[PATCH v3 2/5] powerpc/mm: Enhance 'slice' for supporting PPC32

Christophe LEROY christophe.leroy at c-s.fr
Sat Feb 10 23:55:57 AEDT 2018



Le 29/01/2018 à 07:23, Aneesh Kumar K.V a écrit :
> Christophe Leroy <christophe.leroy at c-s.fr> writes:
> 
>> In preparation for the following patch which will fix an issue on
>> the 8xx by re-using the 'slices', this patch enhances the
>> 'slices' implementation to support 32 bits CPUs.
>>
>> On PPC32, the address space is limited to 4Gbytes, hence only the low
>> slices will be used.
>>
>> This patch moves "slices" functions prototypes from page64.h to slice.h
>>
>> The high slices use bitmaps. As bitmap functions are not prepared to
>> handling bitmaps of size 0, the bitmap_xxx() calls are wrapped into
>> slice_bitmap_xxx() functions which will void on PPC32
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>
>> ---
>>   v2: First patch of v1 serie split in two parts ; added slice_bitmap_xxx() macros.
>>   v3: Moving slice related stuff in slice.h and slice_32/64.h
>>       slice_bitmap_xxx() are now static inline functions and platform dependent
>>       SLICE_LOW_TOP declared ull on PPC32 with correct casts allows to keep it 0x100000000
>>
>>   arch/powerpc/include/asm/page.h     |  1 +
>>   arch/powerpc/include/asm/page_64.h  | 59 ----------------------------------
>>   arch/powerpc/include/asm/slice.h    | 63 +++++++++++++++++++++++++++++++++++++
>>   arch/powerpc/include/asm/slice_32.h | 56 +++++++++++++++++++++++++++++++++
>>   arch/powerpc/include/asm/slice_64.h | 61 +++++++++++++++++++++++++++++++++++
>>   arch/powerpc/mm/slice.c             | 38 ++++++++++++----------
>>   6 files changed, 203 insertions(+), 75 deletions(-)
>>   create mode 100644 arch/powerpc/include/asm/slice.h
>>   create mode 100644 arch/powerpc/include/asm/slice_32.h
>>   create mode 100644 arch/powerpc/include/asm/slice_64.h
>>
>> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
>> index 8da5d4c1cab2..d5f1c41b7dba 100644
>> --- a/arch/powerpc/include/asm/page.h
>> +++ b/arch/powerpc/include/asm/page.h
>> @@ -344,5 +344,6 @@ typedef struct page *pgtable_t;
>>   
>>   #include <asm-generic/memory_model.h>
>>   #endif /* __ASSEMBLY__ */
>> +#include <asm/slice.h>
>>   
>>   #endif /* _ASM_POWERPC_PAGE_H */
>> diff --git a/arch/powerpc/include/asm/page_64.h b/arch/powerpc/include/asm/page_64.h
>> index 56234c6fcd61..af04acdb873f 100644
>> --- a/arch/powerpc/include/asm/page_64.h
>> +++ b/arch/powerpc/include/asm/page_64.h
>> @@ -86,65 +86,6 @@ extern u64 ppc64_pft_size;
>>   
>>   #endif /* __ASSEMBLY__ */
>>   
>> -#ifdef CONFIG_PPC_MM_SLICES
>> -
>> -#define SLICE_LOW_SHIFT		28
>> -#define SLICE_HIGH_SHIFT	40
>> -
>> -#define SLICE_LOW_TOP		(0x100000000ul)
>> -#define SLICE_NUM_LOW		(SLICE_LOW_TOP >> SLICE_LOW_SHIFT)
>> -#define SLICE_NUM_HIGH		(H_PGTABLE_RANGE >> SLICE_HIGH_SHIFT)
>> -
>> -#define GET_LOW_SLICE_INDEX(addr)	((addr) >> SLICE_LOW_SHIFT)
>> -#define GET_HIGH_SLICE_INDEX(addr)	((addr) >> SLICE_HIGH_SHIFT)
>> -
>> -#ifndef __ASSEMBLY__
>> -struct mm_struct;
>> -
>> -extern unsigned long slice_get_unmapped_area(unsigned long addr,
>> -					     unsigned long len,
>> -					     unsigned long flags,
>> -					     unsigned int psize,
>> -					     int topdown);
>> -
>> -extern unsigned int get_slice_psize(struct mm_struct *mm,
>> -				    unsigned long addr);
>> -
>> -extern void slice_set_user_psize(struct mm_struct *mm, unsigned int psize);
