s390: add support for runtime instrumentation
authorJan Glauber <jang@linux.vnet.ibm.com>
Tue, 31 Jul 2012 08:52:05 +0000 (10:52 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Wed, 26 Sep 2012 13:45:02 +0000 (15:45 +0200)
Allow user-space threads to use runtime instrumentation (RI). To enable RI
for a thread there is a new s390 specific system call, sys_s390_runtime_instr,
that takes as parameter a realtime signal number. If the RI facility is
available the system call sets up a control block for the calling thread with
the appropriate permissions for the thread to modify the control block.

The user-space thread can then use the store and modify RI instructions to
alter the control block and start/stop the instrumentation via RION/RIOFF.

If the user specified program buffer runs full RI triggers an external
interrupt. The external interrupt is translated to a real-time signal that
is delivered to the thread that enabled RI on that CPU. The number of
the real-time signal is the number specified in the RI system call. So,
user-space can select any available real-time signal number in case the
application itself uses real-time signals for other purposes.

The kernel saves the RI control blocks on task switch only if the running
thread was enabled for RI. Therefore, the performance impact on task switch
should be negligible if RI is not used.

RI is only enabled for user-space mode and is disabled for the supervisor
state.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
14 files changed:
arch/s390/include/asm/cpu_mf.h
arch/s390/include/asm/irq.h
arch/s390/include/asm/processor.h
arch/s390/include/asm/ptrace.h
arch/s390/include/asm/runtime_instr.h [new file with mode: 0644]
arch/s390/include/asm/switch_to.h
arch/s390/include/asm/unistd.h
arch/s390/kernel/Makefile
arch/s390/kernel/compat_wrapper.S
arch/s390/kernel/dis.c
arch/s390/kernel/irq.c
arch/s390/kernel/process.c
arch/s390/kernel/runtime_instr.c [new file with mode: 0644]
arch/s390/kernel/syscalls.S

index a3afecdae14599bfe0e77a65a19f66eb7e26581b..35f0020b7ba77827fc08a503d8f58f5a6a17844e 100644 (file)
 #define CPU_MF_INT_SF_LSDA     (1 << 22)       /* loss of sample data alert */
 #define CPU_MF_INT_CF_CACA     (1 <<  7)       /* counter auth. change alert */
 #define CPU_MF_INT_CF_LCDA     (1 <<  6)       /* loss of counter data alert */
+#define CPU_MF_INT_RI_HALTED   (1 <<  5)       /* run-time instr. halted */
+#define CPU_MF_INT_RI_BUF_FULL (1 <<  4)       /* run-time instr. program
+                                                  buffer full */
 
 #define CPU_MF_INT_CF_MASK     (CPU_MF_INT_CF_CACA|CPU_MF_INT_CF_LCDA)
 #define CPU_MF_INT_SF_MASK     (CPU_MF_INT_SF_IAE|CPU_MF_INT_SF_ISE|   \
                                 CPU_MF_INT_SF_PRA|CPU_MF_INT_SF_SACA|  \
                                 CPU_MF_INT_SF_LSDA)
+#define CPU_MF_INT_RI_MASK     (CPU_MF_INT_RI_HALTED|CPU_MF_INT_RI_BUF_FULL)
 
 /* CPU measurement facility support */
 static inline int cpum_cf_avail(void)
index 33cc59071581bbc8fafe130cd99aaef34a6cc6d2..6703dd986fd4cad1963a79111d5c18dd9badd658 100644 (file)
@@ -19,6 +19,7 @@ enum interruption_class {
        EXTINT_IUC,
        EXTINT_CMS,
        EXTINT_CMC,
+       EXTINT_CMR,
        IOINT_CIO,
        IOINT_QAI,
        IOINT_DAS,
index d4477ba99a16893d109f1830f4e6fceadfe99403..0fff583d2c7c5bbf2f2409a1b29801c38f249d90 100644 (file)
@@ -17,6 +17,7 @@
 #include <asm/page.h>
 #include <asm/ptrace.h>
 #include <asm/setup.h>
+#include <asm/runtime_instr.h>
 
