s390/uaccess: Make cmpxchg_user_key() library code

Move cmpxchg_user_key() handling to uaccess library code. The generated
code is large in any case so that there is hardly any benefit if it is
inlined.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

1 files changed, 201 insertions, 0 deletions

diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index fa7d98fa1320..f6112c7dfcc7 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -145,3 +145,204 @@ unsigned long _copy_to_user_key(void __user *to, const void *from,
 	return raw_copy_to_user_key(to, from, n, key);
 }
 EXPORT_SYMBOL(_copy_to_user_key);
+
+#define CMPXCHG_USER_KEY_MAX_LOOPS 128
+
+int __cmpxchg_user_key1(unsigned long address, unsigned char *uval,
+			unsigned char old, unsigned char new, unsigned long key)
+{
+	unsigned int prev, shift, mask, _old, _new;
+	unsigned long count;
+	bool sacf_flag;
+	int rc = 0;
+
+	shift = (3 ^ (address & 3)) << 3;
+	address ^= address & 3;
+	_old = (unsigned int)old << shift;
+	_new = (unsigned int)new << shift;
+	mask = ~(0xff << shift);
+	sacf_flag = enable_sacf_uaccess();
+	asm_inline volatile(
+		"	spka	0(%[key])\n"
+		"	sacf	256\n"
+		"	llill	%[count],%[max_loops]\n"
+		"0:	l	%[prev],%[address]\n"
+		"1:	nr	%[prev],%[mask]\n"
+		"	xilf	%[mask],0xffffffff\n"
+		"	or	%[new],%[prev]\n"
+		"	or	%[prev],%[tmp]\n"
+		"2:	lr	%[tmp],%[prev]\n"
+		"3:	cs	%[prev],%[new],%[address]\n"
+		"4:	jnl	5f\n"
+		"	xr	%[tmp],%[prev]\n"
+		"	xr	%[new],%[tmp]\n"
+		"	nr	%[tmp],%[mask]\n"
+		"	jnz	5f\n"
+		"	brct	%[count],2b\n"
+		"5:	sacf	768\n"
+		"	spka	%[default_key]\n"
+		EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
+		EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
+		EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
+		EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
+		: [rc] "+&d" (rc),
+		[prev] "=&d" (prev),
+		[address] "+Q" (*(int *)address),
+		[tmp] "+&d" (_old),
+		[new] "+&d" (_new),
+		[mask] "+&d" (mask),
+		[count] "=a" (count)
+		: [key] "%[count]" (key << 4),
+		[default_key] "J" (PAGE_DEFAULT_KEY),
+		[max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
+		: "memory", "cc");
+	disable_sacf_uaccess(sacf_flag);
+	*uval = prev >> shift;
+	if (!count)
+		rc = -EAGAIN;
+	return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key1);
+
+int __cmpxchg_user_key2(unsigned long address, unsigned short *uval,
+			unsigned short old, unsigned short new, unsigned long key)
+{
+	unsigned int prev, shift, mask, _old, _new;
+	unsigned long count;
+	bool sacf_flag;
+	int rc = 0;
+
+	shift = (2 ^ (address & 2)) << 3;
+	address ^= address & 2;
+	_old = (unsigned int)old << shift;
+	_new = (unsigned int)new << shift;
+	mask = ~(0xffff << shift);
+	sacf_flag = enable_sacf_uaccess();
+	asm_inline volatile(
+		"	spka	0(%[key])\n"
+		"	sacf	256\n"
+		"	llill	%[count],%[max_loops]\n"
+		"0:	l	%[prev],%[address]\n"
+		"1:	nr	%[prev],%[mask]\n"
+		"	xilf	%[mask],0xffffffff\n"
+		"	or	%[new],%[prev]\n"
+		"	or	%[prev],%[tmp]\n"
+		"2:	lr	%[tmp],%[prev]\n"
+		"3:	cs	%[prev],%[new],%[address]\n"
+		"4:	jnl	5f\n"
+		"	xr	%[tmp],%[prev]\n"
+		"	xr	%[new],%[tmp]\n"
+		"	nr	%[tmp],%[mask]\n"
+		"	jnz	5f\n"
+		"	brct	%[count],2b\n"
