+ mm-x86-use-for_each_valid_pfn-from-__ioremap_check_ram.patch added to mm-new branch

+ mm-x86-use-for_each_valid_pfn-from-__ioremap_check_ram.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm, x86: use for_each_valid_pfn() from __ioremap_check_ram()
has been added to the -mm mm-new branch.  Its filename is
     mm-x86-use-for_each_valid_pfn-from-__ioremap_check_ram.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-x86-use-for_each_valid_pfn-from-__ioremap_check_ram.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: David Woodhouse <dwmw@amazon.co.uk>
Subject: mm, x86: use for_each_valid_pfn() from __ioremap_check_ram()
Date: Wed, 23 Apr 2025 14:33:41 +0100

Instead of calling pfn_valid() separately for every single PFN in the
range, use for_each_valid_pfn() and only look at the ones which are.

Link: https://lkml.kernel.org/r/20250423133821.789413-6-dwmw2@infradead.org
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Ruihan Li <lrh2000@pku.edu.cn>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/mm/ioremap.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

--- a/arch/x86/mm/ioremap.c~mm-x86-use-for_each_valid_pfn-from-__ioremap_check_ram
+++ a/arch/x86/mm/ioremap.c
@@ -71,7 +71,7 @@ int ioremap_change_attr(unsigned long va
 static unsigned int __ioremap_check_ram(struct resource *res)
 {
 	unsigned long start_pfn, stop_pfn;
-	unsigned long i;
+	unsigned long pfn;
 
 	if ((res->flags & IORESOURCE_SYSTEM_RAM) != IORESOURCE_SYSTEM_RAM)
 		return 0;
@@ -79,9 +79,8 @@ static unsigned int __ioremap_check_ram(
 	start_pfn = (res->start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	stop_pfn = (res->end + 1) >> PAGE_SHIFT;
 	if (stop_pfn > start_pfn) {
-		for (i = 0; i < (stop_pfn - start_pfn); ++i)
-			if (pfn_valid(start_pfn + i) &&
-			    !PageReserved(pfn_to_page(start_pfn + i)))
+		for_each_valid_pfn(pfn, start_pfn, stop_pfn)
+			if (!PageReserved(pfn_to_page(pfn)))
 				return IORES_MAP_SYSTEM_RAM;
 	}
 
_

Patches currently in -mm which might be from dwmw@amazon.co.uk are

mm-introduce-for_each_valid_pfn-and-use-it-from-reserve_bootmem_region.patch
mm-implement-for_each_valid_pfn-for-config_flatmem.patch
mm-implement-for_each_valid_pfn-for-config_sparsemem.patch
mm-pm-use-for_each_valid_pfn-in-kernel-power-snapshotc.patch
mm-x86-use-for_each_valid_pfn-from-__ioremap_check_ram.patch
mm-use-for_each_valid_pfn-in-memory_hotplug.patch
mm-mm_init-use-for_each_valid_pfn-in-init_unavailable_range.patch