Merge tag 'x86_misc_for_7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 updates from Dave Hansen:
 "The usual smattering of x86/misc changes.

  The IPv6 patch in here surprised me in a couple of ways. First, the
  function it inlines is able to eat a lot more CPU time than I would
  have expected. Second, the inlining does not seem to bloat the kernel,
  at least in the configs folks have tested.

   - Inline x86-specific IPv6 checksum helper

   - Update IOMMU docs to use stable identifiers

   - Print unhashed pointers on fatal stack overflows"

* tag 'x86_misc_for_7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/traps: Print unhashed pointers on stack overflow
  Documentation/x86: Update IOMMU spec references to use stable identifiers
  x86/lib: Inline csum_ipv6_magic()

Author: torvalds

Documentation/arch/x86/iommu.rst

@@ -2,10 +2,11 @@
 x86 IOMMU Support
 =================
 
-The architecture specs can be obtained from the below locations.
+The architecture specs can be obtained from the vendor websites.
+Search for the following documents to obtain the latest versions:
 
-- Intel: http://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/vt-directed-io-spec.pdf
-- AMD: https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/specifications/48882_3_07_PUB.pdf
+- Intel: Intel Virtualization Technology for Directed I/O Architecture Specification (ID: D51397)
+- AMD: AMD I/O Virtualization Technology (IOMMU) Specification (ID: 48882)
 
 This guide gives a quick cheat sheet for some basic understanding.
 

arch/x86/include/asm/checksum_64.h

@@ -9,6 +9,7 @@
  */
 
 #include <linux/compiler.h>
+#include <linux/in6.h>
 #include <asm/byteorder.h>
 
 /**
@@ -145,6 +146,17 @@ extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
  */
 extern __sum16 ip_compute_csum(const void *buff, int len);
 
+static inline unsigned add32_with_carry(unsigned a, unsigned b)
+{
+	asm("addl %2,%0\n\t"
+	    "adcl $0,%0"
+	    : "=r" (a)
+	    : "0" (a), "rm" (b));
+	return a;
+}
+
+#define _HAVE_ARCH_IPV6_CSUM 1
+
 /**
  * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
  * @saddr: source address
@@ -158,20 +170,29 @@ extern __sum16 ip_compute_csum(const void *buff, int len);
  * Returns the unfolded 32bit checksum.
  */
 
-struct in6_addr;
+static inline __sum16 csum_ipv6_magic(
+	const struct in6_addr *_saddr, const struct in6_addr *_daddr,
+	__u32 len, __u8 proto, __wsum sum)
+{
+	const unsigned long *saddr = (const unsigned long *)_saddr;
+	const unsigned long *daddr = (const unsigned long *)_daddr;
+	__u64 sum64;
 
-#define _HAVE_ARCH_IPV6_CSUM 1
-extern __sum16
-csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
-		__u32 len, __u8 proto, __wsum sum);
+	sum64 = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
+		(__force __u64)sum;
 
-static inline unsigned add32_with_carry(unsigned a, unsigned b)
-{
-	asm("addl %2,%0\n\t"
-	    "adcl $0,%0"
-	    : "=r" (a)
-	    : "0" (a), "rm" (b));
-	return a;
+	asm("	addq %1,%[sum64]\n"
+	    "	adcq %2,%[sum64]\n"
+	    "	adcq %3,%[sum64]\n"
+	    "	adcq %4,%[sum64]\n"
+	    "	adcq $0,%[sum64]\n"
+
+	    : [sum64] "+r" (sum64)
+	    : "m" (saddr[0]), "m" (saddr[1]),
+	      "m" (daddr[0]), "m" (daddr[1]));
+
+	return csum_fold(
+	       (__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
 }
 
 #define HAVE_ARCH_CSUM_ADD

arch/x86/kernel/traps.c

@@ -549,7 +549,7 @@ __visible void __noreturn handle_stack_overflow(struct pt_regs *regs,
 {
 	const char *name = stack_type_name(info->type);
 
-	printk(KERN_EMERG "BUG: %s stack guard page was hit at %p (stack is %p..%p)\n",
+	printk(KERN_EMERG "BUG: %s stack guard page was hit at %px (stack is %px..%px)\n",
 	       name, (void *)fault_address, info->begin, info->end);
 
 	die("stack guard page", regs, 0);

arch/x86/lib/csum-wrappers_64.c

@@ -68,25 +68,3 @@ csum_partial_copy_nocheck(const void *src, void *dst, int len)
 }
 EXPORT_SYMBOL(csum_partial_copy_nocheck);
 
-__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
-			const struct in6_addr *daddr,
-			__u32 len, __u8 proto, __wsum sum)
-{
-	__u64 rest, sum64;
-
-	rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
-		(__force __u64)sum;
-
-	asm("	addq (%[saddr]),%[sum]\n"
-	    "	adcq 8(%[saddr]),%[sum]\n"
-	    "	adcq (%[daddr]),%[sum]\n"
-	    "	adcq 8(%[daddr]),%[sum]\n"
-	    "	adcq $0,%[sum]\n"
-
-	    : [sum] "=r" (sum64)
-	    : "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr));
-
-	return csum_fold(
-	       (__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
-}
-EXPORT_SYMBOL(csum_ipv6_magic);