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authorDave Airlie <airlied@redhat.com>2022-11-30 11:45:43 +1000
committerDave Airlie <airlied@redhat.com>2022-11-30 12:01:27 +1000
commit795bd9bb21c694ebcee38e8026ebeac4a63929bf (patch)
tree1df9c5af1e81c891b8ba9e62fa777f336870c015
parent2847b6681547022e5c8f1f6dc104c9256a120c0a (diff)
parent8c5577a5ccc632685e65168fc6890b72a779f93a (diff)
Merge tag 'drm-accel-2022-11-22' of https://git.kernel.org/pub/scm/linux/kernel/git/ogabbay/accel into drm-next
This tag contains the patches that add the new compute acceleration subsystem, which is part of the DRM subsystem. The patches: - Add a new directory at drivers/accel. - Add a new major (261) for compute accelerators. - Add a new DRM minor type for compute accelerators. - Integrate the accel core code with DRM core code. - Add documentation for the accel subsystem. Signed-off-by: Dave Airlie <airlied@redhat.com> some acks from the list (some are in the patch series): Acked-by: Daniel Stone <daniels@collabora.com> Acked-by: Sonal Santan <sonal.santan@amd.com> Acked-by: Maxime Ripard <maxime@cerno.tech> Acked-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com> Tested-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> From: Oded Gabbay <ogabbay@kernel.org> Link: https://patchwork.freedesktop.org/patch/msgid/20221122112222.GA352082@ogabbay-vm-u20.habana-labs.com
-rw-r--r--Documentation/accel/index.rst17
-rw-r--r--Documentation/accel/introduction.rst110
-rw-r--r--Documentation/admin-guide/devices.txt5
-rw-r--r--Documentation/subsystem-apis.rst1
-rw-r--r--MAINTAINERS9
-rw-r--r--drivers/Kconfig2
-rw-r--r--drivers/accel/Kconfig24
-rw-r--r--drivers/accel/drm_accel.c323
-rw-r--r--drivers/gpu/drm/Makefile1
-rw-r--r--drivers/gpu/drm/drm_drv.c101
-rw-r--r--drivers/gpu/drm/drm_file.c2
-rw-r--r--drivers/gpu/drm/drm_sysfs.c24
-rw-r--r--include/drm/drm_accel.h97
-rw-r--r--include/drm/drm_device.h3
-rw-r--r--include/drm/drm_drv.h8
-rw-r--r--include/drm/drm_file.h21
16 files changed, 711 insertions, 37 deletions
diff --git a/Documentation/accel/index.rst b/Documentation/accel/index.rst
new file mode 100644
index 000000000000..2b43c9a7f67b
--- /dev/null
+++ b/Documentation/accel/index.rst
@@ -0,0 +1,17 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+====================
+Compute Accelerators
+====================
+
+.. toctree::
+ :maxdepth: 1
+
+ introduction
+
+.. only:: subproject and html
+
+ Indices
+ =======
+
+ * :ref:`genindex`
diff --git a/Documentation/accel/introduction.rst b/Documentation/accel/introduction.rst
new file mode 100644
index 000000000000..6f31af14b1fc
--- /dev/null
+++ b/Documentation/accel/introduction.rst
@@ -0,0 +1,110 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============
+Introduction
+============
+
+The Linux compute accelerators subsystem is designed to expose compute
+accelerators in a common way to user-space and provide a common set of
+functionality.
+
+These devices can be either stand-alone ASICs or IP blocks inside an SoC/GPU.
+Although these devices are typically designed to accelerate
+Machine-Learning (ML) and/or Deep-Learning (DL) computations, the accel layer
+is not limited to handling these types of accelerators.
+
+Typically, a compute accelerator will belong to one of the following
+categories:
+
+- Edge AI - doing inference at an edge device. It can be an embedded ASIC/FPGA,
+ or an IP inside a SoC (e.g. laptop web camera). These devices
+ are typically configured using registers and can work with or without DMA.
+
+- Inference data-center - single/multi user devices in a large server. This
+ type of device can be stand-alone or an IP inside a SoC or a GPU. It will
+ have on-board DRAM (to hold the DL topology), DMA engines and
+ command submission queues (either kernel or user-space queues).
+ It might also have an MMU to manage multiple users and might also enable
+ virtualization (SR-IOV) to support multiple VMs on the same device. In
+ addition, these devices will usually have some tools, such as profiler and
+ debugger.
+
+- Training data-center - Similar to Inference data-center cards, but typically
+ have more computational power and memory b/w (e.g. HBM) and will likely have
+ a method of scaling-up/out, i.e. connecting to other training cards inside
+ the server or in other servers, respectively.
