--- v6
+++ v1
@@ -1,100 +1,253 @@
-No folio equivalents for page type operations have been defined, so
-define them for later folio conversions.
-
-Also changes the Page##uname macros to take in const struct page* since
-we only read the memory here.
+s390 uses page->index to keep track of page tables for the guest address
+space. In an attempt to consolidate the usage of page fields in s390,
+replace _pt_pad_2 with _pt_s390_gaddr to replace page->index in gmap.
+
+This will help with the splitting of struct ptdesc from struct page, as
+well as allow s390 to use _pt_frag_refcount for fragmented page table
+tracking.
+
+Since page->_pt_s390_gaddr aliases with mapping, ensure its set to NULL
+before freeing the pages as well.
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
-Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
---
- include/linux/page-flags.h | 30 +++++++++++++++++++++++-------
- 1 file changed, 23 insertions(+), 7 deletions(-)
-
-diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
-index 92a2063a0a23..9218028caf33 100644
---- a/include/linux/page-flags.h
-+++ b/include/linux/page-flags.h
-@@ -908,6 +908,8 @@ static inline bool is_page_hwpoison(struct page *page)
-
- #define PageType(page, flag) \
- ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
-+#define folio_test_type(folio, flag) \
-+ ((folio->page.page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
-
- static inline int page_type_has_type(unsigned int page_type)
- {
-@@ -919,27 +921,41 @@ static inline int page_has_type(struct page *page)
- return page_type_has_type(page->page_type);
- }
-
--#define PAGE_TYPE_OPS(uname, lname) \
--static __always_inline int Page##uname(struct page *page) \
-+#define PAGE_TYPE_OPS(uname, lname, fname) \
-+static __always_inline int Page##uname(const struct page *page) \
- { \
- return PageType(page, PG_##lname); \
- } \
-+static __always_inline int folio_test_##fname(const struct folio *folio)\
-+{ \
-+ return folio_test_type(folio, PG_##lname); \
-+} \
- static __always_inline void __SetPage##uname(struct page *page) \
- { \
- VM_BUG_ON_PAGE(!PageType(page, 0), page); \
- page->page_type &= ~PG_##lname; \
- } \
-+static __always_inline void __folio_set_##fname(struct folio *folio) \
-+{ \
-+ VM_BUG_ON_FOLIO(!folio_test_type(folio, 0), folio); \
-+ folio->page.page_type &= ~PG_##lname; \
-+} \
- static __always_inline void __ClearPage##uname(struct page *page) \
- { \
- VM_BUG_ON_PAGE(!Page##uname(page), page); \
- page->page_type |= PG_##lname; \
--}
-+} \
-+static __always_inline void __folio_clear_##fname(struct folio *folio) \
-+{ \
-+ VM_BUG_ON_FOLIO(!folio_test_##fname(folio), folio); \
-+ folio->page.page_type |= PG_##lname; \
-+} \
-
- /*
- * PageBuddy() indicates that the page is free and in the buddy system
- * (see mm/page_alloc.c).
- */
--PAGE_TYPE_OPS(Buddy, buddy)
-+PAGE_TYPE_OPS(Buddy, buddy, buddy)
-
- /*
- * PageOffline() indicates that the page is logically offline although the
-@@ -963,7 +979,7 @@ PAGE_TYPE_OPS(Buddy, buddy)
- * pages should check PageOffline() and synchronize with such drivers using
- * page_offline_freeze()/page_offline_thaw().
- */
--PAGE_TYPE_OPS(Offline, offline)
-+PAGE_TYPE_OPS(Offline, offline, offline)
-
- extern void page_offline_freeze(void);
- extern void page_offline_thaw(void);
-@@ -973,12 +989,12 @@ extern void page_offline_end(void);
- /*
- * Marks pages in use as page tables.
- */
--PAGE_TYPE_OPS(Table, table)
-+PAGE_TYPE_OPS(Table, table, pgtable)
-
- /*
- * Marks guardpages used with debug_pagealloc.
