[PATCH 07/17] fpga: dfl: afu: add AFU state related sysfs interfaces

From: Wu Hao
Date: Sun Mar 24 2019 - 23:24:08 EST

This patch introduces more sysfs interfaces for Accelerated
Function Unit (AFU). These interfaces allow users to read
current AFU Power State (APx), read / clear AFU Power (APx)
events which are sticky to identify transient APx state,
and manage AFU's LTR (latency tolerance reporting).

Signed-off-by: Ananda Ravuri <ananda.ravuri@xxxxxxxxx>
Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-platform-dfl-port | 30 +++++
drivers/fpga/dfl-afu-main.c | 144 ++++++++++++++++++++++
drivers/fpga/dfl.h | 11 ++
3 files changed, 185 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-platform-dfl-port b/Documentation/ABI/testing/sysfs-platform-dfl-port
index 6a92dda..f0c4e92 100644
--- a/Documentation/ABI/testing/sysfs-platform-dfl-port
+++ b/Documentation/ABI/testing/sysfs-platform-dfl-port
@@ -14,3 +14,33 @@ Description: Read-only. User can program different PR bitstreams to FPGA
Accelerator Function Unit (AFU) for different functions. It
returns uuid which could be used to identify which PR bitstream
is programmed in this AFU.
+
+What: /sys/bus/platform/devices/dfl-port.0/power_state
+Date: March 2019
+KernelVersion: 5.2
+Contact: Wu Hao <hao.wu@xxxxxxxxx>
+Description: Read-only. It reports the APx (AFU Power) state, different APx
+ means different throttling level. When reading this file, it
+ returns "0" - Normal / "1" - AP1 / "2" - AP2 / "6" - AP6.
+
+What: /sys/bus/platform/devices/dfl-port.0/ap1_event
+Date: March 2019
+KernelVersion: 5.2
+Contact: Wu Hao <hao.wu@xxxxxxxxx>
+Description: Read-write. Read or set 1 to clear AP1 (AFU Power State 1)
+ event. It's used to indicate transient AP1 state.
+
+What: /sys/bus/platform/devices/dfl-port.0/ap2_event
+Date: March 2019
+KernelVersion: 5.2
+Contact: Wu Hao <hao.wu@xxxxxxxxx>
+Description: Read-write. Read or set 1 to clear AP2 (AFU Power State 2)
+ event. It's used to indicate transient AP2 state.
+
+What: /sys/bus/platform/devices/dfl-port.0/ltr
+Date: March 2019
+KernelVersion: 5.2
+Contact: Wu Hao <hao.wu@xxxxxxxxx>
+Description: Read-write. Read and 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.
diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
index 02baa6a..2ffec06 100644
--- a/drivers/fpga/dfl-afu-main.c
+++ b/drivers/fpga/dfl-afu-main.c
@@ -21,6 +21,8 @@

#include "dfl-afu.h"

+#define DRV_VERSION "0.8"
+
/**
* port_enable - enable a port
* @pdev: port platform device.
@@ -141,8 +143,149 @@ id_show(struct device *dev, struct device_attribute *attr, char *buf)
}
static DEVICE_ATTR_RO(id);

