[PATCH v2 05/15] drm/panthor: Add the GPU logical block

[Boris Brezillon <boris.brezillon@collabora.com>]

Handles everything that's not related to the FW, the MMU or the
scheduler. This is the block dealing with the GPU property retrieval,
the GPU block power on/off logic, and some global operations, like
global cache flushing.

v2:
- Rename the driver (pancsf -> panthor)
- Change the license (GPL2 -> MIT + GPL2)
- Split the driver addition commit
- Use drm_dev_{unplug,enter,exit}() to provide safe device removal
- Use the panthor_irq layer to manage/process IRQs

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
---
 drivers/gpu/drm/panthor/panthor_gpu.c | 463 ++++++++++++++++++++++++++
 drivers/gpu/drm/panthor/panthor_gpu.h |  52 +++
 2 files changed, 515 insertions(+)
 create mode 100644 drivers/gpu/drm/panthor/panthor_gpu.c
 create mode 100644 drivers/gpu/drm/panthor/panthor_gpu.h

diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
new file mode 100644
index 000000000000..47d15334b46e
--- /dev/null
+++ b/drivers/gpu/drm/panthor/panthor_gpu.c
@@ -0,0 +1,463 @@
+// SPDX-License-Identifier: GPL-2.0 or MIT
+/* Copyright 2018 Marty E. Plummer <hanetzer@startmail.com> */
+/* Copyright 2019 Linaro, Ltd., Rob Herring <robh@kernel.org> */
+/* Copyright 2019 Collabora ltd. */
+
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_drv.h>
+#include <drm/drm_managed.h>
+
+#include "panthor_device.h"
+#include "panthor_gpu.h"
+#include "panthor_regs.h"
+
+/**
+ * struct panthor_gpu - GPU block management data.
+ */
+struct panthor_gpu {
+	/** @irq: GPU irq. */
+	struct panthor_irq irq;
+
+	/** @reqs_lock: Lock protecting access to pending_reqs. */
+	spinlock_t reqs_lock;
+
+	/** @pending_reqs: Pending GPU requests. */
+	u32 pending_reqs;
+
+	/** @reqs_acked: GPU request wait queue. */
+	wait_queue_head_t reqs_acked;
+};
+
+/**
+ * struct panthor_model - GPU model description
+ */
+struct panthor_model {
+	/** @name: Model name. */
+	const char *name;
+
+	/** @id: Model ID. */
+	u32 id;
+};
+
+/**
+ * GPU_MODEL() - Define a GPU model.
+ */
+#define GPU_MODEL(_name, _id, ...) \
+{\
+	.name = __stringify(_name),				\
+	.id = _id,						\
+}
+
+#define GPU_MODEL_ID_MASK		0xf00f0000
+
+static const struct panthor_model gpu_models[] = {
+	GPU_MODEL(g610, 0xa0070000),
+	{},
+};
+
+#define GPU_INTERRUPTS_MASK	\
+	(GPU_IRQ_FAULT | \
+	 GPU_IRQ_PROTM_FAULT | \
+	 GPU_IRQ_RESET_COMPLETED | \
+	 GPU_IRQ_MCU_STATUS_CHANGED | \
+	 GPU_IRQ_CLEAN_CACHES_COMPLETED)
+
+static void panthor_gpu_init_info(struct panthor_device *ptdev)
+{
+	const struct panthor_model *model;
+	u32 major, minor, status;
+	unsigned int i;
+
+	ptdev->gpu_info.gpu_id = gpu_read(ptdev, GPU_ID);
+	ptdev->gpu_info.csf_id = gpu_read(ptdev, GPU_CSF_ID);
+	ptdev->gpu_info.gpu_rev = gpu_read(ptdev, GPU_REVID);
+	ptdev->gpu_info.l2_features = gpu_read(ptdev, GPU_L2_FEATURES);
+	ptdev->gpu_info.tiler_features = gpu_read(ptdev, GPU_TILER_FEATURES);
