Commit 03bb2d65 authored by Christophe Leroy's avatar Christophe Leroy Committed by Scott Wood
Browse files

powerpc: get hugetlbpage handling more generic 



Today there are two implementations of hugetlbpages which are managed
by exclusive #ifdefs:
* FSL_BOOKE: several directory entries points to the same single hugepage
* BOOK3S: one upper level directory entry points to a table of hugepages

In preparation of implementation of hugepage support on the 8xx, we
need a mix of the two above solutions, because the 8xx needs both cases
depending on the size of pages:
* In 4k page size mode, each PGD entry covers a 4M bytes area. It means
that 2 PGD entries will be necessary to cover an 8M hugepage while a
single PGD entry will cover 8x 512k hugepages.
* In 16 page size mode, each PGD entry covers a 64M bytes area. It means
that 8x 8M hugepages will be covered by one PGD entry and 64x 512k
hugepages will be covers by one PGD entry.

This patch:
* removes #ifdefs in favor of if/else based on the range sizes
* merges the two huge_pte_alloc() functions as they are pretty similar
* merges the two hugetlbpage_init() functions as they are pretty similar

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> (v3)
Signed-off-by: default avatarScott Wood <oss@buserror.net>
parent 9b081e10

arch/powerpc/mm/hugetlbpage.c

+81 −114
Original line number Diff line number Diff line
@@ -64,14 +64,16 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, 
{

	struct kmem_cache *cachep;

	pte_t *new;



#ifdef CONFIG_PPC_FSL_BOOK3E

	int i;

	int num_hugepd = 1 << (pshift - pdshift);

	int num_hugepd;



	if (pshift >= pdshift) {

		cachep = hugepte_cache;

#else

		num_hugepd = 1 << (pshift - pdshift);

	} else {

		cachep = PGT_CACHE(pdshift - pshift);

#endif

		num_hugepd = 1;

	}



	new = kmem_cache_zalloc(cachep, GFP_KERNEL);
@@ -89,7 +91,7 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, 
	smp_wmb();



	spin_lock(&mm->page_table_lock);

#ifdef CONFIG_PPC_FSL_BOOK3E



	/*

	 * We have multiple higher-level entries that point to the same

	 * actual pte location.  Fill in each as we go and backtrack on error.
@@ -100,8 +102,13 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, 
		if (unlikely(!hugepd_none(*hpdp)))

			break;

		else

#ifdef CONFIG_PPC_BOOK3S_64

			hpdp->pd = __pa(new) |

				   (shift_to_mmu_psize(pshift) << 2);

#else

			/* We use the old format for PPC_FSL_BOOK3E */

			hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;

#endif

	}

	/* If we bailed from the for loop early, an error occurred, clean up */

	if (i < num_hugepd) {
@@ -109,17 +116,6 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, 
			hpdp->pd = 0;

		kmem_cache_free(cachep, new);

	}

#else

	if (!hugepd_none(*hpdp))

		kmem_cache_free(cachep, new);

	else {

#ifdef CONFIG_PPC_BOOK3S_64

		hpdp->pd = __pa(new) | (shift_to_mmu_psize(pshift) << 2);

#else

		hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;

#endif

	}

#endif

	spin_unlock(&mm->page_table_lock);

	return 0;

}
@@ -136,7 +132,6 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, 
#define HUGEPD_PUD_SHIFT PMD_SHIFT

#endif



#ifdef CONFIG_PPC_BOOK3S_64

/*

 * At this point we do the placement change only for BOOK3S 64. This would

 * possibly work on other subarchs.
@@ -153,6 +148,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz 
	addr &= ~(sz-1);

	pg = pgd_offset(mm, addr);



#ifdef CONFIG_PPC_BOOK3S_64

	if (pshift == PGDIR_SHIFT)

		/* 16GB huge page */

		return (pte_t *) pg;
@@ -178,32 +174,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz 
				hpdp = (hugepd_t *)pm;

		}

	}

	if (!hpdp)

		return NULL;



	BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp));



	if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr, pdshift, pshift))

		return NULL;



	return hugepte_offset(*hpdp, addr, pdshift);

}



#else



pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)

{

	pgd_t *pg;

	pud_t *pu;

	pmd_t *pm;

	hugepd_t *hpdp = NULL;

	unsigned pshift = __ffs(sz);

	unsigned pdshift = PGDIR_SHIFT;



	addr &= ~(sz-1);



	pg = pgd_offset(mm, addr);



	if (pshift >= HUGEPD_PGD_SHIFT) {

		hpdp = (hugepd_t *)pg;

	} else {
@@ -217,7 +188,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz 
			hpdp = (hugepd_t *)pm;

