Implement preemption for A5XX targets - this allows multiple
ringbuffers for different priorities with automatic preemption
of a lower priority ringbuffer if a higher one is ready.
Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/Makefile | 1 +
drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 172 +++++++++++++-
drivers/gpu/drm/msm/adreno/a5xx_gpu.h | 105 +++++++++
drivers/gpu/drm/msm/adreno/a5xx_preempt.c | 367 ++++++++++++++++++++++++++++++
drivers/gpu/drm/msm/adreno/adreno_gpu.c | 11 +-
drivers/gpu/drm/msm/adreno/adreno_gpu.h | 5 +
drivers/gpu/drm/msm/msm_drv.h | 2 +-
drivers/gpu/drm/msm/msm_ringbuffer.c | 2 +
drivers/gpu/drm/msm/msm_ringbuffer.h | 1 +
9 files changed, 654 insertions(+), 12 deletions(-)
create mode 100644 drivers/gpu/drm/msm/adreno/a5xx_preempt.c
diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
index 028c24d..8a3d74e 100644
--- a/drivers/gpu/drm/msm/Makefile
+++ b/drivers/gpu/drm/msm/Makefile
@@ -8,6 +8,7 @@ msm-y := \
adreno/a4xx_gpu.o \
adreno/a5xx_gpu.o \
adreno/a5xx_power.o \
+ adreno/a5xx_preempt.o \
hdmi/hdmi.o \
hdmi/hdmi_audio.o \
hdmi/hdmi_bridge.o \
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
index 5f02ff3..b7c6158 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -184,14 +184,66 @@ static int zap_load_mdt(struct platform_device *pdev)
return ret;
}
+static void a5xx_flush(struct msm_gpu *gpu, struct msm_ringbuffer *ring)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ uint32_t wptr;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ring->lock, flags);
+
+ /* Copy the shadow to the actual register */
+ ring->cur = ring->next;
+
+ /* Make sure to wrap wptr if we need to */
+ wptr = (ring->cur - ring->start) % (MSM_GPU_RINGBUFFER_SZ >> 2);
+
+ spin_unlock_irqrestore(&ring->lock, flags);
+
+ /* Make sure everything is posted before making a decision */
+ mb();
+
+ /* Update HW if this is the current ring and we are not in preempt */
+ if (a5xx_gpu->cur_ring == ring && !a5xx_in_preempt(a5xx_gpu))
+ gpu_write(gpu, REG_A5XX_CP_RB_WPTR, wptr);
+}
+
static void a5xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
struct msm_file_private *ctx)
{
struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+
struct msm_drm_private *priv = gpu->dev->dev_private;
struct msm_ringbuffer *ring = submit->ring;
unsigned int i, ibs = 0;
+ OUT_PKT7(ring, CP_PREEMPT_ENABLE_GLOBAL, 1);
+ OUT_RING(ring, 0x02);
+
+ /* Turn off protected mode to write to special registers */
+ OUT_PKT7(ring, CP_SET_PROTECTED_MODE, 1);
+ OUT_RING(ring, 0);
+
+ /* Set the save preemption record for the ring/command */
+ OUT_PKT4(ring, REG_A5XX_CP_CONTEXT_SWITCH_SAVE_ADDR_LO, 2);
+ OUT_RING(ring, lower_32_bits(a5xx_gpu->preempt_iova[submit->ring->id]));
+ OUT_RING(ring, upper_32_bits(a5xx_gpu->preempt_iova[submit->ring->id]));
+
+ /* Turn back on protected mode */
+ OUT_PKT7(ring, CP_SET_PROTECTED_MODE, 1);
+ OUT_RING(ring, 1);
+
+ /* Enable local preemption for finegrain preemption */
+ OUT_PKT7(ring, CP_PREEMPT_ENABLE_GLOBAL, 1);
+ OUT_RING(ring, 0x02);
+
+ /* Allow CP_CONTEXT_SWITCH_YIELD packets in the IB2 */
+ OUT_PKT7(ring, CP_YIELD_ENABLE, 1);
+ OUT_RING(ring, 0x02);
+
+ /* Submit the commands */
for (i = 0; i < submit->nr_cmds; i++) {
switch (submit->cmd[i].type) {
case MSM_SUBMIT_CMD_IB_TARGET_BUF:
