[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>

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) {

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 */

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;
+	unsigned char *ptr;
 
-	asm volatile(".insn s,0xb2b00000,%0" /* stfle */
-		     : "=m" (*(addrtype *) list), "+d" (__nr) : : "cc");
-	return __nr + 1;
-}
-
-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)

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();

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))))
+	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.

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)

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;
 

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

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;
 }

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));

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;
 }
 

drivers/s390/crypto/ap_bus.c

@@ -154,14 +154,7 @@ static inline int ap_instructions_available(void)
  */
 static int ap_interrupts_available(void)
 {
-	unsigned long long facility_bits[2];
-
-	if (stfle(facility_bits, 2) <= 1)
-		return 0;
-	if (!(facility_bits[0] & (1ULL << 61)) ||
-	    !(facility_bits[1] & (1ULL << 62)))
-		return 0;
-	return 1;
+	return test_facility(1) && test_facility(2);
 }
 
 /**