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authorAnton Blanchard <anton@samba.org>2016-10-01 13:41:56 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2016-11-14 03:11:51 +0300
commit5246adec59458b5d325b8e1462ea9ef3ead7f6ae (patch)
treeefb962662f83e50bb5eab32a249f8938e57f5974
parent9e607f72748ddc5620aeeb8d1f32f30c79b360b9 (diff)
downloadlinux-5246adec59458b5d325b8e1462ea9ef3ead7f6ae.tar.xz
powerpc/pseries: Use H_CLEAR_HPT to clear MMU hash table during kexec
An hcall was recently added that does exactly what we need during kexec - it clears the entire MMU hash table, ignoring any VRMA mappings. Try it and fall back to the old method if we get a failure. On a POWER8 box with 5TB of memory, this reduces the time it takes to kexec a new kernel from from 4 minutes to 1 minute. Signed-off-by: Anton Blanchard <anton@samba.org> Tested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> [mpe: Split into separate functions and tweak function naming] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/include/asm/hvcall.h3
-rw-r--r--arch/powerpc/platforms/pseries/lpar.c24
2 files changed, 24 insertions, 3 deletions
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 708edebcf147..489748ed21b4 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -275,7 +275,8 @@
#define H_COP 0x304
#define H_GET_MPP_X 0x314
#define H_SET_MODE 0x31C
-#define MAX_HCALL_OPCODE H_SET_MODE
+#define H_CLEAR_HPT 0x358
+#define MAX_HCALL_OPCODE H_CLEAR_HPT
/* H_VIOCTL functions */
#define H_GET_VIOA_DUMP_SIZE 0x01
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index aa35245d8d6d..24ad43afbb46 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -221,7 +221,7 @@ static long pSeries_lpar_hpte_remove(unsigned long hpte_group)
return -1;
}
-static void pSeries_lpar_hptab_clear(void)
+static void manual_hpte_clear_all(void)
{
unsigned long size_bytes = 1UL << ppc64_pft_size;
unsigned long hpte_count = size_bytes >> 4;
@@ -249,6 +249,26 @@ static void pSeries_lpar_hptab_clear(void)
&(ptes[j].pteh), &(ptes[j].ptel));
}
}
+}
+
+static int hcall_hpte_clear_all(void)
+{
+ int rc;
+
+ do {
+ rc = plpar_hcall_norets(H_CLEAR_HPT);
+ } while (rc == H_CONTINUE);
+
+ return rc;
+}
+
+static void pseries_hpte_clear_all(void)
+{
+ int rc;
+
+ rc = hcall_hpte_clear_all();
+ if (rc != H_SUCCESS)
+ manual_hpte_clear_all();
#ifdef __LITTLE_ENDIAN__
/*
@@ -598,7 +618,7 @@ void __init hpte_init_pseries(void)
mmu_hash_ops.hpte_remove = pSeries_lpar_hpte_remove;
mmu_hash_ops.hpte_removebolted = pSeries_lpar_hpte_removebolted;
mmu_hash_ops.flush_hash_range = pSeries_lpar_flush_hash_range;
- mmu_hash_ops.hpte_clear_all = pSeries_lpar_hptab_clear;
+ mmu_hash_ops.hpte_clear_all = pseries_hpte_clear_all;
mmu_hash_ops.hugepage_invalidate = pSeries_lpar_hugepage_invalidate;
}