linux/drivers/fpga/dfl-afu-error.c
Russ Weight 9a8d3cda8d fpga: dfl: afu: harden port enable logic
Port enable is not complete until ACK = 0. Change
__afu_port_enable() to guarantee that the enable process
is complete by polling for ACK == 0.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Reviewed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Acked-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
2021-03-24 11:15:04 -07:00

250 lines
6.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Driver for FPGA Accelerated Function Unit (AFU) Error Reporting
*
* Copyright 2019 Intel Corporation, Inc.
*
* Authors:
* Wu Hao <hao.wu@linux.intel.com>
* Xiao Guangrong <guangrong.xiao@linux.intel.com>
* Joseph Grecco <joe.grecco@intel.com>
* Enno Luebbers <enno.luebbers@intel.com>
* Tim Whisonant <tim.whisonant@intel.com>
* Ananda Ravuri <ananda.ravuri@intel.com>
* Mitchel Henry <henry.mitchel@intel.com>
*/
#include <linux/fpga-dfl.h>
#include <linux/uaccess.h>
#include "dfl-afu.h"
#define PORT_ERROR_MASK 0x8
#define PORT_ERROR 0x10
#define PORT_FIRST_ERROR 0x18
#define PORT_MALFORMED_REQ0 0x20
#define PORT_MALFORMED_REQ1 0x28
#define ERROR_MASK GENMASK_ULL(63, 0)
/* mask or unmask port errors by the error mask register. */
static void __afu_port_err_mask(struct device *dev, bool mask)
{
void __iomem *base;
base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
writeq(mask ? ERROR_MASK : 0, base + PORT_ERROR_MASK);
}
static void afu_port_err_mask(struct device *dev, bool mask)
{
struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
mutex_lock(&pdata->lock);
__afu_port_err_mask(dev, mask);
mutex_unlock(&pdata->lock);
}
/* clear port errors. */
static int afu_port_err_clear(struct device *dev, u64 err)
{
struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
struct platform_device *pdev = to_platform_device(dev);
void __iomem *base_err, *base_hdr;
int enable_ret = 0, ret = -EBUSY;
u64 v;
base_err = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
base_hdr = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
mutex_lock(&pdata->lock);
/*
* clear Port Errors
*
* - Check for AP6 State
* - Halt Port by keeping Port in reset
* - Set PORT Error mask to all 1 to mask errors
* - Clear all errors
* - Set Port mask to all 0 to enable errors
* - All errors start capturing new errors
* - Enable Port by pulling the port out of reset
*/
/* if device is still in AP6 power state, can not clear any error. */
v = readq(base_hdr + PORT_HDR_STS);
if (FIELD_GET(PORT_STS_PWR_STATE, v) == PORT_STS_PWR_STATE_AP6) {
dev_err(dev, "Could not clear errors, device in AP6 state.\n");
goto done;
}
/* Halt Port by keeping Port in reset */
ret = __afu_port_disable(pdev);
if (ret)
goto done;
/* Mask all errors */
__afu_port_err_mask(dev, true);
/* Clear errors if err input matches with current port errors.*/
v = readq(base_err + PORT_ERROR);
if (v == err) {
writeq(v, base_err + PORT_ERROR);
v = readq(base_err + PORT_FIRST_ERROR);
writeq(v, base_err + PORT_FIRST_ERROR);
} else {
dev_warn(dev, "%s: received 0x%llx, expected 0x%llx\n",
__func__, v, err);
ret = -EINVAL;
}
/* Clear mask */
__afu_port_err_mask(dev, false);
/* Enable the Port by clearing the reset */
enable_ret = __afu_port_enable(pdev);
done:
mutex_unlock(&pdata->lock);
return enable_ret ? enable_ret : ret;
}
static ssize_t errors_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
void __iomem *base;
u64 error;
base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
mutex_lock(&pdata->lock);
error = readq(base + PORT_ERROR);
mutex_unlock(&pdata->lock);
return sprintf(buf, "0x%llx\n", (unsigned long long)error);
}
static ssize_t errors_store(struct device *dev, struct device_attribute *attr,
const char *buff, size_t count)
{
u64 value;
int ret;
if (kstrtou64(buff, 0, &value))
return -EINVAL;
ret = afu_port_err_clear(dev, value);
return ret ? ret : count;
}
static DEVICE_ATTR_RW(errors);
static ssize_t first_error_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
void __iomem *base;
u64 error;
base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
mutex_lock(&pdata->lock);
error = readq(base + PORT_FIRST_ERROR);
mutex_unlock(&pdata->lock);
return sprintf(buf, "0x%llx\n", (unsigned long long)error);
}
static DEVICE_ATTR_RO(first_error);
static ssize_t first_malformed_req_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
void __iomem *base;
u64 req0, req1;
base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
mutex_lock(&pdata->lock);
req0 = readq(base + PORT_MALFORMED_REQ0);
req1 = readq(base + PORT_MALFORMED_REQ1);
mutex_unlock(&pdata->lock);
return sprintf(buf, "0x%016llx%016llx\n",
(unsigned long long)req1, (unsigned long long)req0);
}
static DEVICE_ATTR_RO(first_malformed_req);
static struct attribute *port_err_attrs[] = {
&dev_attr_errors.attr,
&dev_attr_first_error.attr,
&dev_attr_first_malformed_req.attr,
NULL,
};
static umode_t port_err_attrs_visible(struct kobject *kobj,
struct attribute *attr, int n)
{
struct device *dev = kobj_to_dev(kobj);
/*
* sysfs entries are visible only if related private feature is
* enumerated.
*/
if (!dfl_get_feature_by_id(dev, PORT_FEATURE_ID_ERROR))
return 0;
return attr->mode;
}
const struct attribute_group port_err_group = {
.name = "errors",
.attrs = port_err_attrs,
.is_visible = port_err_attrs_visible,
};
static int port_err_init(struct platform_device *pdev,
struct dfl_feature *feature)
{
afu_port_err_mask(&pdev->dev, false);
return 0;
}
static void port_err_uinit(struct platform_device *pdev,
struct dfl_feature *feature)
{
afu_port_err_mask(&pdev->dev, true);
}
static long
port_err_ioctl(struct platform_device *pdev, struct dfl_feature *feature,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case DFL_FPGA_PORT_ERR_GET_IRQ_NUM:
return dfl_feature_ioctl_get_num_irqs(pdev, feature, arg);
case DFL_FPGA_PORT_ERR_SET_IRQ:
return dfl_feature_ioctl_set_irq(pdev, feature, arg);
default:
dev_dbg(&pdev->dev, "%x cmd not handled", cmd);
return -ENODEV;
}
}
const struct dfl_feature_id port_err_id_table[] = {
{.id = PORT_FEATURE_ID_ERROR,},
{0,}
};
const struct dfl_feature_ops port_err_ops = {
.init = port_err_init,
.uinit = port_err_uinit,
.ioctl = port_err_ioctl,
};