From da1adea07576722da4597b0df7d00931f0203229 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 19 May 2020 05:49:25 +0000 Subject: [PATCH] powerpc/8xx: Allow STRICT_KERNEL_RwX with pinned TLB Pinned TLB are 8M. Now that there is no strict boundary anymore between text and RO data, it is possible to use 8M pinned executable TLB that covers both text and RO data. When PIN_TLB_DATA or PIN_TLB_TEXT is selected, enforce 8M RW data alignment and allow STRICT_KERNEL_RWX. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/c535fc97bf0dd8693192e25feeed8088701e00c6.1589866984.git.christophe.leroy@csgroup.eu --- arch/powerpc/Kconfig | 8 +++++--- arch/powerpc/mm/nohash/8xx.c | 9 +++++++-- arch/powerpc/platforms/8xx/Kconfig | 2 +- 3 files changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index d147d379b1b9..f5e82629e2cd 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -779,9 +779,10 @@ config THREAD_SHIFT want. Only change this if you know what you are doing. config DATA_SHIFT_BOOL - bool "Set custom data alignment" if STRICT_KERNEL_RWX && \ - (PPC_BOOK3S_32 || PPC_8xx) + bool "Set custom data alignment" depends on ADVANCED_OPTIONS + depends on STRICT_KERNEL_RWX + depends on PPC_BOOK3S_32 || (PPC_8xx && !PIN_TLB_DATA && !PIN_TLB_TEXT) help This option allows you to set the kernel data alignment. When RAM is mapped by blocks, the alignment needs to fit the size and @@ -803,7 +804,8 @@ config DATA_SHIFT On 8xx, large pages (512kb or 8M) are used to map kernel linear memory. Aligning to 8M reduces TLB misses as only 8M pages are used - in that case. + in that case. If PIN_TLB is selected, it must be aligned to 8M as + 8M pages will be pinned. config FORCE_MAX_ZONEORDER int "Maximum zone order" diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c index ec3ef75895d8..d8697f535c3e 100644 --- a/arch/powerpc/mm/nohash/8xx.c +++ b/arch/powerpc/mm/nohash/8xx.c @@ -127,8 +127,8 @@ void __init mmu_mapin_immr(void) PAGE_KERNEL_NCG, MMU_PAGE_512K, true); } -static void __init mmu_mapin_ram_chunk(unsigned long offset, unsigned long top, - pgprot_t prot, bool new) +static void mmu_mapin_ram_chunk(unsigned long offset, unsigned long top, + pgprot_t prot, bool new) { unsigned long v = PAGE_OFFSET + offset; unsigned long p = offset; @@ -181,6 +181,9 @@ void mmu_mark_initmem_nx(void) mmu_mapin_ram_chunk(0, boundary, PAGE_KERNEL_TEXT, false); mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL, false); + + if (IS_ENABLED(CONFIG_PIN_TLB_TEXT)) + mmu_pin_tlb(block_mapped_ram, false); } #ifdef CONFIG_STRICT_KERNEL_RWX @@ -189,6 +192,8 @@ void mmu_mark_rodata_ro(void) unsigned long sinittext = __pa(_sinittext); mmu_mapin_ram_chunk(0, sinittext, PAGE_KERNEL_ROX, false); + if (IS_ENABLED(CONFIG_PIN_TLB_DATA)) + mmu_pin_tlb(block_mapped_ram, true); } #endif diff --git a/arch/powerpc/platforms/8xx/Kconfig b/arch/powerpc/platforms/8xx/Kconfig index 04ea1a8a0bdc..05669f2fadce 100644 --- a/arch/powerpc/platforms/8xx/Kconfig +++ b/arch/powerpc/platforms/8xx/Kconfig @@ -167,7 +167,7 @@ menu "8xx advanced setup" config PIN_TLB bool "Pinned Kernel TLBs" - depends on ADVANCED_OPTIONS && !DEBUG_PAGEALLOC && !STRICT_KERNEL_RWX + depends on ADVANCED_OPTIONS && !DEBUG_PAGEALLOC help On the 8xx, we have 32 instruction TLBs and 32 data TLBs. In each table 4 TLBs can be pinned.