[RFC PATCH v2] drm/i915: Expose PMU for Observation Architecture
From: Robert Bragg
Date: Mon May 18 2015 - 13:17:31 EST
Gen graphics hardware can be set up to periodically write snapshots of
performance counters into a circular buffer and this patch exposes that
capability to userspace via the perf interface.
To start with this only enables the A (aggregating) counters with the
simplest configuration requirements.
Only Haswell is supported currently.
v2:
- fix deadlock in init_oa_buffer error path
- EBADF for bad drm fd, EINVAL for failure to lookup ctx
- mmio write barriers, after OA reconfigure, before unlocks
- use i915_mutex_lock_interruptible within event init
Signed-off-by: Robert Bragg <robert@xxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/Makefile | 1 +
drivers/gpu/drm/i915/i915_dma.c | 6 +
drivers/gpu/drm/i915/i915_drv.h | 53 +++
drivers/gpu/drm/i915/i915_gem_context.c | 45 +-
drivers/gpu/drm/i915/i915_oa_perf.c | 762 ++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_reg.h | 68 +++
include/uapi/drm/i915_drm.h | 29 ++
7 files changed, 954 insertions(+), 10 deletions(-)
create mode 100644 drivers/gpu/drm/i915/i915_oa_perf.c
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index b7ddf48..b5ebfbe 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -15,6 +15,7 @@ i915-y := i915_drv.o \
i915-$(CONFIG_COMPAT) += i915_ioc32.o
i915-$(CONFIG_DEBUG_FS) += i915_debugfs.o
+i915-$(CONFIG_PERF_EVENTS) += i915_oa_perf.o
# GEM code
i915-y += i915_cmd_parser.o \
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index a238889..c299e18 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -818,6 +818,11 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
mutex_init(&dev_priv->modeset_restore_lock);
mutex_init(&dev_priv->csr_lock);
+ /* Must at least be registered before trying to pin any context
+ * otherwise i915_oa_context_pin_notify() will lock an un-initialized
+ * spinlock, upsetting lockdep checks */
+ i915_oa_pmu_register(dev);
+
intel_pm_setup(dev);
intel_display_crc_init(dev);
@@ -1067,6 +1072,7 @@ int i915_driver_unload(struct drm_device *dev)
return ret;
}
+ i915_oa_pmu_unregister(dev);
intel_power_domains_fini(dev_priv);
intel_gpu_ips_teardown();
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6a66d6b..dd475ca 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -49,6 +49,7 @@
#include <linux/hashtable.h>
#include <linux/intel-iommu.h>
#include <linux/kref.h>
+#include <linux/perf_event.h>
#include <linux/pm_qos.h>
/* General customization:
@@ -1839,6 +1840,35 @@ struct drm_i915_private {
*/
struct workqueue_struct *dp_wq;
+#ifdef CONFIG_PERF_EVENTS
+ struct {
+ struct pmu pmu;
+ spinlock_t lock;
+ struct hrtimer timer;
+ struct pt_regs dummy_regs;
+
+ struct perf_event *exclusive_event;
+ struct intel_context *specific_ctx;
+ bool event_active;
+
+ bool periodic;
+ u32 period_exponent;
+
+ u32 metrics_set;
+
+ struct {
+ struct drm_i915_gem_object *obj;
+ u32 gtt_offset;
+ u8 *addr;
+ u32 head;
+ u32 tail;
+ int format;
+ int format_size;
+ spinlock_t flush_lock;
+ } oa_buffer;
+ } oa_pmu;
+#endif
+
/* Abstract the submission mechanism (legacy ringbuffer or execlists) away */
struct {
int (*execbuf_submit)(struct drm_device *dev, struct drm_file *file,
@@ -3012,6 +3042,20 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv);
+#ifdef CONFIG_PERF_EVENTS
+void i915_oa_context_pin_notify(struct drm_i915_private *dev_priv,
+ struct intel_context *context);
+void i915_oa_context_unpin_notify(struct drm_i915_private *dev_priv,
+ struct intel_context *context);
+#else
+static inline void
+i915_oa_context_pin_notify(struct drm_i915_private *dev_priv,
+ struct intel_context *context) {}
+static inline void
+i915_oa_context_unpin_notify(struct drm_i915_private *dev_priv,
+ struct intel_context *context) {}
+#endif
+
/* i915_gem_evict.c */
int __must_check i915_gem_evict_something(struct drm_device *dev,
struct i915_address_space *vm,
@@ -3121,6 +3165,15 @@ int i915_parse_cmds(struct intel_engine_cs *ring,
u32 batch_len,
bool is_master);
+/* i915_oa_perf.c */
+#ifdef CONFIG_PERF_EVENTS
+extern void i915_oa_pmu_register(struct drm_device *dev);
+extern void i915_oa_pmu_unregister(struct drm_device *dev);
+#else
+static inline void i915_oa_pmu_register(struct drm_device *dev) {}
+static inline void i915_oa_pmu_unregister(struct drm_device *dev) {}
+#endif
+
/* i915_suspend.c */
extern int i915_save_state(struct drm_device *dev);
extern int i915_restore_state(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 5a47eb5..3e9a7f5 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -133,6 +133,33 @@ static int get_context_size(struct drm_device *dev)
return ret;
}
+static int i915_gem_context_pin_state(struct drm_device *dev,
+ struct intel_context *ctx)
+{
+ int ret;
+
+ BUG_ON(!mutex_is_locked(&dev->struct_mutex));
+
+ ret = i915_gem_obj_ggtt_pin(ctx->legacy_hw_ctx.rcs_state,
+ get_context_alignment(dev), 0);
+ if (ret)
+ return ret;
+
+ i915_oa_context_pin_notify(dev->dev_private, ctx);
+
+ return 0;
+}
+
+static void i915_gem_context_unpin_state(struct drm_device *dev,
+ struct intel_context *ctx)
+{
+ /* Ensure that we stop the OA unit referencing the context *before*
+ * actually unpinning the ctx */
+ i915_oa_context_unpin_notify(dev->dev_private, ctx);
+
+ i915_gem_object_ggtt_unpin(ctx->legacy_hw_ctx.rcs_state);
+}
+
void i915_gem_context_free(struct kref *ctx_ref)
{
struct intel_context *ctx = container_of(ctx_ref,
@@ -260,8 +287,7 @@ i915_gem_create_context(struct drm_device *dev,
* be available. To avoid this we always pin the default
* context.
