[PATCH v5 03/14] drm/panthor: Add the device logical block

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

The panthor driver is designed in a modular way, where each logical
block is dealing with a specific HW-block or software feature. In order
for those blocks to communicate with each other, we need a central
panthor_device collecting all the blocks, and exposing some common
features, like interrupt handling, power management, reset, ...

This what this panthor_device logical block is about.

v5:
- Suspend the MMU/GPU blocks if panthor_fw_resume() fails in
  panthor_device_resume()
- Move the pm_runtime_use_autosuspend() call before drm_dev_register()
- Add Liviu's R-b

v4:
- Check drmm_mutex_init() return code
- Fix panthor_device_reset_work() out path
- Fix the race in the unplug logic
- Fix typos
- Unplug blocks when something fails in panthor_device_init()
- Add Steve's R-b

v3:
- Add acks for the MIT+GPL2 relicensing
- Fix 32-bit support
- Shorten the sections protected by panthor_device::pm::mmio_lock to fix
  lock ordering issues.
- Rename panthor_device::pm::lock into panthor_device::pm::mmio_lock to
  better reflect what this lock is protecting
- Use dev_err_probe()
- Make sure we call drm_dev_exit() when something fails half-way in
  panthor_device_reset_work()
- Replace CSF_GPU_LATEST_FLUSH_ID_DEFAULT with a constant '1' and a
  comment to explain. Also remove setting the dummy flush ID on suspend.
- Remove drm_WARN_ON() in panthor_exception_name()
- Check pirq->suspended in panthor_xxx_irq_raw_handler()

Co-developed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Steven Price <steven.price@arm.com> # MIT+GPL2 relicensing,Arm
Acked-by: Grant Likely <grant.likely@linaro.org> # MIT+GPL2 relicensing,Linaro
Acked-by: Boris Brezillon <boris.brezillon@collabora.com> # MIT+GPL2 relicensing,Collabora
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
---
 drivers/gpu/drm/panthor/panthor_device.c | 549 +++++++++++++++++++++++
 drivers/gpu/drm/panthor/panthor_device.h | 393 ++++++++++++++++
 2 files changed, 942 insertions(+)
 create mode 100644 drivers/gpu/drm/panthor/panthor_device.c
 create mode 100644 drivers/gpu/drm/panthor/panthor_device.h

diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
new file mode 100644
index 000000000000..b49939f56a0a
--- /dev/null
+++ b/drivers/gpu/drm/panthor/panthor_device.c
@@ -0,0 +1,549 @@
+// 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 2023 Collabora ltd. */
+
+#include <linux/clk.h>
+#include <linux/reset.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_drv.h>
+#include <drm/drm_managed.h>
+
+#include "panthor_sched.h"
+#include "panthor_device.h"
+#include "panthor_devfreq.h"
+#include "panthor_gpu.h"
+#include "panthor_fw.h"
+#include "panthor_mmu.h"
+#include "panthor_regs.h"
+
+static int panthor_clk_init(struct panthor_device *ptdev)
+{
+	ptdev->clks.core = devm_clk_get(ptdev->base.dev, NULL);
+	if (IS_ERR(ptdev->clks.core))
+		return dev_err_probe(ptdev->base.dev,
+				     PTR_ERR(ptdev->clks.core),
+				     "get 'core' clock failed");
+
+	ptdev->clks.stacks = devm_clk_get_optional(ptdev->base.dev, "stacks");
+	if (IS_ERR(ptdev->clks.stacks))
+		return dev_err_probe(ptdev->base.dev,
+				     PTR_ERR(ptdev->clks.stacks),
+				     "get 'stacks' clock failed");
+
+	ptdev->clks.coregroup = devm_clk_get_optional(ptdev->base.dev, "coregroup");
+	if (IS_ERR(ptdev->clks.coregroup))
+		return dev_err_probe(ptdev->base.dev,
+				     PTR_ERR(ptdev->clks.coregroup),
+				     "get 'coregroup' clock failed");
+
+	drm_info(&ptdev->base, "clock rate = %lu\n", clk_get_rate(ptdev->clks.core));
+	return 0;
+}
+
+void panthor_device_unplug(struct panthor_device *ptdev)
+{
+	/* This function can be called from two different path: the reset work
+	 * and the platform device remove callback. drm_dev_unplug() doesn't
+	 * deal with concurrent callers, so we have to protect drm_dev_unplug()
+	 * calls with our own lock, and bail out if the device is already
+	 * unplugged.
+	 */
+	mutex_lock(&ptdev->unplug.lock);
+	if (drm_dev_is_unplugged(&ptdev->base)) {
+		/* Someone beat us, release the lock and wait for the unplug
+		 * operation to be reported as done.
+		 **/
+		mutex_unlock(&ptdev->unplug.lock);
+		wait_for_completion(&ptdev->unplug.done);
+		return;
+	}
+
+	/* Call drm_dev_unplug() so any access to HW blocks happening after
+	 * that point get rejected.
+	 */
+	drm_dev_unplug(&ptdev->base);
+
+	/* We do the rest of the unplug with the unplug lock released,
+	 * future callers will wait on ptdev->unplug.done anyway.
