powerpc/mce: Remove per cpu variables from MCE handlers

Access to per-cpu variables requires translation to be enabled on
pseries machine running in hash mmu mode, Since part of MCE handler
runs in realmode and part of MCE handling code is shared between ppc
architectures pseries and powernv, it becomes difficult to manage
these variables differently on different architectures, So have
these variables in paca instead of having them as per-cpu variables
to avoid complications.

Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210128104143.70668-2-ganeshgr@linux.ibm.com

diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
index 7d8b6679ec6830ff9e86900a86ca97f3409117df..331d944280b8190007474c045b774b69edf09d12 100644 (file)
--- a/arch/powerpc/include/asm/mce.h
+++ b/arch/powerpc/include/asm/mce.h
@@ -206,6 +206,17 @@ struct mce_error_info {
 
 #define MAX_MC_EVT     10
 
+struct mce_info {
+       int mce_nest_count;
+       struct machine_check_event mce_event[MAX_MC_EVT];
+       /* Queue for delayed MCE events. */
+       int mce_queue_count;
+       struct machine_check_event mce_event_queue[MAX_MC_EVT];
+       /* Queue for delayed MCE UE events. */
+       int mce_ue_count;
+       struct machine_check_event  mce_ue_event_queue[MAX_MC_EVT];
+};
+
 /* Release flags for get_mce_event() */
 #define MCE_EVENT_RELEASE      true
 #define MCE_EVENT_DONTRELEASE  false
@@ -234,4 +245,11 @@ long __machine_check_early_realmode_p8(struct pt_regs *regs);
 long __machine_check_early_realmode_p9(struct pt_regs *regs);
 long __machine_check_early_realmode_p10(struct pt_regs *regs);
 #endif /* CONFIG_PPC_BOOK3S_64 */
+
+#ifdef CONFIG_PPC_BOOK3S_64
+void mce_init(void);
+#else
+static inline void mce_init(void) { };
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
 #endif /* __ASM_PPC64_MCE_H__ */

diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 9454d29ff4b47d27b2cf6bdf9f882da76377c584..38e0c55e845df8089445c6cdb33f5d0779c793e9 100644 (file)
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -29,6 +29,7 @@
 #include <asm/hmi.h>
 #include <asm/cpuidle.h>
 #include <asm/atomic.h>
+#include <asm/mce.h>
 
 #include <asm-generic/mmiowb_types.h>
 
@@ -273,6 +274,9 @@ struct paca_struct {
 #ifdef CONFIG_MMIOWB
        struct mmiowb_state mmiowb_state;
 #endif
+#ifdef CONFIG_PPC_BOOK3S_64
+       struct mce_info *mce_info;
+#endif /* CONFIG_PPC_BOOK3S_64 */
 } ____cacheline_aligned;
 
 extern void copy_mm_to_paca(struct mm_struct *mm);

diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index c381dc2f9858b027978e63e985096d1044e4fc4f..3e3a84127c0eac52213e8af75f0ecf16ffc330d9 100644 (file)
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -17,23 +17,14 @@
 #include <linux/irq_work.h>
 #include <linux/extable.h>
 #include <linux/ftrace.h>
+#include <linux/memblock.h>
 
 #include <asm/machdep.h>
 #include <asm/mce.h>
 #include <asm/nmi.h>
 #include <asm/asm-prototypes.h>
 
-static DEFINE_PER_CPU(int, mce_nest_count);
-static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);
-
-/* Queue for delayed MCE events. */
-static DEFINE_PER_CPU(int, mce_queue_count);
-static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);
-
-/* Queue for delayed MCE UE events. */
-static DEFINE_PER_CPU(int, mce_ue_count);
-static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
-                                       mce_ue_event_queue);
+#include "setup.h"
 
 static void machine_check_process_queued_event(struct irq_work *work);
 static void machine_check_ue_irq_work(struct irq_work *work);
@@ -104,9 +95,10 @@ void save_mce_event(struct pt_regs *regs, long handled,
                    struct mce_error_info *mce_err,
                    uint64_t nip, uint64_t addr, uint64_t phys_addr)
 {
-       int index = __this_cpu_inc_return(mce_nest_count) - 1;
-       struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);
+       int index = local_paca->mce_info->mce_nest_count++;
+       struct machine_check_event *mce;
 
+       mce = &local_paca->mce_info->mce_event[index];
        /*
         * Return if we don't have enough space to log mce event.
         * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
@@ -192,7 +184,7 @@ void save_mce_event(struct pt_regs *regs, long handled,
  */
 int get_mce_event(struct machine_check_event *mce, bool release)
 {
-       int index = __this_cpu_read(mce_nest_count) - 1;
+       int index = local_paca->mce_info->mce_nest_count - 1;
        struct machine_check_event *mc_evt;
        int ret = 0;
 
@@ -202,7 +194,7 @@ int get_mce_event(struct machine_check_event *mce, bool release)
 
        /* Check if we have MCE info to process. */
        if (index < MAX_MC_EVT) {
-               mc_evt = this_cpu_ptr(&mce_event[index]);
+               mc_evt = &local_paca->mce_info->mce_event[index];
                /* Copy the event structure and release the original */
                if (mce)
                        *mce = *mc_evt;
@@ -212,7 +204,7 @@ int get_mce_event(struct machine_check_event *mce, bool release)
        }
        /* Decrement the count to free the slot. */
        if (release)
-               __this_cpu_dec(mce_nest_count);
+               local_paca->mce_info->mce_nest_count--;
 
        return ret;
 }
@@ -234,13 +226,14 @@ static void machine_check_ue_event(struct machine_check_event *evt)
 {
        int index;
 