>> -extern void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
>> -				  unsigned long len, unsigned int psize);
>> -
>> -#endif /* __ASSEMBLY__ */
>> -#else
>> -#define slice_init()
>> -#ifdef CONFIG_PPC_BOOK3S_64
>> -#define get_slice_psize(mm, addr)	((mm)->context.user_psize)
>> -#define slice_set_user_psize(mm, psize)		\
>> -do {						\
>> -	(mm)->context.user_psize = (psize);	\
>> -	(mm)->context.sllp = SLB_VSID_USER | mmu_psize_defs[(psize)].sllp; \
>> -} while (0)
>> -#else /* !CONFIG_PPC_BOOK3S_64 */
>> -#ifdef CONFIG_PPC_64K_PAGES
>> -#define get_slice_psize(mm, addr)	MMU_PAGE_64K
>> -#else /* CONFIG_PPC_64K_PAGES */
>> -#define get_slice_psize(mm, addr)	MMU_PAGE_4K
>> -#endif /* !CONFIG_PPC_64K_PAGES */
>> -#define slice_set_user_psize(mm, psize)	do { BUG(); } while(0)
>> -#endif /* CONFIG_PPC_BOOK3S_64 */
>> -
>> -#define slice_set_range_psize(mm, start, len, psize)	\
>> -	slice_set_user_psize((mm), (psize))
>> -#endif /* CONFIG_PPC_MM_SLICES */
>> -
>> -#ifdef CONFIG_HUGETLB_PAGE
>> -
>> -#ifdef CONFIG_PPC_MM_SLICES
>> -#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
>> -#endif
>> -
>> -#endif /* !CONFIG_HUGETLB_PAGE */
>> -
>>   #define VM_DATA_DEFAULT_FLAGS \
>>   	(is_32bit_task() ? \
>>   	 VM_DATA_DEFAULT_FLAGS32 : VM_DATA_DEFAULT_FLAGS64)
>> diff --git a/arch/powerpc/include/asm/slice.h b/arch/powerpc/include/asm/slice.h
>> new file mode 100644
>> index 000000000000..2b4b70de7e71
>> --- /dev/null
>> +++ b/arch/powerpc/include/asm/slice.h
>> @@ -0,0 +1,63 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef _ASM_POWERPC_SLICE_H
>> +#define _ASM_POWERPC_SLICE_H
>> +
>> +#ifdef CONFIG_PPC_MM_SLICES
>> +
>> +#ifdef CONFIG_PPC64
>> +#include <asm/slice_64.h>
>> +#else
>> +#include <asm/slice_32.h>
>> +#endif
>> +
>> +#ifdef CONFIG_HUGETLB_PAGE
>> +#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
>> +#endif
>> +#define HAVE_ARCH_UNMAPPED_AREA
>> +#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
>> +
>> +#define SLICE_LOW_SHIFT		28
>> +#define SLICE_LOW_TOP		(0x100000000ull)
>> +#define SLICE_NUM_LOW		(SLICE_LOW_TOP >> SLICE_LOW_SHIFT)
>> +#define GET_LOW_SLICE_INDEX(addr)	((addr) >> SLICE_LOW_SHIFT)
>> +
>> +#ifndef __ASSEMBLY__
>> +
>> +struct mm_struct;
>> +
>> +unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
>> +				      unsigned long flags, unsigned int psize,
>> +				      int topdown);
>> +
>> +unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr);
>> +
>> +void slice_set_user_psize(struct mm_struct *mm, unsigned int psize);
>> +void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
>> +			   unsigned long len, unsigned int psize);
>> +
>> +#else
>> +#define slice_init()
>> +#ifdef CONFIG_PPC_BOOK3S_64
>> +#define get_slice_psize(mm, addr)	((mm)->context.user_psize)
>> +#define slice_set_user_psize(mm, psize)		\
>> +do {						\
>> +	(mm)->context.user_psize = (psize);	\
>> +	(mm)->context.sllp = SLB_VSID_USER | mmu_psize_defs[(psize)].sllp; \
>> +} while (0)
>> +#else /* !CONFIG_PPC_BOOK3S_64 */
>> +#ifdef CONFIG_PPC_64K_PAGES
>> +#define get_slice_psize(mm, addr)	MMU_PAGE_64K
>> +#else /* CONFIG_PPC_64K_PAGES */
>> +#define get_slice_psize(mm, addr)	MMU_PAGE_4K
>> +#endif /* !CONFIG_PPC_64K_PAGES */
>> +#define slice_set_user_psize(mm, psize)	do { BUG(); } while(0)
>> +#endif /* CONFIG_PPC_BOOK3S_64 */
>> +
> 
> That #ifder can really got into respective slice_32/64.h

