[v3,18/34] parisc: Implement the new page table range API

Message ID 20230228213738.272178-19-willy@infradead.org
State New
Headers
Series New page table range API |

Commit Message

Matthew Wilcox Feb. 28, 2023, 9:37 p.m. UTC
  Add set_ptes(), update_mmu_cache_range(), flush_dcache_folio()
and flush_icache_pages().  Change the PG_arch_1 (aka PG_dcache_dirty) flag
from being per-page to per-folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
---
 arch/parisc/include/asm/cacheflush.h |  14 ++--
 arch/parisc/include/asm/pgtable.h    |  28 +++++---
 arch/parisc/kernel/cache.c           | 101 +++++++++++++++++++--------
 3 files changed, 99 insertions(+), 44 deletions(-)
  

Comments

John David Anglin March 2, 2023, 4:43 p.m. UTC | #1
On 2023-02-28 4:37 p.m., Matthew Wilcox (Oracle) wrote:
> Add set_ptes(), update_mmu_cache_range(), flush_dcache_folio()
> and flush_icache_pages().  Change the PG_arch_1 (aka PG_dcache_dirty) flag
> from being per-page to per-folio.
I have tested this change on rp3440 at mainline commit e492250d5252635b6c97d52eddf2792ec26f1ec1
and c8000 at mainline commit ee3f96b164688dae21e2466a57f2e806b64e8a37.

So far, I haven't seen an issues on c8000.  On rp3440, I saw the following:

_swap_info_get: Unused swap offset entry 00000320
BUG: Bad page map in process buildd  pte:00032100 pmd:003606c3
addr:0000000000482000 vm_flags:00100077 anon_vma:0000000066f61340 mapping:0000000000000000 index:482
file:(null) fault:0x0 mmap:0x0 read_folio:0x0
CPU: 0 PID: 6813 Comm: buildd Not tainted 6.2.0+ #1
Hardware name: 9000/800/rp3440
Backtrace:
  [<000000004020af50>] show_stack+0x70/0x90
  [<0000000040b7d408>] dump_stack_lvl+0xd8/0x128
  [<0000000040b7d48c>] dump_stack+0x34/0x48
  [<00000000404513a4>] print_bad_pte+0x24c/0x318
  [<00000000404560dc>] zap_pte_range+0x8d4/0x958
  [<0000000040456398>] unmap_page_range+0x1d8/0x490
  [<000000004045681c>] unmap_vmas+0x10c/0x1a8
  [<0000000040466330>] exit_mmap+0x198/0x4a0
  [<0000000040235cbc>] mmput+0x114/0x2a8
  [<0000000040244e90>] do_exit+0x4e0/0xc68
  [<0000000040245938>] do_group_exit+0x68/0x128
  [<000000004025967c>] get_signal+0xae4/0xb60
  [<000000004021a570>] do_signal+0x50/0x228
  [<000000004021ab38>] do_notify_resume+0x68/0x150
  [<00000000402030b4>] intr_check_sig+0x38/0x3c

Disabling lock debugging due to kernel taint
_swap_info_get: Unused swap offset entry 000003a9
BUG: Bad page map in process buildd  pte:0003a940 pmd:003606c3
addr:0000000000523000 vm_flags:00100077 anon_vma:0000000066f61340 mapping:0000000000000000 index:523
file:(null) fault:0x0 mmap:0x0 read_folio:0x0
CPU: 2 PID: 6813 Comm: buildd Tainted: G    B              6.2.0+ #1
Hardware name: 9000/800/rp3440
Backtrace:
  [<000000004020af50>] show_stack+0x70/0x90
  [<0000000040b7d408>] dump_stack_lvl+0xd8/0x128
  [<0000000040b7d48c>] dump_stack+0x34/0x48
  [<00000000404513a4>] print_bad_pte+0x24c/0x318
  [<00000000404560dc>] zap_pte_range+0x8d4/0x958
  [<0000000040456398>] unmap_page_range+0x1d8/0x490
  [<000000004045681c>] unmap_vmas+0x10c/0x1a8
  [<0000000040466330>] exit_mmap+0x198/0x4a0
  [<0000000040235cbc>] mmput+0x114/0x2a8
  [<0000000040244e90>] do_exit+0x4e0/0xc68
  [<0000000040245938>] do_group_exit+0x68/0x128
  [<000000004025967c>] get_signal+0xae4/0xb60
  [<000000004021a570>] do_signal+0x50/0x228
  [<000000004021ab38>] do_notify_resume+0x68/0x150
  [<00000000402030b4>] intr_check_sig+0x38/0x3c
[...]
pagefault_out_of_memory: 1158973 callbacks suppressed
Huh VM_FAULT_OOM leaked out to the #PF handler. Retrying PF
Huh VM_FAULT_OOM leaked out to the #PF handler. Retrying PF
Huh VM_FAULT_OOM leaked out to the #PF handler. Retrying PF

