1 files changed, 436 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/sync_gk20a.c b/drivers/gpu/nvgpu/gk20a/sync_gk20a.c
new file mode 100644
index 00000000..277b3334
--- /dev/null
+++ b/drivers/gpu/nvgpu/gk20a/sync_gk20a.c
@@ -0,0 +1,436 @@
+/*
+ * GK20A Sync Framework Integration
+ *
+ * Copyright (c) 2014-2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/hrtimer.h>
+#include <linux/module.h>
+#include <nvgpu/lock.h>
+#include <uapi/linux/nvgpu.h>
+
+#include <nvgpu/kmem.h>
+#include <nvgpu/semaphore.h>
+#include <nvgpu/bug.h>
+#include <nvgpu/kref.h>
+
+#include "../drivers/staging/android/sync.h"
+
+#include "sync_gk20a.h"
+
+static const struct sync_timeline_ops gk20a_sync_timeline_ops;
+
+struct gk20a_sync_timeline {
+        struct sync_timeline            obj;
+        u32                             max;
+        u32                             min;
+};
+
+/**
+ * The sync framework dups pts when merging fences. We share a single
+ * refcounted gk20a_sync_pt for each duped pt.
+ */
+struct gk20a_sync_pt {
+        struct gk20a                    *g;
+        struct nvgpu_ref                        refcount;
+        u32                             thresh;
+        struct nvgpu_semaphore          *sema;
+        struct gk20a_sync_timeline      *obj;
+
+        /*
+         * Use a spin lock here since it will have better performance
+         * than a mutex - there should be very little contention on this
+         * lock.
+         */
+        struct nvgpu_spinlock                   lock;
+};
+
+struct gk20a_sync_pt_inst {
+        struct sync_pt                  pt;
+        struct gk20a_sync_pt            *shared;
+};
+
+/**
+ * Check if the passed sync_fence is backed by a single GPU semaphore. In such
+ * cases we can short circuit a lot of SW involved in signaling pre-fences and
+ * post fences.
+ *
+ * For now reject multi-sync_pt fences. This could be changed in future. It
+ * would require that the sema fast path push a sema acquire for each semaphore
+ * in the fence.
+ */
+int gk20a_is_sema_backed_sync_fence(struct sync_fence *fence)
+{
+        struct sync_timeline *t;
+
+        struct fence *pt = fence->cbs[0].sync_pt;
+        struct sync_pt *spt = sync_pt_from_fence(pt);
+
+        if (fence->num_fences != 1)
+                return 0;
+
+        if (spt == NULL)
+                return 0;
+
+        t = sync_pt_parent(spt);
+
+        if (t->ops == &gk20a_sync_timeline_ops)
+                return 1;
+        return 0;
+}
+
+struct nvgpu_semaphore *gk20a_sync_fence_get_sema(struct sync_fence *f)
+{
+        struct sync_pt *spt;
+        struct gk20a_sync_pt_inst *pti;
+
+        struct fence *pt;
+
+        if (!f)
+                return NULL;
+
+        if (!gk20a_is_sema_backed_sync_fence(f))
+                return NULL;
+
+        pt = f->cbs[0].sync_pt;
+        spt = sync_pt_from_fence(pt);
+        pti = container_of(spt, struct gk20a_sync_pt_inst, pt);
+
+        return pti->shared->sema;
+}
+
+/**
+ * Compares sync pt values a and b, both of which will trigger either before
+ * or after ref (i.e. a and b trigger before ref, or a and b trigger after
+ * ref). Supplying ref allows us to handle wrapping correctly.
+ *
+ * Returns -1 if a < b (a triggers before b)
+ *          0 if a = b (a and b trigger at the same time)
+ *          1 if a > b (b triggers before a)
+ */
+static int __gk20a_sync_pt_compare_ref(
+        u32 ref,
+        u32 a,
+        u32 b)
+{
+        /*
+         * We normalize both a and b by subtracting ref from them.
+         * Denote the normalized values by a_n and b_n. Note that because
+         * of wrapping, a_n and/or b_n may be negative.
+         *
+         * The normalized values a_n and b_n satisfy:
+         * - a positive value triggers before a negative value
+         * - a smaller positive value triggers before a greater positive value
+         * - a smaller negative value (greater in absolute value) triggers
+         *   before a greater negative value (smaller in absolute value).
+         *
+         * Thus we can just stick to unsigned arithmetic and compare
+         * (u32)a_n to (u32)b_n.
+         *
+         * Just to reiterate the possible cases:
+         *
+         *      1A) ...ref..a....b....
+         *      1B) ...ref..b....a....