+	ptdev->gpu_info.mem_features = gpu_read(ptdev, GPU_MEM_FEATURES);
+	ptdev->gpu_info.mmu_features = gpu_read(ptdev, GPU_MMU_FEATURES);
+	ptdev->gpu_info.thread_features = gpu_read(ptdev, GPU_THREAD_FEATURES);
+	ptdev->gpu_info.max_threads = gpu_read(ptdev, GPU_THREAD_MAX_THREADS);
+	ptdev->gpu_info.thread_max_workgroup_size = gpu_read(ptdev, GPU_THREAD_MAX_WORKGROUP_SIZE);
+	ptdev->gpu_info.thread_max_barrier_size = gpu_read(ptdev, GPU_THREAD_MAX_BARRIER_SIZE);
+	ptdev->gpu_info.coherency_features = gpu_read(ptdev, GPU_COHERENCY_FEATURES);
+	for (i = 0; i < 4; i++)
+		ptdev->gpu_info.texture_features[i] = gpu_read(ptdev, GPU_TEXTURE_FEATURES(i));
+
+	ptdev->gpu_info.as_present = gpu_read(ptdev, GPU_AS_PRESENT);
+
+	ptdev->gpu_info.shader_present = gpu_read(ptdev, GPU_SHADER_PRESENT_LO);
+	ptdev->gpu_info.shader_present |= (u64)gpu_read(ptdev, GPU_SHADER_PRESENT_HI) << 32;
+
+	ptdev->gpu_info.tiler_present = gpu_read(ptdev, GPU_TILER_PRESENT_LO);
+	ptdev->gpu_info.tiler_present |= (u64)gpu_read(ptdev, GPU_TILER_PRESENT_HI) << 32;
+
+	ptdev->gpu_info.l2_present = gpu_read(ptdev, GPU_L2_PRESENT_LO);
+	ptdev->gpu_info.l2_present |= (u64)gpu_read(ptdev, GPU_L2_PRESENT_HI) << 32;
+	ptdev->gpu_info.core_group_count = hweight64(ptdev->gpu_info.l2_present);
+
+	major = (ptdev->gpu_info.gpu_id >> 12) & 0xf;
+	minor = (ptdev->gpu_info.gpu_id >> 4) & 0xff;
+	status = ptdev->gpu_info.gpu_id & 0xf;
+
+	for (model = gpu_models; model->name; model++) {
+		if (model->id == (ptdev->gpu_info.gpu_id & GPU_MODEL_ID_MASK))
+			break;
+	}
+
+	drm_info(&ptdev->base,
+		 "mali-%s id 0x%x major 0x%x minor 0x%x status 0x%x",
+		 model->name ?: "unknown", ptdev->gpu_info.gpu_id >> 16,
+		 major, minor, status);
+
+	drm_info(&ptdev->base,
+		 "Features: L2:0x%08x Tiler:0x%08x Mem:0x%0x MMU:0x%08x AS:0x%x",
+		 ptdev->gpu_info.l2_features,
+		 ptdev->gpu_info.tiler_features,
+		 ptdev->gpu_info.mem_features,
+		 ptdev->gpu_info.mmu_features,
+		 ptdev->gpu_info.as_present);
+
+	drm_info(&ptdev->base,
+		 "shader_present=0x%0llx l2_present=0x%0llx tiler_present=0x%0llx",
+		 ptdev->gpu_info.shader_present, ptdev->gpu_info.l2_present,
+		 ptdev->gpu_info.tiler_present);
+}
+
+static void panthor_gpu_irq_handler(struct panthor_device *ptdev, u32 status)
+{
+	if (status & (GPU_IRQ_FAULT | GPU_IRQ_PROTM_FAULT)) {
+		u32 fault_status = gpu_read(ptdev, GPU_FAULT_STATUS);
+		u64 address = ((u64)gpu_read(ptdev, GPU_FAULT_ADDR_HI) << 32) |
+			      gpu_read(ptdev, GPU_FAULT_ADDR_LO);
+
+		drm_warn(&ptdev->base, "GPU Fault 0x%08x (%s) at 0x%016llx\n",
+			 fault_status, panthor_exception_name(ptdev, fault_status & 0xFF),
+			 address);
+	}
+
+	spin_lock(&ptdev->gpu->reqs_lock);
+	if (status & ptdev->gpu->pending_reqs) {
+		ptdev->gpu->pending_reqs &= ~status;
+		wake_up_all(&ptdev->gpu->reqs_acked);
+	}
+	spin_unlock(&ptdev->gpu->reqs_lock);
+}
+PANTHOR_IRQ_HANDLER(gpu, GPU, panthor_gpu_irq_handler);
+
+/**
+ * panthor_gpu_unplug() - Called when the GPU is unplugged.