Ok, created a nohash/64/slice.h for that.

> 
>> +#define slice_set_range_psize(mm, start, len, psize)	\
>> +	slice_set_user_psize((mm), (psize))
>> +
>> +#endif /* __ASSEMBLY__ */
>> +
>> +#endif /* CONFIG_PPC_MM_SLICES */
>> +
>> +#endif /* _ASM_POWERPC_SLICE_H */
>> diff --git a/arch/powerpc/include/asm/slice_32.h b/arch/powerpc/include/asm/slice_32.h
>> new file mode 100644
>> index 000000000000..7e27c0dfb913
>> --- /dev/null
>> +++ b/arch/powerpc/include/asm/slice_32.h
> 
> Can this be nohash/32/slice.h ? IIUC nobody else use slice

Ok

> 
> 
>> @@ -0,0 +1,56 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef _ASM_POWERPC_SLICE_32_H
>> +#define _ASM_POWERPC_SLICE_32_H
>> +
>> +#define SLICE_HIGH_SHIFT	0
>> +#define SLICE_NUM_HIGH		0ul
>> +#define GET_HIGH_SLICE_INDEX(addr)	(addr & 0)
>> +
>> +#ifndef __ASSEMBLY__
>> +
>> +static inline void slice_bitmap_zero(unsigned long *dst, unsigned int nbits)
>> +{
>> +}
>> +
>> +static inline int slice_bitmap_and(unsigned long *dst,
>> +				   const unsigned long *src1,
>> +				   const unsigned long *src2,
>> +				   unsigned int nbits)
>> +{
>> +	return 0;
>> +}
>> +
>> +static inline void slice_bitmap_or(unsigned long *dst,
>> +				   const unsigned long *src1,
>> +				   const unsigned long *src2,
>> +				   unsigned int nbits)
>> +{
>> +}
>> +
>> +static inline int slice_bitmap_andnot(unsigned long *dst,
>> +				      const unsigned long *src1,
>> +				      const unsigned long *src2,
>> +				      unsigned int nbits)
>> +{
>> +	return 0;
>> +}
>> +
>> +static inline int slice_bitmap_equal(const unsigned long *src1,
>> +				     const unsigned long *src2,
>> +				     unsigned int nbits)
>> +{
>> +	return 1;
>> +}
>> +
>> +static inline int slice_bitmap_empty(const unsigned long *src, unsigned nbits)
>> +{
>> +	return 1;
>> +}
>> +
>> +static inline void slice_bitmap_set(unsigned long *map, unsigned int start,
>> +				    unsigned int nbits)
>> +{
>> +}
>> +#endif /* __ASSEMBLY__ */
>> +
>> +#endif /* _ASM_POWERPC_SLICE_32_H */
>> diff --git a/arch/powerpc/include/asm/slice_64.h b/arch/powerpc/include/asm/slice_64.h
>> new file mode 100644
>> index 000000000000..9d1c97b83010
>> --- /dev/null
>> +++ b/arch/powerpc/include/asm/slice_64.h
> 
> Can this be book3s/63/slice.h ?

Ok

> 
>> @@ -0,0 +1,61 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#ifndef _ASM_POWERPC_SLICE_64_H
>> +#define _ASM_POWERPC_SLICE_64_H
>> +
>> +#define SLICE_HIGH_SHIFT	40
>> +#define SLICE_NUM_HIGH		(H_PGTABLE_RANGE >> SLICE_HIGH_SHIFT)
>> +#define GET_HIGH_SLICE_INDEX(addr)	((addr) >> SLICE_HIGH_SHIFT)
>> +
> 
> Can you keep both LOW and HIGH details together. Even if 32 bit make a
> copy of that?

