Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
authorLinus Torvalds <torvalds@linux-foundation.org>
Mon, 31 Mar 2014 18:58:45 +0000 (11:58 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 31 Mar 2014 18:58:45 +0000 (11:58 -0700)
Pull x86 apic changes from Ingo Molnar:
 "An xAPIC CPU hotplug race fix, plus cleanups and minor fixes"

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Plug racy xAPIC access of CPU hotplug code
  x86/apic: Always define nox2apic and define it as initdata
  x86/apic: Remove unused function prototypes
  x86/apic: Switch wait_for_init_deassert() to a bool flag
  x86/apic: Only use default_wait_for_init_deassert()

14 files changed:
arch/x86/include/asm/apic.h
arch/x86/kernel/apic/apic.c
arch/x86/kernel/apic/apic_flat_64.c
arch/x86/kernel/apic/apic_noop.c
arch/x86/kernel/apic/apic_numachip.c
arch/x86/kernel/apic/bigsmp_32.c
arch/x86/kernel/apic/es7000_32.c
arch/x86/kernel/apic/numaq_32.c
arch/x86/kernel/apic/probe_32.c
arch/x86/kernel/apic/summit_32.c
arch/x86/kernel/apic/x2apic_cluster.c
arch/x86/kernel/apic/x2apic_phys.c
arch/x86/kernel/apic/x2apic_uv_x.c
arch/x86/kernel/smpboot.c

index 1d2091a226bcac5b55b05225816bf1f374860c3c..19b0ebafcd3e3f9d5a7aa5d5d9900de66d03a374 100644 (file)
@@ -93,9 +93,6 @@ static inline int is_vsmp_box(void)
        return 0;
 }
 #endif
-extern void xapic_wait_icr_idle(void);
-extern u32 safe_xapic_wait_icr_idle(void);
-extern void xapic_icr_write(u32, u32);
 extern int setup_profiling_timer(unsigned int);
 
 static inline void native_apic_mem_write(u32 reg, u32 v)
@@ -184,7 +181,6 @@ extern int x2apic_phys;
 extern int x2apic_preenabled;
 extern void check_x2apic(void);
 extern void enable_x2apic(void);
-extern void x2apic_icr_write(u32 low, u32 id);
 static inline int x2apic_enabled(void)
 {
        u64 msr;
@@ -221,7 +217,6 @@ static inline void x2apic_force_phys(void)
 {
 }
 
-#define        nox2apic        0
 #define        x2apic_preenabled 0
 #define        x2apic_supported()      0
 #endif
@@ -351,7 +346,7 @@ struct apic {
        int trampoline_phys_low;
        int trampoline_phys_high;
 
-       void (*wait_for_init_deassert)(atomic_t *deassert);
+       bool wait_for_init_deassert;
        void (*smp_callin_clear_local_apic)(void);
        void (*inquire_remote_apic)(int apicid);
 
@@ -517,13 +512,6 @@ extern int default_cpu_present_to_apicid(int mps_cpu);
 extern int default_check_phys_apicid_present(int phys_apicid);
 #endif
 
-static inline void default_wait_for_init_deassert(atomic_t *deassert)
-{
-       while (!atomic_read(deassert))
-               cpu_relax();
-       return;
-}
-
 extern void generic_bigsmp_probe(void);
 
 
index 7f26c9a70a9e0ada12f46382d7ee2cd73b2d5f29..53e20531470ee1ee125c510bf0c26308f74820d3 100644 (file)
@@ -133,6 +133,10 @@ static inline void imcr_apic_to_pic(void)
  * +1=force-enable
  */
 static int force_enable_local_apic __initdata;
+
+/* Control whether x2APIC mode is enabled or not */
+static bool nox2apic __initdata;
+
 /*
  * APIC command line parameters
  */
@@ -162,8 +166,7 @@ int x2apic_mode;
 /* x2apic enabled before OS handover */
 int x2apic_preenabled;
 static int x2apic_disabled;
-static int nox2apic;
-static __init int setup_nox2apic(char *str)
+static int __init setup_nox2apic(char *str)
 {
        if (x2apic_enabled()) {
                int apicid = native_apic_msr_read(APIC_ID);
@@ -178,7 +181,7 @@ static __init int setup_nox2apic(char *str)
        } else
                setup_clear_cpu_cap(X86_FEATURE_X2APIC);
 
