14 files changed, 61 insertions, 39 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7f7fbd8bd9d5..7a1aa53d188d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -19,7 +19,7 @@ config ARM64
         select ARCH_HAS_FAST_MULTIPLIER
         select ARCH_HAS_FORTIFY_SOURCE
         select ARCH_HAS_GCOV_PROFILE_ALL
-        select ARCH_HAS_GIGANTIC_PAGE if CONTIG_ALLOC
+        select ARCH_HAS_GIGANTIC_PAGE
         select ARCH_HAS_KCOV
         select ARCH_HAS_KEEPINITRD
         select ARCH_HAS_MEMBARRIER_SYNC_CORE
diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index c6a07a3b433e..4aad6382f631 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -70,8 +70,4 @@ extern void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #include <asm-generic/hugetlb.h>
 
-#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
-static inline bool gigantic_page_supported(void) { return true; }
-#endif
-
 #endif /* __ASM_HUGETLB_H */
diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
index 56140d19c85f..12e150e615b7 100644
--- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
+++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
@@ -36,8 +36,8 @@ static inline int hstate_get_psize(struct hstate *hstate)
         }
 }
 
-#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
-static inline bool gigantic_page_supported(void)
+#define __HAVE_ARCH_GIGANTIC_PAGE_RUNTIME_SUPPORTED
+static inline bool gigantic_page_runtime_supported(void)
 {
         /*
          * We used gigantic page reservation with hypervisor assist in some case.
@@ -49,7 +49,6 @@ static inline bool gigantic_page_supported(void)
 
         return true;
 }
-#endif
 
 /* hugepd entry valid bit */
 #define HUGEPD_VAL_BITS         (0x8000000000000000UL)
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 3a31d4289ea4..2794235e9d3e 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -331,7 +331,7 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK
 config PPC_RADIX_MMU
         bool "Radix MMU Support"
         depends on PPC_BOOK3S_64 && HUGETLB_PAGE
-        select ARCH_HAS_GIGANTIC_PAGE if CONTIG_ALLOC
+        select ARCH_HAS_GIGANTIC_PAGE
         select PPC_HAVE_KUEP
         select PPC_HAVE_KUAP
         default y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 724dbc6b7d33..d0c046af65fa 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -63,7 +63,7 @@ config S390
         select ARCH_HAS_ELF_RANDOMIZE
         select ARCH_HAS_FORTIFY_SOURCE
         select ARCH_HAS_GCOV_PROFILE_ALL
-        select ARCH_HAS_GIGANTIC_PAGE if CONTIG_ALLOC
+        select ARCH_HAS_GIGANTIC_PAGE
         select ARCH_HAS_KCOV
         select ARCH_HAS_PTE_SPECIAL
         select ARCH_HAS_SET_MEMORY
diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index 2d1afa58a4b6..bb59dd964590 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -116,7 +116,9 @@ static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
         return pte_modify(pte, newprot);
 }
 
-#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
-static inline bool gigantic_page_supported(void) { return true; }
-#endif
+static inline bool gigantic_page_runtime_supported(void)
+{
+        return true;
+}
+
 #endif /* _ASM_S390_HUGETLB_H */
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 2a5ec643fec0..2a77033e1e7c 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -53,7 +53,7 @@ config SUPERH
         select HAVE_FUTEX_CMPXCHG if FUTEX
         select HAVE_NMI
         select NEED_SG_DMA_LENGTH
-        select ARCH_HAS_GIGANTIC_PAGE if CONTIG_ALLOC
+        select ARCH_HAS_GIGANTIC_PAGE
 
         help
           The SuperH is a RISC processor targeted for use in embedded systems
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 566de738e487..7c93f3121ee6 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -92,7 +92,7 @@ config SPARC64
         select ARCH_CLOCKSOURCE_DATA
         select ARCH_HAS_PTE_SPECIAL
         select PCI_DOMAINS if PCI
-        select ARCH_HAS_GIGANTIC_PAGE if CONTIG_ALLOC
+        select ARCH_HAS_GIGANTIC_PAGE
 
 config ARCH_DEFCONFIG
         string
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 526d95abfe5e..f21bc56e5d7b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -22,7 +22,7 @@ config X86_64
         def_bool y
         depends on 64BIT
         # Options that are inherently 64-bit kernel only:
-        select ARCH_HAS_GIGANTIC_PAGE if CONTIG_ALLOC
+        select ARCH_HAS_GIGANTIC_PAGE
         select ARCH_SUPPORTS_INT128
         select ARCH_USE_CMPXCHG_LOCKREF
         select HAVE_ARCH_SOFT_DIRTY
diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h
index 7469d321f072..f65cfb48cfdd 100644
--- a/arch/x86/include/asm/hugetlb.h
+++ b/arch/x86/include/asm/hugetlb.h
@@ -17,8 +17,4 @@ static inline void arch_clear_hugepage_flags(struct page *page)
 {
 }
 
-#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
-static inline bool gigantic_page_supported(void) { return true; }
-#endif
-
 #endif /* _ASM_X86_HUGETLB_H */
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index 71d7b77eea50..822f433ac95c 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -126,4 +126,11 @@ static inline pte_t huge_ptep_get(pte_t *ptep)
 }
 #endif
 