@@ -209,16 +261,54 @@ static void a5xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
}
}
+ /*
+ * Write the render mode to NULL (0) to indicate to the CP that the IBs
+ * are done rendering - otherwise a lucky preemption would start
+ * replaying from the last checkpoint
+ */
+ OUT_PKT7(ring, CP_SET_RENDER_MODE, 5);
+ OUT_RING(ring, 0);
+ OUT_RING(ring, 0);
+ OUT_RING(ring, 0);
+ OUT_RING(ring, 0);
+ OUT_RING(ring, 0);
+
+ /* Turn off IB level preemptions */
+ OUT_PKT7(ring, CP_YIELD_ENABLE, 1);
+ OUT_RING(ring, 0x01);
+
+ /* Write the fence to the scratch register */
OUT_PKT4(ring, REG_A5XX_CP_SCRATCH_REG(2), 1);
OUT_RING(ring, submit->fence->seqno);
+ /*
+ * Execute a CACHE_FLUSH_TS event. This will ensure that the
+ * timestamp is written to the memory and then triggers the interrupt
+ */
OUT_PKT7(ring, CP_EVENT_WRITE, 4);
OUT_RING(ring, CACHE_FLUSH_TS | (1 << 31));
OUT_RING(ring, lower_32_bits(rbmemptr(adreno_gpu, ring->id, fence)));
OUT_RING(ring, upper_32_bits(rbmemptr(adreno_gpu, ring->id, fence)));
OUT_RING(ring, submit->fence->seqno);
- gpu->funcs->flush(gpu, ring);
+ /* Yield the floor on command completion */
+ OUT_PKT7(ring, CP_CONTEXT_SWITCH_YIELD, 4);
+ /*
+ * If dword[2:1] are non zero, they specify an address for the CP to
+ * write the value of dword[3] to on preemption complete. Write 0 to
+ * skip the write
+ */
+ OUT_RING(ring, 0x00);
+ OUT_RING(ring, 0x00);
+ /* Data value - not used if the address above is 0 */
+ OUT_RING(ring, 0x01);
+ /* Set bit 0 to trigger an interrupt on preempt complete */
+ OUT_RING(ring, 0x01);
+
+ a5xx_flush(gpu, ring);
+
+ /* Check to see if we need to start preemption */
+ a5xx_preempt_trigger(gpu);
}
struct a5xx_hwcg {
@@ -393,6 +483,50 @@ static int a5xx_me_init(struct msm_gpu *gpu)
return a5xx_idle(gpu, ring) ? 0 : -EINVAL;
}
+static int a5xx_preempt_start(struct msm_gpu *gpu)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ struct msm_ringbuffer *ring = gpu->rb[0];
+
+ if (gpu->nr_rings == 1)
+ return 0;
+
+ /* Turn off protected mode to write to special registers */
+ OUT_PKT7(ring, CP_SET_PROTECTED_MODE, 1);
+ OUT_RING(ring, 0);
+
+ /* Set the save preemption record for the ring/command */
+ OUT_PKT4(ring, REG_A5XX_CP_CONTEXT_SWITCH_SAVE_ADDR_LO, 2);
+ OUT_RING(ring, lower_32_bits(a5xx_gpu->preempt_iova[ring->id]));
+ OUT_RING(ring, upper_32_bits(a5xx_gpu->preempt_iova[ring->id]));
+
+ /* Turn back on protected mode */
+ OUT_PKT7(ring, CP_SET_PROTECTED_MODE, 1);
+ OUT_RING(ring, 1);
+
+ OUT_PKT7(ring, CP_PREEMPT_ENABLE_GLOBAL, 1);
+ OUT_RING(ring, 0x00);
+
+ OUT_PKT7(ring, CP_PREEMPT_ENABLE_LOCAL, 1);
+ OUT_RING(ring, 0x01);
+
+ OUT_PKT7(ring, CP_YIELD_ENABLE, 1);
+ OUT_RING(ring, 0x01);
+
+ /* Yield the floor on command completion */
+ OUT_PKT7(ring, CP_CONTEXT_SWITCH_YIELD, 4);
+ OUT_RING(ring, 0x00);
+ OUT_RING(ring, 0x00);
+ OUT_RING(ring, 0x01);
+ OUT_RING(ring, 0x01);
+
+ gpu->funcs->flush(gpu, ring);
+
+ return a5xx_idle(gpu, ring) ? 0 : -EINVAL;
+}
+
+
static struct drm_gem_object *a5xx_ucode_load_bo(struct msm_gpu *gpu,
const struct firmware *fw, u64 *iova)
{
@@ -525,6 +659,7 @@ static int a5xx_zap_shader_init(struct msm_gpu *gpu)
A5XX_RBBM_INT_0_MASK_RBBM_ETS_MS_TIMEOUT | \
A5XX_RBBM_INT_0_MASK_RBBM_ATB_ASYNC_OVERFLOW | \
A5XX_RBBM_INT_0_MASK_CP_HW_ERROR | \
+ A5XX_RBBM_INT_0_MASK_CP_SW | \
A5XX_RBBM_INT_0_MASK_CP_CACHE_FLUSH_TS | \
