Files
linux/drivers/gpu/drm/v3d/v3d_gem.c
Maíra Canal e9d8e02748 drm/v3d: Replace a global spinlock with a per-queue spinlock
Each V3D queue works independently and all the dependencies between the
jobs are handled through the DRM scheduler. Therefore, there is no need
to use one single lock for all queues. Using it, creates unnecessary
contention between different queues that can operate independently.

Replace the global spinlock with per-queue locks to improve parallelism
and reduce contention between different V3D queues (BIN, RENDER, TFU,
CSD). This allows independent queues to operate concurrently while
maintaining proper synchronization within each queue.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Link: https://lore.kernel.org/r/20250826-v3d-queue-lock-v3-3-979efc43e490@igalia.com
Signed-off-by: Maíra Canal <mcanal@igalia.com>
2025-08-29 10:28:10 -03:00

344 lines
8.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/* Copyright (C) 2014-2018 Broadcom */
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/sched/signal.h>
#include <linux/uaccess.h>
#include <drm/drm_managed.h>
#include "v3d_drv.h"
#include "v3d_regs.h"
#include "v3d_trace.h"
static void
v3d_init_core(struct v3d_dev *v3d, int core)
{
/* Set OVRTMUOUT, which means that the texture sampler uniform
* configuration's tmu output type field is used, instead of
* using the hardware default behavior based on the texture
* type. If you want the default behavior, you can still put
* "2" in the indirect texture state's output_type field.
*/
if (v3d->ver < V3D_GEN_41)
V3D_CORE_WRITE(core, V3D_CTL_MISCCFG, V3D_MISCCFG_OVRTMUOUT);
/* Whenever we flush the L2T cache, we always want to flush
* the whole thing.
*/
V3D_CORE_WRITE(core, V3D_CTL_L2TFLSTA, 0);
V3D_CORE_WRITE(core, V3D_CTL_L2TFLEND, ~0);
}
/* Sets invariant state for the HW. */
static void
v3d_init_hw_state(struct v3d_dev *v3d)
{
v3d_init_core(v3d, 0);
}
static void
v3d_idle_axi(struct v3d_dev *v3d, int core)
{
V3D_CORE_WRITE(core, V3D_GMP_CFG(v3d->ver), V3D_GMP_CFG_STOP_REQ);
if (wait_for((V3D_CORE_READ(core, V3D_GMP_STATUS(v3d->ver)) &
(V3D_GMP_STATUS_RD_COUNT_MASK |
V3D_GMP_STATUS_WR_COUNT_MASK |
V3D_GMP_STATUS_CFG_BUSY)) == 0, 100)) {
DRM_ERROR("Failed to wait for safe GMP shutdown\n");
}
}
static void
v3d_idle_gca(struct v3d_dev *v3d)
{
if (v3d->ver >= V3D_GEN_41)
return;
V3D_GCA_WRITE(V3D_GCA_SAFE_SHUTDOWN, V3D_GCA_SAFE_SHUTDOWN_EN);
if (wait_for((V3D_GCA_READ(V3D_GCA_SAFE_SHUTDOWN_ACK) &
V3D_GCA_SAFE_SHUTDOWN_ACK_ACKED) ==
V3D_GCA_SAFE_SHUTDOWN_ACK_ACKED, 100)) {
DRM_ERROR("Failed to wait for safe GCA shutdown\n");
}
}
static void
v3d_reset_by_bridge(struct v3d_dev *v3d)
{
int version = V3D_BRIDGE_READ(V3D_TOP_GR_BRIDGE_REVISION);
if (V3D_GET_FIELD(version, V3D_TOP_GR_BRIDGE_MAJOR) == 2) {
V3D_BRIDGE_WRITE(V3D_TOP_GR_BRIDGE_SW_INIT_0,
V3D_TOP_GR_BRIDGE_SW_INIT_0_V3D_CLK_108_SW_INIT);
V3D_BRIDGE_WRITE(V3D_TOP_GR_BRIDGE_SW_INIT_0, 0);
/* GFXH-1383: The SW_INIT may cause a stray write to address 0
* of the unit, so reset it to its power-on value here.
