Merge tag 'fpga-dfl-for-5.4' of git://git.kernel.org/pub/scm/linux/ke…

…rnel/git/mdf/linux-fpga into char-misc-next

Moritz writes:

FPGA DFL Changes for 5.4

This pull-request contains the FPGA DFL changes for 5.4

- The first three patches are cleanup patches making use of dev_groups and
  making the init callback optional.
- One patch adds userclock sysfs entries that are DFL specific
- One patch exposes AFU port disable/enable functions
- One patch adds error reporting
- One patch adds AFU SignalTap support
- One patch adds FME global error reporting
- The final patch is a documentation patch that decribes the
  virtualization interfaces

This patchset requires the 'dev_groups_all_drivers' tag from drivers
core for the dev_groups refactoring as well as the DFL changes already
in char-misc-next.

Signed-off-by: Moritz Fischer <mdf@kernel.org>

* tag 'fpga-dfl-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mdf/linux-fpga:
  Documentation: fpga: dfl: add descriptions for virtualization and new interfaces.
  fpga: dfl: fme: add global error reporting support
  fpga: dfl: afu: add STP (SignalTap) support
  fpga: dfl: afu: add error reporting support.
  fpga: dfl: afu: expose __afu_port_enable/disable function.
  fpga: dfl: afu: add userclock sysfs interfaces.
  fpga: dfl: afu: convert platform_driver to use dev_groups
  fpga: dfl: fme: convert platform_driver to use dev_groups
  fpga: dfl: make init callback optional
  driver core: add dev_groups to all drivers

Documentation/ABI/testing/sysfs-platform-dfl-fme

@@ -44,3 +44,65 @@ Description:	Read-only. It returns socket_id to indicate which socket
 		this FPGA belongs to, only valid for integrated solution.
 		User only needs this information, in case standard numa node
 		can't provide correct information.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/errors/pcie0_errors
+Date:		August 2019
+KernelVersion:  5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Write. Read this file for errors detected on pcie0 link.
+		Write this file to clear errors logged in pcie0_errors. Write
+		fails with -EINVAL if input parsing fails or input error code
+		doesn't match.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/errors/pcie1_errors
+Date:		August 2019
+KernelVersion:  5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Write. Read this file for errors detected on pcie1 link.
+		Write this file to clear errors logged in pcie1_errors. Write
+		fails with -EINVAL if input parsing fails or input error code
+		doesn't match.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/errors/nonfatal_errors
+Date:		August 2019
+KernelVersion:  5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. It returns non-fatal errors detected.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/errors/catfatal_errors
+Date:		August 2019
+KernelVersion:  5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. It returns catastrophic and fatal errors detected.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/errors/inject_errors
+Date:		August 2019
+KernelVersion:  5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Write. Read this file to check errors injected. Write this
+		file to inject errors for testing purpose. Write fails with
+		-EINVAL if input parsing fails or input inject error code isn't
+		supported.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/errors/fme_errors
+Date:		August 2019
+KernelVersion:  5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Write. Read this file to get errors detected on FME.
+		Write this file to clear errors logged in fme_errors. Write
+		fials with -EINVAL if input parsing fails or input error code
+		doesn't match.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/errors/first_error
+Date:		August 2019
+KernelVersion:  5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. Read this file to get the first error detected by
+		hardware.
+
+What:		/sys/bus/platform/devices/dfl-fme.0/errors/next_error
+Date:		August 2019
+KernelVersion:  5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. Read this file to get the second error detected by
+		hardware.