+static ssize_t
+ltr_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
+ void __iomem *base;
+ u64 v;
+
+ base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+ mutex_lock(&pdata->lock);
+ v = readq(base + PORT_HDR_CTRL);
+ mutex_unlock(&pdata->lock);
+
+ return scnprintf(buf, PAGE_SIZE, "%x\n",
+ (u8)FIELD_GET(PORT_CTRL_LATENCY, v));
+}
+
+static ssize_t
+ltr_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
+ void __iomem *base;
+ u8 ltr;
+ u64 v;
+
+ if (kstrtou8(buf, 0, &ltr) || ltr > 1)
+ return -EINVAL;
+
+ base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+ mutex_lock(&pdata->lock);
+ v = readq(base + PORT_HDR_CTRL);
+ v &= ~PORT_CTRL_LATENCY;
+ v |= FIELD_PREP(PORT_CTRL_LATENCY, ltr);
+ writeq(v, base + PORT_HDR_CTRL);
+ mutex_unlock(&pdata->lock);
+
+ return count;
+}
+static DEVICE_ATTR_RW(ltr);
+
+static ssize_t
+ap1_event_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
+ void __iomem *base;
+ u64 v;
+
+ base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+ mutex_lock(&pdata->lock);
+ v = readq(base + PORT_HDR_STS);
+ mutex_unlock(&pdata->lock);
+
+ return scnprintf(buf, PAGE_SIZE, "%x\n",
+ (u8)FIELD_GET(PORT_STS_AP1_EVT, v));
+}
+
+static ssize_t
+ap1_event_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
+ void __iomem *base;
+ u8 ap1_event;
+
+ if (kstrtou8(buf, 0, &ap1_event) || ap1_event != 1)
+ return -EINVAL;
+
+ base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+ mutex_lock(&pdata->lock);
+ writeq(PORT_STS_AP1_EVT, base + PORT_HDR_STS);
+ mutex_unlock(&pdata->lock);
+
+ return count;
+}
+static DEVICE_ATTR_RW(ap1_event);
+
+static ssize_t
+ap2_event_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
+ void __iomem *base;
+ u64 v;
+
+ base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+ mutex_lock(&pdata->lock);
+ v = readq(base + PORT_HDR_STS);
+ mutex_unlock(&pdata->lock);
+
+ return scnprintf(buf, PAGE_SIZE, "%x\n",
+ (u8)FIELD_GET(PORT_STS_AP2_EVT, v));
+}
+
+static ssize_t
+ap2_event_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
+ void __iomem *base;
+ u8 ap2_event;
+
+ if (kstrtou8(buf, 0, &ap2_event) || ap2_event != 1)
+ return -EINVAL;
+
+ base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+ mutex_lock(&pdata->lock);
+ writeq(PORT_STS_AP2_EVT, base + PORT_HDR_STS);
+ mutex_unlock(&pdata->lock);
+
+ return count;
+}
+static DEVICE_ATTR_RW(ap2_event);
+
+static ssize_t
+power_state_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
+ void __iomem *base;
+ u64 v;
+
+ base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
+
+ mutex_lock(&pdata->lock);
+ v = readq(base + PORT_HDR_STS);
+ mutex_unlock(&pdata->lock);
+
+ return scnprintf(buf, PAGE_SIZE, "0x%x\n",
+ (u8)FIELD_GET(PORT_STS_PWR_STATE, v));
+}
+static DEVICE_ATTR_RO(power_state);
+
static const struct attribute *port_hdr_attrs[] = {
&dev_attr_id.attr,
+ &dev_attr_ltr.attr,
+ &dev_attr_ap1_event.attr,
+ &dev_attr_ap2_event.attr,
+ &dev_attr_power_state.attr,
NULL,
};

@@ -634,3 +777,4 @@ MODULE_DESCRIPTION("FPGA Accelerated Function Unit driver");
MODULE_AUTHOR("Intel Corporation");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:dfl-port");
+MODULE_VERSION(DRV_VERSION);
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index 1350e8e..1525098 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -119,6 +119,7 @@
#define PORT_HDR_NEXT_AFU NEXT_AFU
#define PORT_HDR_CAP 0x30
#define PORT_HDR_CTRL 0x38
+#define PORT_HDR_STS 0x40

/* Port Capability Register Bitfield */
#define PORT_CAP_PORT_NUM GENMASK_ULL(1, 0) /* ID of this port */
@@ -130,6 +131,16 @@
/* Latency tolerance reporting. '1' >= 40us, '0' < 40us.*/
#define PORT_CTRL_LATENCY BIT_ULL(2)
#define PORT_CTRL_SFTRST_ACK BIT_ULL(4) /* HW ack for reset */
+
+/* Port Status Register Bitfield */
+#define PORT_STS_AP2_EVT BIT_ULL(13) /* AP2 event detected */
+#define PORT_STS_AP1_EVT BIT_ULL(12) /* AP1 event detected */
+#define PORT_STS_PWR_STATE GENMASK_ULL(11, 8) /* AFU power states */
+#define PORT_STS_PWR_STATE_NORM 0
+#define PORT_STS_PWR_STATE_AP1 1 /* 50% throttling */
+#define PORT_STS_PWR_STATE_AP2 2 /* 90% throttling */
+#define PORT_STS_PWR_STATE_AP6 6 /* 100% throttling */
+
/**
* struct dfl_fpga_port_ops - port ops
*
--
2.7.4