*/
- ret = i915_gem_obj_ggtt_pin(ctx->legacy_hw_ctx.rcs_state,
- get_context_alignment(dev), 0);
+ ret = i915_gem_context_pin_state(dev, ctx);
if (ret) {
DRM_DEBUG_DRIVER("Couldn't pin %d\n", ret);
goto err_destroy;
@@ -287,7 +313,7 @@ i915_gem_create_context(struct drm_device *dev,
err_unpin:
if (is_global_default_ctx && ctx->legacy_hw_ctx.rcs_state)
- i915_gem_object_ggtt_unpin(ctx->legacy_hw_ctx.rcs_state);
+ i915_gem_context_unpin_state(dev, ctx);
err_destroy:
i915_gem_context_unreference(ctx);
return ERR_PTR(ret);
@@ -314,7 +340,7 @@ void i915_gem_context_reset(struct drm_device *dev)
if (lctx) {
if (lctx->legacy_hw_ctx.rcs_state && i == RCS)
- i915_gem_object_ggtt_unpin(lctx->legacy_hw_ctx.rcs_state);
+ i915_gem_context_unpin_state(dev, lctx);
i915_gem_context_unreference(lctx);
ring->last_context = NULL;
@@ -388,12 +414,12 @@ void i915_gem_context_fini(struct drm_device *dev)
if (dev_priv->ring[RCS].last_context == dctx) {
/* Fake switch to NULL context */
WARN_ON(dctx->legacy_hw_ctx.rcs_state->active);
- i915_gem_object_ggtt_unpin(dctx->legacy_hw_ctx.rcs_state);
+ i915_gem_context_unpin_state(dev, dctx);
i915_gem_context_unreference(dctx);
dev_priv->ring[RCS].last_context = NULL;
}
- i915_gem_object_ggtt_unpin(dctx->legacy_hw_ctx.rcs_state);
+ i915_gem_context_unpin_state(dev, dctx);
}
for (i = 0; i < I915_NUM_RINGS; i++) {
@@ -642,8 +668,7 @@ static int do_switch(struct intel_engine_cs *ring,
/* Trying to pin first makes error handling easier. */
if (ring == &dev_priv->ring[RCS]) {
- ret = i915_gem_obj_ggtt_pin(to->legacy_hw_ctx.rcs_state,
- get_context_alignment(ring->dev), 0);
+ ret = i915_gem_context_pin_state(ring->dev, to);
if (ret)
return ret;
}
@@ -757,7 +782,7 @@ static int do_switch(struct intel_engine_cs *ring,
from->legacy_hw_ctx.rcs_state->last_read_req) != ring);
/* obj is kept alive until the next request by its active ref */
- i915_gem_object_ggtt_unpin(from->legacy_hw_ctx.rcs_state);
+ i915_gem_context_unpin_state(ring->dev, from);
i915_gem_context_unreference(from);
}
@@ -780,7 +805,7 @@ done:
unpin_out:
if (ring->id == RCS)
- i915_gem_object_ggtt_unpin(to->legacy_hw_ctx.rcs_state);
+ i915_gem_context_unpin_state(ring->dev, to);
return ret;
}
diff --git a/drivers/gpu/drm/i915/i915_oa_perf.c b/drivers/gpu/drm/i915/i915_oa_perf.c
new file mode 100644
index 0000000..bf1c1d6
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_oa_perf.c
@@ -0,0 +1,762 @@
+#include <linux/perf_event.h>
+#include <linux/sizes.h>
+
+#include "i915_drv.h"
+#include "intel_ringbuffer.h"
+
+/* Must be a power of two */
+#define OA_BUFFER_SIZE SZ_16M
+#define OA_TAKEN(tail, head) ((tail - head) & (OA_BUFFER_SIZE - 1))
+
+#define FREQUENCY 200
+#define PERIOD max_t(u64, 10000, NSEC_PER_SEC / FREQUENCY)
+
+static int hsw_perf_format_sizes[] = {
+ 64, /* A13_HSW */
+ 128, /* A29_HSW */
+ 128, /* A13_B8_C8_HSW */
+ -1, /* Disallowed since 192 bytes doesn't factor into buffer size
+ (A29_B8_C8_HSW) */
+ 64, /* B4_C8_HSW */
+ 256, /* A45_B8_C8_HSW */
+ 128, /* B4_C8_A16_HSW */
+ 64 /* C4_B8_HSW */
+};
+
+static void forward_one_oa_snapshot_to_event(struct drm_i915_private *dev_priv,
+ u8 *snapshot,
+ struct perf_event *event)
+{
+ struct perf_sample_data data;
+ int snapshot_size = dev_priv->oa_pmu.oa_buffer.format_size;
+ struct perf_raw_record raw;
+
+ WARN_ON(snapshot_size == 0);
+
+ perf_sample_data_init(&data, 0, event->hw.last_period);
+
+ /* Note: the combined u32 raw->size member + raw data itself must be 8
+ * byte aligned. (See note in init_oa_buffer for more details) */
+ raw.size = snapshot_size + 4;
+ raw.data = snapshot;
+
+ data.raw = &raw;
+
+ perf_event_overflow(event, &data, &dev_priv->oa_pmu.dummy_regs);
+}
+
+static u32 forward_oa_snapshots(struct drm_i915_private *dev_priv,
+ u32 head,
+ u32 tail)
+{
+ struct perf_event *exclusive_event = dev_priv->oa_pmu.exclusive_event;
+ int snapshot_size = dev_priv->oa_pmu.oa_buffer.format_size;
+ u8 *oa_buf_base = dev_priv->oa_pmu.oa_buffer.addr;
+ u32 mask = (OA_BUFFER_SIZE - 1);
+ u8 *snapshot;
+ u32 taken;
+
+ head -= dev_priv->oa_pmu.oa_buffer.gtt_offset;
+ tail -= dev_priv->oa_pmu.oa_buffer.gtt_offset;
+
+ /* Note: the gpu doesn't wrap the tail according to the OA buffer size
+ * so when we need to make sure our head/tail values are in-bounds we
+ * use the above mask.
