On Tesla / NV50 family chipsets (nv50, g84, g94, g98, mcp77, mcp79), FIFO fault handling in nv04_fifo_intr_cache_error and nv04_fifo_intr_dma_pusher logs the fault and resets hardware registers but leaves the offending channel running. Compared to Fermi+ which calls nvkm_chan_error from nvkm_runl_rc, Tesla has no escalation: silent state corruption is possible, no telemetry beyond dmesg, and repeated faults on the same channel keep firing forever.
Add a shared recovery helper nv04_fifo_recover() that both intr handlers call after the existing logging+reset sequence. It implements two tiers: Tier-1 (per-fault): nvkm_chan_get_chid + nvkm_chan_error(chan, true). The atomic chan->errored short-circuit means re-faults on the same channel are no-op; other channels are unaffected. Tier-2 (sliding-window): per-fifo lock-protected ring of fault timestamps. When the count within fifo_wedge_window_ms reaches fifo_wedge_count, schedule a workqueue job that emits a drm_dev_wedged_event with DRM_WEDGE_RECOVERY_REBIND. The drm_dev_wedged_event call cannot run from IRQ context because kobject_uevent_env may sleep; the workqueue indirection handles this. Tracepoints (nouveau:fifo_chan_killed, nouveau:fifo_dev_wedged) provide zero-overhead telemetry consumable via perf or bpftrace. Module parameters fifo_wedge_count (default 10, range 0..32, 0=Tier-2 disabled) and fifo_wedge_window_ms (default 60000, range 100..600000) allow tuning without rebuild. Validated on Apple Mac mini Late 2009 (NVAC, MCP79). Signed-off-by: Marek Czernohous <[email protected]> --- .../drm/nouveau/include/nvkm/engine/fifo.h | 12 ++ .../include/trace/events/nouveau_fifo.h | 58 +++++++++ drivers/gpu/drm/nouveau/nouveau_drm.c | 29 +++++ .../gpu/drm/nouveau/nvkm/engine/fifo/Kbuild | 1 + .../gpu/drm/nouveau/nvkm/engine/fifo/base.c | 3 + .../gpu/drm/nouveau/nvkm/engine/fifo/nv04.c | 4 + .../gpu/drm/nouveau/nvkm/engine/fifo/priv.h | 10 ++ .../drm/nouveau/nvkm/engine/fifo/recover.c | 121 ++++++++++++++++++ 8 files changed, 238 insertions(+) create mode 100644 drivers/gpu/drm/nouveau/include/trace/events/nouveau_fifo.h create mode 100644 drivers/gpu/drm/nouveau/nvkm/engine/fifo/recover.c diff --git a/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h b/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h index 96c16cfccf16..7c27b4c8a212 100644 --- a/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h +++ b/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h @@ -55,6 +55,17 @@ void nvkm_chan_put(struct nvkm_chan **, unsigned long irqflags); struct nvkm_chan *nvkm_uchan_chan(struct nvkm_object *); +#define NVKM_FIFO_WEDGE_RING_MAX 32 + +struct nvkm_fifo_wedge { + spinlock_t lock; + u32 count; /* aktuelle Fenster-Tiefe */ + ktime_t ts[NVKM_FIFO_WEDGE_RING_MAX]; /* Ring von Timestamps */ + u32 head; /* Ring-Head */ + struct work_struct work; /* schedules drm_dev_wedged_event */ + atomic_t wedged; /* Tier-2 already fired? */ +}; + struct nvkm_fifo { const struct nvkm_fifo_func *func; struct nvkm_engine engine; @@ -86,6 +97,7 @@ struct nvkm_fifo { spinlock_t lock; struct mutex mutex; + struct nvkm_fifo_wedge wedge; }; void nvkm_fifo_fault(struct nvkm_fifo *, struct nvkm_fault_data *); diff --git a/drivers/gpu/drm/nouveau/include/trace/events/nouveau_fifo.h b/drivers/gpu/drm/nouveau/include/trace/events/nouveau_fifo.h new file mode 100644 index 000000000000..46d043a82850 --- /dev/null +++ b/drivers/gpu/drm/nouveau/include/trace/events/nouveau_fifo.