A5XX_RBBM_INT_0_MASK_UCHE_OOB_ACCESS | \
A5XX_RBBM_INT_0_MASK_GPMU_VOLTAGE_DROOP)
@@ -672,6 +807,8 @@ static int a5xx_hw_init(struct msm_gpu *gpu)
if (ret)
return ret;
+ a5xx_preempt_hw_init(gpu);
+
ret = a5xx_ucode_init(gpu);
if (ret)
return ret;
@@ -724,6 +861,9 @@ static int a5xx_hw_init(struct msm_gpu *gpu)
gpu_write(gpu, REG_A5XX_RBBM_SECVID_TRUST_CNTL, 0x0);
}
+ /* Last step - yield the ringbuffer */
+ a5xx_preempt_start(gpu);
+
return 0;
}
@@ -754,6 +894,8 @@ static void a5xx_destroy(struct msm_gpu *gpu)
DBG("%s", gpu->name);
+ a5xx_preempt_fini(gpu);
+
if (a5xx_gpu->pm4_bo) {
if (a5xx_gpu->pm4_iova)
msm_gem_put_iova(a5xx_gpu->pm4_bo, gpu->aspace);
@@ -791,6 +933,14 @@ static inline bool _a5xx_check_idle(struct msm_gpu *gpu)
bool a5xx_idle(struct msm_gpu *gpu, struct msm_ringbuffer *ring)
{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+
+ if (ring != a5xx_gpu->cur_ring) {
+ WARN(1, "Tried to idle a non-current ringbuffer\n");
+ return false;
+ }
+
/* wait for CP to drain ringbuffer: */
if (!adreno_idle(gpu, ring))
return false;
@@ -957,6 +1107,9 @@ static irqreturn_t a5xx_irq(struct msm_gpu *gpu)
if (status & A5XX_RBBM_INT_0_MASK_CP_CACHE_FLUSH_TS)
msm_gpu_retire(gpu);
+ if (status & A5XX_RBBM_INT_0_MASK_CP_SW)
+ a5xx_preempt_irq(gpu);
+
return IRQ_HANDLED;
}
@@ -1083,6 +1236,14 @@ static void a5xx_show(struct msm_gpu *gpu, struct seq_file *m)
}
#endif
+static struct msm_ringbuffer *a5xx_active_ring(struct msm_gpu *gpu)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+
+ return a5xx_gpu->cur_ring;
+}
+
static const struct adreno_gpu_funcs funcs = {
.base = {
.get_param = adreno_get_param,
@@ -1092,8 +1253,8 @@ static void a5xx_show(struct msm_gpu *gpu, struct seq_file *m)
.recover = a5xx_recover,
.last_fence = adreno_last_fence,
.submit = a5xx_submit,
- .flush = adreno_flush,
- .active_ring = adreno_active_ring,
+ .flush = a5xx_flush,
+ .active_ring = a5xx_active_ring,
.irq = a5xx_irq,
.destroy = a5xx_destroy,
.show = a5xx_show,
@@ -1128,7 +1289,7 @@ struct msm_gpu *a5xx_gpu_init(struct drm_device *dev)
a5xx_gpu->lm_leakage = 0x4E001A;
- ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs, 1);
+ ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs, 4);
if (ret) {
a5xx_destroy(&(a5xx_gpu->base.base));
return ERR_PTR(ret);
@@ -1137,5 +1298,8 @@ struct msm_gpu *a5xx_gpu_init(struct drm_device *dev)
if (gpu->aspace)
msm_mmu_set_fault_handler(gpu->aspace->mmu, gpu, a5xx_fault_handler);
+ /* Set up the preemption specific bits and pieces for each ringbuffer */
+ a5xx_preempt_init(gpu);
+
return gpu;
}
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.h b/drivers/gpu/drm/msm/adreno/a5xx_gpu.h
index 405b563..5993d3a 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.h
@@ -36,10 +36,103 @@ struct a5xx_gpu {
uint32_t gpmu_dwords;
uint32_t lm_leakage;
+
+ struct msm_ringbuffer *cur_ring;
+ struct msm_ringbuffer *next_ring;
+
+ struct drm_gem_object *preempt_bo[MSM_GPU_MAX_RINGS];
+ struct a5xx_preempt_record *preempt[MSM_GPU_MAX_RINGS];
+ uint64_t preempt_iova[MSM_GPU_MAX_RINGS];
+
+ atomic_t preempt_state;
+ struct work_struct preempt_work;
+ struct timer_list preempt_timer;
+
};
#define to_a5xx_gpu(x) container_of(x, struct a5xx_gpu, base)
+/*
+ * In order to do lockless preemption we use a simple state machine to progress
+ * through the process.
