On 04/27/2018, 03:58 PM, Greg Kroah-Hartman wrote:
4.4-stable review patch. If anyone has any objections, please let me know.
From: Martin Schwidefsky schwidefsky@de.ibm.com
[ Upstream commit cf1489984641369611556bf00c48f945c77bcf02 ]
To be able to switch off specific CPU alternatives with kernel parameters make a copy of the facility bit mask provided by STFLE and use the copy for the decision to apply an alternative.
...
--- a/arch/s390/include/asm/facility.h +++ b/arch/s390/include/asm/facility.h @@ -13,6 +13,24 @@ #define MAX_FACILITY_BIT (256*8) /* stfle_fac_list has 256 bytes */
I wonder if the below (plus __test_facility) is correct in 4.4, given MAX_FACILITY_BIT is defined as such and not as sizeof(stfle_fac_list * 8) as in upstream?
+static inline void __set_facility(unsigned long nr, void *facilities) +{
- unsigned char *ptr = (unsigned char *) facilities;
- if (nr >= MAX_FACILITY_BIT)
return;- ptr[nr >> 3] |= 0x80 >> (nr & 7);
+}
+static inline void __clear_facility(unsigned long nr, void *facilities) +{
- unsigned char *ptr = (unsigned char *) facilities;
- if (nr >= MAX_FACILITY_BIT)
return;- ptr[nr >> 3] &= ~(0x80 >> (nr & 7));
+}
static inline int __test_facility(unsigned long nr, void *facilities) { unsigned char *ptr; --- a/arch/s390/include/asm/lowcore.h +++ b/arch/s390/include/asm/lowcore.h @@ -170,7 +170,8 @@ struct _lowcore { __u8 pad_0x0e20[0x0f00-0x0e20]; /* 0x0e20 */ /* Extended facility list */
- __u64 stfle_fac_list[32]; /* 0x0f00 */
- __u64 stfle_fac_list[16]; /* 0x0f00 */
- __u64 alt_stfle_fac_list[16]; /* 0x0f80 */ __u8 pad_0x1000[0x11b0-0x1000]; /* 0x1000 */
thanks,