-       nox2apic = 1;
+       nox2apic = true;
 
        return 0;
 }
@@ -283,8 +286,12 @@ u32 native_safe_apic_wait_icr_idle(void)
 
 void native_apic_icr_write(u32 low, u32 id)
 {
+       unsigned long flags;
+
+       local_irq_save(flags);
        apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
        apic_write(APIC_ICR, low);
+       local_irq_restore(flags);
 }
 
 u64 native_apic_icr_read(void)
index 2c621a6b901a7642838c5a74a54be4bf3fcbe58a..7c1b29479513a1d78f79410915a4ee30e5d1c53e 100644 (file)
@@ -198,7 +198,7 @@ static struct apic apic_flat =  {
 
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
-       .wait_for_init_deassert         = NULL,
+       .wait_for_init_deassert         = false,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,
 
@@ -314,7 +314,7 @@ static struct apic apic_physflat =  {
 
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
-       .wait_for_init_deassert         = NULL,
+       .wait_for_init_deassert         = false,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,
 
index 191ce75c0e54b8f2808cce5f730f5d62c18dfa09..8c7c98249c205f0f596e7c0866e89444dc3d4bc8 100644 (file)
@@ -172,8 +172,7 @@ struct apic apic_noop = {
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
 
-       .wait_for_init_deassert         = NULL,
-
+       .wait_for_init_deassert         = false,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = NULL,
 
index 3e67f9e3d7ef1e8eb093d9e8398b21aaf1a7b93e..a5b45df8bc881cafbc2560f3b7ea72ef02aa7c73 100644 (file)
@@ -248,7 +248,7 @@ static const struct apic apic_numachip __refconst = {
        .wakeup_secondary_cpu           = numachip_wakeup_secondary,
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
-       .wait_for_init_deassert         = NULL,
+       .wait_for_init_deassert         = false,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = NULL, /* REMRD not supported */
 
index d50e3640d5aed53daf4110ef68193cf0cbdac826..e4840aa7a255b63db235ab5cecd07ecabf5c5013 100644 (file)
@@ -199,8 +199,7 @@ static struct apic apic_bigsmp = {
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
 
-       .wait_for_init_deassert         = default_wait_for_init_deassert,
-
+       .wait_for_init_deassert         = true,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,
 
index c55224731b2d7f0de89d6a37a00e71bd4d8792ec..6f8f8b348a39fbf378953936cc796d5e1842849f 100644 (file)
@@ -394,12 +394,6 @@ static void es7000_enable_apic_mode(void)
                WARN(1, "Command failed, status = %x\n", mip_status);
 }
 
-static void es7000_wait_for_init_deassert(atomic_t *deassert)
-{
-       while (!atomic_read(deassert))
-               cpu_relax();
-}
-
 static unsigned int es7000_get_apic_id(unsigned long x)
 {
        return (x >> 24) & 0xFF;
@@ -658,8 +652,7 @@ static struct apic __refdata apic_es7000_cluster = {
        .trampoline_phys_low            = 0x467,
        .trampoline_phys_high           = 0x469,
 
-       .wait_for_init_deassert         = NULL,
-
+       .wait_for_init_deassert         = false,
        /* Nothing to do for most platforms, since cleared by the INIT cycle: */
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,
@@ -722,8 +715,7 @@ static struct apic __refdata apic_es7000 = {
        .trampoline_phys_low            = 0x467,
        .trampoline_phys_high           = 0x469,
 
-       .wait_for_init_deassert         = es7000_wait_for_init_deassert,
-
+       .wait_for_init_deassert         = true,
        /* Nothing to do for most platforms, since cleared by the INIT cycle: */
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,
index 1e42e8f305ee2096ed52c20f6c569fe8a8339b7b..030ea1c04f72b3184e339ed840f7d13382641ba6 100644 (file)
@@ -505,8 +505,7 @@ static struct apic __refdata apic_numaq = {
        .trampoline_phys_high           = NUMAQ_TRAMPOLINE_PHYS_HIGH,
 