+
+All these devices typically have different runtime user-space software stacks,
+that are tailored-made to their h/w. In addition, they will also probably
+include a compiler to generate programs to their custom-made computational
+engines. Typically, the common layer in user-space will be the DL frameworks,
+such as PyTorch and TensorFlow.
+
+Sharing code with DRM
+=====================
+
+Because this type of devices can be an IP inside GPUs or have similar
+characteristics as those of GPUs, the accel subsystem will use the
+DRM subsystem's code and functionality. i.e. the accel core code will
+be part of the DRM subsystem and an accel device will be a new type of DRM
+device.
+
+This will allow us to leverage the extensive DRM code-base and
+collaborate with DRM developers that have experience with this type of
+devices. In addition, new features that will be added for the accelerator
+drivers can be of use to GPU drivers as well.
+
+Differentiation from GPUs
+=========================
+
+Because we want to prevent the extensive user-space graphic software stack
+from trying to use an accelerator as a GPU, the compute accelerators will be
+differentiated from GPUs by using a new major number and new device char files.
+
+Furthermore, the drivers will be located in a separate place in the kernel
+tree - drivers/accel/.
+
+The accelerator devices will be exposed to the user space with the dedicated
+261 major number and will have the following convention:
+
+- device char files - /dev/accel/accel*
+- sysfs - /sys/class/accel/accel*/
+- debugfs - /sys/kernel/debug/accel/accel*/
+
+Getting Started
+===============
+
+First, read the DRM documentation at Documentation/gpu/index.rst.
+Not only it will explain how to write a new DRM driver but it will also
+contain all the information on how to contribute, the Code Of Conduct and
+what is the coding style/documentation. All of that is the same for the
+accel subsystem.
+
+Second, make sure the kernel is configured with CONFIG_DRM_ACCEL.
+
+To expose your device as an accelerator, two changes are needed to
+be done in your driver (as opposed to a standard DRM driver):
+
+- Add the DRIVER_COMPUTE_ACCEL feature flag in your drm_driver's
+ driver_features field. It is important to note that this driver feature is
+ mutually exclusive with DRIVER_RENDER and DRIVER_MODESET. Devices that want
+ to expose both graphics and compute device char files should be handled by
+ two drivers that are connected using the auxiliary bus framework.
+
+- Change the open callback in your driver fops structure to accel_open().
+ Alternatively, your driver can use DEFINE_DRM_ACCEL_FOPS macro to easily
+ set the correct function operations pointers structure.
+
+External References
+===================
+
+email threads
+-------------
+
+* `Initial discussion on the New subsystem for acceleration devices <https://lkml.org/lkml/2022/7/31/83>`_ - Oded Gabbay (2022)
+* `patch-set to add the new subsystem <https://lkml.org/lkml/2022/10/22/544>`_ - Oded Gabbay (2022)
+
+Conference talks
+----------------
+
+* `LPC 2022 Accelerators BOF outcomes summary <https://airlied.blogspot.com/2022/09/accelerators-bof-outcomes-summary.html>`_ - Dave Airlie (2022)
diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt
index 9764d6edb189..06c525e01ea5 100644
--- a/Documentation/admin-guide/devices.txt
+++ b/Documentation/admin-guide/devices.txt
@@ -3080,6 +3080,11 @@
...
255 = /dev/osd255 256th OSD Device
+ 261 char Compute Acceleration Devices
+ 0 = /dev/accel/accel0 First acceleration device
+ 1 = /dev/accel/accel1 Second acceleration device
+ ...
+
384-511 char RESERVED FOR DYNAMIC ASSIGNMENT
Character devices that request a dynamic allocation of major
number will take numbers starting from 511 and downward,
diff --git a/Documentation/subsystem-apis.rst b/Documentation/subsystem-apis.rst
index af65004a80aa..b51f38527e14 100644
--- a/Documentation/subsystem-apis.rst
+++ b/Documentation/subsystem-apis.rst
@@ -43,6 +43,7 @@ needed).
