From 5246adec59458b5d325b8e1462ea9ef3ead7f6ae Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Sat, 1 Oct 2016 20:41:56 +1000 Subject: [PATCH] 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 Tested-by: Mahesh Salgaonkar [mpe: Split into separate functions and tweak function naming] Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/hvcall.h | 3 ++- arch/powerpc/platforms/pseries/lpar.c | 24 ++++++++++++++++++++++-- 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; }