+ *
+ * PREEMPT_NONE - no preemption in progress. Next state START.
+ * PREEMPT_START - The trigger is evaulating if preemption is possible. Next
+ * states: TRIGGERED, NONE
+ * PREEMPT_TRIGGERED: A preemption has been executed on the hardware. Next
+ * states: FAULTED, PENDING
+ * PREEMPT_FAULTED: A preemption timed out (never completed). This will trigger
+ * recovery. Next state: N/A
+ * PREEMPT_PENDING: Preemption complete interrupt fired - the callback is
+ * checking the success of the operation. Next state: COMPLETE, NONE.
+ * PREEMPT_COMPLETE: The complete interrupt fired but the status has not yet
+ * indicated that the preemption was done. This is likely a temporary condition
+ * and a worker has been scheduled to clean up
+ */
+
+enum preempt_state {
+ PREEMPT_NONE = 0,
+ PREEMPT_START,
+ PREEMPT_TRIGGERED,
+ PREEMPT_FAULTED,
+ PREEMPT_PENDING,
+ PREEMPT_COMPLETE
+};
+
+/*
+ * struct a5xx_preempt_record is a shared buffer between the microcode and the
+ * CPU to store the state for preemption. The record itself is much larger
+ * (64k) but most of that is used by the CP for storage.
+ *
+ * There is a preemption record assigned per ringbuffer. When the CPU triggers a
+ * preemption, it fills out the record with the useful information (wptr, ring
+ * base, etc) and the microcode uses that information to set up the CP following
+ * the preemption. When a ring is switched out, the CP will save the ringbuffer
+ * state back to the record. In this way, once the records are properly set up
+ * the CPU can quickly switch back and forth between ringbuffers by only
+ * updating a few registers (often only the wptr).
+ *
+ * These are the CPU aware registers in the record:
+ * @magic: Must always be 0x27C4BAFC
+ * @info: Type of the record - written 0 by the CPU, updated by the CP
+ * @data: Data field from SET_RENDER_MODE or a checkpoint. Written and used by
+ * the CP
+ * @cntl: Value of RB_CNTL written by CPU, save/restored by CP
+ * @rptr: Value of RB_RPTR written by CPU, save/restored by CP
+ * @wptr: Value of RB_WPTR written by CPU, save/restored by CP
+ * @rptr_addr: Value of RB_RPTR_ADDR written by CPU, save/restored by CP
+ * @rbase: Value of RB_BASE written by CPU, save/restored by CP
+ * @counter: GPU address of the storage area for the performance counters
+ */
+struct a5xx_preempt_record {
+ uint32_t magic;
+ uint32_t info;
+ uint32_t data;
+ uint32_t cntl;
+ uint32_t rptr;
+ uint32_t wptr;
+ uint64_t rptr_addr;
+ uint64_t rbase;
+ uint64_t counter;
+};
+
+/* Magic identifier for the preemption record */
+#define A5XX_PREEMPT_RECORD_MAGIC 0x27C4BAFCUL
+
+/*
+ * Even though the structure above is only a few bytes, we need a full 64k to
+ * store the entire preemption record from the CP
+ */
+#define A5XX_PREEMPT_RECORD_SIZE (64 * 1024)
+
+/*
+ * The preemption counter block is a storage area for the value of the
+ * preemption counters that are saved immediately before context switch. We
+ * append it on to the end of the allocadtion for the preemption record.