        /* We don't do anything here because we use NMI's to boot instead */
-       .wait_for_init_deassert         = NULL,
-
+       .wait_for_init_deassert         = false,
        .smp_callin_clear_local_apic    = numaq_smp_callin_clear_local_apic,
        .inquire_remote_apic            = NULL,
 
index eb35ef9ee63f779bde870822a01dcc98bd503b01..cceb352c968c62b13404d3ce78478f64e7a5d3c5 100644 (file)
@@ -119,8 +119,7 @@ static struct apic apic_default = {
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
 
-       .wait_for_init_deassert         = default_wait_for_init_deassert,
-
+       .wait_for_init_deassert         = true,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,
 
index 00146f9b0254315acfb191015314fedf35fa9ab0..b656128611cd3ebd71af4ba0f053e72471845e21 100644 (file)
@@ -532,8 +532,7 @@ static struct apic apic_summit = {
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
 
-       .wait_for_init_deassert         = default_wait_for_init_deassert,
-
+       .wait_for_init_deassert         = true,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,
 
index cac85ee6913f70ca64f3a8656dbff5d5cc603348..e66766bf164191de15d7ea9bf7b62c6506b2d6f2 100644 (file)
@@ -279,7 +279,7 @@ static struct apic apic_x2apic_cluster = {
 
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
-       .wait_for_init_deassert         = NULL,
+       .wait_for_init_deassert         = false,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = NULL,
 
index de231e328cae310bf4a39a1fb70ebc83993bb67c..6d600ebf6c127f94c4bb194a9e8bb25f0c607ffe 100644 (file)
@@ -133,7 +133,7 @@ static struct apic apic_x2apic_phys = {
 
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
-       .wait_for_init_deassert         = NULL,
+       .wait_for_init_deassert         = false,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = NULL,
 
index d263b1307de1e5b30a114cc0f37c017197d5728f..7834389ba5be0952b5e673ff11d6a6c64cee106d 100644 (file)
@@ -396,7 +396,7 @@ static struct apic __refdata apic_x2apic_uv_x = {
        .wakeup_secondary_cpu           = uv_wakeup_secondary,
        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
-       .wait_for_init_deassert         = NULL,
+       .wait_for_init_deassert         = false,
        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = NULL,
 
index a32da804252e374b5d266e6788653f24fc98705d..60179ec39d4ca1d09986632cb17392ae0869c3fc 100644 (file)
@@ -122,8 +122,9 @@ static void smp_callin(void)
         * Since CPU0 is not wakened up by INIT, it doesn't wait for the IPI.
         */
        cpuid = smp_processor_id();
-       if (apic->wait_for_init_deassert && cpuid != 0)
-               apic->wait_for_init_deassert(&init_deasserted);
+       if (apic->wait_for_init_deassert && cpuid)
+               while (!atomic_read(&init_deasserted))
+                       cpu_relax();
 
        /*
         * (This works even if the APIC is not enabled.)
@@ -701,11 +702,15 @@ wakeup_cpu_via_init_nmi(int cpu, unsigned long start_ip, int apicid,
        int id;
        int boot_error;
 
+       preempt_disable();
+
        /*
         * Wake up AP by INIT, INIT, STARTUP sequence.
         */
-       if (cpu)
-               return wakeup_secondary_cpu_via_init(apicid, start_ip);
+       if (cpu) {
+               boot_error = wakeup_secondary_cpu_via_init(apicid, start_ip);
+               goto out;
+       }
 
        /*
         * Wake up BSP by nmi.
@@ -725,6 +730,9 @@ wakeup_cpu_via_init_nmi(int cpu, unsigned long start_ip, int apicid,
                boot_error = wakeup_secondary_cpu_via_nmi(id, start_ip);
        }
 
+out:
+       preempt_enable();
+
        return boot_error;
 }