+		"5:	sacf	768\n"
+		"	spka	%[default_key]\n"
+		EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
+		EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
+		EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
+		EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
+		: [rc] "+&d" (rc),
+		[prev] "=&d" (prev),
+		[address] "+Q" (*(int *)address),
+		[tmp] "+&d" (_old),
+		[new] "+&d" (_new),
+		[mask] "+&d" (mask),
+		[count] "=a" (count)
+		: [key] "%[count]" (key << 4),
+		[default_key] "J" (PAGE_DEFAULT_KEY),
+		[max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
+		: "memory", "cc");
+	disable_sacf_uaccess(sacf_flag);
+	*uval = prev >> shift;
+	if (!count)
+		rc = -EAGAIN;
+	return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key2);
+
+int __cmpxchg_user_key4(unsigned long address, unsigned int *uval,
+			unsigned int old, unsigned int new, unsigned long key)
+{
+	unsigned int prev = old;
+	bool sacf_flag;
+	int rc = 0;
+
+	sacf_flag = enable_sacf_uaccess();
+	asm_inline volatile(
+		"	spka	0(%[key])\n"
+		"	sacf	256\n"
+		"0:	cs	%[prev],%[new],%[address]\n"
+		"1:	sacf	768\n"
+		"	spka	%[default_key]\n"
+		EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
+		EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
+		: [rc] "+&d" (rc),
+		[prev] "+&d" (prev),
+		[address] "+Q" (*(int *)address)
+		: [new] "d" (new),
+		[key] "a" (key << 4),
+		[default_key] "J" (PAGE_DEFAULT_KEY)
+		: "memory", "cc");
+	disable_sacf_uaccess(sacf_flag);
+	*uval = prev;
+	return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key4);
+
+int __cmpxchg_user_key8(unsigned long address, unsigned long *uval,
+			unsigned long old, unsigned long new, unsigned long key)
+{
+	unsigned long prev = old;
+	bool sacf_flag;
+	int rc = 0;
+
+	sacf_flag = enable_sacf_uaccess();
+	asm_inline volatile(
+		"	spka	0(%[key])\n"
+		"	sacf	256\n"
+		"0:	csg	%[prev],%[new],%[address]\n"
+		"1:	sacf	768\n"
+		"	spka	%[default_key]\n"
+		EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
+		EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
+		: [rc] "+&d" (rc),
+		[prev] "+&d" (prev),
+		[address] "+QS" (*(long *)address)
+		: [new] "d" (new),
+		[key] "a" (key << 4),
+		[default_key] "J" (PAGE_DEFAULT_KEY)
+		: "memory", "cc");
+	disable_sacf_uaccess(sacf_flag);
+	*uval = prev;
+	return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key8);
+
+int __cmpxchg_user_key16(unsigned long address, __uint128_t *uval,
+			 __uint128_t old, __uint128_t new, unsigned long key)
+{
+	__uint128_t prev = old;
+	bool sacf_flag;
+	int rc = 0;
+
+	sacf_flag = enable_sacf_uaccess();
+	asm_inline volatile(
+		"	spka	0(%[key])\n"
+		"	sacf	256\n"
+		"0:	cdsg	%[prev],%[new],%[address]\n"
+		"1:	sacf	768\n"
+		"	spka	%[default_key]\n"
+		EX_TABLE_UA_LOAD_REGPAIR(0b, 1b, %[rc], %[prev])
+		EX_TABLE_UA_LOAD_REGPAIR(1b, 1b, %[rc], %[prev])
+		: [rc] "+&d" (rc),
+		[prev] "+&d" (prev),
+		[address] "+QS" (*(__int128_t *)address)
+		: [new] "d" (new),
+		[key] "a" (key << 4),
+		[default_key] "J" (PAGE_DEFAULT_KEY)
+		: "memory", "cc");
+	disable_sacf_uaccess(sacf_flag);
+	*uval = prev;
+	return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key16);