Merge branch 'drm-kms-locking' of git://people.freedesktop.org/~danvet/drm-intel into drm-next

The aim of this locking rework is that ioctls which a compositor should be
might call for every frame (set_cursor, page_flip, addfb, rmfb and
getfb/create_handle) should not be able to block on kms background
activities like output detection. And since each EDID read takes about
25ms (in the best case), that always means we'll drop at least one frame.

The solution is to add per-crtc locking for these ioctls, and restrict
background activities to only use the global lock. Change-the-world type
of events (modeset, dpms, ...) need to grab all locks.

Two tricky parts arose in the conversion:
- A lot of current code assumes that a kms fb object can't disappear while
  holding the global lock, since the current code serializes fb
  destruction with it. Hence proper lifetime management using the already
  created refcounting for fbs need to be instantiated for all ioctls and
  interfaces/users.

- The rmfb ioctl removes the to-be-deleted fb from all active users. But
  unconditionally taking the global kms lock to do so introduces an
  unacceptable potential stall point. And obviously changing the userspace
  abi isn't on the table, either. Hence this conversion opportunistically
  checks whether the rmfb ioctl holds the very last reference, which
  guarantees that the fb isn't in active use on any crtc or plane (thanks
  to the conversion to the new lifetime rules using proper refcounting).
  Only if this is not the case will the code go through the slowpath and
  grab all modeset locks. Sane compositors will never hit this path and so
  avoid the stall, but userspace relying on these semantics will also not
  break.

All these cases are exercised by the newly added subtests for the i-g-t
kms_flip, tested on a machine where a full detect cycle takes around 100
ms.  It works, and no frames are dropped any more with these patches
applied.  kms_flip also contains a special case to exercise the
above-describe rmfb slowpath.

* 'drm-kms-locking' of git://people.freedesktop.org/~danvet/drm-intel: (335 commits)
  drm/fb_helper: check whether fbcon is bound
  drm/doc: updates for new framebuffer lifetime rules
  drm: don't hold crtc mutexes for connector ->detect callbacks
  drm: only grab the crtc lock for pageflips
  drm: optimize drm_framebuffer_remove
  drm/vmwgfx: add proper framebuffer refcounting
  drm/i915: dump refcount into framebuffer debugfs file
  drm: refcounting for crtc framebuffers
  drm: refcounting for sprite framebuffers
  drm: fb refcounting for dirtyfb_ioctl
  drm: don't take modeset locks in getfb ioctl
  drm: push modeset_lock_all into ->fb_create driver callbacks
  drm: nest modeset locks within fpriv->fbs_lock
  drm: reference framebuffers which are on the idr
  drm: revamp framebuffer cleanup interfaces
  drm: create drm_framebuffer_lookup
  drm: revamp locking around fb creation/destruction
  drm: only take the crtc lock for ->cursor_move
  drm: only take the crtc lock for ->cursor_set
  drm: add per-crtc locks
  ...

11 files changed, 106 insertions, 65 deletions

diff --git a/arch/s390/kernel/compat_wrapper.S b/arch/s390/kernel/compat_wrapper.S
index 827e094a2f49..9b9a805656b5 100644
--- a/arch/s390/kernel/compat_wrapper.S
+++ b/arch/s390/kernel/compat_wrapper.S
@@ -1659,3 +1659,9 @@ ENTRY(sys_kcmp_wrapper)
 	llgfr	%r5,%r5			# unsigned long
 	llgfr	%r6,%r6			# unsigned long
 	jg	sys_kcmp
+
+ENTRY(sys_finit_module_wrapper)
+	lgfr	%r2,%r2			# int
+	llgtr	%r3,%r3			# const char __user *
+	lgfr	%r4,%r4			# int
+	jg	sys_finit_module
diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index ba500d8dc392..4e8215e0d4b6 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -1127,13 +1127,14 @@ debug_register_view(debug_info_t * id, struct debug_view *view)
 	if (i == DEBUG_MAX_VIEWS) {
 		pr_err("Registering view %s/%s would exceed the maximum "
 		       "number of views %i\n", id->name, view->name, i);
-		debugfs_remove(pde);
 		rc = -1;
 	} else {
 		id->views[i] = view;
 		id->debugfs_entries[i] = pde;
 	}
 	spin_unlock_irqrestore(&id->lock, flags);
+	if (rc)
+		debugfs_remove(pde);
 out:
 	return rc;
 }
@@ -1146,9 +1147,9 @@ EXPORT_SYMBOL(debug_register_view);
 int
 debug_unregister_view(debug_info_t * id, struct debug_view *view)
 {
-	int rc = 0;
-	int i;
+	struct dentry *dentry = NULL;
 	unsigned long flags;
+	int i, rc = 0;
 