 /*
  * Default implementation of macro that returns current
@@ -78,6 +79,9 @@ struct thread_struct {
         /* pfault_wait is used to block the process on a pfault event */
        unsigned long pfault_wait;
        struct list_head list;
+       /* cpu runtime instrumentation */
+       struct runtime_instr_cb *ri_cb;
+       int ri_signum;
 };
 
 typedef struct thread_struct thread_struct;
index d5f08ea566ed9ac9d03085f8c6ea5cfe378befd5..5c32bae6b7606855a2eb08a66816afe44be79963 100644 (file)
@@ -235,6 +235,7 @@ typedef struct
 #define PSW_MASK_ASC           0x0000C000UL
 #define PSW_MASK_CC            0x00003000UL
 #define PSW_MASK_PM            0x00000F00UL
+#define PSW_MASK_RI            0x00000000UL
 #define PSW_MASK_EA            0x00000000UL
 #define PSW_MASK_BA            0x00000000UL
 
@@ -264,10 +265,11 @@ typedef struct
 #define PSW_MASK_ASC           0x0000C00000000000UL
 #define PSW_MASK_CC            0x0000300000000000UL
 #define PSW_MASK_PM            0x00000F0000000000UL
+#define PSW_MASK_RI            0x0000008000000000UL
 #define PSW_MASK_EA            0x0000000100000000UL
 #define PSW_MASK_BA            0x0000000080000000UL
 
-#define PSW_MASK_USER          0x00003F0180000000UL
+#define PSW_MASK_USER          0x00003F8180000000UL
 
 #define PSW_ADDR_AMODE         0x0000000000000000UL
 #define PSW_ADDR_INSN          0xFFFFFFFFFFFFFFFFUL
diff --git a/arch/s390/include/asm/runtime_instr.h b/arch/s390/include/asm/runtime_instr.h
new file mode 100644 (file)
index 0000000..830da73
--- /dev/null
@@ -0,0 +1,98 @@
+#ifndef _RUNTIME_INSTR_H
+#define _RUNTIME_INSTR_H
+
+#define S390_RUNTIME_INSTR_START       0x1
+#define S390_RUNTIME_INSTR_STOP                0x2
+
+struct runtime_instr_cb {
+       __u64 buf_current;
+       __u64 buf_origin;
+       __u64 buf_limit;
+
+       __u32 valid             : 1;
+       __u32 pstate            : 1;
+       __u32 pstate_set_buf    : 1;
+       __u32 home_space        : 1;
+       __u32 altered           : 1;
+       __u32                   : 3;
+       __u32 pstate_sample     : 1;
+       __u32 sstate_sample     : 1;
+       __u32 pstate_collect    : 1;
+       __u32 sstate_collect    : 1;
+       __u32                   : 1;
+       __u32 halted_int        : 1;
+       __u32 int_requested     : 1;
+       __u32 buffer_full_int   : 1;
+       __u32 key               : 4;
+       __u32                   : 9;
+       __u32 rgs               : 3;
+
+       __u32 mode              : 4;
+       __u32 next              : 1;
+       __u32 mae               : 1;
+       __u32                   : 2;
+       __u32 call_type_br      : 1;
+       __u32 return_type_br    : 1;
+       __u32 other_type_br     : 1;
+       __u32 bc_other_type     : 1;
+       __u32 emit              : 1;
+       __u32 tx_abort          : 1;
+       __u32                   : 2;
+       __u32 bp_xn             : 1;
+       __u32 bp_xt             : 1;
+       __u32 bp_ti             : 1;
+       __u32 bp_ni             : 1;
+       __u32 suppr_y           : 1;
+       __u32 suppr_z           : 1;
+
+       __u32 dc_miss_extra     : 1;
+       __u32 lat_lev_ignore    : 1;
+       __u32 ic_lat_lev        : 4;
+       __u32 dc_lat_lev        : 4;
+
+       __u64 reserved1;
+       __u64 scaling_factor;
+       __u64 rsic;
+       __u64 reserved2;
+} __packed __aligned(8);
+
+extern struct runtime_instr_cb runtime_instr_empty_cb;
+
+static inline void load_runtime_instr_cb(struct runtime_instr_cb *cb)
+{
+       asm volatile(".insn     rsy,0xeb0000000060,0,0,%0"      /* LRIC */
+               : : "Q" (*cb));
+}
+
+static inline void store_runtime_instr_cb(struct runtime_instr_cb *cb)
+{
+       asm volatile(".insn     rsy,0xeb0000000061,0,0,%0"      /* STRIC */
+               : "=Q" (*cb) : : "cc");
+}
+
+static inline void save_ri_cb(struct runtime_instr_cb *cb_prev)
+{
+#ifdef CONFIG_64BIT
+       if (cb_prev)
+               store_runtime_instr_cb(cb_prev);
+#endif
+}
+
+static inline void restore_ri_cb(struct runtime_instr_cb *cb_next,
+                                struct runtime_instr_cb *cb_prev)
+{
+#ifdef CONFIG_64BIT
+       if (cb_next)
+               load_runtime_instr_cb(cb_next);
+       else if (cb_prev)
+               load_runtime_instr_cb(&runtime_instr_empty_cb);
+#endif
+}
+
+#ifdef CONFIG_64BIT
+extern void exit_thread_runtime_instr(void);
+#else
+static inline void exit_thread_runtime_instr(void) { }
+#endif
+
+#endif /* _RUNTIME_INSTR_H */
index f223068b7822601ffff64b07ca4f6e412cff554f..dc4967b0e0560f072fe78ba433fcae8b7b0239b3 100644 (file)
@@ -80,10 +80,12 @@ static inline void restore_access_regs(unsigned int *acrs)
        if (prev->mm) {                                                 \
                save_fp_regs(&prev->thread.fp_regs);                    \
                save_access_regs(&prev->thread.acrs[0]);                \
+               save_ri_cb(prev->thread.ri_cb);                         \
        }                                                               \
        if (next->mm) {                                                 \
                restore_fp_regs(&next->thread.fp_regs);                 \
                restore_access_regs(&next->thread.acrs[0]);             \
+               restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);  \
                update_per_regs(next);                                  \
        }                                                               \
        prev = __switch_to(prev,next);                                  \
index 6756e78f48082f1644f7a0d73cdeecaa5d193da5..da2c2f4f7642dfcdfbf7cb9875e5b85b6dd2d7cb 100644 (file)
 #define __NR_setns             339
 #define __NR_process_vm_readv  340
 #define __NR_process_vm_writev 341
-#define NR_syscalls 342
+#define __NR_s390_runtime_instr 342
+#define NR_syscalls 343
 