input/index
hwmon/index
gpu/index
+ accel/index
security/index
sound/index
crypto/index
diff --git a/MAINTAINERS b/MAINTAINERS
index f3edff6b1cad..1ee75a47af91 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6836,6 +6836,15 @@ F: include/drm/drm*
F: include/linux/vga*
F: include/uapi/drm/drm*
+DRM COMPUTE ACCELERATORS DRIVERS AND FRAMEWORK
+M: Oded Gabbay <ogabbay@kernel.org>
+L: dri-devel@lists.freedesktop.org
+S: Maintained
+C: irc://irc.oftc.net/dri-devel
+T: git https://git.kernel.org/pub/scm/linux/kernel/git/ogabbay/accel.git
+F: Documentation/accel/
+F: drivers/accel/
+
DRM DRIVERS FOR ALLWINNER A10
M: Maxime Ripard <mripard@kernel.org>
M: Chen-Yu Tsai <wens@csie.org>
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 19ee995bd0ae..968bd0a6fd78 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -99,6 +99,8 @@ source "drivers/media/Kconfig"
source "drivers/video/Kconfig"
+source "drivers/accel/Kconfig"
+
source "sound/Kconfig"
source "drivers/hid/Kconfig"
diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig
new file mode 100644
index 000000000000..c9ce849b2984
--- /dev/null
+++ b/drivers/accel/Kconfig
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Compute Acceleration device configuration
+#
+# This framework provides support for compute acceleration devices, such
+# as, but not limited to, Machine-Learning and Deep-Learning acceleration
+# devices
+#
+menuconfig DRM_ACCEL
+ bool "Compute Acceleration Framework"
+ depends on DRM
+ help
+ Framework for device drivers of compute acceleration devices, such
+ as, but not limited to, Machine-Learning and Deep-Learning
+ acceleration devices.
+ If you say Y here, you need to select the module that's right for
+ your acceleration device from the list below.
+ This framework is integrated with the DRM subsystem as compute
+ accelerators and GPUs share a lot in common and can use almost the
+ same infrastructure code.
+ Having said that, acceleration devices will have a different
+ major number than GPUs, and will be exposed to user-space using
+ different device files, called accel/accel* (in /dev, sysfs
+ and debugfs).
diff --git a/drivers/accel/drm_accel.c b/drivers/accel/drm_accel.c
new file mode 100644
index 000000000000..a5ee84a4017a
--- /dev/null
+++ b/drivers/accel/drm_accel.c
@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2022 HabanaLabs, Ltd.
+ * All Rights Reserved.
+ *
+ */
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/idr.h>
+
+#include <drm/drm_accel.h>
+#include <drm/drm_debugfs.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_file.h>
+#include <drm/drm_ioctl.h>
+#include <drm/drm_print.h>
+
+static DEFINE_SPINLOCK(accel_minor_lock);
+static struct idr accel_minors_idr;
+
+static struct dentry *accel_debugfs_root;
+static struct class *accel_class;
+
+static struct device_type accel_sysfs_device_minor = {
+ .name = "accel_minor"
+};
+
+static char *accel_devnode(struct device *dev, umode_t *mode)
+{
+ return kasprintf(GFP_KERNEL, "accel/%s", dev_name(dev));
+}
+
+static int accel_sysfs_init(void)
+{
+ accel_class = class_create(THIS_MODULE, "accel");
+ if (IS_ERR(accel_class))
+ return PTR_ERR(accel_class);
+
+ accel_class->devnode = accel_devnode;
+
+ return 0;
+}
+
+static void accel_sysfs_destroy(void)
+{
+ if (IS_ERR_OR_NULL(accel_class))
+ return;
+ class_destroy(accel_class);
+ accel_class = NULL;
+}
+
+static int accel_name_info(struct seq_file *m, void *data)
+{
+ struct drm_info_node *node = (struct drm_info_node *) m->private;
+ struct drm_minor *minor = node->minor;
+ struct drm_device *dev = minor->dev;
+ struct drm_master *master;
+
+ mutex_lock(&dev->master_mutex);
+ master = dev->master;
+ seq_printf(m, "%s", dev->driver->name);
+ if (dev->dev)
+ seq_printf(m, " dev=%s", dev_name(dev->dev));
+ if (master && master->unique)
+ seq_printf(m, " master=%s", master->unique);
+ if (dev->unique)
+ seq_printf(m, " unique=%s", dev->unique);
+ seq_puts(m, "\n");
+ mutex_unlock(&dev->master_mutex);
+
+ return 0;
+}
+
+static const struct drm_info_list accel_debugfs_list[] = {
+ {"name", accel_name_info, 0}
+};
+#define ACCEL_DEBUGFS_ENTRIES ARRAY_SIZE(accel_debugfs_list)
+
+/**
+ * accel_debugfs_init() - Initialize debugfs for accel minor
+ * @minor: Pointer to the drm_minor instance.