-       index = __this_cpu_inc_return(mce_ue_count) - 1;
+       index = local_paca->mce_info->mce_ue_count++;
        /* If queue is full, just return for now. */
        if (index >= MAX_MC_EVT) {
-               __this_cpu_dec(mce_ue_count);
+               local_paca->mce_info->mce_ue_count--;
                return;
        }
-       memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
+       memcpy(&local_paca->mce_info->mce_ue_event_queue[index],
+              evt, sizeof(*evt));
 
        /* Queue work to process this event later. */
        irq_work_queue(&mce_ue_event_irq_work);
@@ -257,13 +250,14 @@ void machine_check_queue_event(void)
        if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
                return;
 
-       index = __this_cpu_inc_return(mce_queue_count) - 1;
+       index = local_paca->mce_info->mce_queue_count++;
        /* If queue is full, just return for now. */
        if (index >= MAX_MC_EVT) {
-               __this_cpu_dec(mce_queue_count);
+               local_paca->mce_info->mce_queue_count--;
                return;
        }
-       memcpy(this_cpu_ptr(&mce_event_queue[index]), &evt, sizeof(evt));
+       memcpy(&local_paca->mce_info->mce_event_queue[index],
+              &evt, sizeof(evt));
 
        /* Queue irq work to process this event later. */
        irq_work_queue(&mce_event_process_work);
@@ -290,9 +284,9 @@ static void machine_process_ue_event(struct work_struct *work)
        int index;
        struct machine_check_event *evt;
 
-       while (__this_cpu_read(mce_ue_count) > 0) {
-               index = __this_cpu_read(mce_ue_count) - 1;
-               evt = this_cpu_ptr(&mce_ue_event_queue[index]);
+       while (local_paca->mce_info->mce_ue_count > 0) {
+               index = local_paca->mce_info->mce_ue_count - 1;
+               evt = &local_paca->mce_info->mce_ue_event_queue[index];
                blocking_notifier_call_chain(&mce_notifier_list, 0, evt);
 #ifdef CONFIG_MEMORY_FAILURE
                /*
@@ -305,7 +299,7 @@ static void machine_process_ue_event(struct work_struct *work)
                 */
                if (evt->error_type == MCE_ERROR_TYPE_UE) {
                        if (evt->u.ue_error.ignore_event) {
-                               __this_cpu_dec(mce_ue_count);
+                               local_paca->mce_info->mce_ue_count--;
                                continue;
                        }
 
@@ -321,7 +315,7 @@ static void machine_process_ue_event(struct work_struct *work)
                                        "was generated\n");
                }
 #endif
-               __this_cpu_dec(mce_ue_count);
+               local_paca->mce_info->mce_ue_count--;
        }
 }
 /*
@@ -339,17 +333,17 @@ static void machine_check_process_queued_event(struct irq_work *work)
         * For now just print it to console.
         * TODO: log this error event to FSP or nvram.
         */
-       while (__this_cpu_read(mce_queue_count) > 0) {
-               index = __this_cpu_read(mce_queue_count) - 1;
-               evt = this_cpu_ptr(&mce_event_queue[index]);
+       while (local_paca->mce_info->mce_queue_count > 0) {
+               index = local_paca->mce_info->mce_queue_count - 1;
+               evt = &local_paca->mce_info->mce_event_queue[index];
 
                if (evt->error_type == MCE_ERROR_TYPE_UE &&
                    evt->u.ue_error.ignore_event) {
-                       __this_cpu_dec(mce_queue_count);
+                       local_paca->mce_info->mce_queue_count--;
                        continue;
                }
                machine_check_print_event_info(evt, false, false);
-               __this_cpu_dec(mce_queue_count);
+               local_paca->mce_info->mce_queue_count--;
        }
 }
 
@@ -742,3 +736,24 @@ long hmi_exception_realmode(struct pt_regs *regs)
 
        return 1;
 }
+
+void __init mce_init(void)
+{
+       struct mce_info *mce_info;
+       u64 limit;
+       int i;
+
+       limit = min(ppc64_bolted_size(), ppc64_rma_size);
+       for_each_possible_cpu(i) {
+               mce_info = memblock_alloc_try_nid(sizeof(*mce_info),
+                                                 __alignof__(*mce_info),
+                                                 MEMBLOCK_LOW_LIMIT,
+                                                 limit, cpu_to_node(i));
+               if (!mce_info)
+                       goto err;
+               paca_ptrs[i]->mce_info = mce_info;
+       }
+       return;
+err:
+       panic("Failed to allocate memory for MCE event data\n");
+}

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 71f38e9248be15d431b3ef2cf0afa32bdc917bb7..d480f091e0adfdd77e8bc96f58f865e62d8a10ad 100644 (file)
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -64,6 +64,7 @@
 #include <asm/mmu_context.h>
 #include <asm/cpu_has_feature.h>
 #include <asm/kasan.h>
+#include <asm/mce.h>
 
 #include "setup.h"
 
@@ -938,6 +939,7 @@ void __init setup_arch(char **cmdline_p)
        exc_lvl_early_init();
        emergency_stack_init();
 
+       mce_init();
        smp_release_cpus();
 
        initmem_init();