 /* 
  * There are some system calls that are not present on 64 bit, some
index 9a111b621f4e07281c9ace4493cf6434556817fe..bba01bf678a6151e20a34db54a6fdb6d90d28600 100644 (file)
@@ -49,7 +49,7 @@ obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
 obj-$(CONFIG_FTRACE_SYSCALLS)  += ftrace.o
 obj-$(CONFIG_CRASH_DUMP)       += crash_dump.o
 obj-$(CONFIG_PERF_EVENTS)      += perf_event.o perf_cpum_cf.o
-obj-$(CONFIG_64BIT)            += cache.o
+obj-$(CONFIG_64BIT)            += runtime_instr.o cache.o
 
 # Kexec part
 S390_KEXEC_OBJS := machine_kexec.o
index 2d82cfcbce5b8cae9127aa115902fa6a2f3b5123..5f7928fe34ce9e73067a5ceeaa15842fdf1c3480 100644 (file)
@@ -1646,3 +1646,8 @@ ENTRY(compat_sys_process_vm_writev_wrapper)
        llgf    %r0,164(%r15)           # unsigned long
        stg     %r0,160(%r15)
        jg      compat_sys_process_vm_writev
+
+ENTRY(sys_s390_runtime_instr_wrapper)
+       lgfr    %r2,%r2                 # int
+       lgfr    %r3,%r3                 # int
+       jg      sys_s390_runtime_instr
index 84fd7e920bfe93cee63bc89fb99e72f0b1424f83..4bc67db6352297ad0dbeef7f43a834dfce3c3ef1 100644 (file)
@@ -315,6 +315,8 @@ enum {
        LONG_INSN_POPCNT,
        LONG_INSN_RISBHG,
        LONG_INSN_RISBLG,
+       LONG_INSN_RINEXT,
+       LONG_INSN_RIEMIT,
 };
 
 static char *long_insn_name[] = {
@@ -330,6 +332,8 @@ static char *long_insn_name[] = {
        [LONG_INSN_POPCNT] = "popcnt",
        [LONG_INSN_RISBHG] = "risbhg",
        [LONG_INSN_RISBLG] = "risblk",
+       [LONG_INSN_RINEXT] = "rinext",
+       [LONG_INSN_RIEMIT] = "riemit",
 };
 
 static struct insn opcode[] = {
@@ -582,6 +586,17 @@ static struct insn opcode_a7[] = {
        { "", 0, INSTR_INVALID }
 };
 
