Merge tag 'asm-generic-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm-generic updates from Arnd Bergmann:
 "This is mainly set of cleanups of asm-generic/io.h, resolving problems
  with inconsistent semantics of ioread64/iowrite64 that were causing
  runtime and build issues.

  The "GENERIC_IOMAP" version that switches between inb()/outb() and
  readb()/writeb() style accessors is now only used on architectures
  that have PC-style ISA devices that are not memory mapped (x86, uml,
  m68k-q40 and powerpc-powernv), while alpha and parisc use a more
  complicated variant and everything else just maps the ioread
  interfaces to plan MMIO (readb/writeb etc).

  In addition there are two small changes from Raag Jadav to simplify
  the asm-generic/io.h indirect inclusions and from Jann Horn to fix a
  corner case with read_word_at_a_time"

* tag 'asm-generic-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  rwonce: fix crash by removing READ_ONCE() for unaligned read
  rwonce: handle KCSAN like KASAN in read_word_at_a_time()
  m68k: coldfire: select PCI_IOMAP for PCI
  mips: export pci_iounmap()
  mips: fix PCI_IOBASE definition
  m68k/nommu: stop using GENERIC_IOMAP
  mips: drop GENERIC_IOMAP wrapper
  powerpc: asm/io.h: remove split ioread64/iowrite64 helpers
  parisc: stop using asm-generic/iomap.h
  sh: remove duplicate ioread/iowrite helpers
  alpha: stop using asm-generic/iomap.h
  io.h: drop unused headers
  drm/draw: include missing headers
  asm-generic/io.h: rework split ioread64/iowrite64 helpers

2 files changed, 17 insertions, 29 deletions

diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h
index 196087a8126e..9f3f25d7fc58 100644
--- a/include/asm-generic/iomap.h
+++ b/include/asm-generic/iomap.h
@@ -31,42 +31,22 @@ extern unsigned int ioread16(const void __iomem *);
 extern unsigned int ioread16be(const void __iomem *);
 extern unsigned int ioread32(const void __iomem *);
 extern unsigned int ioread32be(const void __iomem *);
-#ifdef CONFIG_64BIT
-extern u64 ioread64(const void __iomem *);
-extern u64 ioread64be(const void __iomem *);
-#endif
 
-#ifdef readq
-#define ioread64_lo_hi ioread64_lo_hi
-#define ioread64_hi_lo ioread64_hi_lo
-#define ioread64be_lo_hi ioread64be_lo_hi
-#define ioread64be_hi_lo ioread64be_hi_lo
-extern u64 ioread64_lo_hi(const void __iomem *addr);
-extern u64 ioread64_hi_lo(const void __iomem *addr);
-extern u64 ioread64be_lo_hi(const void __iomem *addr);
-extern u64 ioread64be_hi_lo(const void __iomem *addr);
-#endif
+extern u64 __ioread64_lo_hi(const void __iomem *addr);
+extern u64 __ioread64_hi_lo(const void __iomem *addr);
+extern u64 __ioread64be_lo_hi(const void __iomem *addr);
+extern u64 __ioread64be_hi_lo(const void __iomem *addr);
 
 extern void iowrite8(u8, void __iomem *);
 extern void iowrite16(u16, void __iomem *);
 extern void iowrite16be(u16, void __iomem *);
 extern void iowrite32(u32, void __iomem *);
 extern void iowrite32be(u32, void __iomem *);
-#ifdef CONFIG_64BIT
-extern void iowrite64(u64, void __iomem *);
-extern void iowrite64be(u64, void __iomem *);
-#endif
 
-#ifdef writeq
-#define iowrite64_lo_hi iowrite64_lo_hi
-#define iowrite64_hi_lo iowrite64_hi_lo
-#define iowrite64be_lo_hi iowrite64be_lo_hi
-#define iowrite64be_hi_lo iowrite64be_hi_lo
-extern void iowrite64_lo_hi(u64 val, void __iomem *addr);
-extern void iowrite64_hi_lo(u64 val, void __iomem *addr);
-extern void iowrite64be_lo_hi(u64 val, void __iomem *addr);
-extern void iowrite64be_hi_lo(u64 val, void __iomem *addr);
-#endif
+extern void __iowrite64_lo_hi(u64 val, void __iomem *addr);
+extern void __iowrite64_hi_lo(u64 val, void __iomem *addr);
+extern void __iowrite64be_lo_hi(u64 val, void __iomem *addr);
+extern void __iowrite64be_hi_lo(u64 val, void __iomem *addr);
 
 /*
  * "string" versions of the above. Note that they
diff --git a/include/asm-generic/rwonce.h b/include/asm-generic/rwonce.h
index 8d0a6280e982..52b969c7cef9 100644
--- a/include/asm-generic/rwonce.h
+++ b/include/asm-generic/rwonce.h
@@ -79,10 +79,18 @@ unsigned long __read_once_word_nocheck(const void *addr)
 	(typeof(x))__read_once_word_nocheck(&(x));			\
 })
 
-static __no_kasan_or_inline
+static __no_sanitize_or_inline
 unsigned long read_word_at_a_time(const void *addr)
 {
+	/* open-coded instrument_read(addr, 1) */
 	kasan_check_read(addr, 1);
+	kcsan_check_read(addr, 1);
+
+	/*
+	 * This load can race with concurrent stores to out-of-bounds memory,
+	 * but READ_ONCE() can't be used because it requires higher alignment
+	 * than plain loads in arm64 builds with LTO.
+	 */
 	return *(unsigned long *)addr;
 }