+ */
+#define A5XX_PREEMPT_COUNTER_SIZE (16 * 4)
+
+
int a5xx_power_init(struct msm_gpu *gpu);
void a5xx_gpmu_ucode_init(struct msm_gpu *gpu);
@@ -58,4 +151,16 @@ static inline int spin_usecs(struct msm_gpu *gpu, uint32_t usecs,
bool a5xx_idle(struct msm_gpu *gpu, struct msm_ringbuffer *ring);
+void a5xx_preempt_init(struct msm_gpu *gpu);
+void a5xx_preempt_hw_init(struct msm_gpu *gpu);
+void a5xx_preempt_trigger(struct msm_gpu *gpu);
+void a5xx_preempt_irq(struct msm_gpu *gpu);
+void a5xx_preempt_fini(struct msm_gpu *gpu);
+
+/* Return true if we are in a preempt state */
+static inline bool a5xx_in_preempt(struct a5xx_gpu *a5xx_gpu)
+{
+ return !(atomic_read(&a5xx_gpu->preempt_state) == PREEMPT_NONE);
+}
+
#endif /* __A5XX_GPU_H__ */
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_preempt.c b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
new file mode 100644
index 0000000..348ead7
--- /dev/null
+++ b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
@@ -0,0 +1,367 @@
+/* Copyright (c) 2016 The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include "msm_gem.h"
+#include "a5xx_gpu.h"
+
+static void *alloc_kernel_bo(struct drm_device *drm, struct msm_gpu *gpu,
+ size_t size, uint32_t flags, struct drm_gem_object **bo,
+ u64 *iova)
+{
+ struct drm_gem_object *_bo;
+ u64 _iova;
+ void *ptr;
+ int ret;
+
+ mutex_lock(&drm->struct_mutex);
+ _bo = msm_gem_new(drm, size, flags);
+ mutex_unlock(&drm->struct_mutex);
+
+ if (IS_ERR(_bo))
+ return _bo;
+
+ ret = msm_gem_get_iova(_bo, gpu->aspace, &_iova);
+ if (ret)
+ goto out;
+
+ ptr = msm_gem_get_vaddr(_bo);
+ if (!ptr) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (bo)
+ *bo = _bo;
+ if (iova)
+ *iova = _iova;
+
+ return ptr;
+out:
+ drm_gem_object_unreference_unlocked(_bo);
+ return ERR_PTR(ret);
+}
+
+/*
+ * Try to transition the preemption state from old to new. Return
+ * true on success or false if the original state wasn't 'old'
+ */
+static inline bool try_preempt_state(struct a5xx_gpu *a5xx_gpu,
+ enum preempt_state old, enum preempt_state new)
+{
+ enum preempt_state cur = atomic_cmpxchg(&a5xx_gpu->preempt_state,
+ old, new);
+
+ return (cur == old);
+}
+
+/*
+ * Force the preemption state to the specified state. This is used in cases
+ * where the current state is known and won't change
+ */
+static inline void set_preempt_state(struct a5xx_gpu *gpu,
+ enum preempt_state new)
+{
+ /* atomic_set() doesn't automatically do barriers, so one before.. */
+ smp_wmb();
+ atomic_set(&gpu->preempt_state, new);
+ /* ... and one after*/
+ smp_wmb();
+}
+
+/* Write the most recent wptr for the given ring into the hardware */
+static inline void update_wptr(struct msm_gpu *gpu, struct msm_ringbuffer *ring)
+{
+ unsigned long flags;
+ uint32_t wptr;
+
+ if (!ring)
+ return;
+
+ spin_lock_irqsave(&ring->lock, flags);
+ wptr = (ring->cur - ring->start) % (MSM_GPU_RINGBUFFER_SZ >> 2);
+ spin_unlock_irqrestore(&ring->lock, flags);
+
+ gpu_write(gpu, REG_A5XX_CP_RB_WPTR, wptr);
+}
+
+/* Return the highest priority ringbuffer with something in it */
+static struct msm_ringbuffer *get_next_ring(struct msm_gpu *gpu)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ unsigned long flags;