+	 */
+	mutex_unlock(&ptdev->unplug.lock);
+
+	drm_WARN_ON(&ptdev->base, pm_runtime_get_sync(ptdev->base.dev) < 0);
+
+	/* Now, try to cleanly shutdown the GPU before the device resources
+	 * get reclaimed.
+	 */
+	panthor_sched_unplug(ptdev);
+	panthor_fw_unplug(ptdev);
+	panthor_mmu_unplug(ptdev);
+	panthor_gpu_unplug(ptdev);
+
+	pm_runtime_dont_use_autosuspend(ptdev->base.dev);
+	pm_runtime_put_sync_suspend(ptdev->base.dev);
+
+	/* Report the unplug operation as done to unblock concurrent
+	 * panthor_device_unplug() callers.
+	 */
+	complete_all(&ptdev->unplug.done);
+}
+
+static void panthor_device_reset_cleanup(struct drm_device *ddev, void *data)
+{
+	struct panthor_device *ptdev = container_of(ddev, struct panthor_device, base);
+
+	cancel_work_sync(&ptdev->reset.work);
+	destroy_workqueue(ptdev->reset.wq);
+}
+
+static void panthor_device_reset_work(struct work_struct *work)
+{
+	struct panthor_device *ptdev = container_of(work, struct panthor_device, reset.work);
+	int ret = 0, cookie;
+
+	if (atomic_read(&ptdev->pm.state) != PANTHOR_DEVICE_PM_STATE_ACTIVE) {
+		/*
+		 * No need for a reset as the device has been (or will be)
+		 * powered down
+		 */
+		atomic_set(&ptdev->reset.pending, 0);
+		return;
+	}
+
+	if (!drm_dev_enter(&ptdev->base, &cookie))
+		return;
+
+	panthor_sched_pre_reset(ptdev);
+	panthor_fw_pre_reset(ptdev, true);
+	panthor_mmu_pre_reset(ptdev);
+	panthor_gpu_soft_reset(ptdev);
+	panthor_gpu_l2_power_on(ptdev);
+	panthor_mmu_post_reset(ptdev);
+	ret = panthor_fw_post_reset(ptdev);
+	if (ret)
+		goto out_dev_exit;
+
+	atomic_set(&ptdev->reset.pending, 0);
+	panthor_sched_post_reset(ptdev);
+
+out_dev_exit:
+	drm_dev_exit(cookie);
+
+	if (ret) {
+		panthor_device_unplug(ptdev);
+		drm_err(&ptdev->base, "Failed to boot MCU after reset, making device unusable.");
+	}
+}
+
+static bool panthor_device_is_initialized(struct panthor_device *ptdev)
+{
+	return !!ptdev->scheduler;
+}
+
+static void panthor_device_free_page(struct drm_device *ddev, void *data)
+{
+	free_page((unsigned long)data);
+}
+
+int panthor_device_init(struct panthor_device *ptdev)
+{
+	struct resource *res;
+	struct page *p;
+	int ret;
+
+	ptdev->coherent = device_get_dma_attr(ptdev->base.dev) == DEV_DMA_COHERENT;
+
+	init_completion(&ptdev->unplug.done);
+	ret = drmm_mutex_init(&ptdev->base, &ptdev->unplug.lock);
+	if (ret)
+		return ret;
+
+	ret = drmm_mutex_init(&ptdev->base, &ptdev->pm.mmio_lock);
+	if (ret)
+		return ret;
+
+	atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_SUSPENDED);
+	p = alloc_page(GFP_KERNEL | __GFP_ZERO);
+	if (!p)
+		return -ENOMEM;
+
+	ptdev->pm.dummy_latest_flush = page_address(p);
+	ret = drmm_add_action_or_reset(&ptdev->base, panthor_device_free_page,
+				       ptdev->pm.dummy_latest_flush);
+	if (ret)
+		return ret;
+
+	/*
+	 * Set the dummy page holding the latest flush to 1. This will cause the
+	 * flush to avoided as we know it isn't necessary if the submission
+	 * happens while the dummy page is mapped. Zero cannot be used because
+	 * that means 'always flush'.