+         *      2A) ...b....ref..a....              b_n < 0
+         *      2B) ...a....ref..b....     a_n > 0
+         *      3A) ...a....b....ref..     a_n < 0, b_n < 0
+         *      3A) ...b....a....ref..     a_n < 0, b_n < 0
+         */
+        u32 a_n = a - ref;
+        u32 b_n = b - ref;
+        if (a_n < b_n)
+                return -1;
+        else if (a_n > b_n)
+                return 1;
+        else
+                return 0;
+}
+
+static struct gk20a_sync_pt *to_gk20a_sync_pt(struct sync_pt *pt)
+{
+        struct gk20a_sync_pt_inst *pti =
+                        container_of(pt, struct gk20a_sync_pt_inst, pt);
+        return pti->shared;
+}
+static struct gk20a_sync_timeline *to_gk20a_timeline(struct sync_timeline *obj)
+{
+        if (WARN_ON(obj->ops != &gk20a_sync_timeline_ops))
+                return NULL;
+        return (struct gk20a_sync_timeline *)obj;
+}
+
+static void gk20a_sync_pt_free_shared(struct nvgpu_ref *ref)
+{
+        struct gk20a_sync_pt *pt =
+                container_of(ref, struct gk20a_sync_pt, refcount);
+        struct gk20a *g = pt->g;
+
+        if (pt->sema)
+                nvgpu_semaphore_put(pt->sema);
+        nvgpu_kfree(g, pt);
+}
+
+static struct gk20a_sync_pt *gk20a_sync_pt_create_shared(
+                struct gk20a *g,
+                struct gk20a_sync_timeline *obj,
+                struct nvgpu_semaphore *sema)
+{
+        struct gk20a_sync_pt *shared;
+
+        shared = nvgpu_kzalloc(g, sizeof(*shared));
+        if (!shared)
+                return NULL;
+
+        nvgpu_ref_init(&shared->refcount);
+        shared->g = g;
+        shared->obj = obj;
+        shared->sema = sema;
+        shared->thresh = ++obj->max; /* sync framework has a lock */
+
+        nvgpu_spinlock_init(&shared->lock);
+
+        nvgpu_semaphore_get(sema);
+
+        return shared;
+}
+
+static struct sync_pt *gk20a_sync_pt_create_inst(
+                struct gk20a *g,
+                struct gk20a_sync_timeline *obj,
+                struct nvgpu_semaphore *sema)
+{
+        struct gk20a_sync_pt_inst *pti;
+
+        pti = (struct gk20a_sync_pt_inst *)
+                sync_pt_create(&obj->obj, sizeof(*pti));
+        if (!pti)
+                return NULL;
+
+        pti->shared = gk20a_sync_pt_create_shared(g, obj, sema);
+        if (!pti->shared) {
+                sync_pt_free(&pti->pt);
+                return NULL;
+        }
+        return &pti->pt;
+}
+
+static void gk20a_sync_pt_free_inst(struct sync_pt *sync_pt)
+{
+        struct gk20a_sync_pt *pt = to_gk20a_sync_pt(sync_pt);
+        if (pt)
+                nvgpu_ref_put(&pt->refcount, gk20a_sync_pt_free_shared);
+}
+
+static struct sync_pt *gk20a_sync_pt_dup_inst(struct sync_pt *sync_pt)
+{
+        struct gk20a_sync_pt_inst *pti;
+        struct gk20a_sync_pt *pt = to_gk20a_sync_pt(sync_pt);
+
+        pti = (struct gk20a_sync_pt_inst *)
+                sync_pt_create(&pt->obj->obj, sizeof(*pti));
+        if (!pti)
+                return NULL;
+        pti->shared = pt;
+        nvgpu_ref_get(&pt->refcount);
+        return &pti->pt;
+}
+
+/*
+ * This function must be able to run on the same sync_pt concurrently. This
+ * requires a lock to protect access to the sync_pt's internal data structures
+ * which are modified as a side effect of calling this function.
+ */
+static int gk20a_sync_pt_has_signaled(struct sync_pt *sync_pt)
+{
+        struct gk20a_sync_pt *pt = to_gk20a_sync_pt(sync_pt);
+        struct gk20a_sync_timeline *obj = pt->obj;
+        bool signaled = true;
+
+        nvgpu_spinlock_acquire(&pt->lock);
+        if (!pt->sema)
+                goto done;
+
+        /* Acquired == not realeased yet == active == not signaled. */
+        signaled = !nvgpu_semaphore_is_acquired(pt->sema);
+
+        if (signaled) {
+                /* Update min if necessary. */
+                if (__gk20a_sync_pt_compare_ref(obj->max, pt->thresh,
+                                                obj->min) == 1)
+                        obj->min = pt->thresh;
+
+                /* Release the semaphore to the pool. */
+                nvgpu_semaphore_put(pt->sema);
+                pt->sema = NULL;
+        }
+done:
+        nvgpu_spinlock_release(&pt->lock);
+
+        return signaled;
+}
+
+static int gk20a_sync_pt_compare(struct sync_pt *a, struct sync_pt *b)
+{
+        bool a_expired;
+        bool b_expired;
+        struct gk20a_sync_pt *pt_a = to_gk20a_sync_pt(a);
+        struct gk20a_sync_pt *pt_b = to_gk20a_sync_pt(b);
+
+        if (WARN_ON(pt_a->obj != pt_b->obj))
+                return 0;
+
+        /* Early out */
+        if (a == b)
+                return 0;
+
+        a_expired = gk20a_sync_pt_has_signaled(a);
+        b_expired = gk20a_sync_pt_has_signaled(b);
+        if (a_expired && !b_expired) {
+                /* Easy, a was earlier */
+                return -1;
+        } else if (!a_expired && b_expired) {
+                /* Easy, b was earlier */
+                return 1;
+        }
+
+        /* Both a and b are expired (trigger before min) or not
+         * expired (trigger after min), so we can use min
+         * as a reference value for __gk20a_sync_pt_compare_ref.