+ * @minor_id: The minor's id
+ *
+ * This function initializes the drm minor's debugfs members and creates
+ * a root directory for the minor in debugfs. It also creates common files
+ * for accelerators and calls the driver's debugfs init callback.
+ */
+void accel_debugfs_init(struct drm_minor *minor, int minor_id)
+{
+ struct drm_device *dev = minor->dev;
+ char name[64];
+
+ INIT_LIST_HEAD(&minor->debugfs_list);
+ mutex_init(&minor->debugfs_lock);
+ sprintf(name, "%d", minor_id);
+ minor->debugfs_root = debugfs_create_dir(name, accel_debugfs_root);
+
+ drm_debugfs_create_files(accel_debugfs_list, ACCEL_DEBUGFS_ENTRIES,
+ minor->debugfs_root, minor);
+
+ if (dev->driver->debugfs_init)
+ dev->driver->debugfs_init(minor);
+}
+
+/**
+ * accel_set_device_instance_params() - Set some device parameters for accel device
+ * @kdev: Pointer to the device instance.
+ * @index: The minor's index
+ *
+ * This function creates the dev_t of the device using the accel major and
+ * the device's minor number. In addition, it sets the class and type of the
+ * device instance to the accel sysfs class and device type, respectively.
+ */
+void accel_set_device_instance_params(struct device *kdev, int index)
+{
+ kdev->devt = MKDEV(ACCEL_MAJOR, index);
+ kdev->class = accel_class;
+ kdev->type = &accel_sysfs_device_minor;
+}
+
+/**
+ * accel_minor_alloc() - Allocates a new accel minor
+ *
+ * This function access the accel minors idr and allocates from it
+ * a new id to represent a new accel minor
+ *
+ * Return: A new id on success or error code in case idr_alloc failed
+ */
+int accel_minor_alloc(void)
+{
+ unsigned long flags;
+ int r;
+
+ spin_lock_irqsave(&accel_minor_lock, flags);
+ r = idr_alloc(&accel_minors_idr, NULL, 0, ACCEL_MAX_MINORS, GFP_NOWAIT);
+ spin_unlock_irqrestore(&accel_minor_lock, flags);
+
+ return r;
+}
+
+/**
+ * accel_minor_remove() - Remove an accel minor
+ * @index: The minor id to remove.
+ *
+ * This function access the accel minors idr and removes from
+ * it the member with the id that is passed to this function.
+ */
+void accel_minor_remove(int index)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&accel_minor_lock, flags);
+ idr_remove(&accel_minors_idr, index);
+ spin_unlock_irqrestore(&accel_minor_lock, flags);
+}
+
+/**
+ * accel_minor_replace() - Replace minor pointer in accel minors idr.
+ * @minor: Pointer to the new minor.
+ * @index: The minor id to replace.
+ *
+ * This function access the accel minors idr structure and replaces the pointer
+ * that is associated with an existing id. Because the minor pointer can be
+ * NULL, we need to explicitly pass the index.
+ *
+ * Return: 0 for success, negative value for error
+ */
+void accel_minor_replace(struct drm_minor *minor, int index)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&accel_minor_lock, flags);
+ idr_replace(&accel_minors_idr, minor, index);
+ spin_unlock_irqrestore(&accel_minor_lock, flags);
+}
+
+/*
+ * Looks up the given minor-ID and returns the respective DRM-minor object. The
+ * refence-count of the underlying device is increased so you must release this
+ * object with accel_minor_release().
+ *
+ * The object can be only a drm_minor that represents an accel device.
+ *
+ * As long as you hold this minor, it is guaranteed that the object and the
+ * minor->dev pointer will stay valid! However, the device may get unplugged and
+ * unregistered while you hold the minor.
+ */
+static struct drm_minor *accel_minor_acquire(unsigned int minor_id)
+{
+ struct drm_minor *minor;
+ unsigned long flags;
+
+ spin_lock_irqsave(&accel_minor_lock, flags);
+ minor = idr_find(&accel_minors_idr, minor_id);
+ if (minor)
+ drm_dev_get(minor->dev);
+ spin_unlock_irqrestore(&accel_minor_lock, flags);
+
+ if (!minor) {
+ return ERR_PTR(-ENODEV);
+ } else if (drm_dev_is_unplugged(minor->dev)) {
+ drm_dev_put(minor->dev);
+ return ERR_PTR(-ENODEV);
+ }
+
+ return minor;
+}
+
+static void accel_minor_release(struct drm_minor *minor)
+{
+ drm_dev_put(minor->dev);
+}
+
+/**
+ * accel_open - open method for ACCEL file
+ * @inode: device inode
+ * @filp: file pointer.