Rebooted rp3440.  Since then, I haven't seen any more problems.

Dave
  
John David Anglin March 2, 2023, 8:40 p.m. UTC | #2
On 2023-03-02 11:43 a.m., John David Anglin wrote:
> On 2023-02-28 4:37 p.m., Matthew Wilcox (Oracle) wrote:
>> Add set_ptes(), update_mmu_cache_range(), flush_dcache_folio()
>> and flush_icache_pages().  Change the PG_arch_1 (aka PG_dcache_dirty) flag
>> from being per-page to per-folio.
> I have tested this change on rp3440 at mainline commit e492250d5252635b6c97d52eddf2792ec26f1ec1
> and c8000 at mainline commit ee3f96b164688dae21e2466a57f2e806b64e8a37.
Here's another one:

------------[ cut here ]------------
kernel BUG at mm/memory.c:3865!
CPU: 1 PID: 6972 Comm: sbuild Not tainted 6.2.0+ #1
Hardware name: 9000/800/rp3440

      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001101111111100001111 Not tainted
r00-03  000000000806ff0f 000000004fab8d40 00000000404584b0 000000004fab8d40
r04-07  0000000040c2f4c0 0000000047fe60c0 000000004fab8b98 0000000000000953
r08-11  000000004de3de00 0000000000000000 0000000047fe60c0 0000004093ff4660
r12-15  0000000000000001 0000000047fe60c0 0000000040000540 000000022f8e9540
r16-19  0000000000000000 000000004c694c40 000000004fab8860 00000000000003d0
r20-23  0000000007be3a40 0000000000000fff 0000000000000000 000000004109f1a0
r24-27  0000000000000000 0000000000000cc0 0000000046de3a68 0000000040c2f4c0
r28-31  80e00000000a0435 000000004fab8df0 000000004fab8e20 0000000000000001
sr00-03  0000000000207c00 0000000000000000 0000000000000000 0000000002f11c00
sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

IASQ: 0000000000000000 0000000000000000 IAOQ: 000000004045908c 0000000040459090
  IIR: 03ffe01f    ISR: 0000000000000000  IOR: 0000000000000000
  CPU:        1   CR30: 0000004095d64c20 CR31: ffffffffffffffff
  ORIG_R28: 000000001c569ad0
  IAOQ[0]: do_swap_page+0x108c/0x1168
  IAOQ[1]: do_swap_page+0x1090/0x1168
  RP(r2): do_swap_page+0x4b0/0x1168
Backtrace:
  [<000000004045a554>] handle_pte_fault+0x244/0x358
  [<000000004045c58c>] __handle_mm_fault+0x104/0x1b8
  [<000000004045c81c>] handle_mm_fault+0x1dc/0x318
  [<000000004044cb38>] faultin_page+0xa8/0x178
  [<000000004044e848>] __get_user_pages+0x328/0x560
  [<0000000040450ac4>] get_dump_page+0x9c/0x128
  [<0000000040596cb8>] dump_user_range+0xc0/0x2d8
  [<000000004058e790>] elf_core_dump+0x5f8/0x708
  [<0000000040596384>] do_coredump+0xc2c/0x14a0
  [<0000000040259040>] get_signal+0x4a8/0xb60
  [<000000004021a570>] do_signal+0x50/0x228
  [<000000004021ab38>] do_notify_resume+0x68/0x150
  [<0000000040203ee0>] syscall_do_signal+0x54/0xa0

