[S390] cleanup facility list handling

Store the facility list once at system startup with stfl/stfle and
reuse the result for all facility tests.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

11 files changed, 65 insertions, 66 deletions

diff --git a/arch/s390/crypto/crypt_s390.h b/arch/s390/crypto/crypt_s390.h
index 0ef9829f2ad6..7ee9a1b4ad9f 100644
--- a/arch/s390/crypto/crypt_s390.h
+++ b/arch/s390/crypto/crypt_s390.h
@@ -297,7 +297,7 @@ static inline int crypt_s390_func_available(int func)
         int ret;
 
         /* check if CPACF facility (bit 17) is available */
-        if (!(stfl() & 1ULL << (31 - 17)))
+        if (!test_facility(17))
                 return 0;
 
         switch (func & CRYPT_S390_OP_MASK) {
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index 0f97ef2d92ac..65e172f8209d 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -150,9 +150,10 @@ struct _lowcore {
          */
         __u32   ipib;                           /* 0x0e00 */
         __u32   ipib_checksum;                  /* 0x0e04 */
+        __u8    pad_0x0e08[0x0f00-0x0e08];      /* 0x0e08 */
 
-        /* Align to the top 1k of prefix area */
-        __u8    pad_0x0e08[0x1000-0x0e08];      /* 0x0e08 */
+        /* Extended facility list */
+        __u64   stfle_fac_list[32];             /* 0x0f00 */
 } __packed;
 
 #else /* CONFIG_32BIT */
@@ -285,7 +286,11 @@ struct _lowcore {
          */
         __u64   ipib;                           /* 0x0e00 */
         __u32   ipib_checksum;                  /* 0x0e08 */
-        __u8    pad_0x0e0c[0x11b8-0x0e0c];      /* 0x0e0c */
+        __u8    pad_0x0e0c[0x0f00-0x0e0c];      /* 0x0e0c */
+
+        /* Extended facility list */
+        __u64   stfle_fac_list[32];             /* 0x0f00 */
+        __u8    pad_0x1000[0x11b8-0x1000];      /* 0x1000 */
 
         /* 64 bit extparam used for pfault/diag 250: defined by architecture */
         __u64   ext_params2;                    /* 0x11B8 */
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index 3c079dd5ee79..3ad16dbf622e 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -420,30 +420,21 @@ extern void smp_ctl_clear_bit(int cr, int bit);
 
 #endif /* CONFIG_SMP */
 
-static inline unsigned int stfl(void)
-{
-        asm volatile(
-                "       .insn   s,0xb2b10000,0(0)\n" /* stfl */
-                "0:\n"
-                EX_TABLE(0b,0b));
-        return S390_lowcore.stfl_fac_list;
-}
+#define MAX_FACILITY_BIT (256*8)        /* stfle_fac_list has 256 bytes */
 
-static inline int __stfle(unsigned long long *list, int doublewords)
+/*
+ * The test_facility function uses the bit odering where the MSB is bit 0.
+ * That makes it easier to query facility bits with the bit number as
+ * documented in the Principles of Operation.
+ */
+static inline int test_facility(unsigned long nr)
 {
-        typedef struct { unsigned long long _[doublewords]; } addrtype;
-        register unsigned long __nr asm("0") = doublewords - 1;
-
-        asm volatile(".insn s,0xb2b00000,%0" /* stfle */
-                     : "=m" (*(addrtype *) list), "+d" (__nr) : : "cc");
-        return __nr + 1;
-}
+        unsigned char *ptr;
 
-static inline int stfle(unsigned long long *list, int doublewords)
-{
-        if (!(stfl() & (1UL << 24)))
-                return -EOPNOTSUPP;
-        return __stfle(list, doublewords);
+        if (nr >= MAX_FACILITY_BIT)
+                return 0;
+        ptr = (unsigned char *) &S390_lowcore.stfle_fac_list + (nr >> 3);
+        return (*ptr & (0x80 >> (nr & 7))) != 0;
 }
 
 static inline unsigned short stap(void)
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 0badc6344eb4..d2455d44d99a 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -256,13 +256,35 @@ static noinline __init void setup_lowcore_early(void)
         s390_base_pgm_handler_fn = early_pgm_check_handler;
 }
 