+ */
+
+ while ((taken = OA_TAKEN(tail, head))) {
+ /* The tail increases in 64 byte increments, not in
+ * format_size steps. */
+ if (taken < snapshot_size)
+ break;
+
+ snapshot = oa_buf_base + (head & mask);
+ head += snapshot_size;
+
+ /* We currently only allow exclusive access to the counters
+ * so only have one event to forward too... */
+ if (dev_priv->oa_pmu.event_active)
+ forward_one_oa_snapshot_to_event(dev_priv, snapshot,
+ exclusive_event);
+ }
+
+ return dev_priv->oa_pmu.oa_buffer.gtt_offset + head;
+}
+
+static void flush_oa_snapshots(struct drm_i915_private *dev_priv,
+ bool skip_if_flushing)
+{
+ unsigned long flags;
+ u32 oastatus2;
+ u32 oastatus1;
+ u32 head;
+ u32 tail;
+
+ /* Can either flush via hrtimer callback or pmu methods/fops */
+ if (skip_if_flushing) {
+
+ /* If the hrtimer triggers at the same time that we are
+ * responding to a userspace initiated flush then we can
+ * just bail out...
+ */
+ if (!spin_trylock_irqsave(&dev_priv->oa_pmu.oa_buffer.flush_lock,
+ flags))
+ return;
+ } else
+ spin_lock_irqsave(&dev_priv->oa_pmu.oa_buffer.flush_lock, flags);
+
+ WARN_ON(!dev_priv->oa_pmu.oa_buffer.addr);
+
+ oastatus2 = I915_READ(GEN7_OASTATUS2);
+ oastatus1 = I915_READ(GEN7_OASTATUS1);
+
+ head = oastatus2 & GEN7_OASTATUS2_HEAD_MASK;
+ tail = oastatus1 & GEN7_OASTATUS1_TAIL_MASK;
+
+ if (oastatus1 & (GEN7_OASTATUS1_OABUFFER_OVERFLOW |
+ GEN7_OASTATUS1_REPORT_LOST)) {
+
+ /* XXX: How can we convey report-lost errors to userspace? It
+ * doesn't look like perf's _REPORT_LOST mechanism is
+ * appropriate in this case; that's just for cases where we
+ * run out of space for samples in the perf circular buffer.
+ *
+ * Maybe we can claim a special report-id and use that to
+ * forward status flags?
+ */
+ pr_debug("OA buffer read error: addr = %p, head = %u, offset = %u, tail = %u cnt o'flow = %d, buf o'flow = %d, rpt lost = %d\n",
+ dev_priv->oa_pmu.oa_buffer.addr,
+ head,
+ head - dev_priv->oa_pmu.oa_buffer.gtt_offset,
+ tail,
+ oastatus1 & GEN7_OASTATUS1_COUNTER_OVERFLOW ? 1 : 0,
+ oastatus1 & GEN7_OASTATUS1_OABUFFER_OVERFLOW ? 1 : 0,
+ oastatus1 & GEN7_OASTATUS1_REPORT_LOST ? 1 : 0);
+
+ I915_WRITE(GEN7_OASTATUS1, oastatus1 &
+ ~(GEN7_OASTATUS1_OABUFFER_OVERFLOW |
+ GEN7_OASTATUS1_REPORT_LOST));
+ }
+
+ head = forward_oa_snapshots(dev_priv, head, tail);
+
+ I915_WRITE(GEN7_OASTATUS2, (head & GEN7_OASTATUS2_HEAD_MASK) |
+ GEN7_OASTATUS2_GGTT);
+
+ spin_unlock_irqrestore(&dev_priv->oa_pmu.oa_buffer.flush_lock, flags);
+}
+
+static void
+oa_buffer_destroy(struct drm_i915_private *i915)
+{
+ mutex_lock(&i915->dev->struct_mutex);
+
+ vunmap(i915->oa_pmu.oa_buffer.addr);
+ i915_gem_object_ggtt_unpin(i915->oa_pmu.oa_buffer.obj);
+ drm_gem_object_unreference(&i915->oa_pmu.oa_buffer.obj->base);
+
+ i915->oa_pmu.oa_buffer.obj = NULL;
+ i915->oa_pmu.oa_buffer.gtt_offset = 0;
+ i915->oa_pmu.oa_buffer.addr = NULL;
+
+ mutex_unlock(&i915->dev->struct_mutex);
+}
+
+static void i915_oa_event_destroy(struct perf_event *event)
+{
+ struct drm_i915_private *i915 =
+ container_of(event->pmu, typeof(*i915), oa_pmu.pmu);
+
+ WARN_ON(event->parent);
+
+ oa_buffer_destroy(i915);
+
+ i915->oa_pmu.specific_ctx = NULL;
+
+ BUG_ON(i915->oa_pmu.exclusive_event != event);
+ i915->oa_pmu.exclusive_event = NULL;
+
+ intel_uncore_forcewake_put(i915, FORCEWAKE_ALL);
+ intel_runtime_pm_put(i915);
+}
+
+static void *vmap_oa_buffer(struct drm_i915_gem_object *obj)
+{
+ int i;
+ void *addr = NULL;
+ struct sg_page_iter sg_iter;
+ struct page **pages;
+
+ pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
+ if (pages == NULL) {
+ DRM_DEBUG_DRIVER("Failed to get space for pages\n");
+ goto finish;
+ }
+
+ i = 0;
+ for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
+ pages[i] = sg_page_iter_page(&sg_iter);
+ i++;
+ }
+
