From 69a1593abdbcf03a76367320d929a8ae7a5e3d71 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 1 Oct 2020 15:35:38 +0000 Subject: [PATCH] powerpc/32s: Setup the early hash table at all time. At the time being, an early hash table is set up when CONFIG_KASAN is selected. There is nothing wrong with setting such an early hash table all the time, even if it is not used. This is a statically allocated 256 kB table which lies in the init data section. This makes the code simpler and may in the future allow to setup early IO mappings with fixmap instead of hard coding BATs. Put create_hpte() and flush_hash_pages() in the .ref.text section in order to avoid warning for the reference to early_hash[]. This reference is removed by MMU_init_hw_patch() before init memory is freed. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b8f8101c368b8a6451844a58d7bd7d83c14cf2aa.1601566529.git.christophe.leroy@csgroup.eu --- arch/powerpc/kernel/head_32.S | 13 +++++-------- arch/powerpc/mm/book3s32/hash_low.S | 9 +++++++-- arch/powerpc/mm/book3s32/mmu.c | 14 +++++--------- arch/powerpc/mm/kasan/kasan_init_32.c | 19 ------------------- 4 files changed, 17 insertions(+), 38 deletions(-) diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index b14524d4534c..6dc77419147e 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -155,9 +155,9 @@ __after_mmu_off: bl initial_bats bl load_segment_registers -#ifdef CONFIG_KASAN +BEGIN_MMU_FTR_SECTION bl early_hash_table -#endif +END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE) #if defined(CONFIG_BOOTX_TEXT) bl setup_disp_bat #endif @@ -936,7 +936,6 @@ _ENTRY(__restore_cpu_setup) * Load stuff into the MMU. Intended to be called with * IR=0 and DR=0. */ -#ifdef CONFIG_KASAN early_hash_table: sync /* Force all PTE updates to finish */ isync @@ -947,8 +946,10 @@ early_hash_table: lis r6, early_hash - PAGE_OFFSET@h ori r6, r6, 3 /* 256kB table */ mtspr SPRN_SDR1, r6 + lis r6, early_hash@h + lis r3, Hash@ha + stw r6, Hash@l(r3) blr -#endif load_up_mmu: sync /* Force all PTE updates to finish */ @@ -1037,11 +1038,7 @@ start_here: bl machine_init bl __save_cpu_setup bl MMU_init -#ifdef CONFIG_KASAN -BEGIN_MMU_FTR_SECTION bl MMU_init_hw_patch -END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE) -#endif /* * Go back to running unmapped so we can load up new values diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S index 3143de6ae769..b2c912e517b9 100644 --- a/arch/powerpc/mm/book3s32/hash_low.S +++ b/arch/powerpc/mm/book3s32/hash_low.S @@ -15,6 +15,7 @@ */ #include +#include #include #include #include @@ -284,9 +285,9 @@ _ASM_NOKPROBE_SYMBOL(add_hash_page) * * For speed, 4 of the instructions get patched once the size and * physical address of the hash table are known. These definitions - * of Hash_base and Hash_bits below are just an example. + * of Hash_base and Hash_bits below are for the early hash table. */ -Hash_base = 0xc0180000 +Hash_base = early_hash Hash_bits = 12 /* e.g. 256kB hash table */ Hash_msk = (((1 << Hash_bits) - 1) * 64) @@ -307,6 +308,7 @@ Hash_msk = (((1 << Hash_bits) - 1) * 64) #define HASH_LEFT 31-(LG_PTEG_SIZE+Hash_bits-1) #define HASH_RIGHT 31-LG_PTEG_SIZE +__REF _GLOBAL(create_hpte) /* Convert linux-style PTE (r5) to low word of PPC-style PTE (r8) */ rlwinm r8,r5,32-9,30,30 /* _PAGE_RW -> PP msb */ @@ -473,6 +475,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT) sync /* make sure pte updates get to memory */ blr + .previous _ASM_NOKPROBE_SYMBOL(create_hpte) .section .bss @@ -493,6 +496,7 @@ htab_hash_searches: * * We assume that there is a hash table in use (Hash != 0). */ +__REF _GLOBAL(flush_hash_pages) /* * We disable interrupts here, even on UP, because we want @@ -626,6 +630,7 @@ _GLOBAL(flush_hash_pages) 19: mtmsr r10 isync blr + .previous EXPORT_SYMBOL(flush_hash_pages) _ASM_NOKPROBE_SYMBOL(flush_hash_pages) diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c index 741e4fc990c7..a59e7ec98180 100644 --- a/arch/powerpc/mm/book3s32/mmu.c +++ b/arch/powerpc/mm/book3s32/mmu.c @@ -31,6 +31,8 @@ #include +u8 __initdata early_hash[SZ_256K] __aligned(SZ_256K) = {0}; + struct hash_pte *Hash; static unsigned long Hash_size, Hash_mask; unsigned long _SDR1; @@ -395,15 +397,6 @@ void __init MMU_init_hw(void) hash_mb2 = hash_mb = 32 - LG_HPTEG_SIZE - lg_n_hpteg; if (lg_n_hpteg > 16) hash_mb2 = 16 - LG_HPTEG_SIZE; - - /* - * When KASAN is selected, there is already an early temporary hash - * table and the switch to the final hash table is done later. - */ - if (IS_ENABLED(CONFIG_KASAN)) - return; - - MMU_init_hw_patch(); } void __init MMU_init_hw_patch(void) @@ -411,6 +404,9 @@ void __init MMU_init_hw_patch(void) unsigned int hmask = Hash_mask >> (16 - LG_HPTEG_SIZE); unsigned int hash = (unsigned int)Hash - PAGE_OFFSET; + if (!mmu_has_feature(MMU_FTR_HPTE_TABLE)) + return; + if (ppc_md.progress) ppc_md.progress("hash:patch", 0x345); if (ppc_md.progress) diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c index 929716ea21e9..59f61efc43af 100644 --- a/arch/powerpc/mm/kasan/kasan_init_32.c +++ b/arch/powerpc/mm/kasan/kasan_init_32.c @@ -174,22 +174,6 @@ void __init kasan_late_init(void) kasan_unmap_early_shadow_vmalloc(); } -#ifdef CONFIG_PPC_BOOK3S_32 -u8 __initdata early_hash[256 << 10] __aligned(256 << 10) = {0}; - -static void __init kasan_early_hash_table(void) -{ - unsigned int hash = __pa(early_hash); - - modify_instruction_site(&patch__hash_page_A0, 0xffff, hash >> 16); - modify_instruction_site(&patch__flush_hash_A0, 0xffff, hash >> 16); - - Hash = (struct hash_pte *)early_hash; -} -#else -static void __init kasan_early_hash_table(void) {} -#endif - void __init kasan_early_init(void) { unsigned long addr = KASAN_SHADOW_START; @@ -205,7 +189,4 @@ void __init kasan_early_init(void) next = pgd_addr_end(addr, end); pmd_populate_kernel(&init_mm, pmd, kasan_early_shadow_pte); } while (pmd++, addr = next, addr != end); - - if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) - kasan_early_hash_table(); } -- 2.17.1