Ok

Christophe

> 
>> +#ifndef __ASSEMBLY__
>> +
>> +#include <linux/bitmap.h>
>> +
>> +static inline void slice_bitmap_zero(unsigned long *dst, unsigned int nbits)
>> +{
>> +	bitmap_zero(dst, nbits);
>> +}
>> +
>> +static inline int slice_bitmap_and(unsigned long *dst,
>> +				   const unsigned long *src1,
>> +				   const unsigned long *src2,
>> +				   unsigned int nbits)
>> +{
>> +	return bitmap_and(dst, src1, src2, nbits);
>> +}
>> +
>> +static inline void slice_bitmap_or(unsigned long *dst,
>> +				   const unsigned long *src1,
>> +				   const unsigned long *src2,
>> +				   unsigned int nbits)
>> +{
>> +	bitmap_or(dst, src1, src2, nbits);
>> +}
>> +
>> +static inline int slice_bitmap_andnot(unsigned long *dst,
>> +				      const unsigned long *src1,
>> +				      const unsigned long *src2,
>> +				      unsigned int nbits)
>> +{
>> +	return bitmap_andnot(dst, src1, src2, nbits);
>> +}
>> +
>> +static inline int slice_bitmap_equal(const unsigned long *src1,
>> +				     const unsigned long *src2,
>> +				     unsigned int nbits)
>> +{
>> +	return bitmap_equal(src1, src2, nbits);
>> +}
>> +
>> +static inline int slice_bitmap_empty(const unsigned long *src, unsigned nbits)
>> +{
>> +	return bitmap_empty(src, nbits);
>> +}
>> +
>> +static inline void slice_bitmap_set(unsigned long *map, unsigned int start,
>> +				    unsigned int nbits)
>> +{
>> +	bitmap_set(map, start, nbits);
>> +}
>> +#endif /* __ASSEMBLY__ */
>> +
>> +#endif /* _ASM_POWERPC_SLICE_64_H */
>> diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
>> index 98b53d48968f..549704dfa777 100644
>> --- a/arch/powerpc/mm/slice.c
>> +++ b/arch/powerpc/mm/slice.c
>> @@ -73,10 +73,11 @@ static void slice_range_to_mask(unsigned long start, unsigned long len,
>>   	unsigned long end = start + len - 1;
>>   
>>   	ret->low_slices = 0;
>> -	bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
>> +	slice_bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
>>   
>>   	if (start < SLICE_LOW_TOP) {
>> -		unsigned long mend = min(end, (SLICE_LOW_TOP - 1));
>> +		unsigned long mend = min(end,
>> +					 (unsigned long)(SLICE_LOW_TOP - 1));
>>   
>>   		ret->low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
>>   			- (1u << GET_LOW_SLICE_INDEX(start));
>> @@ -87,7 +88,7 @@ static void slice_range_to_mask(unsigned long start, unsigned long len,
>>   		unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
>>   		unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
>>   
>> -		bitmap_set(ret->high_slices, start_index, count);
>> +		slice_bitmap_set(ret->high_slices, start_index, count);
>>   	}
>>   }
>>   
>> @@ -113,11 +114,13 @@ static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice)
>>   	unsigned long start = slice << SLICE_HIGH_SHIFT;
>>   	unsigned long end = start + (1ul << SLICE_HIGH_SHIFT);
>>   
>> +#ifdef CONFIG_PPC64
>>   	/* Hack, so that each addresses is controlled by exactly one
>>   	 * of the high or low area bitmaps, the first high area starts
>>   	 * at 4GB, not 0 */
>>   	if (start == 0)
>>   		start = SLICE_LOW_TOP;
>> +#endif
>>   
>>   	return !slice_area_is_free(mm, start, end - start);
>>   }
>> @@ -128,7 +131,7 @@ static void slice_mask_for_free(struct mm_struct *mm, struct slice_mask *ret,
>>   	unsigned long i;
>>   
>>   	ret->low_slices = 0;
>> -	bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
>> +	slice_bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
>>   
>>   	for (i = 0; i < SLICE_NUM_LOW; i++)