 	if (!id)
 		goto out;
@@ -1160,10 +1161,12 @@ debug_unregister_view(debug_info_t * id, struct debug_view *view)
 	if (i == DEBUG_MAX_VIEWS)
 		rc = -1;
 	else {
-		debugfs_remove(id->debugfs_entries[i]);
+		dentry = id->debugfs_entries[i];
 		id->views[i] = NULL;
+		id->debugfs_entries[i] = NULL;
 	}
 	spin_unlock_irqrestore(&id->lock, flags);
+	debugfs_remove(dentry);
 out:
 	return rc;
 }
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index bf24293970ce..9df824ea1667 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -24,43 +24,65 @@
 #include <asm/irq.h>
 #include "entry.h"
 
+DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
+EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
+
 struct irq_class {
 	char *name;
 	char *desc;
 };
 
-static const struct irq_class intrclass_names[] = {
+/*
+ * The list of "main" irq classes on s390. This is the list of interrrupts
+ * that appear both in /proc/stat ("intr" line) and /proc/interrupts.
+ * Historically only external and I/O interrupts have been part of /proc/stat.
+ * We can't add the split external and I/O sub classes since the first field
+ * in the "intr" line in /proc/stat is supposed to be the sum of all other
+ * fields.
+ * Since the external and I/O interrupt fields are already sums we would end
+ * up with having a sum which accounts each interrupt twice.
+ */
+static const struct irq_class irqclass_main_desc[NR_IRQS] = {
 	[EXTERNAL_INTERRUPT] = {.name = "EXT"},
-	[IO_INTERRUPT]	     = {.name = "I/O"},
-	[EXTINT_CLK] = {.name = "CLK", .desc = "[EXT] Clock Comparator"},
-	[EXTINT_EXC] = {.name = "EXC", .desc = "[EXT] External Call"},
-	[EXTINT_EMS] = {.name = "EMS", .desc = "[EXT] Emergency Signal"},
-	[EXTINT_TMR] = {.name = "TMR", .desc = "[EXT] CPU Timer"},
-	[EXTINT_TLA] = {.name = "TAL", .desc = "[EXT] Timing Alert"},
-	[EXTINT_PFL] = {.name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
-	[EXTINT_DSD] = {.name = "DSD", .desc = "[EXT] DASD Diag"},
-	[EXTINT_VRT] = {.name = "VRT", .desc = "[EXT] Virtio"},
-	[EXTINT_SCP] = {.name = "SCP", .desc = "[EXT] Service Call"},
-	[EXTINT_IUC] = {.name = "IUC", .desc = "[EXT] IUCV"},
-	[EXTINT_CMS] = {.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
-	[EXTINT_CMC] = {.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
-	[EXTINT_CMR] = {.name = "CMR", .desc = "[EXT] CPU-Measurement: RI"},
-	[IOINT_CIO]  = {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
-	[IOINT_QAI]  = {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"},
-	[IOINT_DAS]  = {.name = "DAS", .desc = "[I/O] DASD"},
-	[IOINT_C15]  = {.name = "C15", .desc = "[I/O] 3215"},
-	[IOINT_C70]  = {.name = "C70", .desc = "[I/O] 3270"},
-	[IOINT_TAP]  = {.name = "TAP", .desc = "[I/O] Tape"},