CPU: 1 PID: 6972 Comm: sbuild Not tainted 6.2.0+ #1
Hardware name: 9000/800/rp3440
Backtrace:
  [<000000004020af50>] show_stack+0x70/0x90
  [<0000000040b7d408>] dump_stack_lvl+0xd8/0x128
  [<0000000040b7d48c>] dump_stack+0x34/0x48
  [<000000004020b160>] die_if_kernel+0x1d0/0x388
  [<000000004020c1c4>] handle_interruption+0xc34/0xc88
  [<000000004020307c>] intr_check_sig+0x0/0x3c

---[ end trace 0000000000000000 ]---
note: sbuild[6972] exited with preempt_count 1

Dave
  
John David Anglin March 4, 2023, 4:27 p.m. UTC | #3
On 2023-03-02 3:40 p.m., John David Anglin wrote:
> On 2023-03-02 11:43 a.m., John David Anglin wrote:
>> On 2023-02-28 4:37 p.m., Matthew Wilcox (Oracle) wrote:
>>> Add set_ptes(), update_mmu_cache_range(), flush_dcache_folio()
>>> and flush_icache_pages().  Change the PG_arch_1 (aka PG_dcache_dirty) flag
>>> from being per-page to per-folio.
>> I have tested this change on rp3440 at mainline commit e492250d5252635b6c97d52eddf2792ec26f1ec1
>> and c8000 at mainline commit ee3f96b164688dae21e2466a57f2e806b64e8a37.
> Here's another one:
>
> ------------[ cut here ]------------
> kernel BUG at mm/memory.c:3865!
> CPU: 1 PID: 6972 Comm: sbuild Not tainted 6.2.0+ #1
> Hardware name: 9000/800/rp3440
>
>      YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
> PSW: 00001000000001101111111100001111 Not tainted
> r00-03  000000000806ff0f 000000004fab8d40 00000000404584b0 000000004fab8d40
> r04-07  0000000040c2f4c0 0000000047fe60c0 000000004fab8b98 0000000000000953
> r08-11  000000004de3de00 0000000000000000 0000000047fe60c0 0000004093ff4660
> r12-15  0000000000000001 0000000047fe60c0 0000000040000540 000000022f8e9540
> r16-19  0000000000000000 000000004c694c40 000000004fab8860 00000000000003d0
> r20-23  0000000007be3a40 0000000000000fff 0000000000000000 000000004109f1a0
> r24-27  0000000000000000 0000000000000cc0 0000000046de3a68 0000000040c2f4c0
> r28-31  80e00000000a0435 000000004fab8df0 000000004fab8e20 0000000000000001
> sr00-03  0000000000207c00 0000000000000000 0000000000000000 0000000002f11c00
> sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000
>
> IASQ: 0000000000000000 0000000000000000 IAOQ: 000000004045908c 0000000040459090
>  IIR: 03ffe01f    ISR: 0000000000000000  IOR: 0000000000000000
>  CPU:        1   CR30: 0000004095d64c20 CR31: ffffffffffffffff
>  ORIG_R28: 000000001c569ad0
>  IAOQ[0]: do_swap_page+0x108c/0x1168
>  IAOQ[1]: do_swap_page+0x1090/0x1168
>  RP(r2): do_swap_page+0x4b0/0x1168
> Backtrace:
>  [<000000004045a554>] handle_pte_fault+0x244/0x358
>  [<000000004045c58c>] __handle_mm_fault+0x104/0x1b8
>  [<000000004045c81c>] handle_mm_fault+0x1dc/0x318
>  [<000000004044cb38>] faultin_page+0xa8/0x178
>  [<000000004044e848>] __get_user_pages+0x328/0x560
>  [<0000000040450ac4>] get_dump_page+0x9c/0x128
>  [<0000000040596cb8>] dump_user_range+0xc0/0x2d8
>  [<000000004058e790>] elf_core_dump+0x5f8/0x708
>  [<0000000040596384>] do_coredump+0xc2c/0x14a0
>  [<0000000040259040>] get_signal+0x4a8/0xb60
>  [<000000004021a570>] do_signal+0x50/0x228
>  [<000000004021ab38>] do_notify_resume+0x68/0x150
>  [<0000000040203ee0>] syscall_do_signal+0x54/0xa0
Removed new page table API change and still see a swap issue on rp3440.  So, these bugs are probably
unrelated to the API change.

