* [PATCH 1/2] powerpc/8xx: Merge 8M hugepage slice and basepage slice
@ 2020-02-06 19:21 Christophe Leroy
2020-02-06 19:21 ` [PATCH 2/2] powerpc/8xx: Make 8M hugepages also compatible with the 512K pages slice Christophe Leroy
2020-02-14 8:37 ` [PATCH 1/2] powerpc/8xx: Merge 8M hugepage slice and basepage slice Christophe Leroy
0 siblings, 2 replies; 3+ messages in thread
From: Christophe Leroy @ 2020-02-06 19:21 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, aneesh.kumar
Cc: linux-kernel, linuxppc-dev
On 8xx, slices are used because hugepages (512k or 8M) and small
pages (4k or 16k) cannot share the same PGD entry. However, as 8M
entirely covers two PGD entries (One PGD entry covers 4M), there
will implicitely be no conflict between 8M pages and any other size.
So 8M is compatible with the basepage size as well.
Remove the struct slice_mask mask_8m from mm_context_t and make
vma_mmu_pagesize() rely on vma_kernel_pagesize() as the base
slice can now host several sizes.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/include/asm/nohash/32/mmu-8xx.h | 7 ++-----
arch/powerpc/mm/hugetlbpage.c | 3 ++-
2 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
index 76af5b0cb16e..54f7f3362edb 100644
--- a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
@@ -215,9 +215,8 @@ typedef struct {
unsigned char low_slices_psize[SLICE_ARRAY_SIZE];
unsigned char high_slices_psize[0];
unsigned long slb_addr_limit;
- struct slice_mask mask_base_psize; /* 4k or 16k */
+ struct slice_mask mask_base_psize; /* 4k or 16k or 8M */
struct slice_mask mask_512k;
- struct slice_mask mask_8m;
#endif
void *pte_frag;
} mm_context_t;
@@ -257,10 +256,8 @@ static inline struct slice_mask *slice_mask_for_size(mm_context_t *ctx, int psiz
{
if (psize == MMU_PAGE_512K)
return &ctx->mask_512k;
- if (psize == MMU_PAGE_8M)
- return &ctx->mask_8m;
- BUG_ON(psize != mmu_virtual_psize);
+ BUG_ON(psize != mmu_virtual_psize && psize != MMU_PAGE_8M);
return &ctx->mask_base_psize;
}
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index edf511c2a30a..0b4ab741bf09 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -551,7 +551,8 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
{
/* With radix we don't use slice, so derive it from vma*/
- if (IS_ENABLED(CONFIG_PPC_MM_SLICES) && !radix_enabled()) {
+ if (IS_ENABLED(CONFIG_PPC_MM_SLICES) && !IS_ENABLED(CONFIG_PPC_8xx) &&
+ !radix_enabled()) {
unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
return 1UL << mmu_psize_to_shift(psize);
--
2.25.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 2/2] powerpc/8xx: Make 8M hugepages also compatible with the 512K pages slice
2020-02-06 19:21 [PATCH 1/2] powerpc/8xx: Merge 8M hugepage slice and basepage slice Christophe Leroy
@ 2020-02-06 19:21 ` Christophe Leroy
2020-02-14 8:37 ` [PATCH 1/2] powerpc/8xx: Merge 8M hugepage slice and basepage slice Christophe Leroy
1 sibling, 0 replies; 3+ messages in thread
From: Christophe Leroy @ 2020-02-06 19:21 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, aneesh.kumar
Cc: linux-kernel, linuxppc-dev
On 8xx, slices are used because hugepages (512k or 8M) and small
pages (4k or 16k) cannot share the same PGD entry. However, as 8M
entirely covers two PGD entries (One PGD entry covers 4M), there
will implicitely be no conflict between 8M pages and any other size.
So 8M is also compatible with the 512K page slices as well.
Handle 512K page slices as fallback compat mask for 8M pages.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/mm/slice.c | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index dffe1a45b6ed..cb5b532d3d48 100644
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -422,6 +422,8 @@ static inline void slice_andnot_mask(struct slice_mask *dst,
#ifdef CONFIG_PPC_64K_PAGES
#define MMU_PAGE_BASE MMU_PAGE_64K
+#elif defined(CONFIG_PPC_16K_PAGES)
+#define MMU_PAGE_BASE MMU_PAGE_16K
#else
#define MMU_PAGE_BASE MMU_PAGE_4K
#endif
@@ -514,9 +516,19 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
* If we support combo pages, we can allow 64k pages in 4k slices
* The mask copies could be avoided in most cases here if we had
* a pointer to good mask for the next code to use.
+ *
+ * On 8xx, slices are used because hugepages (512k or 8M) and small
+ * pages (4k or 16k) cannot share the same PGD entry. However, as 8M
+ * entirely covers two PGD entries, there will implicitely be no
+ * conflict between 8M pages and any other size. So 8M is compatible
+ * with the 512k page slice as well.