-	[IOINT_VMR]  = {.name = "VMR", .desc = "[I/O] Unit Record Devices"},
-	[IOINT_LCS]  = {.name = "LCS", .desc = "[I/O] LCS"},
-	[IOINT_CLW]  = {.name = "CLW", .desc = "[I/O] CLAW"},
-	[IOINT_CTC]  = {.name = "CTC", .desc = "[I/O] CTC"},
-	[IOINT_APB]  = {.name = "APB", .desc = "[I/O] AP Bus"},
-	[IOINT_ADM]  = {.name = "ADM", .desc = "[I/O] EADM Subchannel"},
-	[IOINT_CSC]  = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"},
-	[IOINT_PCI]  = {.name = "PCI", .desc = "[I/O] PCI Interrupt" },
-	[IOINT_MSI] =  {.name = "MSI", .desc = "[I/O] MSI Interrupt" },
+	[IO_INTERRUPT]	     = {.name = "I/O"}
+};
+
+/*
+ * The list of split external and I/O interrupts that appear only in
+ * /proc/interrupts.
+ * In addition this list contains non external / I/O events like NMIs.
+ */
+static const struct irq_class irqclass_sub_desc[NR_ARCH_IRQS] = {
+	[IRQEXT_CLK] = {.name = "CLK", .desc = "[EXT] Clock Comparator"},
+	[IRQEXT_EXC] = {.name = "EXC", .desc = "[EXT] External Call"},
+	[IRQEXT_EMS] = {.name = "EMS", .desc = "[EXT] Emergency Signal"},
+	[IRQEXT_TMR] = {.name = "TMR", .desc = "[EXT] CPU Timer"},
+	[IRQEXT_TLA] = {.name = "TAL", .desc = "[EXT] Timing Alert"},
+	[IRQEXT_PFL] = {.name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
+	[IRQEXT_DSD] = {.name = "DSD", .desc = "[EXT] DASD Diag"},
+	[IRQEXT_VRT] = {.name = "VRT", .desc = "[EXT] Virtio"},
+	[IRQEXT_SCP] = {.name = "SCP", .desc = "[EXT] Service Call"},
+	[IRQEXT_IUC] = {.name = "IUC", .desc = "[EXT] IUCV"},
+	[IRQEXT_CMS] = {.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
+	[IRQEXT_CMC] = {.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
+	[IRQEXT_CMR] = {.name = "CMR", .desc = "[EXT] CPU-Measurement: RI"},
+	[IRQIO_CIO]  = {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
+	[IRQIO_QAI]  = {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"},
+	[IRQIO_DAS]  = {.name = "DAS", .desc = "[I/O] DASD"},
+	[IRQIO_C15]  = {.name = "C15", .desc = "[I/O] 3215"},
+	[IRQIO_C70]  = {.name = "C70", .desc = "[I/O] 3270"},
+	[IRQIO_TAP]  = {.name = "TAP", .desc = "[I/O] Tape"},
+	[IRQIO_VMR]  = {.name = "VMR", .desc = "[I/O] Unit Record Devices"},
+	[IRQIO_LCS]  = {.name = "LCS", .desc = "[I/O] LCS"},
+	[IRQIO_CLW]  = {.name = "CLW", .desc = "[I/O] CLAW"},
+	[IRQIO_CTC]  = {.name = "CTC", .desc = "[I/O] CTC"},
+	[IRQIO_APB]  = {.name = "APB", .desc = "[I/O] AP Bus"},
+	[IRQIO_ADM]  = {.name = "ADM", .desc = "[I/O] EADM Subchannel"},
+	[IRQIO_CSC]  = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"},
+	[IRQIO_PCI]  = {.name = "PCI", .desc = "[I/O] PCI Interrupt" },
+	[IRQIO_MSI]  = {.name = "MSI", .desc = "[I/O] MSI Interrupt" },
 	[NMI_NMI]    = {.name = "NMI", .desc = "[NMI] Machine Check"},
+	[CPU_RST]    = {.name = "RST", .desc = "[CPU] CPU Restart"},
 };
 