get_swap_device: Bad swap file entry 600000000014ee20
get_swap_device: Bad swap file entry 600000000014ee20
[...]
get_swap_device: Bad swap file entry 600000000014ee20
_swap_info_get: Bad swap file entry 600000000014ee20
BUG: Bad page map in process sh  pte:14ee2418 pmd:01372913
addr:00000000f8406000 vm_flags:00000075 anon_vma:0000000000000000 mapping:000000007f67e1a8 index:25
file:libc.so.6 fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] read_folio:xfs_vm_read_folio [xfs]
CPU: 3 PID: 12702 Comm: sh Not tainted 6.2.0+ #1
Hardware name: 9000/800/rp3440
Backtrace:
  [<000000004020ac50>] show_stack+0x70/0x90
  [<0000000040b7c148>] dump_stack_lvl+0xd8/0x128
  [<0000000040b7c1cc>] dump_stack+0x34/0x48
  [<000000004045020c>] print_bad_pte+0x24c/0x318
  [<0000000040454f78>] zap_pte_range+0x908/0x990
  [<0000000040455238>] unmap_page_range+0x1d8/0x490
  [<00000000404556bc>] unmap_vmas+0x10c/0x1a8
  [<0000000040465278>] exit_mmap+0x198/0x4a0
  [<0000000040234a3c>] mmput+0x114/0x2a8
  [<0000000040243c10>] do_exit+0x4e0/0xc68
  [<00000000402446b8>] do_group_exit+0x68/0x128
  [<00000000402583fc>] get_signal+0xae4/0xb60
  [<0000000040219310>] do_signal+0x50/0x228
  [<00000000402198d8>] do_notify_resume+0x68/0x150
  [<00000000402030b4>] intr_check_sig+0x38/0x3c

Dave
  

Patch

diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index ff07c509e04b..0bf8b69d086b 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -46,16 +46,20 @@  void invalidate_kernel_vmap_range(void *vaddr, int size);
 #define flush_cache_vmap(start, end)		flush_cache_all()
 #define flush_cache_vunmap(start, end)		flush_cache_all()
 
+void flush_dcache_folio(struct folio *folio);
+#define flush_dcache_folio flush_dcache_folio
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
-void flush_dcache_page(struct page *page);
+static inline void flush_dcache_page(struct page *page)
+{
+	flush_dcache_folio(page_folio(page));
+}
 
 #define flush_dcache_mmap_lock(mapping)		xa_lock_irq(&mapping->i_pages)
 #define flush_dcache_mmap_unlock(mapping)	xa_unlock_irq(&mapping->i_pages)
 
-#define flush_icache_page(vma,page)	do { 		\
-	flush_kernel_dcache_page_addr(page_address(page)); \
-	flush_kernel_icache_page(page_address(page)); 	\
-} while (0)
+void flush_icache_pages(struct vm_area_struct *vma, struct page *page,
+		unsigned int nr);
+#define flush_icache_page(vma, page)	flush_icache_pages(vma, page, 1)
 
 #define flush_icache_range(s,e)		do { 		\
 	flush_kernel_dcache_range_asm(s,e); 		\
diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index e2950f5db7c9..78ee9816f423 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -73,14 +73,7 @@  extern void __update_cache(pte_t pte);
 		mb();				\
 	} while(0)
 
-#define set_pte_at(mm, addr, pteptr, pteval)	\
-	do {					\
-		if (pte_present(pteval) &&	\
-		    pte_user(pteval))		\
-			__update_cache(pteval);	\
-		*(pteptr) = (pteval);		\
-		purge_tlb_entries(mm, addr);	\
-	} while (0)
+#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
 