+static noinline __init void setup_facility_list(void)
+{
+        unsigned long nr;
+
+        S390_lowcore.stfl_fac_list = 0;
+        asm volatile(
+                "       .insn   s,0xb2b10000,0(0)\n" /* stfl */
+                "0:\n"
+                EX_TABLE(0b,0b) : "=m" (S390_lowcore.stfl_fac_list));
+        memcpy(&S390_lowcore.stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
+        nr = 4;                         /* # bytes stored by stfl */
+        if (test_facility(7)) {
+                /* More facility bits available with stfle */
+                register unsigned long reg0 asm("0") = MAX_FACILITY_BIT/64 - 1;
+                asm volatile(".insn s,0xb2b00000,%0" /* stfle */
+                             : "=m" (S390_lowcore.stfle_fac_list), "+d" (reg0)
+                             : : "cc");
+                nr = (reg0 + 1) * 8;    /* # bytes stored by stfle */
+        }
+        memset((char *) S390_lowcore.stfle_fac_list + nr, 0,
+               MAX_FACILITY_BIT/8 - nr);
+}
+
 static noinline __init void setup_hpage(void)
 {
 #ifndef CONFIG_DEBUG_PAGEALLOC
         unsigned int facilities;
 
-        facilities = stfl();
-        if (!(facilities & (1UL << 23)) || !(facilities & (1UL << 29)))
+        if (!test_facility(2) || !test_facility(8))
                 return;
         S390_lowcore.machine_flags |= MACHINE_FLAG_HPAGE;
         __ctl_set_bit(0, 23);
@@ -356,18 +378,13 @@ static __init void detect_diag44(void)
 static __init void detect_machine_facilities(void)
 {
 #ifdef CONFIG_64BIT
-        unsigned int facilities;
-        unsigned long long facility_bits;
-
-        facilities = stfl();
-        if (facilities & (1 << 28))
+        if (test_facility(3))
                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
-        if (facilities & (1 << 23))
+        if (test_facility(8))
                 S390_lowcore.machine_flags |= MACHINE_FLAG_PFMF;
-        if (facilities & (1 << 4))
+        if (test_facility(27))
                 S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
-        if ((stfle(&facility_bits, 1) > 0) &&
-            (facility_bits & (1ULL << (63 - 40))))
+        if (test_facility(40))
                 S390_lowcore.machine_flags |= MACHINE_FLAG_SPP;
 #endif
 }
@@ -448,6 +465,7 @@ void __init startup_init(void)
         lockdep_off();
         sort_main_extable();
         setup_lowcore_early();
+        setup_facility_list();
         detect_machine_type();
         ipl_update_parameters();
         setup_boot_command_line();
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 9071e984dcf1..e3ceb911dc75 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -409,6 +409,9 @@ setup_lowcore(void)
         lc->current_task = (unsigned long) init_thread_union.thread_info.task;
         lc->thread_info = (unsigned long) &init_thread_union;
         lc->machine_flags = S390_lowcore.machine_flags;
+        lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
+        memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
+               MAX_FACILITY_BIT/8);
 #ifndef CONFIG_64BIT
         if (MACHINE_HAS_IEEE) {
                 lc->extended_save_area_addr = (__u32)
@@ -675,12 +678,9 @@ setup_memory(void)
 static void __init setup_hwcaps(void)
 {
         static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
-        unsigned long long facility_list_extended;
-        unsigned int facility_list;
         struct cpuid cpu_id;
         int i;
 
-        facility_list = stfl();
         /*
          * The store facility list bits numbers as found in the principles
          * of operation are numbered with bit 1UL<<31 as number 0 to
@@ -700,11 +700,10 @@ static void __init setup_hwcaps(void)
          *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
          */
         for (i = 0; i < 6; i++)
-                if (facility_list & (1UL << (31 - stfl_bits[i])))
+                if (test_facility(stfl_bits[i]))
                         elf_hwcap |= 1UL << i;
 
