nfs: disintegrate UAPI for nfs

This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently.  After these patches, userspace
headers will be segregated into:

        include/uapi/linux/.../foo.h

for the userspace interface stuff, and:

        include/linux/.../foo.h

for the strictly kernel internal stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 150 insertions, 0 deletions

diff --git a/arch/s390/kernel/runtime_instr.c b/arch/s390/kernel/runtime_instr.c
new file mode 100644
index 00000000000..61066f6f71a
--- /dev/null
+++ b/arch/s390/kernel/runtime_instr.c
@@ -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 (s390_user_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);