+ int i;
+
+ for (i = gpu->nr_rings - 1; i >= 0; i--) {
+ bool empty;
+ struct msm_ringbuffer *ring = gpu->rb[i];
+
+ spin_lock_irqsave(&ring->lock, flags);
+ empty = (get_wptr(ring) == adreno_gpu->memptrs->rptr[ring->id]);
+ spin_unlock_irqrestore(&ring->lock, flags);
+
+ if (!empty)
+ return ring;
+ }
+
+ return NULL;
+}
+
+static void a5xx_preempt_worker(struct work_struct *work)
+{
+ struct a5xx_gpu *a5xx_gpu =
+ container_of(work, struct a5xx_gpu, preempt_work);
+ struct msm_gpu *gpu = &a5xx_gpu->base.base;
+ struct drm_device *dev = gpu->dev;
+ struct msm_drm_private *priv = dev->dev_private;
+
+ if (atomic_read(&a5xx_gpu->preempt_state) == PREEMPT_COMPLETE) {
+ uint32_t status = gpu_read(gpu,
+ REG_A5XX_CP_CONTEXT_SWITCH_CNTL);
+
+ if (status == 0) {
+ del_timer(&a5xx_gpu->preempt_timer);
+ a5xx_gpu->cur_ring = a5xx_gpu->next_ring;
+ a5xx_gpu->next_ring = NULL;
+
+ update_wptr(gpu, a5xx_gpu->cur_ring);
+
+ set_preempt_state(a5xx_gpu, PREEMPT_NONE);
+ return;
+ }
+
+ dev_err(dev->dev, "%s: Preemption failed to complete\n",
+ gpu->name);
+ } else if (atomic_read(&a5xx_gpu->preempt_state) == PREEMPT_FAULTED)
+ dev_err(dev->dev, "%s: preemption timed out\n", gpu->name);
+ else
+ return;
+
+ /* Trigger recovery */
+ queue_work(priv->wq, &gpu->recover_work);
+}
+
+static void a5xx_preempt_timer(unsigned long data)
+{
+ struct a5xx_gpu *a5xx_gpu = (struct a5xx_gpu *) data;
+ struct msm_gpu *gpu = &a5xx_gpu->base.base;
+ struct drm_device *dev = gpu->dev;
+ struct msm_drm_private *priv = dev->dev_private;
+
+ if (!try_preempt_state(a5xx_gpu, PREEMPT_TRIGGERED, PREEMPT_FAULTED))
+ return;
+
+ queue_work(priv->wq, &a5xx_gpu->preempt_work);
+}
+
+/* Try to trigger a preemption switch */
+void a5xx_preempt_trigger(struct msm_gpu *gpu)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ unsigned long flags;
+ struct msm_ringbuffer *ring;
+
+ if (gpu->nr_rings == 1)
+ return;
+
+ /*
+ * Try to start preemption by moving from NONE to START. If
+ * unsuccessful, a preemption is already in flight
+ */
+ if (!try_preempt_state(a5xx_gpu, PREEMPT_NONE, PREEMPT_START))
+ return;
+
+ /* Get the next ring to preempt to */
+ ring = get_next_ring(gpu);
+
+ /*
+ * If no ring is populated or the highest priority ring is the current
+ * one do nothing except to update the wptr to the latest and greatest
+ */
+ if (!ring || (a5xx_gpu->cur_ring == ring)) {
+ update_wptr(gpu, ring);
+
+ /* Set the state back to NONE */
+ set_preempt_state(a5xx_gpu, PREEMPT_NONE);
+ return;
+ }
+
+ /* Make sure the wptr doesn't update while we're in motion */
+ spin_lock_irqsave(&ring->lock, flags);
+ a5xx_gpu->preempt[ring->id]->wptr = get_wptr(ring);
+ spin_unlock_irqrestore(&ring->lock, flags);
+
+ /* Set the address of the incoming preemption record */
+ gpu_write64(gpu, REG_A5XX_CP_CONTEXT_SWITCH_RESTORE_ADDR_LO,
+ REG_A5XX_CP_CONTEXT_SWITCH_RESTORE_ADDR_HI,
+ a5xx_gpu->preempt_iova[ring->id]);
+
+ a5xx_gpu->next_ring = ring;
+
+ /* Start a timer to catch a stuck preemption */
+ mod_timer(&a5xx_gpu->preempt_timer, jiffies + msecs_to_jiffies(10000));
+
+ /* Set the preemption state to triggered */