>>   		if (!slice_low_has_vma(mm, i))
>> @@ -151,7 +154,7 @@ static void slice_mask_for_size(struct mm_struct *mm, int psize, struct slice_ma
>>   	u64 lpsizes;
>>   
>>   	ret->low_slices = 0;
>> -	bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
>> +	slice_bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
>>   
>>   	lpsizes = mm->context.low_slices_psize;
>>   	for (i = 0; i < SLICE_NUM_LOW; i++)
>> @@ -180,15 +183,16 @@ static int slice_check_fit(struct mm_struct *mm,
>>   	 */
>>   	unsigned long slice_count = GET_HIGH_SLICE_INDEX(mm->context.slb_addr_limit);
>>   
>> -	bitmap_and(result, mask.high_slices,
>> -		   available.high_slices, slice_count);
>> +	slice_bitmap_and(result, mask.high_slices, available.high_slices,
>> +			 slice_count);
>>   
>>   	return (mask.low_slices & available.low_slices) == mask.low_slices &&
>> -		bitmap_equal(result, mask.high_slices, slice_count);
>> +		slice_bitmap_equal(result, mask.high_slices, slice_count);
>>   }
>>   
>>   static void slice_flush_segments(void *parm)
>>   {
>> +#ifdef CONFIG_PPC64
>>   	struct mm_struct *mm = parm;
>>   	unsigned long flags;
>>   
>> @@ -200,6 +204,7 @@ static void slice_flush_segments(void *parm)
>>   	local_irq_save(flags);
>>   	slb_flush_and_rebolt();
>>   	local_irq_restore(flags);
>> +#endif
>>   }
>>   
>>   static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psize)
>> @@ -389,16 +394,16 @@ static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len,
>>   static inline void slice_or_mask(struct slice_mask *dst, struct slice_mask *src)
>>   {
>>   	dst->low_slices |= src->low_slices;
>> -	bitmap_or(dst->high_slices, dst->high_slices, src->high_slices,
>> -		  SLICE_NUM_HIGH);
>> +	slice_bitmap_or(dst->high_slices, dst->high_slices, src->high_slices,
>> +			SLICE_NUM_HIGH);
>>   }
>>   
>>   static inline void slice_andnot_mask(struct slice_mask *dst, struct slice_mask *src)
>>   {
>>   	dst->low_slices &= ~src->low_slices;
>>   
>> -	bitmap_andnot(dst->high_slices, dst->high_slices, src->high_slices,
>> -		      SLICE_NUM_HIGH);
>> +	slice_bitmap_andnot(dst->high_slices, dst->high_slices,
>> +			    src->high_slices, SLICE_NUM_HIGH);
>>   }
>>   
>>   #ifdef CONFIG_PPC_64K_PAGES
>> @@ -446,14 +451,14 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
>>   	 * init different masks
>>   	 */
>>   	mask.low_slices = 0;
>> -	bitmap_zero(mask.high_slices, SLICE_NUM_HIGH);
>> +	slice_bitmap_zero(mask.high_slices, SLICE_NUM_HIGH);
>>   
>>   	/* silence stupid warning */;
>>   	potential_mask.low_slices = 0;
>> -	bitmap_zero(potential_mask.high_slices, SLICE_NUM_HIGH);
>> +	slice_bitmap_zero(potential_mask.high_slices, SLICE_NUM_HIGH);
>>   
>>   	compat_mask.low_slices = 0;
>> -	bitmap_zero(compat_mask.high_slices, SLICE_NUM_HIGH);
>> +	slice_bitmap_zero(compat_mask.high_slices, SLICE_NUM_HIGH);
>>   
>>   	/* Sanity checks */
>>   	BUG_ON(mm->task_size == 0);
>> @@ -591,7 +596,8 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
>>    convert:
>>   	slice_andnot_mask(&mask, &good_mask);
>>   	slice_andnot_mask(&mask, &compat_mask);
>> -	if (mask.low_slices || !bitmap_empty(mask.high_slices, SLICE_NUM_HIGH)) {
>> +	if (mask.low_slices ||
>> +	    !slice_bitmap_empty(mask.high_slices, SLICE_NUM_HIGH)) {
>>   		slice_convert(mm, mask, psize);
>>   		if (psize > MMU_PAGE_BASE)
>>   			on_each_cpu(slice_flush_segments, mm, 1);
>> -- 
>> 2.13.3


More information about the Linuxppc-dev mailing list