s390/diag: Convert MACHINE_HAS_DIAG9C to machine_has_diag9c()

Use static branch(es) to implement and use machine_has_diag9c() instead of
a runtime check via MACHINE_HAS_DIAG9C.

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

diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 50ae83aaef165ae61618e8acb994c21cead5f904..41dda285ee2cca6e225d6c0908fadea8778e6efb 100644 (file)
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -49,6 +49,37 @@ void error(char *x)
        disabled_wait();
 }
 
+static void detect_diag9c(void)
+{
+       unsigned long reg1, reg2;
+       unsigned int cpu;
+       int rc = 1;
+       psw_t old;
+
+       cpu = stap();
+       asm volatile(
+               "       mvc     0(16,%[psw_old]),0(%[psw_pgm])\n"
+               "       epsw    %[reg1],%[reg2]\n"
+               "       st      %[reg1],0(%[psw_pgm])\n"
+               "       st      %[reg2],4(%[psw_pgm])\n"
+               "       larl    %[reg1],1f\n"
+               "       stg     %[reg1],8(%[psw_pgm])\n"
+               "       diag    %[cpu],0,0x9c\n"
+               "       lhi     %[rc],0\n"
+               "1:     mvc     0(16,%[psw_pgm]),0(%[psw_old])\n"
+               : [reg1] "=&d" (reg1),
+                 [reg2] "=&a" (reg2),
+                 [rc] "+&d" (rc),
+                 "+Q" (get_lowcore()->program_new_psw),
+                 "=Q" (old)
+               : [psw_old] "a" (&old),
+                 [psw_pgm] "a" (&get_lowcore()->program_new_psw),
+                 [cpu] "d" (cpu)
+               : "cc", "memory");
+       if (!rc)
+               set_machine_feature(MFEATURE_DIAG9C);
+}
+
 static void reset_tod_clock(void)
 {
        union tod_clock clk;
@@ -488,6 +519,7 @@ void startup_kernel(void)
        sclp_early_read_info();
        sclp_early_detect_machine_features();
        detect_facilities();
+       detect_diag9c();
        cmma_init();
        sanitize_prot_virt_host();
        max_physmem_end = detect_max_physmem_end();

diff --git a/arch/s390/include/asm/machine.h b/arch/s390/include/asm/machine.h
index dd61146d0a8d039cc79bcddf976011bdf494eacd..4a1f1ab1888a2c05ff25fa6432fbd3063d4bfa7e 100644 (file)
--- a/arch/s390/include/asm/machine.h
+++ b/arch/s390/include/asm/machine.h
@@ -14,6 +14,7 @@
 #define MFEATURE_TLB_GUEST     3
 #define MFEATURE_TX            4
 #define MFEATURE_ESOP          5
+#define MFEATURE_DIAG9C                6
 
 #ifndef __ASSEMBLY__
 
@@ -86,6 +87,7 @@ DEFINE_MACHINE_HAS_FEATURE(scc, MFEATURE_SCC)
 DEFINE_MACHINE_HAS_FEATURE(tlb_guest, MFEATURE_TLB_GUEST)
 DEFINE_MACHINE_HAS_FEATURE(tx, MFEATURE_TX)
 DEFINE_MACHINE_HAS_FEATURE(esop, MFEATURE_ESOP)
+DEFINE_MACHINE_HAS_FEATURE(diag9c, MFEATURE_DIAG9C)
 
 #endif /* __ASSEMBLY__ */
 #endif /* __ASM_S390_MACHINE_H */

diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index a90260f80f6209c10527c9ecfa531b097ab72225..f465f82a9dcab9912f52b3167bb03d48a7e7ec35 100644 (file)
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -20,7 +20,6 @@
 #define MACHINE_FLAG_VM                BIT(0)
 #define MACHINE_FLAG_KVM       BIT(1)
 #define MACHINE_FLAG_LPAR      BIT(2)
-#define MACHINE_FLAG_DIAG9C    BIT(3)
 
 #define LPP_MAGIC              BIT(31)
 #define LPP_PID_MASK           _AC(0xffffffff, UL)
@@ -68,8 +67,6 @@ extern unsigned long mio_wb_bit_mask;
 #define MACHINE_IS_KVM         (get_lowcore()->machine_flags & MACHINE_FLAG_KVM)
 #define MACHINE_IS_LPAR                (get_lowcore()->machine_flags & MACHINE_FLAG_LPAR)
 
-#define MACHINE_HAS_DIAG9C     (get_lowcore()->machine_flags & MACHINE_FLAG_DIAG9C)
-
 /*
  * Console mode. Override with conmode=
  */

diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index cc4e3d4dc55f948d81c8ac9da6de90726df7d8c4..59b15f6a0a0280d72eacd0fbfd730e2c92c0b1f9 100644 (file)
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -203,23 +203,6 @@ static noinline __init void setup_lowcore_early(void)
        lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
 }
 
-static __init void detect_diag9c(void)
-{
-       unsigned int cpu_address;
-       int rc;
-
-       cpu_address = stap();
-       diag_stat_inc(DIAG_STAT_X09C);
-       asm volatile(
-               "       diag    %2,0,0x9c\n"
-               "0:     la      %0,0\n"
-               "1:\n"
-               EX_TABLE(0b,1b)
-               : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
-       if (!rc)
-               get_lowcore()->machine_flags |= MACHINE_FLAG_DIAG9C;
-}
-
 static __init void detect_machine_facilities(void)
 {
        if (test_facility(129))
@@ -269,7 +252,6 @@ void __init startup_init(void)
        detect_machine_type();
        setup_arch_string();
        setup_boot_command_line();
-       detect_diag9c();
        detect_machine_facilities();
        save_vector_registers();
        setup_topology();

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 2bf45d95165bb81bff57462ec14658ec9c8c5bd4..f2f05c5277f41f75781b452bcec1686788258173 100644 (file)
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -39,6 +39,7 @@
 #include <linux/kprobes.h>
 #include <asm/access-regs.h>
 #include <asm/asm-offsets.h>
+#include <asm/machine.h>
 #include <asm/ctlreg.h>
 #include <asm/pfault.h>
 #include <asm/diag.h>
@@ -417,7 +418,7 @@ EXPORT_SYMBOL(arch_vcpu_is_preempted);
 
 void notrace smp_yield_cpu(int cpu)
 {
-       if (!MACHINE_HAS_DIAG9C)
+       if (!machine_has_diag9c())
                return;
        diag_stat_inc_norecursion(DIAG_STAT_X09C);
        asm volatile("diag %0,0,0x9c"