fpga: dfl: add basic support for DFHv1

Version 1 of the Device Feature Header (DFH) definition adds
functionality to the Device Feature List (DFL) bus.

A DFHv1 header may have one or more parameter blocks that
further describes the HW to SW. Add support to the DFL bus
to parse the MSI-X parameter.

The location of a feature's register set is explicitly
described in DFHv1 and can be relative to the base of the DFHv1
or an absolute address. Parse the location and pass the information
to DFL driver.
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230115151447.1353428-4-matthew.gerlach@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/fpga/dfl.h

@@ -111,6 +111,10 @@
 #define DFHv1_PARAM_HDR_NEXT_EOP	BIT_ULL(32)
 #define DFHv1_PARAM_DATA		0x08  /* Offset of Param data from Param header */
 
+#define DFHv1_PARAM_ID_MSI_X		0x1
+#define DFHv1_PARAM_MSI_X_NUMV		GENMASK_ULL(63, 32)
+#define DFHv1_PARAM_MSI_X_STARTV	GENMASK_ULL(31, 0)
+
 /* Next AFU Register Bitfield */
 #define NEXT_AFU_NEXT_DFH_OFST	GENMASK_ULL(23, 0)	/* Offset to next AFU */
 
@@ -263,6 +267,7 @@ struct dfl_feature_irq_ctx {
  *
  * @dev: ptr to pdev of the feature device which has the sub feature.
  * @id: sub feature id.
+ * @revision: revisition of the instance of a feature.
  * @resource_index: each sub feature has one mmio resource for its registers.
  *		    this index is used to find its mmio resource from the
  *		    feature dev (platform device)'s resources.
@@ -272,6 +277,9 @@ struct dfl_feature_irq_ctx {
  * @ops: ops of this sub feature.
  * @ddev: ptr to the dfl device of this sub feature.
  * @priv: priv data of this feature.
+ * @dfh_version: version of the DFH
+ * @param_size: size of dfh parameters
+ * @params: point to memory copy of dfh parameters
  */
 struct dfl_feature {
 	struct platform_device *dev;
@@ -284,6 +292,9 @@ struct dfl_feature {
 	const struct dfl_feature_ops *ops;
 	struct dfl_device *ddev;
 	void *priv;
+	u8 dfh_version;
+	unsigned int param_size;
+	void *params;
 };
 
 #define FEATURE_DEV_ID_UNUSED	(-1)

include/linux/dfl.h

@@ -27,11 +27,15 @@ enum dfl_id_type {
  * @id: id of the dfl device.
  * @type: type of DFL FIU of the device. See enum dfl_id_type.
  * @feature_id: feature identifier local to its DFL FIU type.
+ * @revision: revision of this dfl device feature.
  * @mmio_res: mmio resource of this dfl device.
  * @irqs: list of Linux IRQ numbers of this dfl device.
  * @num_irqs: number of IRQs supported by this dfl device.
  * @cdev: pointer to DFL FPGA container device this dfl device belongs to.
  * @id_entry: matched id entry in dfl driver's id table.
+ * @dfh_version: version of DFH for the device
+ * @param_size: size of the block parameters in bytes
+ * @params: pointer to block of parameters copied memory
  */
 struct dfl_device {
 	struct device dev;
@@ -44,6 +48,9 @@ struct dfl_device {
 	unsigned int num_irqs;
 	struct dfl_fpga_cdev *cdev;
 	const struct dfl_device_id *id_entry;
+	u8 dfh_version;
+	unsigned int param_size;
+	void *params;
 };
 
 /**
@@ -84,4 +91,5 @@ void dfl_driver_unregister(struct dfl_driver *dfl_drv);
 	module_driver(__dfl_driver, dfl_driver_register, \
 		      dfl_driver_unregister)
 
+void *dfh_find_param(struct dfl_device *dfl_dev, int param_id, size_t *pcount);
 #endif /* __LINUX_DFL_H */