- */
--PAGE_TYPE_OPS(Guard, guard)
-+PAGE_TYPE_OPS(Guard, guard, guard)
-
- extern bool is_free_buddy_page(struct page *page);
-
+ arch/s390/mm/gmap.c | 50 +++++++++++++++++++++++++++-------------
+ include/linux/mm_types.h | 2 +-
+ 2 files changed, 35 insertions(+), 17 deletions(-)
+
+diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
+index 5a716bdcba05..a61ea1a491dc 100644
+--- a/arch/s390/mm/gmap.c
++++ b/arch/s390/mm/gmap.c
+@@ -70,7 +70,7 @@ static struct gmap *gmap_alloc(unsigned long limit)
+ page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+ if (!page)
+ goto out_free;
+- page->index = 0;
++ page->_pt_s390_gaddr = 0;
+ list_add(&page->lru, &gmap->crst_list);
+ table = page_to_virt(page);
+ crst_table_init(table, etype);
+@@ -187,16 +187,20 @@ static void gmap_free(struct gmap *gmap)
+ if (!(gmap_is_shadow(gmap) && gmap->removed))
+ gmap_flush_tlb(gmap);
+ /* Free all segment & region tables. */
+- list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
++ list_for_each_entry_safe(page, next, &gmap->crst_list, lru) {
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
++ }
+ gmap_radix_tree_free(&gmap->guest_to_host);
+ gmap_radix_tree_free(&gmap->host_to_guest);
+
+ /* Free additional data for a shadow gmap */
+ if (gmap_is_shadow(gmap)) {
+ /* Free all page tables. */
+- list_for_each_entry_safe(page, next, &gmap->pt_list, lru)
++ list_for_each_entry_safe(page, next, &gmap->pt_list, lru) {
++ page->_pt_s390_gaddr = 0;
+ page_table_free_pgste(page);
++ }
+ gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
+ /* Release reference to the parent */
+ gmap_put(gmap->parent);
+@@ -318,12 +322,14 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
+ list_add(&page->lru, &gmap->crst_list);
+ *table = __pa(new) | _REGION_ENTRY_LENGTH |
+ (*table & _REGION_ENTRY_TYPE_MASK);
+- page->index = gaddr;
++ page->_pt_s390_gaddr = gaddr;
+ page = NULL;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+- if (page)
++ if (page) {
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
++ }
+ return 0;
+ }
+
+@@ -341,7 +347,7 @@ static unsigned long __gmap_segment_gaddr(unsigned long *entry)
+ offset = (unsigned long) entry / sizeof(unsigned long);
+ offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
+ page = pmd_pgtable_page((pmd_t *) entry);
+- return page->index + offset;
++ return page->_pt_s390_gaddr + offset;
+ }
+
+ /**
+@@ -1351,6 +1357,7 @@ static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
+ /* Free page table */
+ page = phys_to_page(pgt);
+ list_del(&page->lru);
++ page->_pt_s390_gaddr = 0;
+ page_table_free_pgste(page);
+ }
+
+@@ -1379,6 +1386,7 @@ static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
+ /* Free page table */
+ page = phys_to_page(pgt);
+ list_del(&page->lru);
++ page->_pt_s390_gaddr = 0;
+ page_table_free_pgste(page);
+ }
+ }
+@@ -1409,6 +1417,7 @@ static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
+ /* Free segment table */
+ page = phys_to_page(sgt);
+ list_del(&page->lru);
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
+ }
+
+@@ -1437,6 +1446,7 @@ static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
+ /* Free segment table */
+ page = phys_to_page(sgt);
+ list_del(&page->lru);
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
+ }
+ }
+@@ -1467,6 +1477,7 @@ static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
+ /* Free region 3 table */
+ page = phys_to_page(r3t);
+ list_del(&page->lru);
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
+ }
+
+@@ -1495,6 +1506,7 @@ static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
+ /* Free region 3 table */
+ page = phys_to_page(r3t);
+ list_del(&page->lru);
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
+ }
+ }
+@@ -1525,6 +1537,7 @@ static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
+ /* Free region 2 table */
+ page = phys_to_page(r2t);
+ list_del(&page->lru);
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
+ }
+
+@@ -1557,6 +1570,7 @@ static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
+ /* Free region 2 table */