+ *
+ * This function must be used by drivers as their &file_operations.open method.
+ * It looks up the correct ACCEL device and instantiates all the per-file
+ * resources for it. It also calls the &drm_driver.open driver callback.
+ *
+ * Return: 0 on success or negative errno value on failure.
+ */
+int accel_open(struct inode *inode, struct file *filp)
+{
+ struct drm_device *dev;
+ struct drm_minor *minor;
+ int retcode;
+
+ minor = accel_minor_acquire(iminor(inode));
+ if (IS_ERR(minor))
+ return PTR_ERR(minor);
+
+ dev = minor->dev;
+
+ atomic_fetch_inc(&dev->open_count);
+
+ /* share address_space across all char-devs of a single device */
+ filp->f_mapping = dev->anon_inode->i_mapping;
+
+ retcode = drm_open_helper(filp, minor);
+ if (retcode)
+ goto err_undo;
+
+ return 0;
+
+err_undo:
+ atomic_dec(&dev->open_count);
+ accel_minor_release(minor);
+ return retcode;
+}
+EXPORT_SYMBOL_GPL(accel_open);
+
+static int accel_stub_open(struct inode *inode, struct file *filp)
+{
+ const struct file_operations *new_fops;
+ struct drm_minor *minor;
+ int err;
+
+ minor = accel_minor_acquire(iminor(inode));
+ if (IS_ERR(minor))
+ return PTR_ERR(minor);
+
+ new_fops = fops_get(minor->dev->driver->fops);
+ if (!new_fops) {
+ err = -ENODEV;
+ goto out;
+ }
+
+ replace_fops(filp, new_fops);
+ if (filp->f_op->open)
+ err = filp->f_op->open(inode, filp);
+ else
+ err = 0;
+
+out:
+ accel_minor_release(minor);
+
+ return err;
+}
+
+static const struct file_operations accel_stub_fops = {
+ .owner = THIS_MODULE,
+ .open = accel_stub_open,
+ .llseek = noop_llseek,
+};
+
+void accel_core_exit(void)
+{
+ unregister_chrdev(ACCEL_MAJOR, "accel");
+ debugfs_remove(accel_debugfs_root);
+ accel_sysfs_destroy();
+ idr_destroy(&accel_minors_idr);
+}
+
+int __init accel_core_init(void)
+{
+ int ret;
+
+ idr_init(&accel_minors_idr);
+
+ ret = accel_sysfs_init();
+ if (ret < 0) {
+ DRM_ERROR("Cannot create ACCEL class: %d\n", ret);
+ goto error;
+ }
+
+ accel_debugfs_root = debugfs_create_dir("accel", NULL);
+
+ ret = register_chrdev(ACCEL_MAJOR, "accel", &accel_stub_fops);
+ if (ret < 0)
+ DRM_ERROR("Cannot register ACCEL major: %d\n", ret);
+
+error:
+ /*
+ * Any cleanup due to errors will be done in drm_core_exit() that
+ * will call accel_core_exit()
+ */
+ return ret;
+}
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index f92cd7892711..cc637343d87b 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -70,6 +70,7 @@ drm-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
drm-$(CONFIG_DRM_PRIVACY_SCREEN) += \
drm_privacy_screen.o \
drm_privacy_screen_x86.o
+drm-$(CONFIG_DRM_ACCEL) += ../../accel/drm_accel.o
obj-$(CONFIG_DRM) += drm.o
obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 203bf8d6c34c..73b845a75d52 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -35,6 +35,7 @@
#include <linux/slab.h>
#include <linux/srcu.h>
+#include <drm/drm_accel.h>
#include <drm/drm_cache.h>
#include <drm/drm_client.h>
#include <drm/drm_color_mgmt.h>
@@ -90,6 +91,8 @@ static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
return &dev->primary;
case DRM_MINOR_RENDER:
return &dev->render;
+ case DRM_MINOR_ACCEL:
+ return &dev->accel;
default:
BUG();
}
@@ -104,9 +107,13 @@ static void drm_minor_alloc_release(struct drm_device *dev, void *data)
put_device(minor->kdev);
- spin_lock_irqsave(&drm_minor_lock, flags);
- idr_remove(&drm_minors_idr, minor->index);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
+ if (minor->type == DRM_MINOR_ACCEL) {
+ accel_minor_remove(minor->index);
+ } else {
+ spin_lock_irqsave(&drm_minor_lock, flags);
+ idr_remove(&drm_minors_idr, minor->index);
+ spin_unlock_irqrestore(&drm_minor_lock, flags);
+ }
}
static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
@@ -123,13 +130,17 @@ static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
minor->dev = dev;
idr_preload(GFP_KERNEL);
- spin_lock_irqsave(&drm_minor_lock, flags);
- r = idr_alloc(&drm_minors_idr,
- NULL,