+	 */
+	*ptdev->pm.dummy_latest_flush = 1;
+
+	INIT_WORK(&ptdev->reset.work, panthor_device_reset_work);
+	ptdev->reset.wq = alloc_ordered_workqueue("panthor-reset-wq", 0);
+	if (!ptdev->reset.wq)
+		return -ENOMEM;
+
+	ret = drmm_add_action_or_reset(&ptdev->base, panthor_device_reset_cleanup, NULL);
+	if (ret)
+		return ret;
+
+	ret = panthor_clk_init(ptdev);
+	if (ret)
+		return ret;
+
+	ret = panthor_devfreq_init(ptdev);
+	if (ret)
+		return ret;
+
+	ptdev->iomem = devm_platform_get_and_ioremap_resource(to_platform_device(ptdev->base.dev),
+							      0, &res);
+	if (IS_ERR(ptdev->iomem))
+		return PTR_ERR(ptdev->iomem);
+
+	ptdev->phys_addr = res->start;
+
+	ret = devm_pm_runtime_enable(ptdev->base.dev);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_resume_and_get(ptdev->base.dev);
+	if (ret)
+		return ret;
+
+	ret = panthor_gpu_init(ptdev);
+	if (ret)
+		goto err_rpm_put;
+
+	ret = panthor_mmu_init(ptdev);
+	if (ret)
+		goto err_unplug_gpu;
+
+	ret = panthor_fw_init(ptdev);
+	if (ret)
+		goto err_unplug_mmu;
+
+	ret = panthor_sched_init(ptdev);
+	if (ret)
+		goto err_unplug_fw;
+
+	/* ~3 frames */
+	pm_runtime_set_autosuspend_delay(ptdev->base.dev, 50);
+	pm_runtime_use_autosuspend(ptdev->base.dev);
+
+	ret = drm_dev_register(&ptdev->base, 0);
+	if (ret)
+		goto err_disable_autosuspend;
+
+	pm_runtime_put_autosuspend(ptdev->base.dev);
+	return 0;
+
+err_disable_autosuspend:
+	pm_runtime_dont_use_autosuspend(ptdev->base.dev);
+	panthor_sched_unplug(ptdev);
+
+err_unplug_fw:
+	panthor_fw_unplug(ptdev);
+
+err_unplug_mmu:
+	panthor_mmu_unplug(ptdev);
+
+err_unplug_gpu:
+	panthor_gpu_unplug(ptdev);
+
+err_rpm_put:
+	pm_runtime_put_sync_suspend(ptdev->base.dev);
+	return ret;
+}
+
+#define PANTHOR_EXCEPTION(id) \
+	[DRM_PANTHOR_EXCEPTION_ ## id] = { \
+		.name = #id, \
+	}
+
+struct panthor_exception_info {
+	const char *name;
+};
+
+static const struct panthor_exception_info panthor_exception_infos[] = {
+	PANTHOR_EXCEPTION(OK),
+	PANTHOR_EXCEPTION(TERMINATED),
+	PANTHOR_EXCEPTION(KABOOM),
+	PANTHOR_EXCEPTION(EUREKA),
+	PANTHOR_EXCEPTION(ACTIVE),
+	PANTHOR_EXCEPTION(CS_RES_TERM),
+	PANTHOR_EXCEPTION(CS_CONFIG_FAULT),
+	PANTHOR_EXCEPTION(CS_ENDPOINT_FAULT),
+	PANTHOR_EXCEPTION(CS_BUS_FAULT),
+	PANTHOR_EXCEPTION(CS_INSTR_INVALID),
+	PANTHOR_EXCEPTION(CS_CALL_STACK_OVERFLOW),
+	PANTHOR_EXCEPTION(CS_INHERIT_FAULT),
+	PANTHOR_EXCEPTION(INSTR_INVALID_PC),
+	PANTHOR_EXCEPTION(INSTR_INVALID_ENC),
+	PANTHOR_EXCEPTION(INSTR_BARRIER_FAULT),
+	PANTHOR_EXCEPTION(DATA_INVALID_FAULT),
+	PANTHOR_EXCEPTION(TILE_RANGE_FAULT),
+	PANTHOR_EXCEPTION(ADDR_RANGE_FAULT),
+	PANTHOR_EXCEPTION(IMPRECISE_FAULT),
+	PANTHOR_EXCEPTION(OOM),
+	PANTHOR_EXCEPTION(CSF_FW_INTERNAL_ERROR),
+	PANTHOR_EXCEPTION(CSF_RES_EVICTION_TIMEOUT),
+	PANTHOR_EXCEPTION(GPU_BUS_FAULT),
+	PANTHOR_EXCEPTION(GPU_SHAREABILITY_FAULT),
+	PANTHOR_EXCEPTION(SYS_SHAREABILITY_FAULT),
+	PANTHOR_EXCEPTION(GPU_CACHEABILITY_FAULT),
+	PANTHOR_EXCEPTION(TRANSLATION_FAULT_0),
+	PANTHOR_EXCEPTION(TRANSLATION_FAULT_1),
+	PANTHOR_EXCEPTION(TRANSLATION_FAULT_2),
+	PANTHOR_EXCEPTION(TRANSLATION_FAULT_3),
+	PANTHOR_EXCEPTION(TRANSLATION_FAULT_4),
+	PANTHOR_EXCEPTION(PERM_FAULT_0),
+	PANTHOR_EXCEPTION(PERM_FAULT_1),
+	PANTHOR_EXCEPTION(PERM_FAULT_2),
+	PANTHOR_EXCEPTION(PERM_FAULT_3),
+	PANTHOR_EXCEPTION(ACCESS_FLAG_1),
+	PANTHOR_EXCEPTION(ACCESS_FLAG_2),
+	PANTHOR_EXCEPTION(ACCESS_FLAG_3),
+	PANTHOR_EXCEPTION(ADDR_SIZE_FAULT_IN),
+	PANTHOR_EXCEPTION(ADDR_SIZE_FAULT_OUT0),
+	PANTHOR_EXCEPTION(ADDR_SIZE_FAULT_OUT1),
+	PANTHOR_EXCEPTION(ADDR_SIZE_FAULT_OUT2),
+	PANTHOR_EXCEPTION(ADDR_SIZE_FAULT_OUT3),
+	PANTHOR_EXCEPTION(MEM_ATTR_FAULT_0),