 #endif /* !__ASSEMBLY__ */
 
@@ -391,11 +384,28 @@  static inline unsigned long pmd_page_vaddr(pmd_t pmd)
 
 extern void paging_init (void);
 
+static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
+		pte_t *ptep, pte_t pte, unsigned int nr)
+{
+	if (pte_present(pte) && pte_user(pte))
+		__update_cache(pte);
+	for (;;) {
+		*ptep = pte;
+		purge_tlb_entries(mm, addr);
+		if (--nr == 0)
+			break;
+		ptep++;
+		pte_val(pte) += 1 << PFN_PTE_SHIFT;
+		addr += PAGE_SIZE;
+	}
+}
+
 /* Used for deferring calls to flush_dcache_page() */
 
 #define PG_dcache_dirty         PG_arch_1
 
-#define update_mmu_cache(vms,addr,ptep) __update_cache(*ptep)
+#define update_mmu_cache_range(vma, addr, ptep, nr) __update_cache(*ptep)
+#define update_mmu_cache(vma, addr, ptep) __update_cache(*ptep)
 
 /*
  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 984d3a1b3828..16057812103b 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -92,11 +92,11 @@  static inline void flush_data_cache(void)
 /* Kernel virtual address of pfn.  */
 #define pfn_va(pfn)	__va(PFN_PHYS(pfn))
 
-void
-__update_cache(pte_t pte)
+void __update_cache(pte_t pte)
 {
 	unsigned long pfn = pte_pfn(pte);
-	struct page *page;
+	struct folio *folio;
+	unsigned int nr;
 
 	/* We don't have pte special.  As a result, we can be called with
 	   an invalid pfn and we don't need to flush the kernel dcache page.
@@ -104,13 +104,17 @@  __update_cache(pte_t pte)
 	if (!pfn_valid(pfn))
 		return;
 
-	page = pfn_to_page(pfn);
-	if (page_mapping_file(page) &&
-	    test_bit(PG_dcache_dirty, &page->flags)) {
-		flush_kernel_dcache_page_addr(pfn_va(pfn));
-		clear_bit(PG_dcache_dirty, &page->flags);
+	folio = page_folio(pfn_to_page(pfn));
+	pfn = folio_pfn(folio);
+	nr = folio_nr_pages(folio);
+	if (folio_flush_mapping(folio) &&
+	    test_bit(PG_dcache_dirty, &folio->flags)) {
+		while (nr--)
+			flush_kernel_dcache_page_addr(pfn_va(pfn + nr));
+		clear_bit(PG_dcache_dirty, &folio->flags);
 	} else if (parisc_requires_coherency())
-		flush_kernel_dcache_page_addr(pfn_va(pfn));
+		while (nr--)
+			flush_kernel_dcache_page_addr(pfn_va(pfn + nr));
 }
 
 void
@@ -365,6 +369,20 @@  static void flush_user_cache_page(struct vm_area_struct *vma, unsigned long vmad
 	preempt_enable();
 }
 
+void flush_icache_pages(struct vm_area_struct *vma, struct page *page,
+		unsigned int nr)
+{
+	void *kaddr = page_address(page);
+
+	for (;;) {
+		flush_kernel_dcache_page_addr(kaddr);
+		flush_kernel_icache_page(kaddr);
+		if (--nr == 0)
+			break;
+		page += PAGE_SIZE;
+	}
+}
+
 static inline pte_t *get_ptep(struct mm_struct *mm, unsigned long addr)
 {
 	pte_t *ptep = NULL;
@@ -393,26 +411,30 @@  static inline bool pte_needs_flush(pte_t pte)
 		== (_PAGE_PRESENT | _PAGE_ACCESSED);
 }
 
