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From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: kvm@vger.kernel.org,
	linux-s390@vger.kernel.org,
	David Hildenbrand <david@redhat.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Alexander Gordeev <agordeev@linux.ibm.com>,
	Christian Borntraeger <borntraeger@linux.ibm.com>,
	Sven Schnelle <svens@linux.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	Claudio Imbrenda <imbrenda@linux.ibm.com>,
	Gerald Schaefer <gerald.schaefer@linux.ibm.com>,
	Matthew Wilcox <willy@infradead.org>,
	Thomas Huth <thuth@redhat.com>
Subject: [PATCH v2 09/10] s390/uv: implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
Date: Fri, 12 Apr 2024 16:21:19 +0200
Message-ID: <20240412142120.220087-10-david@redhat.com>
In-Reply-To: <20240412142120.220087-1-david@redhat.com>
References: <20240412142120.220087-1-david@redhat.com>
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Let's also implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE, so we can convert
arch_make_page_accessible() to be a simple wrapper around
arch_make_folio_accessible(). Unfortuantely, we cannot do that in the
header.

There are only two arch_make_page_accessible() calls remaining in gup.c.
We can now drop HAVE_ARCH_MAKE_PAGE_ACCESSIBLE completely form core-MM.
We'll handle that separately, once the s390x part landed.

Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/s390/include/asm/page.h |  3 +++
 arch/s390/kernel/uv.c        | 18 +++++++++++-------
 arch/s390/mm/fault.c         | 14 ++++++++------
 3 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index b64384872c0f..03bbc782e286 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -162,6 +162,7 @@ static inline int page_reset_referenced(unsigned long addr)
 #define _PAGE_ACC_BITS		0xf0	/* HW access control bits	*/
 
 struct page;
+struct folio;
 void arch_free_page(struct page *page, int order);
 void arch_alloc_page(struct page *page, int order);
 
@@ -174,6 +175,8 @@ static inline int devmem_is_allowed(unsigned long pfn)
 #define HAVE_ARCH_ALLOC_PAGE
 
 #if IS_ENABLED(CONFIG_PGSTE)
+int arch_make_folio_accessible(struct folio *folio);
+#define HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
 int arch_make_page_accessible(struct page *page);
 #define HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
 #endif
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index b456066d72da..fa62fa0e369f 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -498,14 +498,13 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
 EXPORT_SYMBOL_GPL(gmap_destroy_page);
 
 /*
- * To be called with the page locked or with an extra reference! This will
- * prevent gmap_make_secure from touching the page concurrently. Having 2
- * parallel make_page_accessible is fine, as the UV calls will become a
- * no-op if the page is already exported.
+ * To be called with the folio locked or with an extra reference! This will
+ * prevent gmap_make_secure from touching the folio concurrently. Having 2
+ * parallel arch_make_folio_accessible is fine, as the UV calls will become a
+ * no-op if the folio is already exported.
  */
-int arch_make_page_accessible(struct page *page)
+int arch_make_folio_accessible(struct folio *folio)
 {
-	struct folio *folio = page_folio(page);
 	int rc = 0;
 
 	/* See gmap_make_secure(): large folios cannot be secure */
@@ -537,8 +536,13 @@ int arch_make_page_accessible(struct page *page)
 
 	return rc;
 }
-EXPORT_SYMBOL_GPL(arch_make_page_accessible);
+EXPORT_SYMBOL_GPL(arch_make_folio_accessible);
 
+int arch_make_page_accessible(struct page *page)
+{
+	return arch_make_folio_accessible(page_folio(page));
+}
+EXPORT_SYMBOL_GPL(arch_make_page_accessible);
 #endif
 
 #if defined(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) || IS_ENABLED(CONFIG_KVM)
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index c421dd44ffbe..a1ba58460593 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -491,6 +491,7 @@ void do_secure_storage_access(struct pt_regs *regs)
 	unsigned long addr = get_fault_address(regs);
 	struct vm_area_struct *vma;
 	struct mm_struct *mm;
+	struct folio *folio;
 	struct page *page;
 	struct gmap *gmap;
 	int rc;
@@ -538,17 +539,18 @@ void do_secure_storage_access(struct pt_regs *regs)
 			mmap_read_unlock(mm);
 			break;
 		}
-		if (arch_make_page_accessible(page))
+		folio = page_folio(page);
+		if (arch_make_folio_accessible(folio))
 			send_sig(SIGSEGV, current, 0);
-		put_page(page);
+		folio_put(folio);
 		mmap_read_unlock(mm);
 		break;
 	case KERNEL_FAULT:
-		page = phys_to_page(addr);
-		if (unlikely(!try_get_page(page)))
+		folio = phys_to_folio(addr);
+		if (unlikely(!folio_try_get(folio)))
 			break;
-		rc = arch_make_page_accessible(page);
-		put_page(page);
+		rc = arch_make_folio_accessible(folio);
+		folio_put(folio);
 		if (rc)
 			BUG();
 		break;
-- 
2.44.0