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: MIT */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM nouveau + +#if !defined(_TRACE_NOUVEAU_FIFO_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_NOUVEAU_FIFO_H + +#include <linux/tracepoint.h> +#include <drm/drm_device.h> + +TRACE_EVENT(nouveau_fifo_chan_killed, + TP_PROTO(struct drm_device *dev, u32 chid, u32 fault_type, u64 info), + TP_ARGS(dev, chid, fault_type, info), + TP_STRUCT__entry( + __string(devname, dev_name(dev->dev)) + __field(u32, chid) + __field(u32, fault_type) + __field(u64, info) + ), + TP_fast_assign( + __assign_str(devname); + __entry->chid = chid; + __entry->fault_type = fault_type; + __entry->info = info; + ), + TP_printk("dev=%s chid=%u fault=%s info=0x%llx", + __get_str(devname), + __entry->chid, + __entry->fault_type == 0 ? "CACHE_ERROR" : "DMA_PUSHER", + __entry->info) +); + +TRACE_EVENT(nouveau_fifo_dev_wedged, + TP_PROTO(struct drm_device *dev, u32 fault_count, u32 window_ms), + TP_ARGS(dev, fault_count, window_ms), + TP_STRUCT__entry( + __string(devname, dev_name(dev->dev)) + __field(u32, fault_count) + __field(u32, window_ms) + ), + TP_fast_assign( + __assign_str(devname); + __entry->fault_count = fault_count; + __entry->window_ms = window_ms; + ), + TP_printk("dev=%s wedged after %u faults in %u ms", + __get_str(devname), + __entry->fault_count, + __entry->window_ms) +); + +#endif /* _TRACE_NOUVEAU_FIFO_H */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH ../../drivers/gpu/drm/nouveau/include/trace/events +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE nouveau_fifo +#include <trace/define_trace.h> diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c index 517ff2c31dce..c62b7fc3a1d3 100644 --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -22,6 +22,8 @@ * Authors: Ben Skeggs */ +#define CREATE_TRACE_POINTS + #include <linux/aperture.h> #include <linux/delay.h> #include <linux/module.h> @@ -74,6 +76,9 @@ #include "nouveau_uvmm.h" #include "nouveau_sched.h" +#include <engine/fifo.h> +#include <trace/events/nouveau_fifo.h> + DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0, "DRM_UT_CORE", "DRM_UT_DRIVER", @@ -111,6 +116,18 @@ MODULE_PARM_DESC(runpm, "disable (0), force enable (1), optimus only default (-1 static int nouveau_runtime_pm = -1; module_param_named(runpm, nouveau_runtime_pm, int, 0400); +MODULE_PARM_DESC(fifo_wedge_count, + "FIFO faults within window before drm_dev_wedged_event " + "(0=disable Tier-2, max 32, default 10)"); +unsigned int nouveau_fifo_wedge_count = 10; +module_param_named(fifo_wedge_count, nouveau_fifo_wedge_count, uint, 0400); + +MODULE_PARM_DESC(fifo_wedge_window_ms, + "Sliding-window width in milliseconds for fifo_wedge_count " + "(default 60000)"); +unsigned int nouveau_fifo_wedge_window_ms = 60000; +module_param_named(fifo_wedge_window_ms, nouveau_fifo_wedge_window_ms, uint, 0400); + static struct drm_driver driver_stub; static struct drm_driver driver_pci; static struct drm_driver driver_platform; @@ -1495,6 +1512,18 @@ nouveau_drm_init(void) if (!nouveau_modeset) return 0; + if (nouveau_fifo_wedge_count > NVKM_FIFO_WEDGE_RING_MAX) { + pr_warn("nouveau: fifo_wedge_count=%u exceeds max %u; clamping\n", + nouveau_fifo_wedge_count, NVKM_FIFO_WEDGE_RING_MAX); + nouveau_fifo_wedge_count = NVKM_FIFO_WEDGE_RING_MAX; + } + if (nouveau_fifo_wedge_window_ms < 100 || + nouveau_fifo_wedge_window_ms > 600000) { + pr_warn("nouveau: fifo_wedge_window_ms=%u out of range; resetting to 60000\n", + nouveau_fifo_wedge_window_ms); + nouveau_fifo_wedge_window_ms = 60000; + } + nouveau_module_debugfs_init(); #ifdef CONFIG_NOUVEAU_PLATFORM_DRIVER diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild index 376e9c3bcb1a..1ff29753731d 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild +++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild @@ -5,6 +5,7 @@ nvkm-y += nvkm/engine/fifo/chan.o nvkm-y += nvkm/engine/fifo/chid.o nvkm-y += nvkm/engine/fifo/runl.o nvkm-y += nvkm/engine/fifo/runq.o +nvkm-y += nvkm/engine/fifo/recover.o nvkm-y += nvkm/engine/fifo/nv04.o nvkm-y += nvkm/engine/fifo/nv10.o diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/base.c index 9dd924694306..a61183fa38af 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/base.c @@ -337,6 +337,8 @@ nvkm_fifo_dtor(struct nvkm_engine *engine) struct nvkm_runl *runl, *runt; struct nvkm_runq *runq, *rtmp; + nv04_fifo_wedge_fini(fifo); + if (fifo->userd.bar1) nvkm_vmm_put(nvkm_bar_bar1_vmm(engine->subdev.device), &fifo->userd.bar1); nvkm_memory_unref(&fifo->userd.mem); @@ -390,6 +392,7 @@ nvkm_fifo_new_(const struct nvkm_fifo_func *func, struct nvkm_device *device, fifo->timeout.chan_msec = 10000; spin_lock_init(&fifo->lock); mutex_init(&fifo->mutex); + nv04_fifo_wedge_init(fifo); return nvkm_engine_ctor(&nvkm_fifo, device, type, inst, true, &fifo->engine); } diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.c index fa13cd55b593..cb81941ecccd 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.c +++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.c @@ -345,6 +345,8 @@ nv04_fifo_intr_cache_error(struct nvkm_fifo *fifo, u32 chid, u32 get) chid, chan ? chan->name : "unknown", (mthd >> 13) & 7, mthd & 0x1ffc, data); nvkm_chan_put(&chan, flags); + nv04_fifo_recover(fifo, chid, NV04_FAULT_CACHE_ERROR, + ((u64)mthd << 32) | data); } } @@ -410,6 +412,8 @@ nv04_fifo_intr_dma_pusher(struct nvkm_fifo *fifo, u32 chid) } nvkm_chan_put(&chan, flags); + nv04_fifo_recover(fifo, chid, NV04_FAULT_DMA_PUSHER, state); + nvkm_wr32(device, 0x003228, 0x00000000); nvkm_wr32(device, 0x003220, 0x00000001); nvkm_wr32(device, 0x002100, NV_PFIFO_INTR_DMA_PUSHER); diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/priv.h b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/priv.h index fff1428ef267..bf551906dcd4 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/priv.h +++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/priv.h @@ -83,6 +83,16 @@ void nv04_chan_start(struct nvkm_chan *); void nv04_chan_stop(struct nvkm_chan *); void nv04_eobj_ramht_del(struct nvkm_chan *, int); +/* Recovery helper for Tesla cache_error/dma_pusher (recover.c). */ +#define NV04_FAULT_CACHE_ERROR 0 +#define NV04_FAULT_DMA_PUSHER 1 + +void nv04_fifo_recover(struct nvkm_fifo *fifo, u32 chid, u32 fault_type, u64 info); +void nv04_fifo_wedge_init(struct nvkm_fifo *fifo); +void nv04_fifo_wedge_fini(struct nvkm_fifo *fifo); +extern unsigned int nouveau_fifo_wedge_count; +extern unsigned int nouveau_fifo_wedge_window_ms; + int nv10_fifo_chid_nr(struct nvkm_fifo *); int nv50_fifo_chid_nr(struct nvkm_fifo *); diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/recover.