- 64 * type,
- 64 * (type + 1),
- GFP_NOWAIT);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
+ if (type == DRM_MINOR_ACCEL) {
+ r = accel_minor_alloc();
+ } else {
+ spin_lock_irqsave(&drm_minor_lock, flags);
+ r = idr_alloc(&drm_minors_idr,
+ NULL,
+ 64 * type,
+ 64 * (type + 1),
+ GFP_NOWAIT);
+ spin_unlock_irqrestore(&drm_minor_lock, flags);
+ }
idr_preload_end();
if (r < 0)
@@ -161,10 +172,14 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type)
if (!minor)
return 0;
- ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
- if (ret) {
- DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
- goto err_debugfs;
+ if (minor->type == DRM_MINOR_ACCEL) {
+ accel_debugfs_init(minor, minor->index);
+ } else {
+ ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
+ if (ret) {
+ DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
+ goto err_debugfs;
+ }
}
ret = device_add(minor->kdev);
@@ -172,9 +187,13 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type)
goto err_debugfs;
/* replace NULL with @minor so lookups will succeed from now on */
- spin_lock_irqsave(&drm_minor_lock, flags);
- idr_replace(&drm_minors_idr, minor, minor->index);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
+ if (minor->type == DRM_MINOR_ACCEL) {
+ accel_minor_replace(minor, minor->index);
+ } else {
+ spin_lock_irqsave(&drm_minor_lock, flags);
+ idr_replace(&drm_minors_idr, minor, minor->index);
+ spin_unlock_irqrestore(&drm_minor_lock, flags);
+ }
DRM_DEBUG("new minor registered %d\n", minor->index);
return 0;
@@ -194,9 +213,13 @@ static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
return;
/* replace @minor with NULL so lookups will fail from now on */
- spin_lock_irqsave(&drm_minor_lock, flags);
- idr_replace(&drm_minors_idr, NULL, minor->index);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
+ if (minor->type == DRM_MINOR_ACCEL) {
+ accel_minor_replace(NULL, minor->index);
+ } else {
+ spin_lock_irqsave(&drm_minor_lock, flags);
+ idr_replace(&drm_minors_idr, NULL, minor->index);
+ spin_unlock_irqrestore(&drm_minor_lock, flags);
+ }
device_del(minor->kdev);
dev_set_drvdata(minor->kdev, NULL); /* safety belt */
@@ -603,6 +626,13 @@ static int drm_dev_init(struct drm_device *dev,
/* no per-device feature limits by default */
dev->driver_features = ~0u;
+ if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL) &&
+ (drm_core_check_feature(dev, DRIVER_RENDER) ||
+ drm_core_check_feature(dev, DRIVER_MODESET))) {
+ DRM_ERROR("DRM driver can't be both a compute acceleration and graphics driver\n");
+ return -EINVAL;
+ }
+
drm_legacy_init_members(dev);
INIT_LIST_HEAD(&dev->filelist);
INIT_LIST_HEAD(&dev->filelist_internal);
@@ -628,15 +658,21 @@ static int drm_dev_init(struct drm_device *dev,
dev->anon_inode = inode;
- if (drm_core_check_feature(dev, DRIVER_RENDER)) {
- ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
+ if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL)) {
+ ret = drm_minor_alloc(dev, DRM_MINOR_ACCEL);
if (ret)
goto err;
- }
+ } else {
+ if (drm_core_check_feature(dev, DRIVER_RENDER)) {
+ ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
+ if (ret)
+ goto err;
+ }
- ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
- if (ret)
- goto err;
+ ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
+ if (ret)
+ goto err;
+ }
ret = drm_legacy_create_map_hash(dev);
if (ret)
@@ -883,6 +919,10 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags)
if (ret)
goto err_minors;
+ ret = drm_minor_register(dev, DRM_MINOR_ACCEL);
+ if (ret)
+ goto err_minors;
+
ret = create_compat_control_link(dev);
if (ret)
goto err_minors;
@@ -902,12 +942,13 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags)
driver->name, driver->major, driver->minor,
driver->patchlevel, driver->date,
dev->dev ? dev_name(dev->dev) : "virtual device",
- dev->primary->index);
+ dev->primary ? dev->primary->index : dev->accel->index);
goto out_unlock;
err_minors:
remove_compat_control_link(dev);