+	PANTHOR_EXCEPTION(MEM_ATTR_FAULT_1),
+	PANTHOR_EXCEPTION(MEM_ATTR_FAULT_2),
+	PANTHOR_EXCEPTION(MEM_ATTR_FAULT_3),
+};
+
+const char *panthor_exception_name(struct panthor_device *ptdev, u32 exception_code)
+{
+	if (exception_code >= ARRAY_SIZE(panthor_exception_infos) ||
+	    !panthor_exception_infos[exception_code].name)
+		return "Unknown exception type";
+
+	return panthor_exception_infos[exception_code].name;
+}
+
+static vm_fault_t panthor_mmio_vm_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct panthor_device *ptdev = vma->vm_private_data;
+	u64 id = (u64)vma->vm_pgoff << PAGE_SHIFT;
+	unsigned long pfn;
+	pgprot_t pgprot;
+	vm_fault_t ret;
+	bool active;
+	int cookie;
+
+	if (!drm_dev_enter(&ptdev->base, &cookie))
+		return VM_FAULT_SIGBUS;
+
+	mutex_lock(&ptdev->pm.mmio_lock);
+	active = atomic_read(&ptdev->pm.state) == PANTHOR_DEVICE_PM_STATE_ACTIVE;
+
+	switch (panthor_device_mmio_offset(id)) {
+	case DRM_PANTHOR_USER_FLUSH_ID_MMIO_OFFSET:
+		if (active)
+			pfn = __phys_to_pfn(ptdev->phys_addr + CSF_GPU_LATEST_FLUSH_ID);
+		else
+			pfn = virt_to_pfn(ptdev->pm.dummy_latest_flush);
+		break;
+
+	default:
+		ret = VM_FAULT_SIGBUS;
+		goto out_unlock;
+	}
+
+	pgprot = vma->vm_page_prot;
+	if (active)
+		pgprot = pgprot_noncached(pgprot);
+
+	ret = vmf_insert_pfn_prot(vma, vmf->address, pfn, pgprot);
+
+out_unlock:
+	mutex_unlock(&ptdev->pm.mmio_lock);
+	drm_dev_exit(cookie);
+	return ret;
+}
+
+static const struct vm_operations_struct panthor_mmio_vm_ops = {
+	.fault = panthor_mmio_vm_fault,
+};
+
+int panthor_device_mmap_io(struct panthor_device *ptdev, struct vm_area_struct *vma)
+{
+	u64 id = (u64)vma->vm_pgoff << PAGE_SHIFT;
+
+	switch (panthor_device_mmio_offset(id)) {
+	case DRM_PANTHOR_USER_FLUSH_ID_MMIO_OFFSET:
+		if (vma->vm_end - vma->vm_start != PAGE_SIZE ||
+		    (vma->vm_flags & (VM_WRITE | VM_EXEC)))
+			return -EINVAL;
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	/* Defer actual mapping to the fault handler. */
+	vma->vm_private_data = ptdev;
+	vma->vm_ops = &panthor_mmio_vm_ops;
+	vm_flags_set(vma,
+		     VM_IO | VM_DONTCOPY | VM_DONTEXPAND |
+		     VM_NORESERVE | VM_DONTDUMP | VM_PFNMAP);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+int panthor_device_resume(struct device *dev)
+{
+	struct panthor_device *ptdev = dev_get_drvdata(dev);
+	int ret, cookie;
+
+	if (atomic_read(&ptdev->pm.state) != PANTHOR_DEVICE_PM_STATE_SUSPENDED)
+		return -EINVAL;
+
+	atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_RESUMING);
+
+	ret = clk_prepare_enable(ptdev->clks.core);
+	if (ret)
+		goto err_set_suspended;
+
+	ret = clk_prepare_enable(ptdev->clks.stacks);
+	if (ret)
+		goto err_disable_core_clk;
+
+	ret = clk_prepare_enable(ptdev->clks.coregroup);
+	if (ret)
+		goto err_disable_stacks_clk;
+
+	ret = panthor_devfreq_resume(ptdev);
+	if (ret)
+		goto err_disable_coregroup_clk;
+
+	if (panthor_device_is_initialized(ptdev) &&
+	    drm_dev_enter(&ptdev->base, &cookie)) {
+		panthor_gpu_resume(ptdev);
+		panthor_mmu_resume(ptdev);
+		ret = drm_WARN_ON(&ptdev->base, panthor_fw_resume(ptdev));
+		if (!ret) {
+			panthor_sched_resume(ptdev);
+		} else {
+			panthor_mmu_suspend(ptdev);
+			panthor_gpu_suspend(ptdev);
+		}
+
+		drm_dev_exit(cookie);
+
+		if (ret)
+			goto err_suspend_devfreq;
+	}
+
+	if (atomic_read(&ptdev->reset.pending))
+		queue_work(ptdev->reset.wq, &ptdev->reset.work);
+
+	/* Clear all IOMEM mappings pointing to this device after we've
+	 * resumed. This way the fake mappings pointing to the dummy pages
+	 * are removed and the real iomem mapping will be restored on next
+	 * access.