+ */
+void panthor_gpu_unplug(struct panthor_device *ptdev)
+{
+	unsigned long flags;
+
+	/* Make sure the IRQ handler is not running after that point. */
+	panthor_gpu_irq_suspend(&ptdev->gpu->irq);
+
+	/* Wake-up all waiters. */
+	spin_lock_irqsave(&ptdev->gpu->reqs_lock, flags);
+	ptdev->gpu->pending_reqs = 0;
+	wake_up_all(&ptdev->gpu->reqs_acked);
+	spin_unlock_irqrestore(&ptdev->gpu->reqs_lock, flags);
+}
+
+/**
+ * panthor_gpu_init() - Initialize the GPU block
+ * @ptdev: Device.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int panthor_gpu_init(struct panthor_device *ptdev)
+{
+	struct panthor_gpu *gpu;
+	u32 pa_bits;
+	int ret, irq;
+
+	gpu = drmm_kzalloc(&ptdev->base, sizeof(*gpu), GFP_KERNEL);
+	if (!gpu)
+		return -ENOMEM;
+
+	spin_lock_init(&gpu->reqs_lock);
+	init_waitqueue_head(&gpu->reqs_acked);
+	ptdev->gpu = gpu;
+	panthor_gpu_init_info(ptdev);
+
+	dma_set_max_seg_size(ptdev->base.dev, UINT_MAX);
+	pa_bits = GPU_MMU_FEATURES_PA_BITS(ptdev->gpu_info.mmu_features);
+	ret = dma_set_mask_and_coherent(ptdev->base.dev, DMA_BIT_MASK(pa_bits));
+	if (ret)
+		return ret;
+
+	irq = platform_get_irq_byname(to_platform_device(ptdev->base.dev), "gpu");
+	if (irq <= 0)
+		return ret;
+
+	ret = panthor_request_gpu_irq(ptdev, &ptdev->gpu->irq, irq, GPU_INTERRUPTS_MASK);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/**
+ * panthor_gpu_block_power_off() - Power-off a specific block of the GPU
+ * @ptdev: Device.
+ * @blk_name: Block name.
+ * @pwroff_reg: Power-off register for this block.
+ * @pwrtrans_reg: Power transition register for this block.
+ * @mask: Sub-elements to power-off.
+ * @timeout_ms: Timeout in milliseconds.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int panthor_gpu_block_power_off(struct panthor_device *ptdev,
+				const char *blk_name,
+				u32 pwroff_reg, u32 pwrtrans_reg,
+				u64 mask, u32 timeout_us)
+{
+	u32 val, i;
+	int ret;
+
+	for (i = 0; i < 2; i++) {
+		u32 mask32 = mask >> (i * 32);
+
+		if (!mask32)
+			continue;
+
+		ret = readl_relaxed_poll_timeout(ptdev->iomem + pwrtrans_reg + (i * 4),
+						 val, !(mask32 & val),
+						 100, timeout_us);
+		if (ret) {
+			drm_err(&ptdev->base, "timeout waiting on %s:%llx power transition",
+				blk_name, mask);
+			return ret;
+		}
+	}
+
+	if (mask & GENMASK(31, 0))
+		gpu_write(ptdev, pwroff_reg, mask);
+
+	if (mask >> 32)
+		gpu_write(ptdev, pwroff_reg, mask >> 32);
+
+	for (i = 0; i < 2; i++) {
+		u32 mask32 = mask >> (i * 32);
+
+		if (!mask32)
+			continue;
+
+		ret = readl_relaxed_poll_timeout(ptdev->iomem + pwrtrans_reg + (i * 4),
+						 val, !(mask & val),
+						 100, timeout_us);
+		if (ret) {
+			drm_err(&ptdev->base, "timeout waiting on %s:%llx power transition",
+				blk_name, mask);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * panthor_gpu_block_power_on() - Power-on a specific block of the GPU
+ * @ptdev: Device.
+ * @blk_name: Block name.
+ * @pwron_reg: Power-on register for this block.
+ * @pwrtrans_reg: Power transition register for this block.
+ * @mask: Sub-elements to power-on.