+ drm_minor_unregister(dev, DRM_MINOR_ACCEL);
drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
drm_minor_unregister(dev, DRM_MINOR_RENDER);
out_unlock:
@@ -950,6 +991,7 @@ void drm_dev_unregister(struct drm_device *dev)
drm_legacy_rmmaps(dev);
remove_compat_control_link(dev);
+ drm_minor_unregister(dev, DRM_MINOR_ACCEL);
drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
drm_minor_unregister(dev, DRM_MINOR_RENDER);
}
@@ -1034,6 +1076,7 @@ static const struct file_operations drm_stub_fops = {
static void drm_core_exit(void)
{
drm_privacy_screen_lookup_exit();
+ accel_core_exit();
unregister_chrdev(DRM_MAJOR, "drm");
debugfs_remove(drm_debugfs_root);
drm_sysfs_destroy();
@@ -1061,6 +1104,10 @@ static int __init drm_core_init(void)
if (ret < 0)
goto error;
+ ret = accel_core_init();
+ if (ret < 0)
+ goto error;
+
drm_privacy_screen_lookup_init();
drm_core_init_complete = true;
diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index a8b4d918e9a3..64b4a3a87fbb 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -326,7 +326,7 @@ static int drm_cpu_valid(void)
* Creates and initializes a drm_file structure for the file private data in \p
* filp and add it into the double linked list in \p dev.
*/
-static int drm_open_helper(struct file *filp, struct drm_minor *minor)
+int drm_open_helper(struct file *filp, struct drm_minor *minor)
{
struct drm_device *dev = minor->dev;
struct drm_file *priv;
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index 430e00b16eec..b8da978d85bb 100644
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -19,6 +19,7 @@
#include <linux/kdev_t.h>
#include <linux/slab.h>
+#include <drm/drm_accel.h>
#include <drm/drm_connector.h>
#include <drm/drm_device.h>
#include <drm/drm_file.h>
@@ -471,19 +472,26 @@ struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
struct device *kdev;
int r;
- if (minor->type == DRM_MINOR_RENDER)
- minor_str = "renderD%d";
- else
- minor_str = "card%d";
-
kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
if (!kdev)
return ERR_PTR(-ENOMEM);
device_initialize(kdev);
- kdev->devt = MKDEV(DRM_MAJOR, minor->index);
- kdev->class = drm_class;
- kdev->type = &drm_sysfs_device_minor;
+
+ if (minor->type == DRM_MINOR_ACCEL) {
+ minor_str = "accel%d";
+ accel_set_device_instance_params(kdev, minor->index);
+ } else {
+ if (minor->type == DRM_MINOR_RENDER)
+ minor_str = "renderD%d";
+ else
+ minor_str = "card%d";
+
+ kdev->devt = MKDEV(DRM_MAJOR, minor->index);
+ kdev->class = drm_class;
+ kdev->type = &drm_sysfs_device_minor;
+ }
+
kdev->parent = minor->dev->dev;
kdev->release = drm_sysfs_release;
dev_set_drvdata(kdev, minor);
diff --git a/include/drm/drm_accel.h b/include/drm/drm_accel.h
new file mode 100644
index 000000000000..65c0affbd306
--- /dev/null
+++ b/include/drm/drm_accel.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright 2022 HabanaLabs, Ltd.
+ * All Rights Reserved.
+ *
+ */
+
+#ifndef DRM_ACCEL_H_
+#define DRM_ACCEL_H_
+
+#include <drm/drm_file.h>
+
+#define ACCEL_MAJOR 261
+#define ACCEL_MAX_MINORS 256
+
+/**
+ * DRM_ACCEL_FOPS - Default drm accelerators file operations
+ *
+ * This macro provides a shorthand for setting the accelerator file ops in the
+ * &file_operations structure. If all you need are the default ops, use
+ * DEFINE_DRM_ACCEL_FOPS instead.
+ */
+#define DRM_ACCEL_FOPS \
+ .open = accel_open,\
+ .release = drm_release,\
+ .unlocked_ioctl = drm_ioctl,\
+ .compat_ioctl = drm_compat_ioctl,\
+ .poll = drm_poll,\
+ .read = drm_read,\
+ .llseek = noop_llseek
+
+/**
+ * DEFINE_DRM_ACCEL_FOPS() - macro to generate file operations for accelerators drivers
+ * @name: name for the generated structure
+ *
+ * This macro autogenerates a suitable &struct file_operations for accelerators based
+ * drivers, which can be assigned to &drm_driver.fops. Note that this structure
+ * cannot be shared between drivers, because it contains a reference to the
+ * current module using THIS_MODULE.