+	 */
+	mutex_lock(&ptdev->pm.mmio_lock);
+	unmap_mapping_range(ptdev->base.anon_inode->i_mapping,
+			    DRM_PANTHOR_USER_MMIO_OFFSET, 0, 1);
+	atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_ACTIVE);
+	mutex_unlock(&ptdev->pm.mmio_lock);
+	return 0;
+
+err_suspend_devfreq:
+	panthor_devfreq_suspend(ptdev);
+
+err_disable_coregroup_clk:
+	clk_disable_unprepare(ptdev->clks.coregroup);
+
+err_disable_stacks_clk:
+	clk_disable_unprepare(ptdev->clks.stacks);
+
+err_disable_core_clk:
+	clk_disable_unprepare(ptdev->clks.core);
+
+err_set_suspended:
+	atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_SUSPENDED);
+	return ret;
+}
+
+int panthor_device_suspend(struct device *dev)
+{
+	struct panthor_device *ptdev = dev_get_drvdata(dev);
+	int ret, cookie;
+
+	if (atomic_read(&ptdev->pm.state) != PANTHOR_DEVICE_PM_STATE_ACTIVE)
+		return -EINVAL;
+
+	/* Clear all IOMEM mappings pointing to this device before we
+	 * shutdown the power-domain and clocks. Failing to do that results
+	 * in external aborts when the process accesses the iomem region.
+	 * We change the state and call unmap_mapping_range() with the
+	 * mmio_lock held to make sure the vm_fault handler won't set up
+	 * invalid mappings.
+	 */
+	mutex_lock(&ptdev->pm.mmio_lock);
+	atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_SUSPENDING);
+	unmap_mapping_range(ptdev->base.anon_inode->i_mapping,
+			    DRM_PANTHOR_USER_MMIO_OFFSET, 0, 1);
+	mutex_unlock(&ptdev->pm.mmio_lock);
+
+	if (panthor_device_is_initialized(ptdev) &&
+	    drm_dev_enter(&ptdev->base, &cookie)) {
+		cancel_work_sync(&ptdev->reset.work);
+
+		/* We prepare everything as if we were resetting the GPU.
+		 * The end of the reset will happen in the resume path though.
+		 */
+		panthor_sched_suspend(ptdev);
+		panthor_fw_suspend(ptdev);
+		panthor_mmu_suspend(ptdev);
+		panthor_gpu_suspend(ptdev);
+		drm_dev_exit(cookie);
+	}
+
+	ret = panthor_devfreq_suspend(ptdev);
+	if (ret) {
+		if (panthor_device_is_initialized(ptdev) &&
+		    drm_dev_enter(&ptdev->base, &cookie)) {
+			panthor_gpu_resume(ptdev);
+			panthor_mmu_resume(ptdev);
+			drm_WARN_ON(&ptdev->base, panthor_fw_resume(ptdev));
+			panthor_sched_resume(ptdev);
+			drm_dev_exit(cookie);
+		}
+
+		goto err_set_active;
+	}
+
+	clk_disable_unprepare(ptdev->clks.coregroup);
+	clk_disable_unprepare(ptdev->clks.stacks);
+	clk_disable_unprepare(ptdev->clks.core);
+	atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_SUSPENDED);
+	return 0;
+
+err_set_active:
+	/* If something failed and we have to revert back to an
+	 * active state, we also need to clear the MMIO userspace
+	 * mappings, so any dumb pages that were mapped while we
+	 * were trying to suspend gets invalidated.
+	 */
+	mutex_lock(&ptdev->pm.mmio_lock);
+	atomic_set(&ptdev->pm.state, PANTHOR_DEVICE_PM_STATE_ACTIVE);
+	unmap_mapping_range(ptdev->base.anon_inode->i_mapping,
+			    DRM_PANTHOR_USER_MMIO_OFFSET, 0, 1);
+	mutex_unlock(&ptdev->pm.mmio_lock);
+	return ret;
+}
+#endif
diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
new file mode 100644
index 000000000000..7e385541b448
--- /dev/null
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -0,0 +1,393 @@
+/* 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 2023 Collabora ltd. */
+
+#ifndef __PANTHOR_DEVICE_H__
+#define __PANTHOR_DEVICE_H__
+
+#include <linux/atomic.h>
+#include <linux/io-pgtable.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <drm/drm_device.h>
+#include <drm/drm_mm.h>
+#include <drm/gpu_scheduler.h>
+#include <drm/panthor_drm.h>
+
+struct panthor_csf;
+struct panthor_csf_ctx;
+struct panthor_device;
+struct panthor_gpu;
+struct panthor_group_pool;
+struct panthor_heap_pool;
+struct panthor_job;
+struct panthor_mmu;
+struct panthor_fw;
+struct panthor_perfcnt;
+struct panthor_vm;
+struct panthor_vm_pool;
+
+/**
+ * enum panthor_device_pm_state - PM state
+ */
+enum panthor_device_pm_state {
+	/** @PANTHOR_DEVICE_PM_STATE_SUSPENDED: Device is suspended. */
+	PANTHOR_DEVICE_PM_STATE_SUSPENDED = 0,
+
+	/** @PANTHOR_DEVICE_PM_STATE_RESUMING: Device is being resumed. */
+	PANTHOR_DEVICE_PM_STATE_RESUMING,
+
+	/** @PANTHOR_DEVICE_PM_STATE_ACTIVE: Device is active. */
+	PANTHOR_DEVICE_PM_STATE_ACTIVE,
+
+	/** @PANTHOR_DEVICE_PM_STATE_SUSPENDING: Device is being suspended. */
+	PANTHOR_DEVICE_PM_STATE_SUSPENDING,
+};
+
+/**
+ * struct panthor_irq - IRQ data
+ *
+ * Used to automate IRQ handling for the 3 different IRQs we have in this driver.