+         */
+        return __gk20a_sync_pt_compare_ref(pt_a->obj->min,
+                        pt_a->thresh, pt_b->thresh);
+}
+
+static u32 gk20a_sync_timeline_current(struct gk20a_sync_timeline *obj)
+{
+        return obj->min;
+}
+
+static void gk20a_sync_timeline_value_str(struct sync_timeline *timeline,
+                char *str, int size)
+{
+        struct gk20a_sync_timeline *obj =
+                (struct gk20a_sync_timeline *)timeline;
+        snprintf(str, size, "%d", gk20a_sync_timeline_current(obj));
+}
+
+static void gk20a_sync_pt_value_str_for_sema(struct gk20a_sync_pt *pt,
+                                             char *str, int size)
+{
+        struct nvgpu_semaphore *s = pt->sema;
+
+        snprintf(str, size, "S: c=%d [v=%u,r_v=%u]",
+                 s->hw_sema->ch->chid,
+                 nvgpu_semaphore_get_value(s),
+                 nvgpu_semaphore_read(s));
+}
+
+static void gk20a_sync_pt_value_str(struct sync_pt *sync_pt, char *str,
+                int size)
+{
+        struct gk20a_sync_pt *pt = to_gk20a_sync_pt(sync_pt);
+
+        if (pt->sema) {
+                gk20a_sync_pt_value_str_for_sema(pt, str, size);
+                return;
+        }
+
+        snprintf(str, size, "%d", pt->thresh);
+}
+
+static const struct sync_timeline_ops gk20a_sync_timeline_ops = {
+        .driver_name = "nvgpu_semaphore",
+        .dup = gk20a_sync_pt_dup_inst,
+        .has_signaled = gk20a_sync_pt_has_signaled,
+        .compare = gk20a_sync_pt_compare,
+        .free_pt = gk20a_sync_pt_free_inst,
+        .timeline_value_str = gk20a_sync_timeline_value_str,
+        .pt_value_str = gk20a_sync_pt_value_str,
+};
+
+/* Public API */
+
+struct sync_fence *gk20a_sync_fence_fdget(int fd)
+{
+        return sync_fence_fdget(fd);
+}
+
+void gk20a_sync_timeline_signal(struct sync_timeline *timeline)
+{
+        sync_timeline_signal(timeline, 0);
+}
+
+void gk20a_sync_timeline_destroy(struct sync_timeline *timeline)
+{
+        sync_timeline_destroy(timeline);
+}
+
+struct sync_timeline *gk20a_sync_timeline_create(
+                const char *fmt, ...)
+{
+        struct gk20a_sync_timeline *obj;
+        char name[30];
+        va_list args;
+
+        va_start(args, fmt);
+        vsnprintf(name, sizeof(name), fmt, args);
+        va_end(args);
+
+        obj = (struct gk20a_sync_timeline *)
+                sync_timeline_create(&gk20a_sync_timeline_ops,
+                                     sizeof(struct gk20a_sync_timeline),
+                                     name);
+        if (!obj)
+                return NULL;
+        obj->max = 0;
+        obj->min = 0;
+        return &obj->obj;
+}
+
+struct sync_fence *gk20a_sync_fence_create(
+                struct gk20a *g,
+                struct sync_timeline *obj,
+                struct nvgpu_semaphore *sema,
+                const char *fmt, ...)
+{
+        char name[30];
+        va_list args;
+        struct sync_pt *pt;
+        struct sync_fence *fence;
+        struct gk20a_sync_timeline *timeline = to_gk20a_timeline(obj);
+
+        pt = gk20a_sync_pt_create_inst(g, timeline, sema);
+        if (pt == NULL)
+                return NULL;
+
+        va_start(args, fmt);
+        vsnprintf(name, sizeof(name), fmt, args);
+        va_end(args);
+
+        fence = sync_fence_create(name, pt);
+        if (fence == NULL) {
+                sync_pt_free(pt);
+                return NULL;
+        }
+        return fence;
+}