| Message ID | 20220214112619.219761-3-tianfei.zhang@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Add Intel OFS support for DFL driver | expand |
On 2/14/22 3:26 AM, Tianfei zhang wrote: > From: Tianfei Zhang <tianfei.zhang@intel.com> > > The feature ID of "Port User Interrupt" and the > "PMCI Subsystem" are identical, 0x12, but one is for FME, > other is for Port. It should check the feature type While > parsing the irq info in parse_feature_irqs(). This seems like a bug fix and not part of iofs feature. Split this out of the patchset. This is a workaround a hardware problem, there should be some comments to the effect that you can't trust _this_ or _that_ feature id and some special handling earlier. The ambiguity of feature id is a problem, and this sort of bug will happen again. What can be done to prevent this in the future ? > > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com> > --- > drivers/fpga/dfl.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > index 599bb21d86af..26f8cf890700 100644 > --- a/drivers/fpga/dfl.c > +++ b/drivers/fpga/dfl.c > @@ -940,9 +940,14 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo, > { > void __iomem *base = binfo->ioaddr + ofst; > unsigned int i, ibase, inr = 0; > + enum dfl_id_type type; > int virq; > u64 v; > > + type = feature_dev_id_type(binfo->feature_dev); > + if (type >= DFL_ID_MAX) > + return -EINVAL; > + > /* > * Ideally DFL framework should only read info from DFL header, but > * current version DFL only provides mmio resources information for > @@ -959,16 +964,22 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo, > */ > switch (fid) { > case PORT_FEATURE_ID_UINT: > + if (type != PORT_ID) > + break; Instead of embedding a break in the switch, break the switch into fme switch and port switch if (type == PORT_ID) port-switch else if (type == FME_ID fme-switch Tom > v = readq(base + PORT_UINT_CAP); > ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); > inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); > break; > case PORT_FEATURE_ID_ERROR: > + if (type != PORT_ID) > + break; > v = readq(base + PORT_ERROR_CAP); > ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); > inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); > break; > case FME_FEATURE_ID_GLOBAL_ERR: > + if (type != FME_ID) > + break; > v = readq(base + FME_ERROR_CAP); > ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); > inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v);
> Subject: [PATCH v1 2/7] fpga: dfl: check feature type before parse irq info > > From: Tianfei Zhang <tianfei.zhang@intel.com> > > The feature ID of "Port User Interrupt" and the > "PMCI Subsystem" are identical, 0x12, but one is for FME, > other is for Port. It should check the feature type While > parsing the irq info in parse_feature_irqs(). > > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com> > --- > drivers/fpga/dfl.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > index 599bb21d86af..26f8cf890700 100644 > --- a/drivers/fpga/dfl.c > +++ b/drivers/fpga/dfl.c > @@ -940,9 +940,14 @@ static int parse_feature_irqs(struct > build_feature_devs_info *binfo, > { > void __iomem *base = binfo->ioaddr + ofst; > unsigned int i, ibase, inr = 0; > + enum dfl_id_type type; > int virq; > u64 v; > > + type = feature_dev_id_type(binfo->feature_dev); > + if (type >= DFL_ID_MAX) > + return -EINVAL; > + You don't have to check this, it doesn't allow creating feature dev with type >= DFL_ID_MAX. > /* > * Ideally DFL framework should only read info from DFL header, but > * current version DFL only provides mmio resources information for > @@ -959,16 +964,22 @@ static int parse_feature_irqs(struct > build_feature_devs_info *binfo, > */ > switch (fid) { > case PORT_FEATURE_ID_UINT: > + if (type != PORT_ID) > + break; > v = readq(base + PORT_UINT_CAP); > ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); > inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); > break; > case PORT_FEATURE_ID_ERROR: > + if (type != PORT_ID) > + break; > v = readq(base + PORT_ERROR_CAP); > ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); > inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); > break; > case FME_FEATURE_ID_GLOBAL_ERR: > + if (type != FME_ID) > + break; > v = readq(base + FME_ERROR_CAP); > ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); > inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v); > -- > 2.17.1
