include/asm-ia64/mca.h

@@ -22,6 +22,11 @@
 
 #define IA64_MCA_RENDEZ_TIMEOUT		(20 * 1000)	/* value in milliseconds - 20 seconds */
 
+typedef struct ia64_fptr {
+	unsigned long fp;
+	unsigned long gp;
+} ia64_fptr_t;
+
 typedef union cmcv_reg_u {
 	u64	cmcv_regval;
 	struct	{
@@ -114,6 +119,7 @@ extern void ia64_mca_ucmc_handler(void);
 extern void ia64_monarch_init_handler(void);
 extern void ia64_slave_init_handler(void);
 extern void ia64_mca_cmc_vector_setup(void);
+extern int  (*ia64_mca_ucmc_other_recover_fp)(void *,ia64_mca_sal_to_os_state_t *,ia64_mca_os_to_sal_state_t *);
 
 #endif /* !__ASSEMBLY__ */
 #endif /* _ASM_IA64_MCA_H */