*/
- if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) {
- compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_4K);
+ if ((IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) ||
+ (IS_ENABLED(CONFIG_PPC_8xx) && psize == MMU_PAGE_8M)) {
+ if (IS_ENABLED(CONFIG_PPC_8xx))
+ compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_512K);
+ else
+ compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_4K);
if (fixed)
slice_or_mask(&good_mask, maskp, compat_maskp);
else
@@ -593,9 +605,8 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
newaddr = slice_find_area(mm, len, &potential_mask,
psize, topdown, high_limit);
- if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && newaddr == -ENOMEM &&
- psize == MMU_PAGE_64K) {
- /* retry the search with 4k-page slices included */
+ if (compat_maskp && newaddr == -ENOMEM) {
+ /* retry the search with compatible slices included */
slice_or_mask(&potential_mask, &potential_mask, compat_maskp);
newaddr = slice_find_area(mm, len, &potential_mask,
psize, topdown, high_limit);
@@ -767,12 +778,16 @@ int slice_is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
maskp = slice_mask_for_size(&mm->context, psize);
- /* We need to account for 4k slices too */
- if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) {
+ /* We need to account for compatible slices too */
+ if ((IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) ||
+ (IS_ENABLED(CONFIG_PPC_8xx) && psize == MMU_PAGE_8M)) {
const struct slice_mask *compat_maskp;
struct slice_mask available;
- compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_4K);
+ if (IS_ENABLED(CONFIG_PPC_8xx))
+ compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_512K);
+ else
+ compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_4K);
slice_or_mask(&available, maskp, compat_maskp);
return !slice_check_range_fits(mm, &available, addr, len);
}
--
2.25.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 1/2] powerpc/8xx: Merge 8M hugepage slice and basepage slice
2020-02-06 19:21 [PATCH 1/2] powerpc/8xx: Merge 8M hugepage slice and basepage slice Christophe Leroy
2020-02-06 19:21 ` [PATCH 2/2] powerpc/8xx: Make 8M hugepages also compatible with the 512K pages slice Christophe Leroy
@ 2020-02-14 8:37 ` Christophe Leroy
1 sibling, 0 replies; 3+ messages in thread
From: Christophe Leroy @ 2020-02-14 8:37 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, aneesh.kumar
Cc: linuxppc-dev, linux-kernel
Le 06/02/2020 à 20:21, Christophe Leroy a écrit :
> On 8xx, slices are used because hugepages (512k or 8M) and small
> pages (4k or 16k) cannot share the same PGD entry. However, as 8M
> entirely covers two PGD entries (One PGD entry covers 4M), there
> will implicitely be no conflict between 8M pages and any other size.
> So 8M is compatible with the basepage size as well.
>
> Remove the struct slice_mask mask_8m from mm_context_t and make
> vma_mmu_pagesize() rely on vma_kernel_pagesize() as the base
> slice can now host several sizes.
I'm working on getting rid of CONFIG_PPC_MM_SLICES on the 8xx, so this
little series is probably not worth merging.
Christophe
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
> arch/powerpc/include/asm/nohash/32/mmu-8xx.h | 7 ++-----
> arch/powerpc/mm/hugetlbpage.c | 3 ++-
> 2 files changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
> index 76af5b0cb16e..54f7f3362edb 100644
> --- a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
> +++ b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
> @@ -215,9 +215,8 @@ typedef struct {
> unsigned char low_slices_psize[SLICE_ARRAY_SIZE];
> unsigned char high_slices_psize[0];
> unsigned long slb_addr_limit;
> - struct slice_mask mask_base_psize; /* 4k or 16k */
> + struct slice_mask mask_base_psize; /* 4k or 16k or 8M */
> struct slice_mask mask_512k;
> - struct slice_mask mask_8m;
> #endif
> void *pte_frag;
> } mm_context_t;
> @@ -257,10 +256,8 @@ static inline struct slice_mask *slice_mask_for_size(mm_context_t *ctx, int psiz
> {
> if (psize == MMU_PAGE_512K)
> return &ctx->mask_512k;
> - if (psize == MMU_PAGE_8M)
> - return &ctx->mask_8m;
>
> - BUG_ON(psize != mmu_virtual_psize);
> + BUG_ON(psize != mmu_virtual_psize && psize != MMU_PAGE_8M);
>
> return &ctx->mask_base_psize;
> }
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index edf511c2a30a..0b4ab741bf09 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -551,7 +551,8 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
> unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
> {
> /* With radix we don't use slice, so derive it from vma*/
> - if (IS_ENABLED(CONFIG_PPC_MM_SLICES) && !radix_enabled()) {
> + if (IS_ENABLED(CONFIG_PPC_MM_SLICES) && !IS_ENABLED(CONFIG_PPC_8xx) &&
> + !radix_enabled()) {
> unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
>
> return 1UL << mmu_psize_to_shift(psize);
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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