s390: raise minimum supported machine generation to z10

Machine generations up to z9 (released in May 2006) have been officially
out of service for several years now (z9 end of service - January 31, 2019).
No distributions build kernels supporting those old machine generations
anymore, except Debian, which seems to pick the oldest supported
generation. The team supporting Debian on s390 has been notified about
the change.

Raising minimum supported machine generation to z10 helps to reduce
maintenance cost and effectively remove code, which is not getting
enough testing coverage due to lack of older hardware and distributions
support. Besides that this unblocks some optimization opportunities and
allows to use wider instruction set in asm files for future features
implementation. Due to this change spectre mitigation and usercopy
implementations could be drastically simplified and many newer instructions
could be converted from ".insn" encoding to instruction names.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 7 insertions, 163 deletions

diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index fe7803c653a2..a37f6fdc01e8 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -8,14 +8,10 @@
  *		 Gerald Schaefer (gerald.schaefer@de.ibm.com)
  */
 
-#include <linux/jump_label.h>
 #include <linux/uaccess.h>
 #include <linux/export.h>
-#include <linux/errno.h>
 #include <linux/mm.h>
 #include <asm/asm-extable.h>
-#include <asm/mmu_context.h>
-#include <asm/facility.h>
 
 #ifdef CONFIG_DEBUG_ENTRY
 void debug_user_asce(int exit)
@@ -35,32 +31,8 @@ void debug_user_asce(int exit)
 }
 #endif /*CONFIG_DEBUG_ENTRY */
 
-#ifndef CONFIG_HAVE_MARCH_Z10_FEATURES
-static DEFINE_STATIC_KEY_FALSE(have_mvcos);
-
-static int __init uaccess_init(void)
-{
-	if (test_facility(27))
-		static_branch_enable(&have_mvcos);
-	return 0;
-}
-early_initcall(uaccess_init);
-
-static inline int copy_with_mvcos(void)
-{
-	if (static_branch_likely(&have_mvcos))
-		return 1;
-	return 0;
-}
-#else
-static inline int copy_with_mvcos(void)
-{
-	return 1;
-}
-#endif
-
-static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
-						 unsigned long size, unsigned long key)
+static unsigned long raw_copy_from_user_key(void *to, const void __user *from,
+					    unsigned long size, unsigned long key)
 {
 	unsigned long tmp1, tmp2;
 	union oac spec = {
@@ -90,55 +62,12 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr
 		"4: slgr  %0,%0\n"
 		"5:\n"
 		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
-		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: "+a" (size), "+a" (from), "+a" (to), "+a" (tmp1), "=a" (tmp2)
 		: [spec] "d" (spec.val)
 		: "cc", "memory", "0");
 	return size;
 }
 
-static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
-						unsigned long size, unsigned long key)
-{
-	unsigned long tmp1, tmp2;
-
-	tmp1 = -256UL;
-	asm volatile(
-		"   sacf  0\n"
-		"0: mvcp  0(%0,%2),0(%1),%[key]\n"
-		"7: jz    5f\n"
-		"1: algr  %0,%3\n"
-		"   la    %1,256(%1)\n"
-		"   la    %2,256(%2)\n"
-		"2: mvcp  0(%0,%2),0(%1),%[key]\n"
-		"8: jnz   1b\n"
-		"   j     5f\n"
-		"3: la    %4,255(%1)\n"	/* %4 = ptr + 255 */
-		"   lghi  %3,-4096\n"
-		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
-		"   slgr  %4,%1\n"
-		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
-		"   jnh   6f\n"
-		"4: mvcp  0(%4,%2),0(%1),%[key]\n"
-		"9: slgr  %0,%4\n"
-		"   j     6f\n"
-		"5: slgr  %0,%0\n"
-		"6: sacf  768\n"
-		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
-		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
-		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
-		: [key] "d" (key << 4)
-		: "cc", "memory");
-	return size;
-}
-
-static unsigned long raw_copy_from_user_key(void *to, const void __user *from,
-					    unsigned long n, unsigned long key)
-{
-	if (copy_with_mvcos())
-		return copy_from_user_mvcos(to, from, n, key);
-	return copy_from_user_mvcp(to, from, n, key);
-}
-
 unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 {
 	return raw_copy_from_user_key(to, from, n, 0);
@@ -161,8 +90,8 @@ unsigned long _copy_from_user_key(void *to, const void __user *from,
 }
 EXPORT_SYMBOL(_copy_from_user_key);
 