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/recover.c new file mode 100644 index 000000000000..14c0eebf7040 --- /dev/null +++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/recover.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: MIT +/* + * nv04_fifo_recover - shared recovery helper for Tesla cache_error and + * dma_pusher fault paths. + * + * Tier-1: kill the offending channel via nvkm_chan_error. + * Tier-2: after a configurable burst of faults within a sliding time + * window, request a device-wide drm_dev_wedged_event so userspace + * can rebind the driver. + */ + +#include "priv.h" +#include "chan.h" + +#include <core/device.h> +#include <subdev/timer.h> + +#include <linux/workqueue.h> +#include <linux/jiffies.h> +#include <linux/ktime.h> +#include <drm/drm_drv.h> +#include <drm/drm_device.h> + +#include "nouveau_drv.h" +#include <trace/events/nouveau_fifo.h> + +static struct drm_device * +nv04_fifo_drm_device(struct nvkm_fifo *fifo) +{ + struct nvkm_device *device = fifo->engine.subdev.device; + struct nouveau_drm *drm = dev_get_drvdata(device->dev); + + return (drm && drm->dev) ? drm->dev : NULL; +} + +void +nv04_fifo_recover(struct nvkm_fifo *fifo, u32 chid, u32 fault_type, u64 info) +{ + struct drm_device *drm_dev = nv04_fifo_drm_device(fifo); + struct nvkm_chan *chan; + unsigned long flags; + ktime_t now, cutoff; + u32 i, count; + + if (drm_dev) + trace_nouveau_fifo_chan_killed(drm_dev, chid, fault_type, info); + + chan = nvkm_chan_get_chid(&fifo->engine, chid, &flags); + if (chan) { + nvkm_chan_error(chan, true); + nvkm_chan_put(&chan, flags); + } + + if (nouveau_fifo_wedge_count == 0) + return; + + now = ktime_get(); + cutoff = ktime_sub_ms(now, nouveau_fifo_wedge_window_ms); + + spin_lock_irqsave(&fifo->wedge.lock, flags); + + /* Insert current first, then purge expired and count survivors. */ + fifo->wedge.ts[fifo->wedge.head] = now; + fifo->wedge.head = (fifo->wedge.head + 1) % NVKM_FIFO_WEDGE_RING_MAX; + + count = 0; + for (i = 0; i < NVKM_FIFO_WEDGE_RING_MAX; i++) { + if (!ktime_to_ns(fifo->wedge.ts[i])) + continue; + if (ktime_before(fifo->wedge.ts[i], cutoff)) + fifo->wedge.ts[i] = 0; + else + count++; + } + fifo->wedge.count = count; + + if (count >= nouveau_fifo_wedge_count) + schedule_work(&fifo->wedge.work); + + spin_unlock_irqrestore(&fifo->wedge.lock, flags); +} + +static void +nv04_fifo_wedge_work(struct work_struct *work) +{ + struct nvkm_fifo_wedge *w = container_of(work, struct nvkm_fifo_wedge, work); + struct nvkm_fifo *fifo = container_of(w, struct nvkm_fifo, wedge); + struct drm_device *drm_dev = nv04_fifo_drm_device(fifo); + u32 fault_count; + + if (atomic_xchg(&w->wedged, 1) != 0) + return; /* already wedged this cycle */ + + if (!drm_dev) + return; + + fault_count = w->count; + + dev_info(drm_dev->dev, + "nouveau: fifo wedged after %u faults in %u ms\n", + fault_count, nouveau_fifo_wedge_window_ms); + + trace_nouveau_fifo_dev_wedged(drm_dev, fault_count, + nouveau_fifo_wedge_window_ms); + + drm_dev_wedged_event(drm_dev, DRM_WEDGE_RECOVERY_REBIND, NULL); +} + +void +nv04_fifo_wedge_init(struct nvkm_fifo *fifo) +{ + spin_lock_init(&fifo->wedge.lock); + INIT_WORK(&fifo->wedge.work, nv04_fifo_wedge_work); + atomic_set(&fifo->wedge.wedged, 0); +} + +void +nv04_fifo_wedge_fini(struct nvkm_fifo *fifo) +{ + cancel_work_sync(&fifo->wedge.work); +} -- 2.53.0
