Subject: [PATCH v2 08/16] powerpc/64s/powernv: machine check dump SLB contents

From: Nicholas Piggin <[email-masked]>
Date: Thu, 11 Jul 2019 01:19:42 +1000

Re-use the code introduced in pseries to save and dump the contents
of the SLB in the case of an SLB involved machine check exception.

This patch also avoids allocating the SLB save array on pseries radix.

Signed-off-by: Nicholas Piggin <[email-masked]>
---
 arch/powerpc/kernel/mce.c              |  6 ++++++
 arch/powerpc/kernel/mce_power.c        |  4 ++++
 arch/powerpc/platforms/powernv/setup.c |  9 +++++++++
 arch/powerpc/platforms/pseries/setup.c | 24 +++++++++++++-----------
 4 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index b18df633eae9..38b560f92d12 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -486,6 +486,12 @@ void machine_check_print_event_info(struct machine_check_event *evt,
 	subtype = evt->error_class < ARRAY_SIZE(mc_error_class) ?
 		mc_error_class[evt->error_class] : "Unknown";
 	printk("%sMCE: CPU%d: %s\n", level, evt->cpu, subtype);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+	/* Display faulty slb contents for SLB errors. */
+	if (evt->error_type == MCE_ERROR_TYPE_SLB)
+		slb_dump_contents(local_paca->mce_faulty_slbs);
+#endif
 }
 EXPORT_SYMBOL_GPL(machine_check_print_event_info);
 
diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c
index e39536aad30d..c4d0e0c6e7d3 100644
--- a/arch/powerpc/kernel/mce_power.c
+++ b/arch/powerpc/kernel/mce_power.c
@@ -398,6 +398,8 @@ static int mce_handle_ierror(struct pt_regs *regs,
 		/* attempt to correct the error */
 		switch (table[i].error_type) {
 		case MCE_ERROR_TYPE_SLB:
+			if (local_paca->in_mce == 1)
+				slb_save_contents(local_paca->mce_faulty_slbs);
 			handled = mce_flush(MCE_FLUSH_SLB);
 			break;
 		case MCE_ERROR_TYPE_ERAT:
@@ -483,6 +485,8 @@ static int mce_handle_derror(struct pt_regs *regs,
 		/* attempt to correct the error */
 		switch (table[i].error_type) {
 		case MCE_ERROR_TYPE_SLB:
+			if (local_paca->in_mce == 1)
+				slb_save_contents(local_paca->mce_faulty_slbs);
 			if (mce_flush(MCE_FLUSH_SLB))
 				handled = 1;
 			break;
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index a5e52f9eed3c..83498604d322 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -24,6 +24,7 @@
 #include <linux/bug.h>
 #include <linux/pci.h>
 #include <linux/cpufreq.h>
+#include <linux/memblock.h>
 
 #include <asm/machdep.h>
 #include <asm/firmware.h>
@@ -166,6 +167,14 @@ static void __init pnv_init(void)
 	else
 #endif
 		add_preferred_console("hvc", 0, NULL);
+
+	if (!radix_enabled()) {
+		int i;
+
+		/* Allocate per cpu area to save old slb contents during MCE */
+		for_each_possible_cpu(i)
+			paca_ptrs[i]->mce_faulty_slbs = memblock_alloc_node(mmu_slb_size, __alignof__(*paca_ptrs[i]->mce_faulty_slbs), cpu_to_node(i));
+	}
 }
 
 static void __init pnv_init_IRQ(void)
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index ab38a6c8dffb..637d59f4c5ce 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -139,17 +139,19 @@ static void __init fwnmi_init(void)
 	}
 
 #ifdef CONFIG_PPC_BOOK3S_64
-	/* Allocate per cpu slb area to save old slb contents during MCE */
-	size = sizeof(struct slb_entry) * mmu_slb_size * nr_cpus;
-	slb_ptr = memblock_alloc_try_nid_raw(size, sizeof(struct slb_entry),
-					MEMBLOCK_LOW_LIMIT, ppc64_rma_size,
-					NUMA_NO_NODE);
-	if (!slb_ptr)
-		panic("Failed to allocate %zu bytes below %pa for slb area\n",
-		      size, &ppc64_rma_size);
-
-	for_each_possible_cpu(i)
-		paca_ptrs[i]->mce_faulty_slbs = slb_ptr + (mmu_slb_size * i);
+	if (!radix_enabled()) {
+		/* Allocate per cpu area to save old slb contents during MCE */
+		size = sizeof(struct slb_entry) * mmu_slb_size * nr_cpus;
+		slb_ptr = memblock_alloc_try_nid_raw(size,
+				sizeof(struct slb_entry), MEMBLOCK_LOW_LIMIT,
+				ppc64_rma_size, NUMA_NO_NODE);
+		if (!slb_ptr)
+			panic("Failed to allocate %zu bytes below %pa for slb area\n",
+			      size, &ppc64_rma_size);
+
+		for_each_possible_cpu(i)
+			paca_ptrs[i]->mce_faulty_slbs = slb_ptr + (mmu_slb_size * i);
+	}
 #endif
 }
 
-- 
2.20.1