Hi Oleksii,
On 15/02/2024 16:54, Oleksii wrote:
On 14/02/2024 09:32, Oleksii wrote:
On Tue, 2024-02-13 at 18:09 +0000, Julien Grall wrote:
+#ifdef CONFIG_HAS_PASSTHROUGH
+ struct iommu_fwspec *iommu_fwspec; /* per-device IOMMU
instance data */
+#endif
+};
+
+typedef struct device device_t;
+
+#ifdef CONFIG_HAS_DEVICE_TREE
+
+#include <xen/device_tree.h>
+
+#define dev_is_dt(dev) ((dev)->type == DEV_DT)
+
+/**
+ * device_init - Initialize a device
+ * @dev: device to initialize
+ * @class: class of the device (serial, network...)
+ * @data: specific data for initializing the device
+ *
+ * Return 0 on success.
+ */
+int device_init(struct dt_device_node *dev, enum device_class
class,
+ const void *data);
+
+/**
+ * device_get_type - Get the type of the device
+ * @dev: device to match
+ *
+ * Return the device type on success or DEVICE_ANY on failure
+ */
+enum device_class device_get_class(const struct dt_device_node
*dev);
+
+#define DT_DEVICE_START(name_, namestr_, class_) \
+static const struct device_desc __dev_desc_##name_ __used \
+__section(".dev.info") = { \
+ .name = namestr_, \
+ .class = class_,
+
+#define DT_DEVICE_END \
+};
+
+#else /* !CONFIG_HAS_DEVICE_TREE */
+#define dev_is_dt(dev) ((void)(dev), false)
+#endif /* CONFIG_HAS_DEVICE_TREE */
+
+#define dev_is_pci(dev) ((dev)->type == DEV_PCI)
+
+struct device_desc {
+ /* Device name */
+ const char *name;
+ /* Device class */
+ enum device_class class;
+
+#ifdef CONFIG_HAS_DEVICE_TREE
+
+ /* List of devices supported by this driver */
+ const struct dt_device_match *dt_match;
+ /*
+ * Device initialization.
+ *
+ * -EAGAIN is used to indicate that device probing is
deferred.
+ */
+ int (*init)(struct dt_device_node *dev, const void *data);
+
+#endif
+};
I am not sure I fully understand why "device_desc" is not
protected
by
CONFIG_HAS_DEVICE_TREE. The structure doesn't mean much when the
config
is disabled. Can you clarify?
I thought that one day struct device_desc and acpi_device_desc will
be
"merged", and so decided just to #ifdef only DEVICE_TREE specific
fields.
It might be possible to merge the two if we were using an union for
the
ACPI/DT specific part. However the majority of the parsing code needs
to
differ. So I am not convinced there would be any value to merge the
two
structures.
In this case, let's have two separate structures.
This is not the current situation, and I don't have a specific example.
It appears that all architectures will use Device Tree or ACPI.
However, does it make sense to keep 'struct device_desc' more generic
to accommodate non-DT or non-ACPI cases?
I am not entirely sure what else to say. As I wrote before yes it could
be made generic. But right now I don't see any values.
If you have any idea how to share the structure. Then feel free to make
a proposal and I will review it.
Cheers,
--
Julien Grall