+ */
+struct panthor_irq {
+	/** @ptdev: Panthor device */
+	struct panthor_device *ptdev;
+
+	/** @irq: IRQ number. */
+	int irq;
+
+	/** @mask: Current mask being applied to xxx_INT_MASK. */
+	u32 mask;
+
+	/** @suspended: Set to true when the IRQ is suspended. */
+	atomic_t suspended;
+};
+
+/**
+ * struct panthor_device - Panthor device
+ */
+struct panthor_device {
+	/** @base: Base drm_device. */
+	struct drm_device base;
+
+	/** @phys_addr: Physical address of the iomem region. */
+	phys_addr_t phys_addr;
+
+	/** @iomem: CPU mapping of the IOMEM region. */
+	void __iomem *iomem;
+
+	/** @clks: GPU clocks. */
+	struct {
+		/** @core: Core clock. */
+		struct clk *core;
+
+		/** @stacks: Stacks clock. This clock is optional. */
+		struct clk *stacks;
+
+		/** @coregroup: Core group clock. This clock is optional. */
+		struct clk *coregroup;
+	} clks;
+
+	/** @coherent: True if the CPU/GPU are memory coherent. */
+	bool coherent;
+
+	/** @gpu_info: GPU information. */
+	struct drm_panthor_gpu_info gpu_info;
+
+	/** @csif_info: Command stream interface information. */
+	struct drm_panthor_csif_info csif_info;
+
+	/** @gpu: GPU management data. */
+	struct panthor_gpu *gpu;
+
+	/** @fw: FW management data. */
+	struct panthor_fw *fw;
+
+	/** @mmu: MMU management data. */
+	struct panthor_mmu *mmu;
+
+	/** @scheduler: Scheduler management data. */
+	struct panthor_scheduler *scheduler;
+
+	/** @devfreq: Device frequency scaling management data. */
+	struct panthor_devfreq *devfreq;
+
+	/** @unplug: Device unplug related fields. */
+	struct {
+		/** @lock: Lock used to serialize unplug operations. */
+		struct mutex lock;
+
+		/**
+		 * @done: Completion object signaled when the unplug
+		 * operation is done.
+		 */
+		struct completion done;
+	} unplug;
+
+	/** @reset: Reset related fields. */
+	struct {
+		/** @wq: Ordered worqueud used to schedule reset operations. */
+		struct workqueue_struct *wq;
+
+		/** @work: Reset work. */
+		struct work_struct work;
+
+		/** @pending: Set to true if a reset is pending. */
+		atomic_t pending;
+	} reset;
+
+	/** @pm: Power management related data. */
+	struct {
+		/** @state: Power state. */
+		atomic_t state;
+
+		/**
+		 * @mmio_lock: Lock protecting MMIO userspace CPU mappings.
+		 *
+		 * This is needed to ensure we map the dummy IO pages when
+		 * the device is being suspended, and the real IO pages when
+		 * the device is being resumed. We can't just do with the
+		 * state atomicity to deal with this race.
+		 */
+		struct mutex mmio_lock;
+
+		/**
+		 * @dummy_latest_flush: Dummy LATEST_FLUSH page.
+		 *
+		 * Used to replace the real LATEST_FLUSH page when the GPU
+		 * is suspended.
+		 */
+		u32 *dummy_latest_flush;
+	} pm;
+};
+
+/**
+ * struct panthor_file - Panthor file
+ */
+struct panthor_file {
+	/** @ptdev: Device attached to this file. */
+	struct panthor_device *ptdev;
+
+	/** @vms: VM pool attached to this file. */
+	struct panthor_vm_pool *vms;
+
+	/** @groups: Scheduling group pool attached to this file. */
+	struct panthor_group_pool *groups;
+};
+
+int panthor_device_init(struct panthor_device *ptdev);
+void panthor_device_unplug(struct panthor_device *ptdev);
+
+/**
+ * panthor_device_schedule_reset() - Schedules a reset operation
+ */
+static inline void panthor_device_schedule_reset(struct panthor_device *ptdev)
+{
+	if (!atomic_cmpxchg(&ptdev->reset.pending, 0, 1) &&
+	    atomic_read(&ptdev->pm.state) == PANTHOR_DEVICE_PM_STATE_ACTIVE)
+		queue_work(ptdev->reset.wq, &ptdev->reset.work);
+}
+
+/**
+ * panthor_device_reset_is_pending() - Checks if a reset is pending.
+ *
+ * Return: true if a reset is pending, false otherwise.