+#ifndef __HAVE_ARCH_GIGANTIC_PAGE_RUNTIME_SUPPORTED
+static inline bool gigantic_page_runtime_supported(void)
+{
+        return IS_ENABLED(CONFIG_ARCH_HAS_GIGANTIC_PAGE);
+}
+#endif /* __HAVE_ARCH_GIGANTIC_PAGE_RUNTIME_SUPPORTED */
+
 #endif /* _ASM_GENERIC_HUGETLB_H */
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index e77ab30e9328..fb07b503dc45 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -589,8 +589,8 @@ static inline bool pm_suspended_storage(void)
 /* The below functions must be run on a range from a single zone. */
 extern int alloc_contig_range(unsigned long start, unsigned long end,
                               unsigned migratetype, gfp_t gfp_mask);
-extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
 #endif
+void free_contig_range(unsigned long pfn, unsigned int nr_pages);
 
 #ifdef CONFIG_CMA
 /* CMA stuff */
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dffe5d9d03ae..2f901a6e13d2 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1059,6 +1059,7 @@ static void free_gigantic_page(struct page *page, unsigned int order)
         free_contig_range(page_to_pfn(page), 1 << order);
 }
 
+#ifdef CONFIG_CONTIG_ALLOC
 static int __alloc_gigantic_page(unsigned long start_pfn,
                                 unsigned long nr_pages, gfp_t gfp_mask)
 {
@@ -1143,11 +1144,20 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
 
 static void prep_new_huge_page(struct hstate *h, struct page *page, int nid);
 static void prep_compound_gigantic_page(struct page *page, unsigned int order);
+#else /* !CONFIG_CONTIG_ALLOC */
+static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
+                                        int nid, nodemask_t *nodemask)
+{
+        return NULL;
+}
+#endif /* CONFIG_CONTIG_ALLOC */
 
 #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */
-static inline bool gigantic_page_supported(void) { return false; }
 static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
-                int nid, nodemask_t *nodemask) { return NULL; }
+                                        int nid, nodemask_t *nodemask)
+{
+        return NULL;
+}
 static inline void free_gigantic_page(struct page *page, unsigned int order) { }
 static inline void destroy_compound_gigantic_page(struct page *page,
                                                 unsigned int order) { }
@@ -1157,7 +1167,7 @@ static void update_and_free_page(struct hstate *h, struct page *page)
 {
         int i;
 
-        if (hstate_is_gigantic(h) && !gigantic_page_supported())
+        if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
                 return;
 
         h->nr_huge_pages--;
@@ -2278,13 +2288,27 @@ found:
 }
 
 #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
-static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
-                                                nodemask_t *nodes_allowed)
+static int set_max_huge_pages(struct hstate *h, unsigned long count,
+                              nodemask_t *nodes_allowed)
 {
         unsigned long min_count, ret;
 
-        if (hstate_is_gigantic(h) && !gigantic_page_supported())
-                return h->max_huge_pages;
+        spin_lock(&hugetlb_lock);
+
+        /*
+         * Gigantic pages runtime allocation depend on the capability for large
+         * page range allocation.
+         * If the system does not provide this feature, return an error when
+         * the user tries to allocate gigantic pages but let the user free the
+         * boottime allocated gigantic pages.
+         */
+        if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) {
+                if (count > persistent_huge_pages(h)) {
+                        spin_unlock(&hugetlb_lock);
+                        return -EINVAL;
+                }
+                /* Fall through to decrease pool */
+        }
 
         /*
          * Increase the pool size
@@ -2297,7 +2321,6 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
          * pool might be one hugepage larger than it needs to be, but
          * within all the constraints specified by the sysctls.
          */
-        spin_lock(&hugetlb_lock);
         while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
                 if (!adjust_pool_surplus(h, nodes_allowed, -1))
                         break;
@@ -2352,9 +2375,10 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
                         break;
         }
 out:
-        ret = persistent_huge_pages(h);
+        h->max_huge_pages = persistent_huge_pages(h);
         spin_unlock(&hugetlb_lock);
-        return ret;
+
+        return 0;
 }
 
 #define HSTATE_ATTR_RO(_name) \
@@ -2406,7 +2430,7 @@ static ssize_t __nr_hugepages_store_common(bool obey_mempolicy,
         int err;
         NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);
 
-        if (hstate_is_gigantic(h) && !gigantic_page_supported()) {
+        if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) {
                 err = -EINVAL;
                 goto out;
         }
@@ -2430,15 +2454,13 @@ static ssize_t __nr_hugepages_store_common(bool obey_mempolicy,
         } else
                 nodes_allowed = &node_states[N_MEMORY];
 
-        h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed);
+        err = set_max_huge_pages(h, count, nodes_allowed);
 
+out:
         if (nodes_allowed != &node_states[N_MEMORY])
                 NODEMASK_FREE(nodes_allowed);
 
-        return len;
-out:
-        NODEMASK_FREE(nodes_allowed);
-        return err;
+        return err ? err : len;
 }
 
 static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2efb6525d932..4ea71bc70413 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8346,8 +8346,9 @@ done:
                                 pfn_max_align_up(end), migratetype);
         return ret;
 }
+#endif /* CONFIG_CONTIG_ALLOC */
 
-void free_contig_range(unsigned long pfn, unsigned nr_pages)
+void free_contig_range(unsigned long pfn, unsigned int nr_pages)
 {
         unsigned int count = 0;
 
@@ -8359,7 +8360,6 @@ void free_contig_range(unsigned long pfn, unsigned nr_pages)
         }
         WARN(count != 0, "%d pages are still in use!\n", count);
 }
-#endif
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 /*