+ addr = vmap(pages, i, 0, PAGE_KERNEL);
+ if (addr == NULL) {
+ DRM_DEBUG_DRIVER("Failed to vmap pages\n");
+ goto finish;
+ }
+
+finish:
+ if (pages)
+ drm_free_large(pages);
+ return addr;
+}
+
+static int init_oa_buffer(struct perf_event *event)
+{
+ struct drm_i915_private *dev_priv =
+ container_of(event->pmu, typeof(*dev_priv), oa_pmu.pmu);
+ struct drm_i915_gem_object *bo;
+ int ret;
+
+ BUG_ON(!IS_HASWELL(dev_priv->dev));
+ BUG_ON(mutex_is_locked(&dev_priv->dev->struct_mutex));
+ BUG_ON(dev_priv->oa_pmu.oa_buffer.obj);
+
+ ret = i915_mutex_lock_interruptible(dev_priv->dev);
+ if (ret)
+ return ret;
+
+ spin_lock_init(&dev_priv->oa_pmu.oa_buffer.flush_lock);
+
+ /* NB: We over allocate the OA buffer due to the way raw sample data
+ * gets copied from the gpu mapped circular buffer into the perf
+ * circular buffer so that only one copy is required.
+ *
+ * For each perf sample (raw->size + 4) needs to be 8 byte aligned,
+ * where the 4 corresponds to the 32bit raw->size member that's
+ * added to the sample header that userspace sees.
+ *
+ * Due to the + 4 for the size member: when we copy a report to the
+ * userspace facing perf buffer we always copy an additional 4 bytes
+ * from the subsequent report to make up for the miss alignment, but
+ * when a report is at the end of the gpu mapped buffer we need to
+ * read 4 bytes past the end of the buffer.
+ */
+ bo = i915_gem_alloc_object(dev_priv->dev, OA_BUFFER_SIZE + PAGE_SIZE);
+ if (bo == NULL) {
+ DRM_ERROR("Failed to allocate OA buffer\n");
+ ret = -ENOMEM;
+ goto unlock;
+ }
+ dev_priv->oa_pmu.oa_buffer.obj = bo;
+
+ ret = i915_gem_object_set_cache_level(bo, I915_CACHE_LLC);
+ if (ret)
+ goto err_unref;
+
+ /* PreHSW required 512K alignment, HSW requires 16M */
+ ret = i915_gem_obj_ggtt_pin(bo, SZ_16M, 0);
+ if (ret)
+ goto err_unref;
+
+ dev_priv->oa_pmu.oa_buffer.gtt_offset = i915_gem_obj_ggtt_offset(bo);
+ dev_priv->oa_pmu.oa_buffer.addr = vmap_oa_buffer(bo);
+
+ /* Pre-DevBDW: OABUFFER must be set with counters off,
+ * before OASTATUS1, but after OASTATUS2 */
+ I915_WRITE(GEN7_OASTATUS2, dev_priv->oa_pmu.oa_buffer.gtt_offset |
+ GEN7_OASTATUS2_GGTT); /* head */
+ I915_WRITE(GEN7_OABUFFER, dev_priv->oa_pmu.oa_buffer.gtt_offset);
+ I915_WRITE(GEN7_OASTATUS1, dev_priv->oa_pmu.oa_buffer.gtt_offset |
+ GEN7_OASTATUS1_OABUFFER_SIZE_16M); /* tail */
+
+ DRM_DEBUG_DRIVER("OA Buffer initialized, gtt offset = 0x%x, vaddr = %p",
+ dev_priv->oa_pmu.oa_buffer.gtt_offset,
+ dev_priv->oa_pmu.oa_buffer.addr);
+
+ goto unlock;
+
+err_unref:
+ drm_gem_object_unreference(&bo->base);
+
+unlock:
+ mutex_unlock(&dev_priv->dev->struct_mutex);
+ return ret;
+}
+
+static enum hrtimer_restart hrtimer_sample(struct hrtimer *hrtimer)
+{
+ struct drm_i915_private *i915 =
+ container_of(hrtimer, typeof(*i915), oa_pmu.timer);
+
+ flush_oa_snapshots(i915, true);
+
+ hrtimer_forward_now(hrtimer, ns_to_ktime(PERIOD));
+ return HRTIMER_RESTART;
+}
+
+static struct intel_context *
+lookup_context(struct drm_i915_private *dev_priv,
+ struct file *user_filp,
+ u32 ctx_user_handle)
+{
+ struct intel_context *ctx;
+
+ mutex_lock(&dev_priv->dev->struct_mutex);
+ list_for_each_entry(ctx, &dev_priv->context_list, link) {
+ struct drm_file *drm_file;
+
+ if (!ctx->file_priv)
+ continue;
+
+ drm_file = ctx->file_priv->file;
+
+ if (user_filp->private_data == drm_file &&
+ ctx->user_handle == ctx_user_handle) {
+ mutex_unlock(&dev_priv->dev->struct_mutex);
+ return ctx;
+ }
+ }
+ mutex_unlock(&dev_priv->dev->struct_mutex);
+
+ return NULL;
+}
+
+static int i915_oa_copy_attr(drm_i915_oa_attr_t __user *uattr,
+ drm_i915_oa_attr_t *attr)
+{
+ u32 size;
+ int ret;
+
+ if (!access_ok(VERIFY_WRITE, uattr, I915_OA_ATTR_SIZE_VER0))
+ return -EFAULT;
+
+ /*
+ * zero the full structure, so that a short copy will be nice.