*/
V3D_WRITE(V3D_HUB_AXICFG, V3D_HUB_AXICFG_MAX_LEN_MASK);
} else {
WARN_ON_ONCE(V3D_GET_FIELD(version,
V3D_TOP_GR_BRIDGE_MAJOR) != 7);
V3D_BRIDGE_WRITE(V3D_TOP_GR_BRIDGE_SW_INIT_1,
V3D_TOP_GR_BRIDGE_SW_INIT_1_V3D_CLK_108_SW_INIT);
V3D_BRIDGE_WRITE(V3D_TOP_GR_BRIDGE_SW_INIT_1, 0);
}
}
static void
v3d_reset_v3d(struct v3d_dev *v3d)
{
if (v3d->reset)
reset_control_reset(v3d->reset);
else
v3d_reset_by_bridge(v3d);
v3d_init_hw_state(v3d);
}
void
v3d_reset_sms(struct v3d_dev *v3d)
{
if (v3d->ver < V3D_GEN_71)
return;
V3D_SMS_WRITE(V3D_SMS_REE_CS, V3D_SET_FIELD(0x4, V3D_SMS_STATE));
if (wait_for(!(V3D_GET_FIELD(V3D_SMS_READ(V3D_SMS_REE_CS),
V3D_SMS_STATE) == V3D_SMS_ISOLATING_FOR_RESET) &&
!(V3D_GET_FIELD(V3D_SMS_READ(V3D_SMS_REE_CS),
V3D_SMS_STATE) == V3D_SMS_RESETTING), 100)) {
DRM_ERROR("Failed to wait for SMS reset\n");
}
}
void
v3d_reset(struct v3d_dev *v3d)
{
struct drm_device *dev = &v3d->drm;
DRM_DEV_ERROR(dev->dev, "Resetting GPU for hang.\n");
DRM_DEV_ERROR(dev->dev, "V3D_ERR_STAT: 0x%08x\n",
V3D_CORE_READ(0, V3D_ERR_STAT));
trace_v3d_reset_begin(dev);
/* XXX: only needed for safe powerdown, not reset. */
if (false)
v3d_idle_axi(v3d, 0);
v3d_irq_disable(v3d);
v3d_idle_gca(v3d);
v3d_reset_sms(v3d);
v3d_reset_v3d(v3d);
v3d_mmu_set_page_table(v3d);
v3d_irq_reset(v3d);
v3d_perfmon_stop(v3d, v3d->active_perfmon, false);
trace_v3d_reset_end(dev);
}
static void
v3d_flush_l3(struct v3d_dev *v3d)
{
if (v3d->ver < V3D_GEN_41) {
u32 gca_ctrl = V3D_GCA_READ(V3D_GCA_CACHE_CTRL);
V3D_GCA_WRITE(V3D_GCA_CACHE_CTRL,
gca_ctrl | V3D_GCA_CACHE_CTRL_FLUSH);
if (v3d->ver < V3D_GEN_33) {
V3D_GCA_WRITE(V3D_GCA_CACHE_CTRL,
gca_ctrl & ~V3D_GCA_CACHE_CTRL_FLUSH);
}
}
}
/* Invalidates the (read-only) L2C cache. This was the L2 cache for
* uniforms and instructions on V3D 3.2.
*/
static void
v3d_invalidate_l2c(struct v3d_dev *v3d, int core)
{
if (v3d->ver >= V3D_GEN_33)
return;
V3D_CORE_WRITE(core, V3D_CTL_L2CACTL,
V3D_L2CACTL_L2CCLR |
V3D_L2CACTL_L2CENA);
}
/* Invalidates texture L2 cachelines */
static void
v3d_flush_l2t(struct v3d_dev *v3d, int core)
{
/* While there is a busy bit (V3D_L2TCACTL_L2TFLS), we don't
* need to wait for completion before dispatching the job --
* L2T accesses will be stalled until the flush has completed.
* However, we do need to make sure we don't try to trigger a
* new flush while the L2_CLEAN queue is trying to
* synchronously clean after a job.
*/
mutex_lock(&v3d->cache_clean_lock);
V3D_CORE_WRITE(core, V3D_CTL_L2TCACTL,
V3D_L2TCACTL_L2TFLS |
V3D_SET_FIELD(V3D_L2TCACTL_FLM_FLUSH, V3D_L2TCACTL_FLM));
mutex_unlock(&v3d->cache_clean_lock);
}
/* Cleans texture L1 and L2 cachelines (writing back dirty data).
*
* For cleaning, which happens from the CACHE_CLEAN queue after CSD has
* executed, we need to make sure that the clean is done before
* signaling job completion. So, we synchronously wait before
* returning, and we make sure that L2 invalidates don't happen in the
* meantime to confuse our are-we-done checks.