+ */
+static inline bool panthor_device_reset_is_pending(struct panthor_device *ptdev)
+{
+	return atomic_read(&ptdev->reset.pending) != 0;
+}
+
+int panthor_device_mmap_io(struct panthor_device *ptdev,
+			   struct vm_area_struct *vma);
+
+int panthor_device_resume(struct device *dev);
+int panthor_device_suspend(struct device *dev);
+
+enum drm_panthor_exception_type {
+	DRM_PANTHOR_EXCEPTION_OK = 0x00,
+	DRM_PANTHOR_EXCEPTION_TERMINATED = 0x04,
+	DRM_PANTHOR_EXCEPTION_KABOOM = 0x05,
+	DRM_PANTHOR_EXCEPTION_EUREKA = 0x06,
+	DRM_PANTHOR_EXCEPTION_ACTIVE = 0x08,
+	DRM_PANTHOR_EXCEPTION_CS_RES_TERM = 0x0f,
+	DRM_PANTHOR_EXCEPTION_MAX_NON_FAULT = 0x3f,
+	DRM_PANTHOR_EXCEPTION_CS_CONFIG_FAULT = 0x40,
+	DRM_PANTHOR_EXCEPTION_CS_ENDPOINT_FAULT = 0x44,
+	DRM_PANTHOR_EXCEPTION_CS_BUS_FAULT = 0x48,
+	DRM_PANTHOR_EXCEPTION_CS_INSTR_INVALID = 0x49,
+	DRM_PANTHOR_EXCEPTION_CS_CALL_STACK_OVERFLOW = 0x4a,
+	DRM_PANTHOR_EXCEPTION_CS_INHERIT_FAULT = 0x4b,
+	DRM_PANTHOR_EXCEPTION_INSTR_INVALID_PC = 0x50,
+	DRM_PANTHOR_EXCEPTION_INSTR_INVALID_ENC = 0x51,
+	DRM_PANTHOR_EXCEPTION_INSTR_BARRIER_FAULT = 0x55,
+	DRM_PANTHOR_EXCEPTION_DATA_INVALID_FAULT = 0x58,
+	DRM_PANTHOR_EXCEPTION_TILE_RANGE_FAULT = 0x59,
+	DRM_PANTHOR_EXCEPTION_ADDR_RANGE_FAULT = 0x5a,
+	DRM_PANTHOR_EXCEPTION_IMPRECISE_FAULT = 0x5b,
+	DRM_PANTHOR_EXCEPTION_OOM = 0x60,
+	DRM_PANTHOR_EXCEPTION_CSF_FW_INTERNAL_ERROR = 0x68,
+	DRM_PANTHOR_EXCEPTION_CSF_RES_EVICTION_TIMEOUT = 0x69,
+	DRM_PANTHOR_EXCEPTION_GPU_BUS_FAULT = 0x80,
+	DRM_PANTHOR_EXCEPTION_GPU_SHAREABILITY_FAULT = 0x88,
+	DRM_PANTHOR_EXCEPTION_SYS_SHAREABILITY_FAULT = 0x89,
+	DRM_PANTHOR_EXCEPTION_GPU_CACHEABILITY_FAULT = 0x8a,
+	DRM_PANTHOR_EXCEPTION_TRANSLATION_FAULT_0 = 0xc0,
+	DRM_PANTHOR_EXCEPTION_TRANSLATION_FAULT_1 = 0xc1,
+	DRM_PANTHOR_EXCEPTION_TRANSLATION_FAULT_2 = 0xc2,
+	DRM_PANTHOR_EXCEPTION_TRANSLATION_FAULT_3 = 0xc3,
+	DRM_PANTHOR_EXCEPTION_TRANSLATION_FAULT_4 = 0xc4,
+	DRM_PANTHOR_EXCEPTION_PERM_FAULT_0 = 0xc8,
+	DRM_PANTHOR_EXCEPTION_PERM_FAULT_1 = 0xc9,
+	DRM_PANTHOR_EXCEPTION_PERM_FAULT_2 = 0xca,
+	DRM_PANTHOR_EXCEPTION_PERM_FAULT_3 = 0xcb,
+	DRM_PANTHOR_EXCEPTION_ACCESS_FLAG_1 = 0xd9,
+	DRM_PANTHOR_EXCEPTION_ACCESS_FLAG_2 = 0xda,
+	DRM_PANTHOR_EXCEPTION_ACCESS_FLAG_3 = 0xdb,
+	DRM_PANTHOR_EXCEPTION_ADDR_SIZE_FAULT_IN = 0xe0,
+	DRM_PANTHOR_EXCEPTION_ADDR_SIZE_FAULT_OUT0 = 0xe4,
+	DRM_PANTHOR_EXCEPTION_ADDR_SIZE_FAULT_OUT1 = 0xe5,
+	DRM_PANTHOR_EXCEPTION_ADDR_SIZE_FAULT_OUT2 = 0xe6,
+	DRM_PANTHOR_EXCEPTION_ADDR_SIZE_FAULT_OUT3 = 0xe7,
+	DRM_PANTHOR_EXCEPTION_MEM_ATTR_FAULT_0 = 0xe8,
+	DRM_PANTHOR_EXCEPTION_MEM_ATTR_FAULT_1 = 0xe9,
+	DRM_PANTHOR_EXCEPTION_MEM_ATTR_FAULT_2 = 0xea,
+	DRM_PANTHOR_EXCEPTION_MEM_ATTR_FAULT_3 = 0xeb,
+};
+
+/**
+ * panthor_exception_is_fault() - Checks if an exception is a fault.
+ *
+ * Return: true if the exception is a fault, false otherwise.
+ */
+static inline bool
+panthor_exception_is_fault(u32 exception_code)
+{
+	return exception_code > DRM_PANTHOR_EXCEPTION_MAX_NON_FAULT;
+}
+
+const char *panthor_exception_name(struct panthor_device *ptdev,
+				   u32 exception_code);
+
+/**
+ * PANTHOR_IRQ_HANDLER() - Define interrupt handlers and the interrupt
+ * registration function.