Documentation/ABI/testing/sysfs-platform-dfl-port

@@ -46,3 +46,56 @@ Contact:	Wu Hao <hao.wu@intel.com>
 Description:	Read-write. Read or set AFU latency tolerance reporting value.
 		Set ltr to 1 if the AFU can tolerate latency >= 40us or set it
 		to 0 if it is latency sensitive.
+
+What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqcmd
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Write-only. User writes command to this interface to set
+		userclock to AFU.
+
+What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqsts
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. Read this file to get the status of issued command
+		to userclck_freqcmd.
+
+What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqcntrcmd
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Write-only. User writes command to this interface to set
+		userclock counter.
+
+What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqcntrsts
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. Read this file to get the status of issued command
+		to userclck_freqcntrcmd.
+
+What:		/sys/bus/platform/devices/dfl-port.0/errors/errors
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-Write. Read this file to get errors detected on port and
+		Accelerated Function Unit (AFU). Write error code to this file
+		to clear errors. Write fails with -EINVAL if input parsing
+		fails or input error code doesn't match. Write fails with
+		-EBUSY or -ETIMEDOUT if error can't be cleared as hardware
+		in low power state (-EBUSY) or not respoding (-ETIMEDOUT).
+
+What:		/sys/bus/platform/devices/dfl-port.0/errors/first_error
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. Read this file to get the first error detected by
+		hardware.
+
+What:		/sys/bus/platform/devices/dfl-port.0/errors/first_malformed_req
+Date:		August 2019
+KernelVersion:	5.4
+Contact:	Wu Hao <hao.wu@intel.com>
+Description:	Read-only. Read this file to get the first malformed request
+		captured by hardware.

Documentation/fpga/dfl.rst

@@ -87,6 +87,8 @@ The following functions are exposed through ioctls:
 - Get driver API version (DFL_FPGA_GET_API_VERSION)
 - Check for extensions (DFL_FPGA_CHECK_EXTENSION)
 - Program bitstream (DFL_FPGA_FME_PORT_PR)
+- Assign port to PF (DFL_FPGA_FME_PORT_ASSIGN)
+- Release port from PF (DFL_FPGA_FME_PORT_RELEASE)
 
 More functions are exposed through sysfs
 (/sys/class/fpga_region/regionX/dfl-fme.n/):
@@ -102,6 +104,10 @@ More functions are exposed through sysfs
      one FPGA device may have more than one port, this sysfs interface indicates
      how many ports the FPGA device has.
 
+ Global error reporting management (errors/)
+     error reporting sysfs interfaces allow user to read errors detected by the
+     hardware, and clear the logged errors.
+
 
 FIU - PORT
 ==========
@@ -143,6 +149,10 @@ More functions are exposed through sysfs:
  Read Accelerator GUID (afu_id)
      afu_id indicates which PR bitstream is programmed to this AFU.
 
+ Error reporting (errors/)
+     error reporting sysfs interfaces allow user to read port/afu errors
+     detected by the hardware, and clear the logged errors.
+
 
 DFL Framework Overview
 ======================
@@ -218,6 +228,101 @@ the compat_id exposed by the target FPGA region. This check is usually done by
 userspace before calling the reconfiguration IOCTL.
 