 /*
@@ -68,30 +90,34 @@ static const struct irq_class intrclass_names[] = {
  */
 int show_interrupts(struct seq_file *p, void *v)
 {
-	int i = *(loff_t *) v, j;
+	int irq = *(loff_t *) v;
+	int cpu;
 
 	get_online_cpus();
-	if (i == 0) {
+	if (irq == 0) {
 		seq_puts(p, "           ");
-		for_each_online_cpu(j)
-			seq_printf(p, "CPU%d       ",j);
+		for_each_online_cpu(cpu)
+			seq_printf(p, "CPU%d       ", cpu);
 		seq_putc(p, '\n');
 	}
-
-	if (i < NR_IRQS) {
-		seq_printf(p, "%s: ", intrclass_names[i].name);
-#ifndef CONFIG_SMP
-		seq_printf(p, "%10u ", kstat_irqs(i));
-#else
-		for_each_online_cpu(j)
-			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
-#endif
-		if (intrclass_names[i].desc)
-			seq_printf(p, "  %s", intrclass_names[i].desc);
-                seq_putc(p, '\n');
-        }
+	if (irq < NR_IRQS) {
+		seq_printf(p, "%s: ", irqclass_main_desc[irq].name);
+		for_each_online_cpu(cpu)
+			seq_printf(p, "%10u ", kstat_cpu(cpu).irqs[irq]);
+		seq_putc(p, '\n');
+		goto skip_arch_irqs;
+	}
+	for (irq = 0; irq < NR_ARCH_IRQS; irq++) {
+		seq_printf(p, "%s: ", irqclass_sub_desc[irq].name);
+		for_each_online_cpu(cpu)
+			seq_printf(p, "%10u ", per_cpu(irq_stat, cpu).irqs[irq]);
+		if (irqclass_sub_desc[irq].desc)
+			seq_printf(p, "  %s", irqclass_sub_desc[irq].desc);
+		seq_putc(p, '\n');
+	}
+skip_arch_irqs:
 	put_online_cpus();
-        return 0;
+	return 0;
 }
 
 /*
@@ -222,7 +248,7 @@ void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
 		/* Serve timer interrupts first. */
 		clock_comparator_work();
 	}
-	kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
+	kstat_incr_irqs_this_cpu(EXTERNAL_INTERRUPT, NULL);
 	if (ext_code.code != 0x1004)
 		__get_cpu_var(s390_idle).nohz_delay = 1;
 
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index a6daa5c5cdb0..7918fbea36bb 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -254,7 +254,7 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
 	int umode;
 
 	nmi_enter();
-	kstat_cpu(smp_processor_id()).irqs[NMI_NMI]++;
+	inc_irq_stat(NMI_NMI);
 	mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
 	mcck = &__get_cpu_var(cpu_mcck);
 	umode = user_mode(regs);
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c
index c4e7269d4a09..86ec7447e1f5 100644
--- a/arch/s390/kernel/perf_cpum_cf.c
+++ b/arch/s390/kernel/perf_cpum_cf.c
@@ -229,7 +229,7 @@ static void cpumf_measurement_alert(struct ext_code ext_code,
 	if (!(alert & CPU_MF_INT_CF_MASK))
 		return;
 
-	kstat_cpu(smp_processor_id()).irqs[EXTINT_CMC]++;
+	inc_irq_stat(IRQEXT_CMC);
 	cpuhw = &__get_cpu_var(cpu_hw_events);
 
 	/* Measurement alerts are shared and might happen when the PMU
diff --git a/arch/s390/kernel/runtime_instr.c b/arch/s390/kernel/runtime_instr.c
index 61066f6f71a5..077a99389b07 100644
--- a/arch/s390/kernel/runtime_instr.c
+++ b/arch/s390/kernel/runtime_instr.c
@@ -71,7 +71,7 @@ static void runtime_instr_int_handler(struct ext_code ext_code,
 	if (!(param32 & CPU_MF_INT_RI_MASK))
 		return;
 
-	kstat_cpu(smp_processor_id()).irqs[EXTINT_CMR]++;
+	inc_irq_stat(IRQEXT_CMR);
 
 	if (!current->thread.ri_cb)
 		return;
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 2568590973ad..a5360de85ec7 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -16,7 +16,7 @@
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/errno.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/memblock.h>
@@ -289,6 +289,7 @@ void machine_power_off(void)
  * Dummy power off function.
  */
 void (*pm_power_off)(void) = machine_power_off;
+EXPORT_SYMBOL_GPL(pm_power_off);
 
 static int __init early_parse_mem(char *p)
 {
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 0b45baa55438..7433a2f9e5cc 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -433,9 +433,9 @@ static void do_ext_call_interrupt(struct ext_code ext_code,
 
 	cpu = smp_processor_id();
 	if (ext_code.code == 0x1202)
-		kstat_cpu(cpu).irqs[EXTINT_EXC]++;
+		inc_irq_stat(IRQEXT_EXC);
 	else
-		kstat_cpu(cpu).irqs[EXTINT_EMS]++;
+		inc_irq_stat(IRQEXT_EMS);
 	/*
 	 * handle bit signal external calls
 	 */
@@ -623,9 +623,10 @@ static struct sclp_cpu_info *smp_get_cpu_info(void)
 	return info;
 }
 