-void flush_dcache_page(struct page *page)
+void flush_dcache_folio(struct folio *folio)
 {
-	struct address_space *mapping = page_mapping_file(page);
-	struct vm_area_struct *mpnt;
-	unsigned long offset;
+	struct address_space *mapping = folio_flush_mapping(folio);
+	struct vm_area_struct *vma;
 	unsigned long addr, old_addr = 0;
+	void *kaddr;
 	unsigned long count = 0;
+	unsigned long i, nr;
 	pgoff_t pgoff;
 
 	if (mapping && !mapping_mapped(mapping)) {
-		set_bit(PG_dcache_dirty, &page->flags);
+		set_bit(PG_dcache_dirty, &folio->flags);
 		return;
 	}
 
-	flush_kernel_dcache_page_addr(page_address(page));
+	nr = folio_nr_pages(folio);
+	kaddr = folio_address(folio);
+	for (i = 0; i < nr; i++)
+		flush_kernel_dcache_page_addr(kaddr + i * PAGE_SIZE);
 
 	if (!mapping)
 		return;
 
-	pgoff = page->index;
+	pgoff = folio->index;
 
 	/*
 	 * We have carefully arranged in arch_get_unmapped_area() that
@@ -422,15 +444,29 @@  void flush_dcache_page(struct page *page)
 	 * on machines that support equivalent aliasing
 	 */
 	flush_dcache_mmap_lock(mapping);
-	vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
-		offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
-		addr = mpnt->vm_start + offset;
-		if (parisc_requires_coherency()) {
-			pte_t *ptep;
+	vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff + nr - 1) {
+		unsigned long offset = pgoff - vma->vm_pgoff;
+		unsigned long pfn = folio_pfn(folio);
+
+		addr = vma->vm_start;
+		nr = folio_nr_pages(folio);
+		if (offset > -nr) {
+			pfn -= offset;
+			nr += offset;
+		} else {
+			addr += offset * PAGE_SIZE;
+		}
+		if (addr + nr * PAGE_SIZE > vma->vm_end)
+			nr = (vma->vm_end - addr) / PAGE_SIZE;
 
-			ptep = get_ptep(mpnt->vm_mm, addr);
-			if (ptep && pte_needs_flush(*ptep))
-				flush_user_cache_page(mpnt, addr);
+		if (parisc_requires_coherency()) {
+			for (i = 0; i < nr; i++) {
+				pte_t *ptep = get_ptep(vma->vm_mm,
+							addr + i * PAGE_SIZE);
+				if (ptep && pte_needs_flush(*ptep))
+					flush_user_cache_page(vma,
+							addr + i * PAGE_SIZE);
+			}
 		} else {
 			/*
 			 * The TLB is the engine of coherence on parisc:
@@ -443,27 +479,32 @@  void flush_dcache_page(struct page *page)
 			 * in (until the user or kernel specifically
 			 * accesses it, of course)
 			 */
-			flush_tlb_page(mpnt, addr);
+			for (i = 0; i < nr; i++)
+				flush_tlb_page(vma, addr + i * PAGE_SIZE);
 			if (old_addr == 0 || (old_addr & (SHM_COLOUR - 1))
 					!= (addr & (SHM_COLOUR - 1))) {
-				__flush_cache_page(mpnt, addr, page_to_phys(page));
+				for (i = 0; i < nr; i++)
+					__flush_cache_page(vma,
+						addr + i * PAGE_SIZE,
+						(pfn + i) * PAGE_SIZE);
 				/*
 				 * Software is allowed to have any number
 				 * of private mappings to a page.
 				 */
-				if (!(mpnt->vm_flags & VM_SHARED))
+				if (!(vma->vm_flags & VM_SHARED))
 					continue;
 				if (old_addr)
 					pr_err("INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %pD\n",
-						old_addr, addr, mpnt->vm_file);
-				old_addr = addr;
+						old_addr, addr, vma->vm_file);
+				if (nr == folio_nr_pages(folio))
+					old_addr = addr;
 			}
 		}
 		WARN_ON(++count == 4096);
 	}
 	flush_dcache_mmap_unlock(mapping);
 }
-EXPORT_SYMBOL(flush_dcache_page);
+EXPORT_SYMBOL(flush_dcache_folio);
 
 /* Defined in arch/parisc/kernel/pacache.S */
 EXPORT_SYMBOL(flush_kernel_dcache_range_asm);