+ */
+ memset(attr, 0, sizeof(*attr));
+
+ ret = get_user(size, &uattr->size);
+ if (ret)
+ return ret;
+
+ if (size > PAGE_SIZE) /* silly large */
+ goto err_size;
+
+ if (size < I915_OA_ATTR_SIZE_VER0)
+ goto err_size;
+
+ /*
+ * If we're handed a bigger struct than we know of,
+ * ensure all the unknown bits are 0 - i.e. new
+ * user-space does not rely on any kernel feature
+ * extensions we dont know about yet.
+ */
+ if (size > sizeof(*attr)) {
+ unsigned char __user *addr;
+ unsigned char __user *end;
+ unsigned char val;
+
+ addr = (void __user *)uattr + sizeof(*attr);
+ end = (void __user *)uattr + size;
+
+ for (; addr < end; addr++) {
+ ret = get_user(val, addr);
+ if (ret)
+ return ret;
+ if (val)
+ goto err_size;
+ }
+ size = sizeof(*attr);
+ }
+
+ ret = copy_from_user(attr, uattr, size);
+ if (ret)
+ return -EFAULT;
+
+ if (attr->__reserved_1)
+ return -EINVAL;
+
+out:
+ return ret;
+
+err_size:
+ put_user(sizeof(*attr), &uattr->size);
+ ret = -E2BIG;
+ goto out;
+}
+
+static int i915_oa_event_init(struct perf_event *event)
+{
+ struct drm_i915_private *dev_priv =
+ container_of(event->pmu, typeof(*dev_priv), oa_pmu.pmu);
+ drm_i915_oa_attr_t oa_attr;
+ u64 report_format;
+ int ret = 0;
+
+ if (event->attr.type != event->pmu->type)
+ return -ENOENT;
+
+ ret = i915_oa_copy_attr(to_user_ptr(event->attr.config), &oa_attr);
+ if (ret)
+ return ret;
+
+ /* To avoid the complexity of having to accurately filter
+ * counter snapshots and marshal to the appropriate client
+ * we currently only allow exclusive access */
+ if (dev_priv->oa_pmu.oa_buffer.obj)
+ return -EBUSY;
+
+ report_format = oa_attr.format;
+ dev_priv->oa_pmu.oa_buffer.format = report_format;
+ dev_priv->oa_pmu.metrics_set = oa_attr.metrics_set;
+
+ if (IS_HASWELL(dev_priv->dev)) {
+ int snapshot_size;
+
+ if (report_format >= ARRAY_SIZE(hsw_perf_format_sizes))
+ return -EINVAL;
+
+ snapshot_size = hsw_perf_format_sizes[report_format];
+ if (snapshot_size < 0)
+ return -EINVAL;
+
+ dev_priv->oa_pmu.oa_buffer.format_size = snapshot_size;
+ } else {
+ BUG(); /* pmu shouldn't have been registered */
+ return -ENODEV;
+ }
+
+ /* Since we are limited to an exponential scale for
+ * programming the OA sampling period we don't allow userspace
+ * to pass a precise attr.sample_period. */
+ if (event->attr.freq ||
+ (event->attr.sample_period != 0 &&
+ event->attr.sample_period != 1))
+ return -EINVAL;
+
+ dev_priv->oa_pmu.periodic = event->attr.sample_period;
+
+ /* Instead of allowing userspace to configure the period via
+ * attr.sample_period we instead accept an exponent whereby
+ * the sample_period will be:
+ *
+ * 80ns * 2^(period_exponent + 1)
+ *
+ * Programming a period of 160 nanoseconds would not be very
+ * polite, so higher frequencies are reserved for root.
+ */
+ if (dev_priv->oa_pmu.periodic) {
+ u64 period_exponent = oa_attr.timer_exponent;
+
+ if (period_exponent > 63)
+ return -EINVAL;
+
+ if (period_exponent < 15 && !capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ dev_priv->oa_pmu.period_exponent = period_exponent;
+ } else if (oa_attr.timer_exponent)
+ return -EINVAL;
+
+ /* We bypass the default perf core perf_paranoid_cpu() ||
+ * CAP_SYS_ADMIN check by using the PERF_PMU_CAP_IS_DEVICE
+ * flag and instead authenticate based on whether the current
+ * pid owns the specified context, or require CAP_SYS_ADMIN
+ * when collecting cross-context metrics.
+ */
+ dev_priv->oa_pmu.specific_ctx = NULL;
+ if (oa_attr.single_context) {
+ u32 ctx_id = oa_attr.ctx_id;
+ unsigned int drm_fd = oa_attr.drm_fd;
+ struct fd fd = fdget(drm_fd);
+
+ if (!fd.file)
+ return -EBADF;
+
+ dev_priv->oa_pmu.specific_ctx =
+ lookup_context(dev_priv, fd.file, ctx_id);
+ fdput(fd);
+
+ if (!dev_priv->oa_pmu.specific_ctx)
+ return -EINVAL;
+ }
+
+ if (!dev_priv->oa_pmu.specific_ctx && !capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ ret = init_oa_buffer(event);
+ if (ret)
+ return ret;
+
+ BUG_ON(dev_priv->oa_pmu.exclusive_event);
+ dev_priv->oa_pmu.exclusive_event = event;
+
+ event->destroy = i915_oa_event_destroy;
+
+ /* PRM - observability performance counters:
+ *
+ * OACONTROL, performance counter enable, note:
+ *
+ * "When this bit is set, in order to have coherent counts,
+ * RC6 power state and trunk clock gating must be disabled.