-static int smp_add_present_cpu(int cpu);
+static int __cpuinit smp_add_present_cpu(int cpu);
 
-static int __smp_rescan_cpus(struct sclp_cpu_info *info, int sysfs_add)
+static int __cpuinit __smp_rescan_cpus(struct sclp_cpu_info *info,
+				       int sysfs_add)
 {
 	struct pcpu *pcpu;
 	cpumask_t avail;
@@ -708,6 +709,7 @@ static void __cpuinit smp_start_secondary(void *cpuvoid)
 	pfault_init();
 	notify_cpu_starting(smp_processor_id());
 	set_cpu_online(smp_processor_id(), true);
+	inc_irq_stat(CPU_RST);
 	local_irq_enable();
 	/* cpu_idle will call schedule for us */
 	cpu_idle();
@@ -985,7 +987,7 @@ static int __cpuinit smp_cpu_notify(struct notifier_block *self,
 	return notifier_from_errno(err);
 }
 
-static int smp_add_present_cpu(int cpu)
+static int __cpuinit smp_add_present_cpu(int cpu)
 {
 	struct cpu *c = &pcpu_devices[cpu].cpu;
 	struct device *s = &c->dev;
diff --git a/arch/s390/kernel/syscalls.S b/arch/s390/kernel/syscalls.S
index 48174850f3b0..6a6c61f94dd3 100644
--- a/arch/s390/kernel/syscalls.S
+++ b/arch/s390/kernel/syscalls.S
@@ -352,3 +352,4 @@ SYSCALL(sys_process_vm_readv,sys_process_vm_readv,compat_sys_process_vm_readv_wr
 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)
 SYSCALL(sys_kcmp,sys_kcmp,sys_kcmp_wrapper)
+SYSCALL(sys_finit_module,sys_finit_module,sys_finit_module_wrapper)
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 7fcd690d42c7..a5f4f5a1d24b 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -63,7 +63,7 @@ static DEFINE_PER_CPU(struct clock_event_device, comparators);
  */
 unsigned long long notrace __kprobes sched_clock(void)
 {
-	return (get_clock_monotonic() * 125) >> 9;
+	return tod_to_ns(get_clock_monotonic());
 }
 
 /*
@@ -168,7 +168,7 @@ static void clock_comparator_interrupt(struct ext_code ext_code,
 				       unsigned int param32,
 				       unsigned long param64)
 {
-	kstat_cpu(smp_processor_id()).irqs[EXTINT_CLK]++;
+	inc_irq_stat(IRQEXT_CLK);
 	if (S390_lowcore.clock_comparator == -1ULL)
 		set_clock_comparator(S390_lowcore.clock_comparator);
 }
@@ -179,7 +179,7 @@ static void stp_timing_alert(struct stp_irq_parm *);
 static void timing_alert_interrupt(struct ext_code ext_code,
 				   unsigned int param32, unsigned long param64)
 {
-	kstat_cpu(smp_processor_id()).irqs[EXTINT_TLA]++;
+	inc_irq_stat(IRQEXT_TLA);
 	if (param32 & 0x00c40000)
 		etr_timing_alert((struct etr_irq_parm *) &param32);
 	if (param32 & 0x00038000)
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index f1aba87cceb8..4b2e3e317004 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -10,6 +10,7 @@
 #include <linux/bootmem.h>
 #include <linux/cpuset.h>
 #include <linux/device.h>
+#include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/init.h>
@@ -42,6 +43,7 @@ static struct mask_info socket_info;
 static struct mask_info book_info;
 
 struct cpu_topology_s390 cpu_topology[NR_CPUS];
+EXPORT_SYMBOL_GPL(cpu_topology);
 
 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
 {