+ * @timeout_ms: Timeout in milliseconds.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int panthor_gpu_block_power_on(struct panthor_device *ptdev,
+			       const char *blk_name,
+			       u32 pwron_reg, u32 pwrtrans_reg,
+			       u32 rdy_reg, u64 mask, u32 timeout_us)
+{
+	u32 val, i;
+	int ret;
+
+	for (i = 0; i < 2; i++) {
+		u32 mask32 = mask >> (i * 32);
+
+		if (!mask32)
+			continue;
+
+		ret = readl_relaxed_poll_timeout(ptdev->iomem + pwrtrans_reg + (i * 4),
+						 val, !(mask32 & val),
+						 100, timeout_us);
+		if (ret) {
+			drm_err(&ptdev->base, "timeout waiting on %s:%llx power transition",
+				blk_name, mask);
+			return ret;
+		}
+	}
+
+	if (mask & GENMASK(31, 0))
+		gpu_write(ptdev, pwron_reg, mask);
+
+	if (mask >> 32)
+		gpu_write(ptdev, pwron_reg + 4, mask >> 32);
+
+	for (i = 0; i < 2; i++) {
+		u32 mask32 = mask >> (i * 32);
+
+		if (!mask32)
+			continue;
+
+		ret = readl_relaxed_poll_timeout(ptdev->iomem + rdy_reg + (i * 4),
+						 val, (mask32 & val) == mask32,
+						 100, timeout_us);
+		if (ret) {
+			drm_err(&ptdev->base, "timeout waiting on %s:%llx readyness",
+				blk_name, mask);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * panthor_gpu_l2_power_on() - Power-on the L2-cache
+ * @ptdev: Device.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int panthor_gpu_l2_power_on(struct panthor_device *ptdev)
+{
+	u64 core_mask = U64_MAX;
+
+	if (ptdev->gpu_info.l2_present != 1) {
+		/*
+		 * Only support one core group now.
+		 * ~(l2_present - 1) unsets all bits in l2_present except
+		 * the bottom bit. (l2_present - 2) has all the bits in
+		 * the first core group set. AND them together to generate
+		 * a mask of cores in the first core group.
+		 */
+		core_mask = ~(ptdev->gpu_info.l2_present - 1) &
+			     (ptdev->gpu_info.l2_present - 2);
+		drm_info_once(&ptdev->base, "using only 1st core group (%lu cores from %lu)\n",
+			      hweight64(core_mask),
+			      hweight64(ptdev->gpu_info.shader_present));
+	}
+
+	return panthor_gpu_power_on(ptdev, L2,
+				    ptdev->gpu_info.l2_present & core_mask,
+				    20000);
+}
+
+/**
+ * panthor_gpu_flush_caches() - Flush caches
+ * @ptdev: Device.
+ * @l2: L2 flush type.
+ * @lsc: LSC flush type.
+ * @other: Other flush type.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int panthor_gpu_flush_caches(struct panthor_device *ptdev,
+			     u32 l2, u32 lsc, u32 other)
+{
+	bool timedout = false;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ptdev->gpu->reqs_lock, flags);
+	if (!drm_WARN_ON(&ptdev->base,
+			 ptdev->gpu->pending_reqs & GPU_IRQ_CLEAN_CACHES_COMPLETED)) {
+		ptdev->gpu->pending_reqs |= GPU_IRQ_CLEAN_CACHES_COMPLETED;
+		gpu_write(ptdev, GPU_CMD, GPU_FLUSH_CACHES(l2, lsc, other));
+	}
+	spin_unlock_irqrestore(&ptdev->gpu->reqs_lock, flags);
+
+	if (!wait_event_timeout(ptdev->gpu->reqs_acked,
+				!(ptdev->gpu->pending_reqs & GPU_IRQ_CLEAN_CACHES_COMPLETED),
+				msecs_to_jiffies(100))) {
+		spin_lock_irqsave(&ptdev->gpu->reqs_lock, flags);
+		if ((ptdev->gpu->pending_reqs & GPU_IRQ_CLEAN_CACHES_COMPLETED) != 0 &&
+		    !(gpu_read(ptdev, GPU_INT_RAWSTAT) & GPU_IRQ_CLEAN_CACHES_COMPLETED))
+			timedout = true;
+		spin_unlock_irqrestore(&ptdev->gpu->reqs_lock, flags);
+	}
+
+	if (timedout) {
+		drm_err(&ptdev->base, "Flush caches timeout");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+/**
+ * panthor_gpu_soft_reset() - Issue a soft-reset
+ * @ptdev: Device.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int panthor_gpu_soft_reset(struct panthor_device *ptdev)
+{
+	bool timedout = false;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ptdev->gpu->reqs_lock, flags);
+	if (!drm_WARN_ON(&ptdev->base,
+			 ptdev->gpu->pending_reqs & GPU_IRQ_RESET_COMPLETED)) {
+		ptdev->gpu->pending_reqs |= GPU_IRQ_RESET_COMPLETED;
+		gpu_write(ptdev, GPU_INT_CLEAR, GPU_IRQ_RESET_COMPLETED);
+		gpu_write(ptdev, GPU_CMD, GPU_SOFT_RESET);
+	}
+	spin_unlock_irqrestore(&ptdev->gpu->reqs_lock, flags);
+
+	if (!wait_event_timeout(ptdev->gpu->reqs_acked,
+				!(ptdev->gpu->pending_reqs & GPU_IRQ_RESET_COMPLETED),
+				msecs_to_jiffies(100))) {
+		spin_lock_irqsave(&ptdev->gpu->reqs_lock, flags);
+		if ((ptdev->gpu->pending_reqs & GPU_IRQ_RESET_COMPLETED) != 0 &&
+		    !(gpu_read(ptdev, GPU_INT_RAWSTAT) & GPU_IRQ_RESET_COMPLETED))
+			timedout = true;
+		spin_unlock_irqrestore(&ptdev->gpu->reqs_lock, flags);
+	}
+
+	if (timedout) {
+		drm_err(&ptdev->base, "Soft reset timeout");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+/**
+ * panthor_gpu_suspend() - Suspend the GPU block.