+ * This can be achieved by programming MMIO registers as
+ * 0xA094=0 and 0xA090[31]=1"
+ *
+ * In our case we are expected that taking pm + FORCEWAKE
+ * references will effectively disable RC6 and trunk clock
+ * gating.
+ */
+ intel_runtime_pm_get(dev_priv);
+ intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
+
+ return 0;
+}
+
+static void update_oacontrol(struct drm_i915_private *dev_priv)
+{
+ BUG_ON(!spin_is_locked(&dev_priv->oa_pmu.lock));
+
+ if (dev_priv->oa_pmu.event_active) {
+ unsigned long ctx_id = 0;
+ bool pinning_ok = false;
+
+ if (dev_priv->oa_pmu.specific_ctx) {
+ struct intel_context *ctx =
+ dev_priv->oa_pmu.specific_ctx;
+ struct drm_i915_gem_object *obj =
+ ctx->legacy_hw_ctx.rcs_state;
+
+ if (i915_gem_obj_is_pinned(obj)) {
+ ctx_id = i915_gem_obj_ggtt_offset(obj);
+ pinning_ok = true;
+ }
+ }
+
+ if ((ctx_id == 0 || pinning_ok)) {
+ bool periodic = dev_priv->oa_pmu.periodic;
+ u32 period_exponent = dev_priv->oa_pmu.period_exponent;
+ u32 report_format = dev_priv->oa_pmu.oa_buffer.format;
+
+ I915_WRITE(GEN7_OACONTROL,
+ (ctx_id & GEN7_OACONTROL_CTX_MASK) |
+ (period_exponent <<
+ GEN7_OACONTROL_TIMER_PERIOD_SHIFT) |
+ (periodic ?
+ GEN7_OACONTROL_TIMER_ENABLE : 0) |
+ (report_format <<
+ GEN7_OACONTROL_FORMAT_SHIFT) |
+ (ctx_id ?
+ GEN7_OACONTROL_PER_CTX_ENABLE : 0) |
+ GEN7_OACONTROL_ENABLE);
+ return;
+ }
+ }
+
+ I915_WRITE(GEN7_OACONTROL, 0);
+}
+
+static void i915_oa_event_start(struct perf_event *event, int flags)
+{
+ struct drm_i915_private *dev_priv =
+ container_of(event->pmu, typeof(*dev_priv), oa_pmu.pmu);
+ unsigned long lock_flags;
+ u32 oastatus1, tail;
+
+ /* PRM - observability performance counters:
+ *
+ * OACONTROL, specific context enable:
+ *
+ * "OA unit level clock gating must be ENABLED when using
+ * specific ContextID feature."
+ *
+ * Assuming we don't ever disable OA unit level clock gating
+ * lets just assert that this condition is met...
+ */
+ WARN_ONCE(I915_READ(GEN6_UCGCTL3) & GEN6_OACSUNIT_CLOCK_GATE_DISABLE,
+ "disabled OA unit level clock gating will result in incorrect per-context OA counters");
+
+ /* XXX: On Haswell, when threshold disable mode is desired,
+ * instead of setting the threshold enable to '0', we need to
+ * program it to '1' and set OASTARTTRIG1 bits 15:0 to 0
+ * (threshold value of 0)
+ */
+ I915_WRITE(OASTARTTRIG6, (OASTARTTRIG6_B4_TO_B7_THRESHOLD_ENABLE |
+ OASTARTTRIG6_B4_CUSTOM_EVENT_ENABLE));
+ I915_WRITE(OASTARTTRIG5, 0); /* threshold value */
+
+ I915_WRITE(OASTARTTRIG2, (OASTARTTRIG2_B0_TO_B3_THRESHOLD_ENABLE |
+ OASTARTTRIG2_B0_CUSTOM_EVENT_ENABLE));
+ I915_WRITE(OASTARTTRIG1, 0); /* threshold value */
+
+ /* Setup B0 as the gpu clock counter... */
+ I915_WRITE(OACEC0_0, OACEC0_0_B0_COMPARE_GREATER_OR_EQUAL); /* to 0 */
+ I915_WRITE(OACEC0_1, 0xfffe); /* Select NOA[0] */
+
+ spin_lock_irqsave(&dev_priv->oa_pmu.lock, lock_flags);
+
+ dev_priv->oa_pmu.event_active = true;
+ update_oacontrol(dev_priv);
+
+ /* Reset the head ptr to ensure we don't forward reports relating
+ * to a previous perf event */
+ oastatus1 = I915_READ(GEN7_OASTATUS1);
+ tail = oastatus1 & GEN7_OASTATUS1_TAIL_MASK;
+ I915_WRITE(GEN7_OASTATUS2, (tail & GEN7_OASTATUS2_HEAD_MASK) |
+ GEN7_OASTATUS2_GGTT);
+
+ mmiowb();
+ spin_unlock_irqrestore(&dev_priv->oa_pmu.lock, lock_flags);
+
+ if (event->attr.sample_period)
+ __hrtimer_start_range_ns(&dev_priv->oa_pmu.timer,
+ ns_to_ktime(PERIOD), 0,
+ HRTIMER_MODE_REL_PINNED, 0);
+
+ event->hw.state = 0;
+}
+
+static void i915_oa_event_stop(struct perf_event *event, int flags)
+{
+ struct drm_i915_private *dev_priv =
+ container_of(event->pmu, typeof(*dev_priv), oa_pmu.pmu);
+ unsigned long lock_flags;
+
+ spin_lock_irqsave(&dev_priv->oa_pmu.lock, lock_flags);
+
+ dev_priv->oa_pmu.event_active = false;
+ update_oacontrol(dev_priv);
+