-static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
-					       unsigned long size, unsigned long key)
+static unsigned long raw_copy_to_user_key(void __user *to, const void *from,
+					  unsigned long size, unsigned long key)
 {
 	unsigned long tmp1, tmp2;
 	union oac spec = {
@@ -192,55 +121,12 @@ static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
 		"4: slgr  %0,%0\n"
 		"5:\n"
 		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
-		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+		: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
 		: [spec] "d" (spec.val)
 		: "cc", "memory", "0");
 	return size;
 }
 
-static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
-					      unsigned long size, unsigned long key)
-{
-	unsigned long tmp1, tmp2;
-
-	tmp1 = -256UL;
-	asm volatile(
-		"   sacf  0\n"
-		"0: mvcs  0(%0,%1),0(%2),%[key]\n"
-		"7: jz    5f\n"
-		"1: algr  %0,%3\n"
-		"   la    %1,256(%1)\n"
-		"   la    %2,256(%2)\n"
-		"2: mvcs  0(%0,%1),0(%2),%[key]\n"
-		"8: jnz   1b\n"
-		"   j     5f\n"
-		"3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
-		"   lghi  %3,-4096\n"
-		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
-		"   slgr  %4,%1\n"
-		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
-		"   jnh   6f\n"
-		"4: mvcs  0(%4,%1),0(%2),%[key]\n"
-		"9: slgr  %0,%4\n"
-		"   j     6f\n"
-		"5: slgr  %0,%0\n"
-		"6: sacf  768\n"
-		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
-		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
-		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
-		: [key] "d" (key << 4)
-		: "cc", "memory");
-	return size;
-}
-
-static unsigned long raw_copy_to_user_key(void __user *to, const void *from,
-					  unsigned long n, unsigned long key)
-{
-	if (copy_with_mvcos())
-		return copy_to_user_mvcos(to, from, n, key);
-	return copy_to_user_mvcs(to, from, n, key);
-}
-
 unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 {
 	return raw_copy_to_user_key(to, from, n, 0);
@@ -258,7 +144,7 @@ unsigned long _copy_to_user_key(void __user *to, const void *from,
 }
 EXPORT_SYMBOL(_copy_to_user_key);
 
-static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
+unsigned long __clear_user(void __user *to, unsigned long size)
 {
 	unsigned long tmp1, tmp2;
 	union oac spec = {
@@ -290,46 +176,4 @@ static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size
 		: "cc", "memory", "0");
 	return size;
 }
-
-static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
-{
-	unsigned long tmp1, tmp2;
-
-	asm volatile(
-		"   sacf  256\n"
-		"   aghi  %0,-1\n"
-		"   jo    5f\n"
-		"   bras  %3,3f\n"
-		"   xc    0(1,%1),0(%1)\n"
-		"0: aghi  %0,257\n"
-		"   la    %2,255(%1)\n" /* %2 = ptr + 255 */
-		"   srl   %2,12\n"
-		"   sll   %2,12\n"	/* %2 = (ptr + 255) & -4096 */
-		"   slgr  %2,%1\n"
-		"   clgr  %0,%2\n"	/* clear crosses next page boundary? */
-		"   jnh   5f\n"
-		"   aghi  %2,-1\n"
-		"1: ex    %2,0(%3)\n"
-		"   aghi  %2,1\n"
-		"   slgr  %0,%2\n"
-		"   j     5f\n"
-		"2: xc    0(256,%1),0(%1)\n"
-		"   la    %1,256(%1)\n"
-		"3: aghi  %0,-256\n"
-		"   jnm   2b\n"
-		"4: ex    %0,0(%3)\n"
-		"5: slgr  %0,%0\n"
-		"6: sacf  768\n"
-		EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
-		: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
-		: : "cc", "memory");
-	return size;
-}
-
-unsigned long __clear_user(void __user *to, unsigned long size)
-{
-	if (copy_with_mvcos())
-			return clear_user_mvcos(to, size);
-	return clear_user_xc(to, size);
-}
 EXPORT_SYMBOL(__clear_user);