-        if ((facility_list & (1UL << (31 - 22)))
-            && (facility_list & (1UL << (31 - 30))))
+        if (test_facility(22) && test_facility(30))
                 elf_hwcap |= HWCAP_S390_ETF3EH;
 
         /*
@@ -720,12 +719,8 @@ static void __init setup_hwcaps(void)
          * translated to:
          *   HWCAP_S390_DFP bit 6 (42 && 44).
          */
-        if ((elf_hwcap & (1UL << 2)) &&
-            __stfle(&facility_list_extended, 1) > 0) {
-                if ((facility_list_extended & (1ULL << (63 - 42)))
-                    && (facility_list_extended & (1ULL << (63 - 44))))
-                        elf_hwcap |= HWCAP_S390_DFP;
-        }
+        if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
+                elf_hwcap |= HWCAP_S390_DFP;
 
         /*
          * Huge page support HWCAP_S390_HPAGE is bit 7.
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 354589d096b1..94cf510b8fe1 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -594,6 +594,8 @@ int __cpuinit __cpu_up(unsigned int cpu)
         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
         cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
         cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
+        memcpy(cpu_lowcore->stfle_fac_list, S390_lowcore.stfle_fac_list,
+               MAX_FACILITY_BIT/8);
         eieio();
 
         while (sigp(cpu, sigp_restart) == sigp_busy)
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index eb0bc4752ae8..91fb66baa50b 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -351,13 +351,10 @@ static void alloc_masks(struct tl_info *info, struct mask_info *mask, int offset
 
 void __init s390_init_cpu_topology(void)
 {
-        unsigned long long facility_bits;
         struct tl_info *info;
         int i;
 
-        if (stfle(&facility_bits, 1) <= 0)
-                return;
-        if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
+        if (!test_facility(2) || !test_facility(11))
                 return;
         machine_has_topology = 1;
 
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 6b83870507d5..e3150dd2fe74 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -84,11 +84,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data;
  */
 static void vdso_init_data(struct vdso_data *vd)
 {
-        unsigned int facility_list;
-
-        facility_list = stfl();
-        vd->ectg_available =
-                user_mode != HOME_SPACE_MODE && (facility_list & 1);
+        vd->ectg_available = user_mode != HOME_SPACE_MODE && test_facility(31);
 }
 
 #ifdef CONFIG_64BIT
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 76482b65ba3e..985d825494f1 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -740,7 +740,7 @@ static int __init kvm_s390_init(void)
                 kvm_exit();
                 return -ENOMEM;
         }
-        stfle(facilities, 1);
+        memcpy(facilities, S390_lowcore.stfle_fac_list, 16);
         facilities[0] &= 0xff00fff3f47c0000ULL;
         return 0;
 }
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 44205507717c..9194a4b52b22 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -154,12 +154,12 @@ static int handle_chsc(struct kvm_vcpu *vcpu)
 
 static int handle_stfl(struct kvm_vcpu *vcpu)
 {
-        unsigned int facility_list = stfl();
+        unsigned int facility_list;
         int rc;
 
         vcpu->stat.instruction_stfl++;
         /* only pass the facility bits, which we can handle */
-        facility_list &= 0xff00fff3;
+        facility_list = S390_lowcore.stfl_fac_list & 0xff00fff3;
 
         rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
                            &facility_list, sizeof(facility_list));
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index b4aad0c1f562..fe5701e9efbf 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -56,12 +56,7 @@ static unsigned long store_indication;
 
 void fault_init(void)
 {
-        unsigned long long facility_list[2];
-
-        if (stfle(facility_list, 2) < 2)
-                return;
-        if ((facility_list[0] & (1ULL << 61)) &&
-            (facility_list[1] & (1ULL << 52)))
+        if (test_facility(2) && test_facility(75))
                 store_indication = 0xc00;
 }