+ *
+ * Note that the declaration is already marked as static - if you need a
+ * non-static version of this you're probably doing it wrong and will break the
+ * THIS_MODULE reference by accident.
+ */
+#define DEFINE_DRM_ACCEL_FOPS(name) \
+ static const struct file_operations name = {\
+ .owner = THIS_MODULE,\
+ DRM_ACCEL_FOPS,\
+ }
+
+#if IS_ENABLED(CONFIG_DRM_ACCEL)
+
+void accel_core_exit(void);
+int accel_core_init(void);
+void accel_minor_remove(int index);
+int accel_minor_alloc(void);
+void accel_minor_replace(struct drm_minor *minor, int index);
+void accel_set_device_instance_params(struct device *kdev, int index);
+int accel_open(struct inode *inode, struct file *filp);
+void accel_debugfs_init(struct drm_minor *minor, int minor_id);
+
+#else
+
+static inline void accel_core_exit(void)
+{
+}
+
+static inline int __init accel_core_init(void)
+{
+ /* Return 0 to allow drm_core_init to complete successfully */
+ return 0;
+}
+
+static inline void accel_minor_remove(int index)
+{
+}
+
+static inline int accel_minor_alloc(void)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline void accel_minor_replace(struct drm_minor *minor, int index)
+{
+}
+
+static inline void accel_set_device_instance_params(struct device *kdev, int index)
+{
+}
+
+static inline void accel_debugfs_init(struct drm_minor *minor, int minor_id)
+{
+}
+
+#endif /* IS_ENABLED(CONFIG_DRM_ACCEL) */
+
+#endif /* DRM_ACCEL_H_ */
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index 9923c7a6885e..933ce2048e20 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -93,6 +93,9 @@ struct drm_device {
/** @render: Render node */
struct drm_minor *render;
+ /** @accel: Compute Acceleration node */
+ struct drm_minor *accel;
+
/**
* @registered:
*
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 700d3857e088..d7c521e8860f 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -96,6 +96,14 @@ enum drm_driver_feature {
* synchronization of command submission.
*/
DRIVER_SYNCOBJ_TIMELINE = BIT(6),
+ /**
+ * @DRIVER_COMPUTE_ACCEL:
+ *
+ * Driver supports compute acceleration devices. This flag is mutually exclusive with
+ * @DRIVER_RENDER and @DRIVER_MODESET. Devices that support both graphics and compute
+ * acceleration should be handled by two drivers that are connected using auxiliary bus.
+ */
+ DRIVER_COMPUTE_ACCEL = BIT(7),
/* IMPORTANT: Below are all the legacy flags, add new ones above. */
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index d780fd151789..0d1f853092ab 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -51,11 +51,15 @@ struct file;
/* Note that the order of this enum is ABI (it determines
* /dev/dri/renderD* numbers).
+ *
+ * Setting DRM_MINOR_ACCEL to 32 gives enough space for more drm minors to
+ * be implemented before we hit any future
*/
enum drm_minor_type {
DRM_MINOR_PRIMARY,
DRM_MINOR_CONTROL,
DRM_MINOR_RENDER,
+ DRM_MINOR_ACCEL = 32,
};
/**
@@ -70,7 +74,7 @@ enum drm_minor_type {
struct drm_minor {
/* private: */
int index; /* Minor device number */
- int type; /* Control or render */
+ int type; /* Control or render or accel */
struct device *kdev; /* Linux device */
struct drm_device *dev;
@@ -397,7 +401,22 @@ static inline bool drm_is_render_client(const struct drm_file *file_priv)
return file_priv->minor->type == DRM_MINOR_RENDER;
}
+/**
+ * drm_is_accel_client - is this an open file of the compute acceleration node
+ * @file_priv: DRM file
+ *
+ * Returns true if this is an open file of the compute acceleration node, i.e.
+ * &drm_file.minor of @file_priv is a accel minor.
+ *
+ * See also the :ref:`section on accel nodes <drm_accel_node>`.
+ */
+static inline bool drm_is_accel_client(const struct drm_file *file_priv)
+{
+ return file_priv->minor->type == DRM_MINOR_ACCEL;
+}
+
int drm_open(struct inode *inode, struct file *filp);
+int drm_open_helper(struct file *filp, struct drm_minor *minor);
ssize_t drm_read(struct file *filp, char __user *buffer,
size_t count, loff_t *offset);
int drm_release(struct inode *inode, struct file *filp);