+ * @ptdev: Device.
+ *
+ * Soft reset and suspend the GPU irq. This should be called last
+ * in the suspend procedure, after all other blocks have been suspented.
+ */
+void panthor_gpu_suspend(struct panthor_device *ptdev)
+{
+	panthor_gpu_soft_reset(ptdev);
+	panthor_gpu_irq_suspend(&ptdev->gpu->irq);
+}
+
+/**
+ * panthor_gpu_resume() - Resume the GPU block.
+ *
+ * Resume the IRQ handler and power-on the L2-cache.
+ * The FW takes care of powering the other blocks.
+ */
+void panthor_gpu_resume(struct panthor_device *ptdev)
+{
+	panthor_gpu_irq_resume(&ptdev->gpu->irq, GPU_INTERRUPTS_MASK);
+	panthor_gpu_l2_power_on(ptdev);
+}
diff --git a/drivers/gpu/drm/panthor/panthor_gpu.h b/drivers/gpu/drm/panthor/panthor_gpu.h
new file mode 100644
index 000000000000..bba7555dd3c6
--- /dev/null
+++ b/drivers/gpu/drm/panthor/panthor_gpu.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 or MIT */
+/* Copyright 2018 Marty E. Plummer <hanetzer@startmail.com> */
+/* Copyright 2019 Collabora ltd. */
+
+#ifndef __PANTHOR_GPU_H__
+#define __PANTHOR_GPU_H__
+
+struct panthor_device;
+
+int panthor_gpu_init(struct panthor_device *ptdev);
+void panthor_gpu_unplug(struct panthor_device *ptdev);
+void panthor_gpu_suspend(struct panthor_device *ptdev);
+void panthor_gpu_resume(struct panthor_device *ptdev);
+
+int panthor_gpu_block_power_on(struct panthor_device *ptdev,
+			       const char *blk_name,
+			       u32 pwron_reg, u32 pwrtrans_reg,
+			       u32 rdy_reg, u64 mask, u32 timeout_us);
+int panthor_gpu_block_power_off(struct panthor_device *ptdev,
+				const char *blk_name,
+				u32 pwroff_reg, u32 pwrtrans_reg,
+				u64 mask, u32 timeout_us);
+
+/**
+ * panthor_gpu_power_on() - Power on the GPU block.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+#define panthor_gpu_power_on(ptdev, type, mask, timeout_us) \
+	panthor_gpu_block_power_on(ptdev, #type, \
+				  type ## _PWRON_LO, \
+				  type ## _PWRTRANS_LO, \
+				  type ## _READY_LO, \
+				  mask, timeout_us)
+
+/**
+ * panthor_gpu_power_off() - Power off the GPU block.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+#define panthor_gpu_power_off(ptdev, type, mask, timeout_us) \
+	panthor_gpu_block_power_off(ptdev, #type, \
+				   type ## _PWROFF_LO, \
+				   type ## _PWRTRANS_LO, \
+				   mask, timeout_us)
+
+int panthor_gpu_l2_power_on(struct panthor_device *ptdev);
+int panthor_gpu_flush_caches(struct panthor_device *ptdev,
+			     u32 l2, u32 lsc, u32 other);
+int panthor_gpu_soft_reset(struct panthor_device *ptdev);
+
+#endif
-- 
2.41.0