| Message ID | 20210303014543.68292-1-russell.h.weight@intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [v8,1/1] fpga: dfl: afu: harden port enable logic | expand |
On 3/2/21 5:45 PM, Russ Weight wrote: > 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> > --- > v8: > - Rebased to 5.12-rc1 (there were no conflicts) > v7: > - Added Acked-by tag from Wu Hao > v6: > - Fixed the dev_warn statement, which had "__func__" embedded in the > string instead of treated as a parameter to the format string. > v5: > - Added Reviewed-by tag to commit message > v4: > - Added a dev_warn() call for the -EINVAL case of afu_port_err_clear() > - Modified dev_err() message in __afu_port_disable() to say "disable" > instead of "reset" > v3: > - afu_port_err_clear() changed to prioritize port_enable failure over > other a detected mismatch in port errors. > - reorganized code in port_reset() to be more readable. > v2: > - Fixed typo in commit message > --- > drivers/fpga/dfl-afu-error.c | 10 ++++++---- > drivers/fpga/dfl-afu-main.c | 33 +++++++++++++++++++++++---------- > drivers/fpga/dfl-afu.h | 2 +- > 3 files changed, 30 insertions(+), 15 deletions(-) > > diff --git a/drivers/fpga/dfl-afu-error.c b/drivers/fpga/dfl-afu-error.c > index c4691187cca9..ab7be6217368 100644 > --- a/drivers/fpga/dfl-afu-error.c > +++ b/drivers/fpga/dfl-afu-error.c > @@ -52,7 +52,7 @@ 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 ret = -EBUSY; > + int enable_ret = 0, ret = -EBUSY; > u64 v; > > base_err = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR); > @@ -96,18 +96,20 @@ static int afu_port_err_clear(struct device *dev, u64 err) > 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 clear the reset */ > - __afu_port_enable(pdev); > + /* Enable the Port by clearing the reset */ > + enable_ret = __afu_port_enable(pdev); > > done: > mutex_unlock(&pdata->lock); > - return ret; > + return enable_ret ? enable_ret : ret; > } > > static ssize_t errors_show(struct device *dev, struct device_attribute *attr, > diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c > index 753cda4b2568..77dadaae5b8f 100644 > --- a/drivers/fpga/dfl-afu-main.c > +++ b/drivers/fpga/dfl-afu-main.c > @@ -21,6 +21,9 @@ > > #include "dfl-afu.h" > > +#define RST_POLL_INVL 10 /* us */ > +#define RST_POLL_TIMEOUT 1000 /* us */ > + > /** > * __afu_port_enable - enable a port by clear reset > * @pdev: port platform device. > @@ -32,7 +35,7 @@ > * > * The caller needs to hold lock for protection. > */ > -void __afu_port_enable(struct platform_device *pdev) > +int __afu_port_enable(struct platform_device *pdev) > { > struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); > void __iomem *base; > @@ -41,7 +44,7 @@ void __afu_port_enable(struct platform_device *pdev) > WARN_ON(!pdata->disable_count); > > if (--pdata->disable_count != 0) > - return; > + return 0; > > base = dfl_get_feature_ioaddr_by_id(&pdev->dev, PORT_FEATURE_ID_HEADER); > > @@ -49,10 +52,20 @@ void __afu_port_enable(struct platform_device *pdev) > v = readq(base + PORT_HDR_CTRL); > v &= ~PORT_CTRL_SFTRST; > writeq(v, base + PORT_HDR_CTRL); > -} > > -#define RST_POLL_INVL 10 /* us */ > -#define RST_POLL_TIMEOUT 1000 /* us */ > + /* > + * HW clears the ack bit to indicate that the port is fully out > + * of reset. > + */ > + if (readq_poll_timeout(base + PORT_HDR_CTRL, v, > + !(v & PORT_CTRL_SFTRST_ACK), > + RST_POLL_INVL, RST_POLL_TIMEOUT)) { > + dev_err(&pdev->dev, "timeout, failure to enable device\n"); > + return -ETIMEDOUT; > + } > + > + return 0; > +} > > /** > * __afu_port_disable - disable a port by hold reset > @@ -86,7 +99,7 @@ int __afu_port_disable(struct platform_device *pdev) > if (readq_poll_timeout(base + PORT_HDR_CTRL, v, > v & PORT_CTRL_SFTRST_ACK, > RST_POLL_INVL, RST_POLL_TIMEOUT)) { > - dev_err(&pdev->dev, "timeout, fail to reset device\n"); > + dev_err(&pdev->dev, "timeout, failure to disable device\n"); > return -ETIMEDOUT; > } > > @@ -111,9 +124,9 @@ static int __port_reset(struct platform_device *pdev) > > ret = __afu_port_disable(pdev); > if (!ret) The sense of the above condition should have been reversed with this reorganization of the code. I'll submit a new patch. - Russ > - __afu_port_enable(pdev); > + return ret; > > - return ret; > + return __afu_port_enable(pdev); > } > > static int port_reset(struct platform_device *pdev) > @@ -872,11 +885,11 @@ static int afu_dev_destroy(struct platform_device *pdev) > static int port_enable_set(struct platform_device *pdev, bool