 
+FPGA virtualization - PCIe SRIOV
+================================
+This section describes the virtualization support on DFL based FPGA device to
+enable accessing an accelerator from applications running in a virtual machine
+(VM). This section only describes the PCIe based FPGA device with SRIOV support.
+
+Features supported by the particular FPGA device are exposed through Device
+Feature Lists, as illustrated below:
+
+::
+
+    +-------------------------------+  +-------------+
+    |              PF               |  |     VF      |
+    +-------------------------------+  +-------------+
+        ^            ^         ^              ^
+        |            |         |              |
+  +-----|------------|---------|--------------|-------+
+  |     |            |         |              |       |
+  |  +-----+     +-------+ +-------+      +-------+   |
+  |  | FME |     | Port0 | | Port1 |      | Port2 |   |
+  |  +-----+     +-------+ +-------+      +-------+   |
+  |                  ^         ^              ^       |
+  |                  |         |              |       |
+  |              +-------+ +------+       +-------+   |
+  |              |  AFU  | |  AFU |       |  AFU  |   |
+  |              +-------+ +------+       +-------+   |
+  |                                                   |
+  |            DFL based FPGA PCIe Device             |
+  +---------------------------------------------------+
+
+FME is always accessed through the physical function (PF).
+
+Ports (and related AFUs) are accessed via PF by default, but could be exposed
+through virtual function (VF) devices via PCIe SRIOV. Each VF only contains
+1 Port and 1 AFU for isolation. Users could assign individual VFs (accelerators)
+created via PCIe SRIOV interface, to virtual machines.
+
+The driver organization in virtualization case is illustrated below:
+::
+
+    +-------++------++------+             |
+    | FME   || FME  || FME  |             |
+    | FPGA  || FPGA || FPGA |             |
+    |Manager||Bridge||Region|             |
+    +-------++------++------+             |
+    +-----------------------+  +--------+ |             +--------+
+    |          FME          |  |  AFU   | |             |  AFU   |
+    |         Module        |  | Module | |             | Module |
+    +-----------------------+  +--------+ |             +--------+
+          +-----------------------+       |       +-----------------------+
+          | FPGA Container Device |       |       | FPGA Container Device |
+          |  (FPGA Base Region)   |       |       |  (FPGA Base Region)   |
+          +-----------------------+       |       +-----------------------+
+            +------------------+          |         +------------------+
+            | FPGA PCIE Module |          | Virtual | FPGA PCIE Module |
+            +------------------+   Host   | Machine +------------------+
+   -------------------------------------- | ------------------------------
+             +---------------+            |          +---------------+
+             | PCI PF Device |            |          | PCI VF Device |
+             +---------------+            |          +---------------+
+
+FPGA PCIe device driver is always loaded first once a FPGA PCIe PF or VF device
+is detected. It:
+
+* Finishes enumeration on both FPGA PCIe PF and VF device using common
+  interfaces from DFL framework.
+* Supports SRIOV.
+
+The FME device driver plays a management role in this driver architecture, it
+provides ioctls to release Port from PF and assign Port to PF. After release
+a port from PF, then it's safe to expose this port through a VF via PCIe SRIOV
+sysfs interface.
+
+To enable accessing an accelerator from applications running in a VM, the
+respective AFU's port needs to be assigned to a VF using the following steps:
+
+#. The PF owns all AFU ports by default. Any port that needs to be
+   reassigned to a VF must first be released through the
+   DFL_FPGA_FME_PORT_RELEASE ioctl on the FME device.
+
+#. Once N ports are released from PF, then user can use command below
+   to enable SRIOV and VFs. Each VF owns only one Port with AFU.
+
+   ::
+
+      echo N > $PCI_DEVICE_PATH/sriov_numvfs
+
+#. Pass through the VFs to VMs
+
+#. The AFU under VF is accessible from applications in VM (using the
+   same driver inside the VF).
+
+Note that an FME can't be assigned to a VF, thus PR and other management
+functions are only available via the PF.
+
 Device enumeration
 ==================
 This section introduces how applications enumerate the fpga device from

drivers/base/dd.c

@@ -554,9 +554,16 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 			goto probe_failed;
 	}
 
+	if (device_add_groups(dev, drv->dev_groups)) {
+		dev_err(dev, "device_add_groups() failed\n");
+		goto dev_groups_failed;
+	}
+
 	if (test_remove) {
 		test_remove = false;
 
+		device_remove_groups(dev, drv->dev_groups);
+
 		if (dev->bus->remove)
 			dev->bus->remove(dev);
 		else if (drv->remove)
@@ -584,6 +591,11 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 		 drv->bus->name, __func__, dev_name(dev), drv->name);
 	goto done;
 
+dev_groups_failed:
+	if (dev->bus->remove)
+		dev->bus->remove(dev);
+	else if (drv->remove)
+		drv->remove(dev);
 probe_failed:
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
@@ -1114,6 +1126,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 
 		pm_runtime_put_sync(dev);
 
+		device_remove_groups(dev, drv->dev_groups);
+
 		if (dev->bus && dev->bus->remove)
 			dev->bus->remove(dev);
 		else if (drv->remove)

drivers/fpga/Makefile

@@ -39,8 +39,9 @@ obj-$(CONFIG_FPGA_DFL_FME_BRIDGE)	+= dfl-fme-br.o
 obj-$(CONFIG_FPGA_DFL_FME_REGION)	+= dfl-fme-region.o
 obj-$(CONFIG_FPGA_DFL_AFU)		+= dfl-afu.o
 
-dfl-fme-objs := dfl-fme-main.o dfl-fme-pr.o
+dfl-fme-objs := dfl-fme-main.o dfl-fme-pr.o dfl-fme-error.o
 dfl-afu-objs := dfl-afu-main.o dfl-afu-region.o dfl-afu-dma-region.o
+dfl-afu-objs += dfl-afu-error.o
 
 # Drivers for FPGAs which implement DFL
 obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o