+ set_preempt_state(a5xx_gpu, PREEMPT_TRIGGERED);
+
+ /* Make sure everything is written before hitting the button */
+ wmb();
+
+ /* And actually start the preemption */
+ gpu_write(gpu, REG_A5XX_CP_CONTEXT_SWITCH_CNTL, 1);
+}
+
+void a5xx_preempt_irq(struct msm_gpu *gpu)
+{
+ uint32_t status;
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ struct drm_device *dev = gpu->dev;
+ struct msm_drm_private *priv = dev->dev_private;
+
+ if (!try_preempt_state(a5xx_gpu, PREEMPT_TRIGGERED, PREEMPT_PENDING))
+ return;
+
+ status = gpu_read(gpu, REG_A5XX_CP_CONTEXT_SWITCH_CNTL);
+ if (status) {
+ set_preempt_state(a5xx_gpu, PREEMPT_COMPLETE);
+ queue_work(priv->wq, &a5xx_gpu->preempt_work);
+ return;
+ }
+
+ del_timer(&a5xx_gpu->preempt_timer);
+
+ a5xx_gpu->cur_ring = a5xx_gpu->next_ring;
+ a5xx_gpu->next_ring = NULL;
+
+ update_wptr(gpu, a5xx_gpu->cur_ring);
+
+ set_preempt_state(a5xx_gpu, PREEMPT_NONE);
+}
+
+void a5xx_preempt_hw_init(struct msm_gpu *gpu)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ struct msm_ringbuffer *ring;
+ int i;
+
+ if (gpu->nr_rings > 1) {
+ /* Clear the preemption records */
+ FOR_EACH_RING(gpu, ring, i) {
+ if (ring) {
+ a5xx_gpu->preempt[ring->id]->wptr = 0;
+ a5xx_gpu->preempt[ring->id]->rptr = 0;
+ a5xx_gpu->preempt[ring->id]->rbase = ring->iova;
+ }
+ }
+ }
+
+ /* Write a 0 to signal that we aren't switching pagetables */
+ gpu_write64(gpu, REG_A5XX_CP_CONTEXT_SWITCH_SMMU_INFO_LO,
+ REG_A5XX_CP_CONTEXT_SWITCH_SMMU_INFO_HI, 0);
+
+ /* Reset the preemption state */
+ set_preempt_state(a5xx_gpu, PREEMPT_NONE);
+
+ /* Always come up on rb 0 */
+ a5xx_gpu->cur_ring = gpu->rb[0];
+}
+
+static int preempt_init_ring(struct a5xx_gpu *a5xx_gpu,
+ struct msm_ringbuffer *ring)
+{
+ struct adreno_gpu *adreno_gpu = &a5xx_gpu->base;
+ struct msm_gpu *gpu = &adreno_gpu->base;
+ struct a5xx_preempt_record *ptr;
+ struct drm_gem_object *bo;
+ u64 iova;
+
+ ptr = alloc_kernel_bo(gpu->dev, gpu,
+ A5XX_PREEMPT_RECORD_SIZE + A5XX_PREEMPT_COUNTER_SIZE,
+ MSM_BO_UNCACHED, &bo, &iova);
+
+ if (IS_ERR(ptr))
+ return PTR_ERR(ptr);
+
+ a5xx_gpu->preempt_bo[ring->id] = bo;
+ a5xx_gpu->preempt_iova[ring->id] = iova;
+ a5xx_gpu->preempt[ring->id] = ptr;
+
+ /* Set up the defaults on the preemption record */
+
+ ptr->magic = A5XX_PREEMPT_RECORD_MAGIC;
+ ptr->info = 0;
+ ptr->data = 0;
+ ptr->cntl = MSM_GPU_RB_CNTL_DEFAULT;
+ ptr->rptr_addr = rbmemptr(adreno_gpu, ring->id, rptr);
+ ptr->counter = iova + A5XX_PREEMPT_RECORD_SIZE;
+
+ return 0;
+}
+
+void a5xx_preempt_fini(struct msm_gpu *gpu)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ struct msm_ringbuffer *ring;
+ int i;
+
+ FOR_EACH_RING(gpu, ring, i) {
+ if (!ring || !a5xx_gpu->preempt_bo[i])
+ continue;
+
+ if (a5xx_gpu->preempt[i])
+ msm_gem_put_vaddr(a5xx_gpu->preempt_bo[i]);
+
+ if (a5xx_gpu->preempt_iova[i])
+ msm_gem_put_iova(a5xx_gpu->preempt_bo[i], gpu->aspace);
+
+ drm_gem_object_unreference_unlocked(a5xx_gpu->preempt_bo[i]);
+
+ a5xx_gpu->preempt_bo[i] = NULL;
+ }
+}
+
+void a5xx_preempt_init(struct msm_gpu *gpu)
+{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
+ struct msm_ringbuffer *ring;
+ int i;
+
+ /* No preemption if we only have one ring */