		}

	}



#endif

	if (!hpdp)

		return NULL;
@@ -228,7 +199,6 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz 


	return hugepte_offset(*hpdp, addr, pdshift);

}

#endif



#ifdef CONFIG_PPC_FSL_BOOK3E

/* Build list of addresses of gigantic pages.  This function is used in early
@@ -310,7 +280,11 @@ static int __init do_gpage_early_setup(char *param, char *val, 
				npages = 0;

			if (npages > MAX_NUMBER_GPAGES) {

				pr_warn("MMU: %lu pages requested for page "

#ifdef CONFIG_PHYS_ADDR_T_64BIT

					"size %llu KB, limiting to "

#else

					"size %u KB, limiting to "

#endif

					__stringify(MAX_NUMBER_GPAGES) "\n",

					npages, size / 1024);

				npages = MAX_NUMBER_GPAGES;
@@ -442,6 +416,8 @@ static void hugepd_free(struct mmu_gather *tlb, void *hugepte) 
	}

	put_cpu_var(hugepd_freelist_cur);

}

#else

static inline void hugepd_free(struct mmu_gather *tlb, void *hugepte) {}

#endif



static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshift,
@@ -453,13 +429,11 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif 


	unsigned long pdmask = ~((1UL << pdshift) - 1);

	unsigned int num_hugepd = 1;

	unsigned int shift = hugepd_shift(*hpdp);



#ifdef CONFIG_PPC_FSL_BOOK3E

	/* Note: On fsl the hpdp may be the first of several */

	num_hugepd = (1 << (hugepd_shift(*hpdp) - pdshift));

#else

	unsigned int shift = hugepd_shift(*hpdp);

#endif

	if (shift > pdshift)

		num_hugepd = 1 << (shift - pdshift);



	start &= pdmask;

	if (start < floor)
@@ -475,11 +449,10 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif 
	for (i = 0; i < num_hugepd; i++, hpdp++)

		hpdp->pd = 0;



#ifdef CONFIG_PPC_FSL_BOOK3E

	if (shift >= pdshift)

		hugepd_free(tlb, hugepte);

#else

	else

		pgtable_free_tlb(tlb, hugepte, pdshift - shift);

#endif

}



static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
@@ -492,6 +465,8 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud, 


	start = addr;

	do {

		unsigned long more;



		pmd = pmd_offset(pud, addr);

		next = pmd_addr_end(addr, end);

		if (!is_hugepd(__hugepd(pmd_val(*pmd)))) {
@@ -502,15 +477,16 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud, 
			WARN_ON(!pmd_none_or_clear_bad(pmd));

			continue;

		}

#ifdef CONFIG_PPC_FSL_BOOK3E

		/*

		 * Increment next by the size of the huge mapping since

		 * there may be more than one entry at this level for a

		 * single hugepage, but all of them point to

		 * the same kmem cache that holds the hugepte.

		 */

		next = addr + (1 << hugepd_shift(*(hugepd_t *)pmd));

#endif

		more = addr + (1 << hugepd_shift(*(hugepd_t *)pmd));

		if (more > next)

			next = more;



		free_hugepd_range(tlb, (hugepd_t *)pmd, PMD_SHIFT,

				  addr, next, floor, ceiling);

	} while (addr = next, addr != end);
@@ -550,15 +526,17 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, 
			hugetlb_free_pmd_range(tlb, pud, addr, next, floor,

					       ceiling);

		} else {

#ifdef CONFIG_PPC_FSL_BOOK3E

			unsigned long more;

			/*

			 * Increment next by the size of the huge mapping since

			 * there may be more than one entry at this level for a

			 * single hugepage, but all of them point to

			 * the same kmem cache that holds the hugepte.

			 */

			next = addr + (1 << hugepd_shift(*(hugepd_t *)pud));

#endif

			more = addr + (1 << hugepd_shift(*(hugepd_t *)pud));

			if (more > next)

				next = more;



			free_hugepd_range(tlb, (hugepd_t *)pud, PUD_SHIFT,

					  addr, next, floor, ceiling);

		}
@@ -615,15 +593,17 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb, 
				continue;

			hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);

		} else {

#ifdef CONFIG_PPC_FSL_BOOK3E

			unsigned long more;

			/*

			 * Increment next by the size of the huge mapping since

			 * there may be more than one entry at the pgd level

			 * for a single hugepage, but all of them point to the

			 * same kmem cache that holds the hugepte.