+ mmiowb();
+ spin_unlock_irqrestore(&dev_priv->oa_pmu.lock, lock_flags);
+
+ if (event->attr.sample_period) {
+ hrtimer_cancel(&dev_priv->oa_pmu.timer);
+ flush_oa_snapshots(dev_priv, false);
+ }
+
+ event->hw.state = PERF_HES_STOPPED;
+}
+
+static int i915_oa_event_add(struct perf_event *event, int flags)
+{
+ if (flags & PERF_EF_START)
+ i915_oa_event_start(event, flags);
+
+ return 0;
+}
+
+static void i915_oa_event_del(struct perf_event *event, int flags)
+{
+ i915_oa_event_stop(event, flags);
+}
+
+static void i915_oa_event_read(struct perf_event *event)
+{
+ struct drm_i915_private *i915 =
+ container_of(event->pmu, typeof(*i915), oa_pmu.pmu);
+
+ /* XXX: What counter would be useful here? */
+ local64_set(&event->count, 0);
+}
+
+static int i915_oa_event_flush(struct perf_event *event)
+{
+ if (event->attr.sample_period) {
+ struct drm_i915_private *i915 =
+ container_of(event->pmu, typeof(*i915), oa_pmu.pmu);
+
+ flush_oa_snapshots(i915, true);
+ }
+
+ return 0;
+}
+
+static int i915_oa_event_event_idx(struct perf_event *event)
+{
+ return 0;
+}
+
+void i915_oa_context_pin_notify(struct drm_i915_private *dev_priv,
+ struct intel_context *context)
+{
+ unsigned long flags;
+
+ if (dev_priv->oa_pmu.pmu.event_init == NULL)
+ return;
+
+ spin_lock_irqsave(&dev_priv->oa_pmu.lock, flags);
+
+ if (dev_priv->oa_pmu.specific_ctx == context)
+ update_oacontrol(dev_priv);
+
+ mmiowb();
+ spin_unlock_irqrestore(&dev_priv->oa_pmu.lock, flags);
+}
+
+void i915_oa_context_unpin_notify(struct drm_i915_private *dev_priv,
+ struct intel_context *context)
+{
+ unsigned long flags;
+
+ if (dev_priv->oa_pmu.pmu.event_init == NULL)
+ return;
+
+ spin_lock_irqsave(&dev_priv->oa_pmu.lock, flags);
+
+ if (dev_priv->oa_pmu.specific_ctx == context)
+ update_oacontrol(dev_priv);
+
+ mmiowb();
+ spin_unlock_irqrestore(&dev_priv->oa_pmu.lock, flags);
+}
+
+void i915_oa_pmu_register(struct drm_device *dev)
+{
+ struct drm_i915_private *i915 = to_i915(dev);
+
+ if (!IS_HASWELL(dev))
+ return;
+
+ /* We need to be careful about forwarding cpu metrics to
+ * userspace considering that PERF_PMU_CAP_IS_DEVICE bypasses
+ * the events/core security check that stops an unprivileged
+ * process collecting metrics for other processes.
+ */
+ i915->oa_pmu.dummy_regs = *task_pt_regs(current);
+
+ hrtimer_init(&i915->oa_pmu.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ i915->oa_pmu.timer.function = hrtimer_sample;
+
+ spin_lock_init(&i915->oa_pmu.lock);
+
+ i915->oa_pmu.pmu.capabilities = PERF_PMU_CAP_IS_DEVICE;
+
+ /* Effectively disallow opening an event with a specific pid
+ * since we aren't interested in processes running on the cpu...
+ */
+ i915->oa_pmu.pmu.task_ctx_nr = perf_invalid_context;
+
+ i915->oa_pmu.pmu.event_init = i915_oa_event_init;
+ i915->oa_pmu.pmu.add = i915_oa_event_add;
+ i915->oa_pmu.pmu.del = i915_oa_event_del;
+ i915->oa_pmu.pmu.start = i915_oa_event_start;
+ i915->oa_pmu.pmu.stop = i915_oa_event_stop;
+ i915->oa_pmu.pmu.read = i915_oa_event_read;
+ i915->oa_pmu.pmu.flush = i915_oa_event_flush;
+ i915->oa_pmu.pmu.event_idx = i915_oa_event_event_idx;
+
+ if (perf_pmu_register(&i915->oa_pmu.pmu, "i915_oa", -1))
+ i915->oa_pmu.pmu.event_init = NULL;
+}
+
+void i915_oa_pmu_unregister(struct drm_device *dev)
+{
+ struct drm_i915_private *i915 = to_i915(dev);
+
+ if (i915->oa_pmu.pmu.event_init == NULL)
+ return;
+
+ perf_pmu_unregister(&i915->oa_pmu.pmu);
+ i915->oa_pmu.pmu.event_init = NULL;
+}
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index dc6907b..40fc44f 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -516,6 +516,73 @@
#define GEN7_3DPRIM_BASE_VERTEX 0x2440
#define GEN7_OACONTROL 0x2360
+#define GEN7_OACONTROL_CTX_MASK 0xFFFFF000
+#define GEN7_OACONTROL_TIMER_PERIOD_MASK 0x3F
+#define GEN7_OACONTROL_TIMER_PERIOD_SHIFT 6