enable) > { > struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); > - int ret = 0; > + int ret; > > mutex_lock(&pdata->lock); > if (enable) > - __afu_port_enable(pdev); > + ret = __afu_port_enable(pdev); > else > ret = __afu_port_disable(pdev); > mutex_unlock(&pdata->lock); > diff --git a/drivers/fpga/dfl-afu.h b/drivers/fpga/dfl-afu.h > index 576e94960086..e5020e2b1f3d 100644 > --- a/drivers/fpga/dfl-afu.h > +++ b/drivers/fpga/dfl-afu.h > @@ -80,7 +80,7 @@ struct dfl_afu { > }; > > /* hold pdata->lock when call __afu_port_enable/disable */ > -void __afu_port_enable(struct platform_device *pdev); > +int __afu_port_enable(struct platform_device *pdev); > int __afu_port_disable(struct platform_device *pdev); > > void afu_mmio_region_init(struct dfl_feature_platform_data *pdata);
diff --git a/drivers/fpga/dfl-afu-error.c b/drivers/fpga/dfl-afu-error.c index c4691187cca9..ab7be6217368 100644 --- a/drivers/fpga/dfl-afu-error.c +++ b/drivers/fpga/dfl-afu-error.c @@ -52,7 +52,7 @@ 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 ret = -EBUSY; + int enable_ret = 0, ret = -EBUSY; u64 v; base_err = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR); @@ -96,18 +96,20 @@ static int afu_port_err_clear(struct device *dev, u64 err) 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 clear the reset */ - __afu_port_enable(pdev); + /* Enable the Port by clearing the reset */ + enable_ret = __afu_port_enable(pdev); done: mutex_unlock(&pdata->lock); - return ret; + return enable_ret ? enable_ret : ret; } static ssize_t errors_show(struct device *dev, struct device_attribute *attr, diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c index 753cda4b2568..77dadaae5b8f 100644 --- a/drivers/fpga/dfl-afu-main.c +++ b/drivers/fpga/dfl-afu-main.c @@ -21,6 +21,9 @@ #include "dfl-afu.h" +#define RST_POLL_INVL 10 /* us */ +#define RST_POLL_TIMEOUT 1000 /* us */ + /** * __afu_port_enable - enable a port by clear reset * @pdev: port platform device. @@ -32,7 +35,7 @@ * * The caller needs to hold lock for protection. */ -void __afu_port_enable(struct platform_device *pdev) +int __afu_port_enable(struct platform_device *pdev) { struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); void __iomem *base; @@ -41,7 +44,7 @@ void __afu_port_enable(struct platform_device *pdev) WARN_ON(!pdata->disable_count); if (--pdata->disable_count != 0) - return; + return 0; base = dfl_get_feature_ioaddr_by_id(&pdev->dev, PORT_FEATURE_ID_HEADER); @@ -49,10 +52,20 @@ void __afu_port_enable(struct platform_device *pdev) v = readq(base + PORT_HDR_CTRL); v &= ~PORT_CTRL_SFTRST; writeq(v, base + PORT_HDR_CTRL); -} -#define RST_POLL_INVL 10 /* us */ -#define RST_POLL_TIMEOUT 1000 /* us */ + /* + * HW clears the ack bit to indicate that the port is fully out + * of reset. + */ + if (readq_poll_timeout(base + PORT_HDR_CTRL, v, + !(v & PORT_CTRL_SFTRST_ACK), + RST_POLL_INVL, RST_POLL_TIMEOUT)) { + dev_err(&pdev->dev, "timeout, failure to enable device\n"); + return -ETIMEDOUT; + } + + return 0; +} /** * __afu_port_disable - disable a port by hold reset @@ -86,7 +99,7 @@ int __afu_port_disable(struct platform_device *pdev) if (readq_poll_timeout(base + PORT_HDR_CTRL, v, v & PORT_CTRL_SFTRST_ACK, RST_POLL_INVL, RST_POLL_TIMEOUT)) { - dev_err(&pdev->dev, "timeout, fail to reset device\n"); + dev_err(&pdev->dev, "timeout, failure to disable device\n"); return -ETIMEDOUT; } @@ -111,9 +124,9 @@ static int __port_reset(struct platform_device *pdev) ret = __afu_port_disable(pdev); if (!ret) - __afu_port_enable(pdev); + return ret; - return ret; + return __afu_port_enable(pdev); } static int port_reset(struct platform_device *pdev) @@ -872,11 +885,11 @@ static int afu_dev_destroy(struct platform_device *pdev) static int port_enable_set(struct platform_device *pdev, bool enable) { struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); - int ret = 0; + int ret; mutex_lock(&pdata->lock); if (enable) - __afu_port_enable(pdev); + ret = __afu_port_enable(pdev); else ret = __afu_port_disable(pdev); mutex_unlock(&pdata->lock); diff --git a/drivers/fpga/dfl-afu.h b/drivers/fpga/dfl-afu.h index 576e94960086..e5020e2b1f3d 100644 --- a/drivers/fpga/dfl-afu.h +++ b/drivers/fpga/dfl-afu.h @@ -80,7 +80,7 @@ struct dfl_afu { }; /* hold pdata->lock when call __afu_port_enable/disable */ -void __afu_port_enable(struct platform_device *pdev); +int __afu_port_enable(struct platform_device *pdev); int __afu_port_disable(struct platform_device *pdev); void afu_mmio_region_init(struct dfl_feature_platform_data *pdata);