Merge Linus master into drm-next

The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.

I've included the patch into the merge to fix the build.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 37 insertions, 33 deletions

diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 2eb34bdfc613..8a993a53fcd6 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -1,7 +1,7 @@
 /*
  * Access kernel memory without faulting -- s390 specific implementation.
  *
- * Copyright IBM Corp. 2009
+ * Copyright IBM Corp. 2009, 2015
  *
  *   Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
  *
@@ -16,51 +16,55 @@
 #include <asm/ctl_reg.h>
 #include <asm/io.h>
 
-/*
- * This function writes to kernel memory bypassing DAT and possible
- * write protection. It copies one to four bytes from src to dst
- * using the stura instruction.
- * Returns the number of bytes copied or -EFAULT.
- */
-static long probe_kernel_write_odd(void *dst, const void *src, size_t size)
+static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t size)
 {
-	unsigned long count, aligned;
-	int offset, mask;
-	int rc = -EFAULT;
+	unsigned long aligned, offset, count;
+	char tmp[8];
 
-	aligned = (unsigned long) dst & ~3UL;
-	offset = (unsigned long) dst & 3;
-	count = min_t(unsigned long, 4 - offset, size);
-	mask = (0xf << (4 - count)) & 0xf;
-	mask >>= offset;
+	aligned = (unsigned long) dst & ~7UL;
+	offset = (unsigned long) dst & 7UL;
+	size = min(8UL - offset, size);
+	count = size - 1;
 	asm volatile(
 		"	bras	1,0f\n"
-		"	icm	0,0,0(%3)\n"
-		"0:	l	0,0(%1)\n"
-		"	lra	%1,0(%1)\n"
-		"1:	ex	%2,0(1)\n"
-		"2:	stura	0,%1\n"
-		"	la	%0,0\n"
-		"3:\n"
-		EX_TABLE(0b,3b) EX_TABLE(1b,3b) EX_TABLE(2b,3b)
-		: "+d" (rc), "+a" (aligned)
-		: "a" (mask), "a" (src) : "cc", "memory", "0", "1");
-	return rc ? rc : count;
+		"	mvc	0(1,%4),0(%5)\n"
+		"0:	mvc	0(8,%3),0(%0)\n"
+		"	ex	%1,0(1)\n"
+		"	lg	%1,0(%3)\n"
+		"	lra	%0,0(%0)\n"
+		"	sturg	%1,%0\n"
+		: "+&a" (aligned), "+&a" (count), "=m" (tmp)
+		: "a" (&tmp), "a" (&tmp[offset]), "a" (src)
+		: "cc", "memory", "1");
+	return size;
 }
 
-long probe_kernel_write(void *dst, const void *src, size_t size)
+/*
+ * s390_kernel_write - write to kernel memory bypassing DAT
+ * @dst: destination address
+ * @src: source address
+ * @size: number of bytes to copy
+ *
+ * This function writes to kernel memory bypassing DAT and possible page table
+ * write protection. It writes to the destination using the sturg instruction.
+ * Therefore we have a read-modify-write sequence: the function reads eight
+ * bytes from destination at an eight byte boundary, modifies the bytes
+ * requested and writes the result back in a loop.
+ *
+ * Note: this means that this function may not be called concurrently on
+ *	 several cpus with overlapping words, since this may potentially
+ *	 cause data corruption.
+ */
+void notrace s390_kernel_write(void *dst, const void *src, size_t size)
 {
-	long copied = 0;
+	long copied;
 
 	while (size) {
-		copied = probe_kernel_write_odd(dst, src, size);
-		if (copied < 0)
-			break;
+		copied = s390_kernel_write_odd(dst, src, size);
 		dst += copied;
 		src += copied;
 		size -= copied;
 	}
-	return copied < 0 ? -EFAULT : 0;
 }
 
 static int __memcpy_real(void *dest, void *src, size_t count)