+ page = phys_to_page(r2t);
+ list_del(&page->lru);
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
+ }
+ }
+@@ -1762,9 +1776,9 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
+ page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+ if (!page)
+ return -ENOMEM;
+- page->index = r2t & _REGION_ENTRY_ORIGIN;
++ page->_pt_s390_gaddr = r2t & _REGION_ENTRY_ORIGIN;
+ if (fake)
+- page->index |= GMAP_SHADOW_FAKE_TABLE;
++ page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
+ s_r2t = page_to_phys(page);
+ /* Install shadow region second table */
+ spin_lock(&sg->guest_table_lock);
+@@ -1814,6 +1828,7 @@ int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
+ return rc;
+ out_free:
+ spin_unlock(&sg->guest_table_lock);
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
+ return rc;
+ }
+@@ -1846,9 +1861,9 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
+ page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+ if (!page)
+ return -ENOMEM;
+- page->index = r3t & _REGION_ENTRY_ORIGIN;
++ page->_pt_s390_gaddr = r3t & _REGION_ENTRY_ORIGIN;
+ if (fake)
+- page->index |= GMAP_SHADOW_FAKE_TABLE;
++ page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
+ s_r3t = page_to_phys(page);
+ /* Install shadow region second table */
+ spin_lock(&sg->guest_table_lock);
+@@ -1898,6 +1913,7 @@ int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
+ return rc;
+ out_free:
+ spin_unlock(&sg->guest_table_lock);
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
+ return rc;
+ }
+@@ -1930,9 +1946,9 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
+ page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
+ if (!page)
+ return -ENOMEM;
+- page->index = sgt & _REGION_ENTRY_ORIGIN;
++ page->_pt_s390_gaddr = sgt & _REGION_ENTRY_ORIGIN;
+ if (fake)
+- page->index |= GMAP_SHADOW_FAKE_TABLE;
++ page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
+ s_sgt = page_to_phys(page);
+ /* Install shadow region second table */
+ spin_lock(&sg->guest_table_lock);
+@@ -1982,6 +1998,7 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
+ return rc;
+ out_free:
+ spin_unlock(&sg->guest_table_lock);
++ page->_pt_s390_gaddr = 0;
+ __free_pages(page, CRST_ALLOC_ORDER);
+ return rc;
+ }
+@@ -2014,9 +2031,9 @@ int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
+ if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
+ /* Shadow page tables are full pages (pte+pgste) */
+ page = pfn_to_page(*table >> PAGE_SHIFT);
+- *pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
++ *pgt = page->_pt_s390_gaddr & ~GMAP_SHADOW_FAKE_TABLE;
+ *dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
+- *fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
++ *fake = !!(page->_pt_s390_gaddr & GMAP_SHADOW_FAKE_TABLE);
+ rc = 0;
+ } else {
+ rc = -EAGAIN;
+@@ -2054,9 +2071,9 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
+ page = page_table_alloc_pgste(sg->mm);
+ if (!page)
+ return -ENOMEM;
+- page->index = pgt & _SEGMENT_ENTRY_ORIGIN;
++ page->_pt_s390_gaddr = pgt & _SEGMENT_ENTRY_ORIGIN;
+ if (fake)
+- page->index |= GMAP_SHADOW_FAKE_TABLE;
++ page->_pt_s390_gaddr |= GMAP_SHADOW_FAKE_TABLE;
+ s_pgt = page_to_phys(page);
+ /* Install shadow page table */
+ spin_lock(&sg->guest_table_lock);
+@@ -2101,6 +2118,7 @@ int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
+ return rc;
+ out_free:
+ spin_unlock(&sg->guest_table_lock);
++ page->_pt_s390_gaddr = 0;
+ page_table_free_pgste(page);
+ return rc;
+
+diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
+index 3fc9e680f174..2616d64c0e8c 100644
+--- a/include/linux/mm_types.h
++++ b/include/linux/mm_types.h
+@@ -144,7 +144,7 @@ struct page {
+ struct { /* Page table pages */
+ unsigned long _pt_pad_1; /* compound_head */
+ pgtable_t pmd_huge_pte; /* protected by page->ptl */
+- unsigned long _pt_pad_2; /* mapping */
++ unsigned long _pt_s390_gaddr; /* mapping */
+ union {
+ struct mm_struct *pt_mm; /* x86 pgds only */
+ atomic_t pt_frag_refcount; /* powerpc */
--
-2.40.1
+2.39.2
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