+static struct insn opcode_aa[] = {
+#ifdef CONFIG_64BIT
+       { { 0, LONG_INSN_RINEXT }, 0x00, INSTR_RI_RI },
+       { "rion", 0x01, INSTR_RI_RI },
+       { "tric", 0x02, INSTR_RI_RI },
+       { "rioff", 0x03, INSTR_RI_RI },
+       { { 0, LONG_INSN_RIEMIT }, 0x04, INSTR_RI_RI },
+#endif
+       { "", 0, INSTR_INVALID }
+};
+
 static struct insn opcode_b2[] = {
 #ifdef CONFIG_64BIT
        { "sske", 0x2b, INSTR_RRF_M0RR },
@@ -1210,6 +1225,9 @@ static struct insn opcode_eb[] = {
        { "cliy", 0x55, INSTR_SIY_URD },
        { "oiy", 0x56, INSTR_SIY_URD },
        { "xiy", 0x57, INSTR_SIY_URD },
+       { "lric", 0x60, INSTR_RSY_RDRM },
+       { "stric", 0x61, INSTR_RSY_RDRM },
+       { "mric", 0x62, INSTR_RSY_RDRM },
        { "icmh", 0x80, INSTR_RSE_RURD },
        { "icmh", 0x80, INSTR_RSY_RURD },
        { "icmy", 0x81, INSTR_RSY_RURD },
@@ -1408,6 +1426,9 @@ static struct insn *find_insn(unsigned char *code)
        case 0xa7:
                table = opcode_a7;
                break;
+       case 0xaa:
+               table = opcode_aa;
+               break;
        case 0xb2:
                table = opcode_b2;
                break;
index a22fdca6a663a69b6d6a98ac85d04a227efbe451..c1b44934fe64b7596248dd88dcd12448ca3390d8 100644 (file)
@@ -44,6 +44,7 @@ static const struct irq_class intrclass_names[] = {
        {.name = "IUC", .desc = "[EXT] IUCV" },
        {.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling" },
        {.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter" },
+       {.name = "CMR", .desc = "[EXT] CPU-Measurement: RI" },
        {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt" },
        {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" },
        {.name = "DAS", .desc = "[I/O] DASD" },
index 733175373a4c6e9a95c204f30f47214d81351f73..cb4328e49c752205812bdc8b07501cad2dfd14f8 100644 (file)
@@ -30,6 +30,7 @@
 #include <asm/nmi.h>
 #include <asm/smp.h>
 #include <asm/switch_to.h>
+#include <asm/runtime_instr.h>
 #include "entry.h"
 
 asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
@@ -132,6 +133,7 @@ EXPORT_SYMBOL(kernel_thread);
  */
 void exit_thread(void)
 {
+       exit_thread_runtime_instr();
 }
 
 void flush_thread(void)
@@ -170,6 +172,11 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
        /* Save access registers to new thread structure. */
        save_access_regs(&p->thread.acrs[0]);
 
