From 15472423ce47d6397d08d48daaae8590c9f9f242 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 22 Feb 2018 15:27:28 +0100 Subject: [PATCH] powerpc/mm/slice: Allow up to 64 low slices While the implementation of the "slices" address space allows a significant amount of high slices, it limits the number of low slices to 16 due to the use of a single u64 low_slices_psize element in struct mm_context_t On the 8xx, the minimum slice size is the size of the area covered by a single PMD entry, ie 4M in 4K pages mode and 64M in 16K pages mode. This means we could have at least 64 slices. In order to override this limitation, this patch switches the handling of low_slices_psize to char array as done already for high_slices_psize. Signed-off-by: Christophe Leroy Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/book3s/64/mmu.h | 3 +- arch/powerpc/include/asm/mmu-8xx.h | 7 +++- arch/powerpc/include/asm/paca.h | 2 +- arch/powerpc/kernel/paca.c | 3 +- arch/powerpc/mm/hash_utils_64.c | 13 ++++---- arch/powerpc/mm/slb_low.S | 8 +++-- arch/powerpc/mm/slice.c | 57 +++++++++++++++++--------------- 7 files changed, 52 insertions(+), 41 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h index 0abeb0e..bef6e39 100644 --- a/arch/powerpc/include/asm/book3s/64/mmu.h +++ b/arch/powerpc/include/asm/book3s/64/mmu.h @@ -91,7 +91,8 @@ typedef struct { struct npu_context *npu_context; #ifdef CONFIG_PPC_MM_SLICES - u64 low_slices_psize; /* SLB page size encodings */ + /* SLB page size encodings*/ + unsigned char low_slices_psize[BITS_PER_LONG / BITS_PER_BYTE]; unsigned char high_slices_psize[SLICE_ARRAY_SIZE]; unsigned long slb_addr_limit; #else diff --git a/arch/powerpc/include/asm/mmu-8xx.h b/arch/powerpc/include/asm/mmu-8xx.h index b324ab4..d3d7e79 100644 --- a/arch/powerpc/include/asm/mmu-8xx.h +++ b/arch/powerpc/include/asm/mmu-8xx.h @@ -186,6 +186,11 @@ #define M_APG2 0x00000040 #define M_APG3 0x00000060 +#ifdef CONFIG_PPC_MM_SLICES +#include +#define SLICE_ARRAY_SIZE (1 << (32 - SLICE_LOW_SHIFT - 1)) +#endif + #ifndef __ASSEMBLY__ typedef struct { unsigned int id; @@ -193,7 +198,7 @@ typedef struct { unsigned long vdso_base; #ifdef CONFIG_PPC_MM_SLICES u16 user_psize; /* page size index */ - u64 low_slices_psize; /* page size encodings */ + unsigned char low_slices_psize[SLICE_ARRAY_SIZE]; unsigned char high_slices_psize[0]; unsigned long slb_addr_limit; #endif diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index b62c310..d2bf71d 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -141,7 +141,7 @@ struct paca_struct { #ifdef CONFIG_PPC_BOOK3S mm_context_id_t mm_ctx_id; #ifdef CONFIG_PPC_MM_SLICES - u64 mm_ctx_low_slices_psize; + unsigned char mm_ctx_low_slices_psize[BITS_PER_LONG / BITS_PER_BYTE]; unsigned char mm_ctx_high_slices_psize[SLICE_ARRAY_SIZE]; unsigned long mm_ctx_slb_addr_limit; #else diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c index 95ffedf..2fd563d 100644 --- a/arch/powerpc/kernel/paca.c +++ b/arch/powerpc/kernel/paca.c @@ -265,7 +265,8 @@ void copy_mm_to_paca(struct mm_struct *mm) #ifdef CONFIG_PPC_MM_SLICES VM_BUG_ON(!mm->context.slb_addr_limit); get_paca()->mm_ctx_slb_addr_limit = mm->context.slb_addr_limit; - get_paca()->mm_ctx_low_slices_psize = context->low_slices_psize; + memcpy(&get_paca()->mm_ctx_low_slices_psize, + &context->low_slices_psize, sizeof(context->low_slices_psize)); memcpy(&get_paca()->mm_ctx_high_slices_psize, &context->high_slices_psize, TASK_SLICE_ARRAY_SZ(mm)); #else /* CONFIG_PPC_MM_SLICES */ diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index cf290d41..b578148 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -1110,19 +1110,18 @@ unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap) #ifdef CONFIG_PPC_MM_SLICES static unsigned int get_paca_psize(unsigned long addr) { - u64 lpsizes; - unsigned char *hpsizes; + unsigned char *psizes; unsigned long index, mask_index; if (addr < SLICE_LOW_TOP) { - lpsizes = get_paca()->mm_ctx_low_slices_psize; + psizes = get_paca()->mm_ctx_low_slices_psize; index = GET_LOW_SLICE_INDEX(addr); - return (lpsizes >> (index * 4)) & 0xF; + } else { + psizes = get_paca()->mm_ctx_high_slices_psize; + index = GET_HIGH_SLICE_INDEX(addr); } - hpsizes = get_paca()->mm_ctx_high_slices_psize; - index = GET_HIGH_SLICE_INDEX(addr); mask_index = index & 0x1; - return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF; + return (psizes[index >> 1] >> (mask_index * 4)) & 0xF; } #else diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S index 2cf5ef3..2c7c717 100644 --- a/arch/powerpc/mm/slb_low.S +++ b/arch/powerpc/mm/slb_low.S @@ -200,10 +200,12 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT) 5: /* * Handle lpsizes - * r9 is get_paca()->context.low_slices_psize, r11 is index + * r9 is get_paca()->context.low_slices_psize[index], r11 is mask_index */ - ld r9,PACALOWSLICESPSIZE(r13) - mr r11,r10 + srdi r11,r10,1 /* index */ + addi r9,r11,PACALOWSLICESPSIZE + lbzx r9,r13,r9 /* r9 is lpsizes[r11] */ + rldicl r11,r10,0,63 /* r11 = r10 & 0x1 */ 6: sldi r11,r11,2 /* index * 4 */ /* Extract the psize and multiply to get an array offset */ diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c index 0beca1b..5e9e1e5 100644 --- a/arch/powerpc/mm/slice.c +++ b/arch/powerpc/mm/slice.c @@ -150,19 +150,21 @@ static void slice_mask_for_free(struct mm_struct *mm, struct slice_mask *ret, static void slice_mask_for_size(struct mm_struct *mm, int psize, struct slice_mask *ret, unsigned long high_limit) { - unsigned char *hpsizes; + unsigned char *hpsizes, *lpsizes; int index, mask_index; unsigned long i; - u64 lpsizes; ret->low_slices = 0; if (SLICE_NUM_HIGH) bitmap_zero(ret->high_slices, SLICE_NUM_HIGH); lpsizes = mm->context.low_slices_psize; - for (i = 0; i < SLICE_NUM_LOW; i++) - if (((lpsizes >> (i * 4)) & 0xf) == psize) + for (i = 0; i < SLICE_NUM_LOW; i++) { + mask_index = i & 0x1; + index = i >> 1; + if (((lpsizes[index] >> (mask_index * 4)) & 0xf) == psize) ret->low_slices |= 1u << i; + } if (high_limit <= SLICE_LOW_TOP) return; @@ -218,8 +220,7 @@ static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psiz { int index, mask_index; /* Write the new slice psize bits */ - unsigned char *hpsizes; - u64 lpsizes; + unsigned char *hpsizes, *lpsizes; unsigned long i, flags; slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize); @@ -232,12 +233,13 @@ static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psiz lpsizes = mm->context.low_slices_psize; for (i = 0; i < SLICE_NUM_LOW; i++) - if (mask.low_slices & (1u << i)) - lpsizes = (lpsizes & ~(0xful << (i * 4))) | - (((unsigned long)psize) << (i * 4)); - - /* Assign the value back */ - mm->context.low_slices_psize = lpsizes; + if (mask.low_slices & (1u << i)) { + mask_index = i & 0x1; + index = i >> 1; + lpsizes[index] = (lpsizes[index] & + ~(0xf << (mask_index * 4))) | + (((unsigned long)psize) << (mask_index * 4)); + } hpsizes = mm->context.high_slices_psize; for (i = 0; i < GET_HIGH_SLICE_INDEX(mm->context.slb_addr_limit); i++) { @@ -644,7 +646,7 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr) { - unsigned char *hpsizes; + unsigned char *psizes; int index, mask_index; /* @@ -658,15 +660,14 @@ unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr) #endif } if (addr < SLICE_LOW_TOP) { - u64 lpsizes; - lpsizes = mm->context.low_slices_psize; + psizes = mm->context.low_slices_psize; index = GET_LOW_SLICE_INDEX(addr); - return (lpsizes >> (index * 4)) & 0xf; + } else { + psizes = mm->context.high_slices_psize; + index = GET_HIGH_SLICE_INDEX(addr); } - hpsizes = mm->context.high_slices_psize; - index = GET_HIGH_SLICE_INDEX(addr); mask_index = index & 0x1; - return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xf; + return (psizes[index >> 1] >> (mask_index * 4)) & 0xf; } EXPORT_SYMBOL_GPL(get_slice_psize); @@ -687,8 +688,8 @@ EXPORT_SYMBOL_GPL(get_slice_psize); void slice_set_user_psize(struct mm_struct *mm, unsigned int psize) { int index, mask_index; - unsigned char *hpsizes; - unsigned long flags, lpsizes; + unsigned char *hpsizes, *lpsizes; + unsigned long flags; unsigned int old_psize; int i; @@ -706,12 +707,14 @@ void slice_set_user_psize(struct mm_struct *mm, unsigned int psize) wmb(); lpsizes = mm->context.low_slices_psize; - for (i = 0; i < SLICE_NUM_LOW; i++) - if (((lpsizes >> (i * 4)) & 0xf) == old_psize) - lpsizes = (lpsizes & ~(0xful << (i * 4))) | - (((unsigned long)psize) << (i * 4)); - /* Assign the value back */ - mm->context.low_slices_psize = lpsizes; + for (i = 0; i < SLICE_NUM_LOW; i++) { + mask_index = i & 0x1; + index = i >> 1; + if (((lpsizes[index] >> (mask_index * 4)) & 0xf) == old_psize) + lpsizes[index] = (lpsizes[index] & + ~(0xf << (mask_index * 4))) | + (((unsigned long)psize) << (mask_index * 4)); + } hpsizes = mm->context.high_slices_psize; for (i = 0; i < SLICE_NUM_HIGH; i++) { -- 2.7.4