*/
void
v3d_clean_caches(struct v3d_dev *v3d)
{
struct drm_device *dev = &v3d->drm;
int core = 0;
trace_v3d_cache_clean_begin(dev);
V3D_CORE_WRITE(core, V3D_CTL_L2TCACTL, V3D_L2TCACTL_TMUWCF);
if (wait_for(!(V3D_CORE_READ(core, V3D_CTL_L2TCACTL) &
V3D_L2TCACTL_TMUWCF), 100)) {
DRM_ERROR("Timeout waiting for TMU write combiner flush\n");
}
mutex_lock(&v3d->cache_clean_lock);
V3D_CORE_WRITE(core, V3D_CTL_L2TCACTL,
V3D_L2TCACTL_L2TFLS |
V3D_SET_FIELD(V3D_L2TCACTL_FLM_CLEAN, V3D_L2TCACTL_FLM));
if (wait_for(!(V3D_CORE_READ(core, V3D_CTL_L2TCACTL) &
V3D_L2TCACTL_L2TFLS), 100)) {
DRM_ERROR("Timeout waiting for L2T clean\n");
}
mutex_unlock(&v3d->cache_clean_lock);
trace_v3d_cache_clean_end(dev);
}
/* Invalidates the slice caches. These are read-only caches. */
static void
v3d_invalidate_slices(struct v3d_dev *v3d, int core)
{
V3D_CORE_WRITE(core, V3D_CTL_SLCACTL,
V3D_SET_FIELD(0xf, V3D_SLCACTL_TVCCS) |
V3D_SET_FIELD(0xf, V3D_SLCACTL_TDCCS) |
V3D_SET_FIELD(0xf, V3D_SLCACTL_UCC) |
V3D_SET_FIELD(0xf, V3D_SLCACTL_ICC));
}
void
v3d_invalidate_caches(struct v3d_dev *v3d)
{
/* Invalidate the caches from the outside in. That way if
* another CL's concurrent use of nearby memory were to pull
* an invalidated cacheline back in, we wouldn't leave stale
* data in the inner cache.
*/
v3d_flush_l3(v3d);
v3d_invalidate_l2c(v3d, 0);
v3d_flush_l2t(v3d, 0);
v3d_invalidate_slices(v3d, 0);
}
int
v3d_gem_init(struct drm_device *dev)
{
struct v3d_dev *v3d = to_v3d_dev(dev);
u32 pt_size = 4096 * 1024;
int ret, i;
for (i = 0; i < V3D_MAX_QUEUES; i++) {
struct v3d_queue_state *queue = &v3d->queue[i];
queue->fence_context = dma_fence_context_alloc(1);
memset(&queue->stats, 0, sizeof(queue->stats));
seqcount_init(&queue->stats.lock);
spin_lock_init(&queue->queue_lock);
}
spin_lock_init(&v3d->mm_lock);
ret = drmm_mutex_init(dev, &v3d->bo_lock);
if (ret)
return ret;
ret = drmm_mutex_init(dev, &v3d->reset_lock);
if (ret)
return ret;
ret = drmm_mutex_init(dev, &v3d->sched_lock);
if (ret)
return ret;
ret = drmm_mutex_init(dev, &v3d->cache_clean_lock);
if (ret)
return ret;
/* Note: We don't allocate address 0. Various bits of HW
* treat 0 as special, such as the occlusion query counters
* where 0 means "disabled".
*/
drm_mm_init(&v3d->mm, 1, pt_size / sizeof(u32) - 1);
v3d->pt = dma_alloc_wc(v3d->drm.dev, pt_size,
&v3d->pt_paddr,
GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
if (!v3d->pt) {
drm_mm_takedown(&v3d->mm);
dev_err(v3d->drm.dev,
"Failed to allocate page tables. Please ensure you have DMA enabled.\n");
return -ENOMEM;
}
v3d_init_hw_state(v3d);
v3d_mmu_set_page_table(v3d);
v3d_gemfs_init(v3d);
ret = v3d_sched_init(v3d);
if (ret) {
drm_mm_takedown(&v3d->mm);
dma_free_coherent(v3d->drm.dev, pt_size, (void *)v3d->pt,
v3d->pt_paddr);
return ret;
}
return 0;
}
void
v3d_gem_destroy(struct drm_device *dev)
{
struct v3d_dev *v3d = to_v3d_dev(dev);
enum v3d_queue q;
v3d_sched_fini(v3d);
v3d_gemfs_fini(v3d);
/* Waiting for jobs to finish would need to be done before
* unregistering V3D.
*/
for (q = 0; q < V3D_MAX_QUEUES; q++)
WARN_ON(v3d->queue[q].active_job);
drm_mm_takedown(&v3d->mm);
dma_free_coherent(v3d->drm.dev, 4096 * 1024, (void *)v3d->pt,
v3d->pt_paddr);
}