+       /* Don't copy runtime instrumentation info */
+       p->thread.ri_cb = NULL;
+       p->thread.ri_signum = 0;
+       frame->childregs.psw.mask &= ~PSW_MASK_RI;
+
 #ifndef CONFIG_64BIT
        /*
         * save fprs to current->thread.fp_regs to merge them with
diff --git a/arch/s390/kernel/runtime_instr.c b/arch/s390/kernel/runtime_instr.c
new file mode 100644 (file)
index 0000000..e27e23d
--- /dev/null
@@ -0,0 +1,150 @@
+/*
+ * Copyright IBM Corp. 2012
+ * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/syscalls.h>
+#include <linux/signal.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/kernel_stat.h>
+#include <asm/runtime_instr.h>
+#include <asm/cpu_mf.h>
+#include <asm/irq.h>
+
+/* empty control block to disable RI by loading it */
+struct runtime_instr_cb runtime_instr_empty_cb;
+
+static int runtime_instr_avail(void)
+{
+       return test_facility(64);
+}
+
+static void disable_runtime_instr(void)
+{
+       struct pt_regs *regs = task_pt_regs(current);
+
+       load_runtime_instr_cb(&runtime_instr_empty_cb);
+
+       /*
+        * Make sure the RI bit is deleted from the PSW. If the user did not
+        * switch off RI before the system call the process will get a
+        * specification exception otherwise.
+        */
+       regs->psw.mask &= ~PSW_MASK_RI;
+}
+
+static void init_runtime_instr_cb(struct runtime_instr_cb *cb)
+{
+       cb->buf_limit = 0xfff;
+       if (addressing_mode == HOME_SPACE_MODE)
+               cb->home_space = 1;
+       cb->int_requested = 1;
+       cb->pstate = 1;
+       cb->pstate_set_buf = 1;
+       cb->pstate_sample = 1;
+       cb->pstate_collect = 1;
+       cb->key = PAGE_DEFAULT_KEY;
+       cb->valid = 1;
+}
+
+void exit_thread_runtime_instr(void)
+{
+       struct task_struct *task = current;
+
+       if (!task->thread.ri_cb)
+               return;
+       disable_runtime_instr();
+       kfree(task->thread.ri_cb);
+       task->thread.ri_signum = 0;
+       task->thread.ri_cb = NULL;
+}
+
+static void runtime_instr_int_handler(struct ext_code ext_code,
+                               unsigned int param32, unsigned long param64)
+{
+       struct siginfo info;
+
+       if (!(param32 & CPU_MF_INT_RI_MASK))
+               return;
+
+       kstat_cpu(smp_processor_id()).irqs[EXTINT_CMR]++;
+
+       if (!current->thread.ri_cb)
+               return;
+       if (current->thread.ri_signum < SIGRTMIN ||
+           current->thread.ri_signum > SIGRTMAX) {
+               WARN_ON_ONCE(1);
+               return;
+       }
+
+       memset(&info, 0, sizeof(info));
+       info.si_signo = current->thread.ri_signum;
+       info.si_code = SI_QUEUE;
+       if (param32 & CPU_MF_INT_RI_BUF_FULL)
+               info.si_int = ENOBUFS;
+       else if (param32 & CPU_MF_INT_RI_HALTED)
+               info.si_int = ECANCELED;
+       else
+               return; /* unknown reason */
+
+       send_sig_info(current->thread.ri_signum, &info, current);
+}
+
+SYSCALL_DEFINE2(s390_runtime_instr, int, command, int, signum)
+{
+       struct runtime_instr_cb *cb;
+
+       if (!runtime_instr_avail())
+               return -EOPNOTSUPP;
+
+       if (command == S390_RUNTIME_INSTR_STOP) {
+               preempt_disable();
+               exit_thread_runtime_instr();
+               preempt_enable();
+               return 0;
+       }
+
+       if (command != S390_RUNTIME_INSTR_START ||
+           (signum < SIGRTMIN || signum > SIGRTMAX))
+               return -EINVAL;
+
+       if (!current->thread.ri_cb) {
+               cb = kzalloc(sizeof(*cb), GFP_KERNEL);
+               if (!cb)
+                       return -ENOMEM;
+       } else {
+               cb = current->thread.ri_cb;
+               memset(cb, 0, sizeof(*cb));
+       }
+
+       init_runtime_instr_cb(cb);
+       current->thread.ri_signum = signum;
+
+       /* now load the control block to make it available */
+       preempt_disable();
+       current->thread.ri_cb = cb;
+       load_runtime_instr_cb(cb);
+       preempt_enable();
+       return 0;
+}
+
+static int __init runtime_instr_init(void)
+{
+       int rc;
+
+       if (!runtime_instr_avail())
+               return 0;
+
+       measurement_alert_subclass_register();
+       rc = register_external_interrupt(0x1407, runtime_instr_int_handler);
+       if (rc)
+               measurement_alert_subclass_unregister();
+       else
+               pr_info("Runtime instrumentation facility initialized\n");
+       return rc;
+}
+device_initcall(runtime_instr_init);
index bcab2f04ba581f7648426a1790485d53626d8fda..539f0a7701e479322ce632a5a658636e3e103763 100644 (file)
@@ -350,3 +350,4 @@ SYSCALL(sys_syncfs,sys_syncfs,sys_syncfs_wrapper)
 SYSCALL(sys_setns,sys_setns,sys_setns_wrapper)
 SYSCALL(sys_process_vm_readv,sys_process_vm_readv,compat_sys_process_vm_readv_wrapper) /* 340 */
 SYSCALL(sys_process_vm_writev,sys_process_vm_writev,compat_sys_process_vm_writev_wrapper)
+SYSCALL(sys_ni_syscall,sys_s390_runtime_instr,sys_s390_runtime_instr_wrapper)