+#define GEN7_OACONTROL_TIMER_ENABLE (1<<5)
+#define GEN7_OACONTROL_FORMAT_A13 (0<<2)
+#define GEN7_OACONTROL_FORMAT_A29 (1<<2)
+#define GEN7_OACONTROL_FORMAT_A13_B8_C8 (2<<2)
+#define GEN7_OACONTROL_FORMAT_A29_B8_C8 (3<<2)
+#define GEN7_OACONTROL_FORMAT_B4_C8 (4<<2)
+#define GEN7_OACONTROL_FORMAT_A45_B8_C8 (5<<2)
+#define GEN7_OACONTROL_FORMAT_B4_C8_A16 (6<<2)
+#define GEN7_OACONTROL_FORMAT_C4_B8 (7<<2)
+#define GEN7_OACONTROL_FORMAT_SHIFT 2
+#define GEN7_OACONTROL_PER_CTX_ENABLE (1<<1)
+#define GEN7_OACONTROL_ENABLE (1<<0)
+
+#define OASTARTTRIG5 0x02720
+#define OASTARTTRIG5_THRESHOLD_VALUE_MASK 0xffff
+
+#define OASTARTTRIG6 0x02724
+#define OASTARTTRIG6_B4_TO_B7_THRESHOLD_ENABLE (1<<23)
+#define OASTARTTRIG6_B4_CUSTOM_EVENT_ENABLE (1<<28)
+
+#define OASTARTTRIG1 0x02710
+#define OASTARTTRIG1_THRESHOLD_VALUE_MASK 0xffff
+
+#define OASTARTTRIG2 0x02714
+#define OASTARTTRIG2_B0_TO_B3_THRESHOLD_ENABLE (1<<23)
+#define OASTARTTRIG2_B0_CUSTOM_EVENT_ENABLE (1<<28)
+
+#define OACEC0_0 0x2770
+#define OACEC0_0_B0_COMPARE_ANY_EQUAL 0
+#define OACEC0_0_B0_COMPARE_OR 0
+#define OACEC0_0_B0_COMPARE_GREATER_THAN 1
+#define OACEC0_0_B0_COMPARE_EQUAL 2
+#define OACEC0_0_B0_COMPARE_GREATER_OR_EQUAL 3
+#define OACEC0_0_B0_COMPARE_LESS_THAN 4
+#define OACEC0_0_B0_COMPARE_NOT_EQUAL 5
+#define OACEC0_0_B0_COMPARE_LESS_OR_EQUAL 6
+#define OACEC0_0_B0_COMPARE_VALUE_MASK 0xffff
+#define OACEC0_0_B0_COMPARE_VALUE_SHIFT 3
+
+#define OACEC0_1 0x2774
+
+#define GEN7_OABUFFER 0x23B0 /* R/W */
+#define GEN7_OABUFFER_OVERRUN_DISABLE (1<<3)
+#define GEN7_OABUFFER_EDGE_TRIGGER (1<<2)
+#define GEN7_OABUFFER_STOP_RESUME_ENABLE (1<<1)
+#define GEN7_OABUFFER_RESUME (1<<0)
+
+#define GEN7_OASTATUS1 0x2364
+#define GEN7_OASTATUS1_TAIL_MASK 0xffffffc0
+#define GEN7_OASTATUS1_OABUFFER_SIZE_128K (0<<3)
+#define GEN7_OASTATUS1_OABUFFER_SIZE_256K (1<<3)
+#define GEN7_OASTATUS1_OABUFFER_SIZE_512K (2<<3)
+#define GEN7_OASTATUS1_OABUFFER_SIZE_1M (3<<3)
+#define GEN7_OASTATUS1_OABUFFER_SIZE_2M (4<<3)
+#define GEN7_OASTATUS1_OABUFFER_SIZE_4M (5<<3)
+#define GEN7_OASTATUS1_OABUFFER_SIZE_8M (6<<3)
+#define GEN7_OASTATUS1_OABUFFER_SIZE_16M (7<<3)
+#define GEN7_OASTATUS1_COUNTER_OVERFLOW (1<<2)
+#define GEN7_OASTATUS1_OABUFFER_OVERFLOW (1<<1)
+#define GEN7_OASTATUS1_REPORT_LOST (1<<0)
+
+#define GEN7_OASTATUS2 0x2368
+#define GEN7_OASTATUS2_HEAD_MASK 0xffffffc0
+#define GEN7_OASTATUS2_GGTT 0x1
#define _GEN7_PIPEA_DE_LOAD_SL 0x70068
#define _GEN7_PIPEB_DE_LOAD_SL 0x71068
@@ -6545,6 +6612,7 @@ enum skl_disp_power_wells {
# define GEN6_RCCUNIT_CLOCK_GATE_DISABLE (1 << 11)
#define GEN6_UCGCTL3 0x9408
+# define GEN6_OACSUNIT_CLOCK_GATE_DISABLE (1 << 20)
#define GEN7_UCGCTL4 0x940c
#define GEN7_L3BANK2X_CLOCK_GATE_DISABLE (1<<25)
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 4851d66..f78f232 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -58,6 +58,35 @@
#define I915_ERROR_UEVENT "ERROR"
#define I915_RESET_UEVENT "RESET"
+/**
+ * DOC: perf events configuration exposed by i915 through /sys/bus/event_sources/drivers/i915_oa
+ *
+ */
+
+#define I915_OA_FORMAT_A13_HSW 0
+#define I915_OA_FORMAT_A29_HSW 1
+#define I915_OA_FORMAT_A13_B8_C8_HSW 2
+#define I915_OA_FORMAT_B4_C8_HSW 4
+#define I915_OA_FORMAT_A45_B8_C8_HSW 5
+#define I915_OA_FORMAT_B4_C8_A16_HSW 6
+#define I915_OA_FORMAT_C4_B8_HSW 7
+
+#define I915_OA_ATTR_SIZE_VER0 32 /* sizeof first published struct */
+
+typedef struct _drm_i915_oa_attr {
+ __u32 size;
+
+ __u32 format;
+ __u32 metrics_set;
+ __u32 timer_exponent;
+
+ __u32 drm_fd;
+ __u32 ctx_id;
+
+ __u64 single_context : 1,
+ __reserved_1 : 63;
+} drm_i915_oa_attr_t;
+
/* Each region is a minimum of 16k, and there are at most 255 of them.
*/
#define I915_NR_TEX_REGIONS 255 /* table size 2k - maximum due to use
--
2.4.1
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