			 */

			next = addr + (1 << hugepd_shift(*(hugepd_t *)pgd));

#endif

			more = addr + (1 << hugepd_shift(*(hugepd_t *)pgd));

			if (more > next)

				next = more;



			free_hugepd_range(tlb, (hugepd_t *)pgd, PGDIR_SHIFT,

					  addr, next, floor, ceiling);

		}
@@ -753,12 +733,13 @@ static int __init add_huge_page_size(unsigned long long size) 


	/* Check that it is a page size supported by the hardware and

	 * that it fits within pagetable and slice limits. */

	if (size <= PAGE_SIZE)

		return -EINVAL;

#ifdef CONFIG_PPC_FSL_BOOK3E

	if ((size < PAGE_SIZE) || !is_power_of_4(size))

	if (!is_power_of_4(size))

		return -EINVAL;

#else

	if (!is_power_of_2(size)

	    || (shift > SLICE_HIGH_SHIFT) || (shift <= PAGE_SHIFT))

	if (!is_power_of_2(size) || (shift > SLICE_HIGH_SHIFT))

		return -EINVAL;

#endif
@@ -791,53 +772,15 @@ static int __init hugepage_setup_sz(char *str) 
}

__setup("hugepagesz=", hugepage_setup_sz);



#ifdef CONFIG_PPC_FSL_BOOK3E

struct kmem_cache *hugepte_cache;

static int __init hugetlbpage_init(void)

{

	int psize;



	for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {

		unsigned shift;



		if (!mmu_psize_defs[psize].shift)

			continue;



		shift = mmu_psize_to_shift(psize);



		/* Don't treat normal page sizes as huge... */

		if (shift != PAGE_SHIFT)

			if (add_huge_page_size(1ULL << shift) < 0)

				continue;

	}



	/*

	 * Create a kmem cache for hugeptes.  The bottom bits in the pte have

	 * size information encoded in them, so align them to allow this

	 */

	hugepte_cache =  kmem_cache_create("hugepte-cache", sizeof(pte_t),

					   HUGEPD_SHIFT_MASK + 1, 0, NULL);

	if (hugepte_cache == NULL)

		panic("%s: Unable to create kmem cache for hugeptes\n",

		      __func__);



	/* Default hpage size = 4M */

	if (mmu_psize_defs[MMU_PAGE_4M].shift)

		HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_4M].shift;

	else

		panic("%s: Unable to set default huge page size\n", __func__);





	return 0;

}

#else

static int __init hugetlbpage_init(void)

{

	int psize;



#if !defined(CONFIG_PPC_FSL_BOOK3E)

	if (!radix_enabled() && !mmu_has_feature(MMU_FTR_16M_PAGE))

		return -ENODEV;



#endif

	for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {

		unsigned shift;

		unsigned pdshift;
@@ -850,9 +793,9 @@ static int __init hugetlbpage_init(void) 
		if (add_huge_page_size(1ULL << shift) < 0)

			continue;



		if (shift < PMD_SHIFT)

		if (shift < HUGEPD_PUD_SHIFT)

			pdshift = PMD_SHIFT;

		else if (shift < PUD_SHIFT)

		else if (shift < HUGEPD_PGD_SHIFT)

			pdshift = PUD_SHIFT;

		else

			pdshift = PGDIR_SHIFT;
@@ -860,14 +803,36 @@ static int __init hugetlbpage_init(void) 
		 * if we have pdshift and shift value same, we don't

		 * use pgt cache for hugepd.

		 */

		if (pdshift != shift) {

		if (pdshift > shift) {

			pgtable_cache_add(pdshift - shift, NULL);

			if (!PGT_CACHE(pdshift - shift))

				panic("hugetlbpage_init(): could not create "

				      "pgtable cache for %d bit pagesize\n", shift);

		}

#ifdef CONFIG_PPC_FSL_BOOK3E

		else if (!hugepte_cache) {

			/*

			 * Create a kmem cache for hugeptes.  The bottom bits in

			 * the pte have size information encoded in them, so

			 * align them to allow this

			 */

			hugepte_cache = kmem_cache_create("hugepte-cache",

							  sizeof(pte_t),

							  HUGEPD_SHIFT_MASK + 1,

							  0, NULL);

			if (hugepte_cache == NULL)

				panic("%s: Unable to create kmem cache "

				      "for hugeptes\n", __func__);



		}

#endif

	}



#ifdef CONFIG_PPC_FSL_BOOK3E

	/* Default hpage size = 4M */

	if (mmu_psize_defs[MMU_PAGE_4M].shift)

		HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_4M].shift;

#else

	/* Set default large page size. Currently, we pick 16M or 1M

	 * depending on what is available

	 */
@@ -877,11 +842,13 @@ static int __init hugetlbpage_init(void) 
		HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_1M].shift;

	else if (mmu_psize_defs[MMU_PAGE_2M].shift)

		HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_2M].shift;



#endif

	else

		panic("%s: Unable to set default huge page size\n", __func__);



	return 0;

}

#endif



arch_initcall(hugetlbpage_init);



void flush_dcache_icache_hugepage(struct page *page)

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