drm/imagination: Implement firmware infrastructure and META FW support

The infrastructure includes parsing of the firmware image, initialising
FW-side structures, handling the kernel and firmware command
ringbuffers and starting & stopping the firmware processor.

This patch also adds the necessary support code for the META firmware
processor.

Changes since v8:
- Fix documentation for pvr_fwccb_process()
- Corrected license identifiers

Changes since v6:
- Add a minimum retry count to pvr_kccb_reserve_slot_sync()

Changes since v5:
- Add workaround for BRN 71242
- Attempt to recover GPU on MMU flush command failure

Changes since v4:
- Remove use of drm_gem_shmem_get_pages()
- Remove interrupt resource name

Changes since v3:
- Hard reset FW processor on watchdog timeout
- Switch to threaded IRQ
- Rework FW object creation/initialisation to aid hard reset
- Added MODULE_FIRMWARE()
- Use drm_dev_{enter,exit}

Signed-off-by: Sarah Walker <sarah.walker@imgtec.com>
Signed-off-by: Donald Robson <donald.robson@imgtec.com>
Link: https://lore.kernel.org/r/bb52a8dc84f296b37dc6668dfe8fbaf2ba551139.1700668843.git.donald.robson@imgtec.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

1 files changed, 103 insertions, 0 deletions

diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c
index e16282325178..1be14cdbdace 100644
--- a/drivers/gpu/drm/imagination/pvr_device.c
+++ b/drivers/gpu/drm/imagination/pvr_device.c
@@ -114,6 +114,87 @@ static int pvr_device_clk_init(struct pvr_device *pvr_dev)
 	return 0;
 }
 
+static irqreturn_t pvr_device_irq_thread_handler(int irq, void *data)
+{
+	struct pvr_device *pvr_dev = data;
+	irqreturn_t ret = IRQ_NONE;
+
+	/* We are in the threaded handler, we can keep dequeuing events until we
+	 * don't see any. This should allow us to reduce the number of interrupts
+	 * when the GPU is receiving a massive amount of short jobs.
+	 */
+	while (pvr_fw_irq_pending(pvr_dev)) {
+		pvr_fw_irq_clear(pvr_dev);
+
+		if (pvr_dev->fw_dev.booted) {
+			pvr_fwccb_process(pvr_dev);
+			pvr_kccb_wake_up_waiters(pvr_dev);
+		}
+
+		pm_runtime_mark_last_busy(from_pvr_device(pvr_dev)->dev);
+
+		ret = IRQ_HANDLED;
+	}
+
+	/* Unmask FW irqs before returning, so new interrupts can be received. */
+	pvr_fw_irq_enable(pvr_dev);
+	return ret;
+}
+
+static irqreturn_t pvr_device_irq_handler(int irq, void *data)
+{
+	struct pvr_device *pvr_dev = data;
+
+	if (!pvr_fw_irq_pending(pvr_dev))
+		return IRQ_NONE; /* Spurious IRQ - ignore. */
+
+	/* Mask the FW interrupts before waking up the thread. Will be unmasked
+	 * when the thread handler is done processing events.
+	 */
+	pvr_fw_irq_disable(pvr_dev);
+	return IRQ_WAKE_THREAD;
+}
+
+/**
+ * pvr_device_irq_init() - Initialise IRQ required by a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ *
+ * Returns:
+ *  * 0 on success,
+ *  * Any error returned by platform_get_irq_byname(), or
+ *  * Any error returned by request_irq().
+ */
+static int
+pvr_device_irq_init(struct pvr_device *pvr_dev)
+{
+	struct drm_device *drm_dev = from_pvr_device(pvr_dev);
+	struct platform_device *plat_dev = to_platform_device(drm_dev->dev);
+
+	init_waitqueue_head(&pvr_dev->kccb.rtn_q);
+
+	pvr_dev->irq = platform_get_irq(plat_dev, 0);
+	if (pvr_dev->irq < 0)
+		return pvr_dev->irq;
+
+	/* Clear any pending events before requesting the IRQ line. */
+	pvr_fw_irq_clear(pvr_dev);
+	pvr_fw_irq_enable(pvr_dev);
+
+	return request_threaded_irq(pvr_dev->irq, pvr_device_irq_handler,
+				    pvr_device_irq_thread_handler,
+				    IRQF_SHARED, "gpu", pvr_dev);
+}
+
+/**
+ * pvr_device_irq_fini() - Deinitialise IRQ required by a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ */
+static void
+pvr_device_irq_fini(struct pvr_device *pvr_dev)
+{
+	free_irq(pvr_dev->irq, pvr_dev);
+}
+
 /**
  * pvr_build_firmware_filename() - Construct a PowerVR firmware filename
  * @pvr_dev: Target PowerVR device.
@@ -324,7 +405,19 @@ pvr_device_gpu_init(struct pvr_device *pvr_dev)
 			return PTR_ERR(pvr_dev->kernel_vm_ctx);
 	}
 
+	err = pvr_fw_init(pvr_dev);
+	if (err)
+		goto err_vm_ctx_put;
+
 	return 0;
+
+err_vm_ctx_put:
+	if (pvr_dev->fw_dev.processor_type != PVR_FW_PROCESSOR_TYPE_MIPS) {
+		pvr_vm_context_put(pvr_dev->kernel_vm_ctx);
+		pvr_dev->kernel_vm_ctx = NULL;
+	}
+
+	return err;
 }
 
 /**
@@ -334,6 +427,8 @@ pvr_device_gpu_init(struct pvr_device *pvr_dev)
 static void
 pvr_device_gpu_fini(struct pvr_device *pvr_dev)
 {
+	pvr_fw_fini(pvr_dev);
+
 	if (pvr_dev->fw_dev.processor_type != PVR_FW_PROCESSOR_TYPE_MIPS) {
 		WARN_ON(!pvr_vm_context_put(pvr_dev->kernel_vm_ctx));
 		pvr_dev->kernel_vm_ctx = NULL;
@@ -386,10 +481,17 @@ pvr_device_init(struct pvr_device *pvr_dev)
 	if (err)
 		goto err_pm_runtime_put;
 
+	err = pvr_device_irq_init(pvr_dev);
+	if (err)
+		goto err_device_gpu_fini;
+
 	pm_runtime_put(dev);
 
 	return 0;
 
+err_device_gpu_fini:
+	pvr_device_gpu_fini(pvr_dev);
+
 err_pm_runtime_put:
 	pm_runtime_put_sync_suspend(dev);
 
@@ -407,6 +509,7 @@ pvr_device_fini(struct pvr_device *pvr_dev)
 	 * Deinitialization stages are performed in reverse order compared to
 	 * the initialization stages in pvr_device_init().
 	 */
+	pvr_device_irq_fini(pvr_dev);
 	pvr_device_gpu_fini(pvr_dev);
 }