+ if (gpu->nr_rings <= 1)
+ return;
+
+ FOR_EACH_RING(gpu, ring, i) {
+ if (!ring)
+ continue;
+
+ if (preempt_init_ring(a5xx_gpu, ring)) {
+ /*
+ * On any failure our adventure is over. Clean up and
+ * set nr_rings to 1 to force preemption off
+ */
+ a5xx_preempt_fini(gpu);
+ gpu->nr_rings = 1;
+
+ return;
+ }
+ }
+
+ INIT_WORK(&a5xx_gpu->preempt_work, a5xx_preempt_worker);
+
+ setup_timer(&a5xx_gpu->preempt_timer, a5xx_preempt_timer,
+ (unsigned long) a5xx_gpu);
+}
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index aca1fc3..5149188 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -93,11 +93,6 @@ int adreno_hw_init(struct msm_gpu *gpu)
return 0;
}
-static uint32_t get_wptr(struct msm_ringbuffer *ring)
-{
- return ring->cur - ring->start;
-}
-
/* Use this helper to read rptr, since a430 doesn't update rptr in memory */
static uint32_t get_rptr(struct adreno_gpu *adreno_gpu,
struct msm_ringbuffer *ring)
@@ -145,6 +140,7 @@ void adreno_recover(struct msm_gpu *gpu)
if (!ring)
continue;
+ /* No need for a lock here, nobody else is peeking in */
ring->cur = ring->start;
ring->next = ring->start;
@@ -269,8 +265,9 @@ bool adreno_idle(struct msm_gpu *gpu, struct msm_ringbuffer *ring)
return true;
/* TODO maybe we need to reset GPU here to recover from hang? */
- DRM_ERROR("%s: timeout waiting to drain ringbuffer %d!\n", gpu->name,
- ring->id);
+ DRM_ERROR("%s: timeout waiting to drain ringbuffer %d rptr/wptr = %X/%X\n",
+ gpu->name, ring->id, get_rptr(adreno_gpu, ring), wptr);
+
return false;
}
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
index f5118ad..4fcccd4 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
@@ -334,6 +334,11 @@ static inline void adreno_gpu_write64(struct adreno_gpu *gpu,
adreno_gpu_write(gpu, hi, upper_32_bits(data));
}
+static inline uint32_t get_wptr(struct msm_ringbuffer *ring)
+{
+ return ring->cur - ring->start;
+}
+
/*
* Given a register and a count, return a value to program into
* REG_CP_PROTECT_REG(n) - this will block both reads and writes for _len
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 7ff7a83..e54baba 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -78,7 +78,7 @@ struct msm_vblank_ctrl {
spinlock_t lock;
};
-#define MSM_GPU_MAX_RINGS 1
+#define MSM_GPU_MAX_RINGS 4
struct msm_drm_private {
diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c
index b885979..f42ce09 100644
--- a/drivers/gpu/drm/msm/msm_ringbuffer.c
+++ b/drivers/gpu/drm/msm/msm_ringbuffer.c
@@ -50,6 +50,8 @@ struct msm_ringbuffer *msm_ringbuffer_new(struct msm_gpu *gpu, int id)
ring->next = ring->start;
ring->cur = ring->start;
+ spin_lock_init(&ring->lock);
+
return ring;
fail:
diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.h b/drivers/gpu/drm/msm/msm_ringbuffer.h
index 865b21a..0f91db0 100644
--- a/drivers/gpu/drm/msm/msm_ringbuffer.h
+++ b/drivers/gpu/drm/msm/msm_ringbuffer.h
@@ -29,6 +29,7 @@ struct msm_ringbuffer {
/* last_fence == completed_fence --> no pending work */
uint32_t last_fence;
uint32_t completed_fence;
+ spinlock_t lock;
};
struct msm_ringbuffer *msm_ringbuffer_new(struct msm_gpu *gpu, int id);
--
1.9.1
--
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