+ *
+ * The boiler-plate to gracefully deal with shared interrupts is
+ * auto-generated. All you have to do is call PANTHOR_IRQ_HANDLER()
+ * just after the actual handler. The handler prototype is:
+ *
+ * void (*handler)(struct panthor_device *, u32 status);
+ */
+#define PANTHOR_IRQ_HANDLER(__name, __reg_prefix, __handler)					\
+static irqreturn_t panthor_ ## __name ## _irq_raw_handler(int irq, void *data)			\
+{												\
+	struct panthor_irq *pirq = data;							\
+	struct panthor_device *ptdev = pirq->ptdev;						\
+												\
+	if (atomic_read(&pirq->suspended))							\
+		return IRQ_NONE;								\
+	if (!gpu_read(ptdev, __reg_prefix ## _INT_STAT))					\
+		return IRQ_NONE;								\
+												\
+	gpu_write(ptdev, __reg_prefix ## _INT_MASK, 0);						\
+	return IRQ_WAKE_THREAD;									\
+}												\
+												\
+static irqreturn_t panthor_ ## __name ## _irq_threaded_handler(int irq, void *data)		\
+{												\
+	struct panthor_irq *pirq = data;							\
+	struct panthor_device *ptdev = pirq->ptdev;						\
+	irqreturn_t ret = IRQ_NONE;								\
+												\
+	while (true) {										\
+		u32 status = gpu_read(ptdev, __reg_prefix ## _INT_RAWSTAT) & pirq->mask;	\
+												\
+		if (!status)									\
+			break;									\
+												\
+		gpu_write(ptdev, __reg_prefix ## _INT_CLEAR, status);				\
+												\
+		__handler(ptdev, status);							\
+		ret = IRQ_HANDLED;								\
+	}											\
+												\
+	if (!atomic_read(&pirq->suspended))							\
+		gpu_write(ptdev, __reg_prefix ## _INT_MASK, pirq->mask);			\
+												\
+	return ret;										\
+}												\
+												\
+static inline void panthor_ ## __name ## _irq_suspend(struct panthor_irq *pirq)			\
+{												\
+	int cookie;										\
+												\
+	atomic_set(&pirq->suspended, true);							\
+												\
+	if (drm_dev_enter(&pirq->ptdev->base, &cookie)) {					\
+		gpu_write(pirq->ptdev, __reg_prefix ## _INT_MASK, 0);				\
+		synchronize_irq(pirq->irq);							\
+		drm_dev_exit(cookie);								\
+	}											\
+												\
+	pirq->mask = 0;										\
+}												\
+												\
+static inline void panthor_ ## __name ## _irq_resume(struct panthor_irq *pirq, u32 mask)	\
+{												\
+	int cookie;										\
+												\
+	atomic_set(&pirq->suspended, false);							\
+	pirq->mask = mask;									\
+												\
+	if (drm_dev_enter(&pirq->ptdev->base, &cookie)) {					\
+		gpu_write(pirq->ptdev, __reg_prefix ## _INT_CLEAR, mask);			\
+		gpu_write(pirq->ptdev, __reg_prefix ## _INT_MASK, mask);			\
+		drm_dev_exit(cookie);								\
+	}											\
+}												\
+												\
+static int panthor_request_ ## __name ## _irq(struct panthor_device *ptdev,			\
+					      struct panthor_irq *pirq,				\
+					      int irq, u32 mask)				\
+{												\
+	pirq->ptdev = ptdev;									\
+	pirq->irq = irq;									\
+	panthor_ ## __name ## _irq_resume(pirq, mask);						\
+												\
+	return devm_request_threaded_irq(ptdev->base.dev, irq,					\
+					 panthor_ ## __name ## _irq_raw_handler,		\
+					 panthor_ ## __name ## _irq_threaded_handler,		\
+					 IRQF_SHARED, KBUILD_MODNAME "-" # __name,		\
+					 pirq);							\
+}
+
+/**
+ * panthor_device_mmio_offset() - Turn a user MMIO offset into a kernel one
+ * @offset: Offset to convert.
+ *
+ * With 32-bit systems being limited by the 32-bit representation of mmap2's
+ * pgoffset field, we need to make the MMIO offset arch specific. This function
+ * converts a user MMIO offset into something the kernel driver understands.
+ *
+ * If the kernel and userspace architecture match, the offset is unchanged. If
+ * the kernel is 64-bit and userspace is 32-bit, the offset is adjusted to match
+ * 64-bit offsets. 32-bit kernel with 64-bit userspace is impossible.
+ *
+ * Return: Adjusted offset.
+ */
+static inline u64 panthor_device_mmio_offset(u64 offset)
+{
+#ifdef CONFIG_ARM64
+	if (test_tsk_thread_flag(current, TIF_32BIT))
+		offset += DRM_PANTHOR_USER_MMIO_OFFSET_64BIT - DRM_PANTHOR_USER_MMIO_OFFSET_32BIT;
+#endif
+
+	return offset;
+}
+
+extern struct workqueue_struct *panthor_cleanup_wq;
+
+#endif
-- 
2.43.0