On Tue, Feb 15, 2022 at 06:49:05AM -0800, Tom Rix wrote: > > On 2/14/22 3:26 AM, Tianfei zhang wrote: > > From: Tianfei Zhang <tianfei.zhang@intel.com> > > > > The feature ID of "Port User Interrupt" and the > > "PMCI Subsystem" are identical, 0x12, but one is for FME, > > other is for Port. It should check the feature type While > > parsing the irq info in parse_feature_irqs(). > > This seems like a bug fix and not part of iofs feature. > > Split this out of the patchset. > > This is a workaround a hardware problem, there should be some comments to > the effect that you can't trust _this_ or _that_ feature id and some special > handling earlier. > > The ambiguity of feature id is a problem, and this sort of bug will happen Actually this is not the feature id definition problem. The identity of the feature is determined by the dfl_id_type(FME, PORT) AND feature_id. So the driver should match the dfl_id_type & feature_id to know what feature it is. Thanks, Yilun > again. > > What can be done to prevent this in the future ? > > > > > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com> > > --- > > drivers/fpga/dfl.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > > index 599bb21d86af..26f8cf890700 100644 > > --- a/drivers/fpga/dfl.c > > +++ b/drivers/fpga/dfl.c > > @@ -940,9 +940,14 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo, > > { > > void __iomem *base = binfo->ioaddr + ofst; > > unsigned int i, ibase, inr = 0; > > + enum dfl_id_type type; > > int virq; > > u64 v; > > + type = feature_dev_id_type(binfo->feature_dev); > > + if (type >= DFL_ID_MAX) > > + return -EINVAL; > > + > > /* > > * Ideally DFL framework should only read info from DFL header, but > > * current version DFL only provides mmio resources information for > > @@ -959,16 +964,22 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo, > > */ > > switch (fid) { > > case PORT_FEATURE_ID_UINT: > > + if (type != PORT_ID) > > + break; > > Instead of embedding a break in the switch, break the switch into fme switch > and port switch > > if (type == PORT_ID) > > port-switch > > else if (type == FME_ID > > fme-switch > > Tom > > > v = readq(base + PORT_UINT_CAP); > > ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); > > inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); > > break; > > case PORT_FEATURE_ID_ERROR: > > + if (type != PORT_ID) > > + break; > > v = readq(base + PORT_ERROR_CAP); > > ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); > > inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); > > break; > > case FME_FEATURE_ID_GLOBAL_ERR: > > + if (type != FME_ID) > > + break; > > v = readq(base + FME_ERROR_CAP); > > ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); > > inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v);
> -----Original Message----- > From: Tom Rix <trix@redhat.com> > Sent: Tuesday, February 15, 2022 10:49 PM > To: Zhang, Tianfei <tianfei.zhang@intel.com>; Wu, Hao <hao.wu@intel.com>; > mdf@kernel.org; Xu, Yilun <yilun.xu@intel.com>; linux-fpga@vger.kernel.org; > linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org > Cc: corbet@lwn.net > Subject: Re: [PATCH v1 2/7] fpga: dfl: check feature type before parse irq info > > > On 2/14/22 3:26 AM, Tianfei zhang wrote: > > From: Tianfei Zhang <tianfei.zhang@intel.com> > > > > The feature ID of "Port User Interrupt" and the "PMCI Subsystem" are > > identical, 0x12, but one is for FME, other is for Port. It should > > check the feature type While parsing the irq info in > > parse_feature_irqs(). > > This seems like a bug fix and not part of iofs feature. > > Split this out of the patchset. > > This is a workaround a hardware problem, there should be some comments to > the effect that you can't trust _this_ or _that_ feature id and some special > handling earlier. > > The ambiguity of feature id is a problem, and this sort of bug will happen again. > > What can be done to prevent this in the future ? This patch is not workaround, this is a bug fix for DFL driver. The root cause is that DLF driver miss check the feature type while parsing the interrupt information, because some Feature IDs are identical between FME and Port, like PMCI in FME and "Port User Interrupt" in Port. The definition of Feature ID is here: https://github.com/OPAE/linux-dfl-feature-id/blob/master/dfl-feature-ids.rst > > > > > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com> > > --- > > drivers/fpga/dfl.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index > > 599bb21d86af..26f8cf890700 100644 > > --- a/drivers/fpga/dfl.c > > +++ b/drivers/fpga/dfl.c > > @@ -940,9 +940,14 @@ static int parse_feature_irqs(struct > build_feature_devs_info *binfo, > > { > > void __iomem *base = binfo->ioaddr + ofst; > > unsigned int i, ibase, inr = 0; > > + enum dfl_id_type type; > > int virq; > > u64 v; > > > > + type = feature_dev_id_type(binfo->feature_dev); > > + if (type >= DFL_ID_MAX) > > + return -EINVAL; > > + > > /* > > * Ideally DFL framework should only read info from DFL header, but > > * current version DFL only provides mmio resources information for > > @@ -959,16 +964,22 @@ static int parse_feature_irqs(struct > build_feature_devs_info *binfo, > > */ > > switch (fid) { > > case PORT_FEATURE_ID_UINT: > > + if (type != PORT_ID) > > + break; > > Instead of embedding a break in the switch, break the switch into fme switch > and port switch > > if (type == PORT_ID) > > port-switch > > else if (type == FME_ID > > fme-switch Your suggestion is looks good for me, I will change on next version. > > Tom > > > v = readq(base + PORT_UINT_CAP); > > ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); > > inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); > > break; > > case PORT_FEATURE_ID_ERROR: > > + if (type != PORT_ID) > > + break; > > v = readq(base + PORT_ERROR_CAP); > > ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); > > inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); > > break; > > case FME_FEATURE_ID_GLOBAL_ERR: > > + if (type != FME_ID) > > + break; > > v = readq(base + FME_ERROR_CAP); > > ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); > > inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v);
On 2/17/22 10:53 PM, Zhang, Tianfei wrote: > >> -----Original Message----- >> From: Tom Rix <trix@redhat.com> >> Sent: Tuesday, February 15, 2022 10:49 PM >> To: Zhang, Tianfei <tianfei.zhang@intel.com>; Wu, Hao <hao.wu@intel.com>; >> mdf@kernel.org; Xu, Yilun <yilun.xu@intel.com>; linux-fpga@vger.kernel.org; >> linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org >> Cc: corbet@lwn.net >> Subject: Re: [PATCH v1 2/7] fpga: dfl: check feature type before parse irq info >> >> >> On 2/14/22 3:26 AM, Tianfei zhang wrote: >>> From: Tianfei Zhang <tianfei.zhang@intel.com> >>> >>> The feature ID of "Port User Interrupt" and the "PMCI Subsystem" are >>> identical, 0x12, but one is for FME, other is for Port. It should >>> check the feature type While parsing the irq info in >>> parse_feature_irqs(). >> This seems like a bug fix and not part of iofs feature. >> >> Split this out of the patchset. ? >> >> This is a workaround a hardware problem, there should be some comments to >> the effect that you can't trust _this_ or _that_ feature id and some special >> handling earlier. >> >> The ambiguity of feature id is a problem, and this sort of bug will happen again. >> >> What can be done to prevent this in the future ? > This patch is not workaround, this is a bug fix for DFL driver. > The root cause is that DLF driver miss check the feature type while parsing the interrupt information, > because some Feature IDs are identical between FME and Port, like PMCI in FME and "Port User Interrupt" > in Port. > The definition of Feature ID is here: > https://github.com/OPAE/linux-dfl-feature-id/blob/master/dfl-feature-ids.rst Helpful but hidden. At least a link to this should be added to Documentation/fpga/dfl.rst. >>> Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com> >>> --- >>> drivers/fpga/dfl.c | 11 +++++++++++ >>> 1 file changed, 11 insertions(+) >>> >>> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index >>> 599bb21d86af..26f8cf890700 100644 >>> --- a/drivers/fpga/dfl.c >>> +++ b/drivers/fpga/dfl.c >>> @@ -940,9 +940,14 @@ static int parse_feature_irqs(struct >> build_feature_devs_info *binfo, >>> { >>> void __iomem *base = binfo->ioaddr + ofst; >>> unsigned int i, ibase, inr = 0; >>> + enum dfl_id_type type; >>> int virq; >>> u64 v; >>> >>> + type = feature_dev_id_type(binfo->feature_dev); >>> + if (type >= DFL_ID_MAX) >>> + return -EINVAL; >>> + >>> /* >>> * Ideally DFL framework should only read info from DFL header, but >>> * current version DFL only provides mmio resources information for >>> @@ -959,16 +964,22 @@ static int parse_feature_irqs(struct >> build_feature_devs_info *binfo, >>> */ >>> switch (fid) { >>> case PORT_FEATURE_ID_UINT: >>> + if (type != PORT_ID) >>> + break; >> Instead of embedding a break in the switch, break the switch into fme switch >> and port switch >> >> if (type == PORT_ID) >> >> port-switch >> >> else if (type == FME_ID >> >> fme-switch > Your suggestion is looks good for me, I will change on next version. > >> Tom >> >>> v = readq(base + PORT_UINT_CAP); >>> ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); >>> inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); >>> break; >>> case PORT_FEATURE_ID_ERROR: >>> + if (type != PORT_ID) >>> + break; >>> v = readq(base + PORT_ERROR_CAP); >>> ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); >>> inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); >>> break; >>> case FME_FEATURE_ID_GLOBAL_ERR: >>> + if (type != FME_ID) >>> + break; >>> v = readq(base + FME_ERROR_CAP); >>> ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); >>> inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v);
> -----Original Message----- > From: Wu, Hao <hao.wu@intel.com> > Sent: Wednesday, February 16, 2022 11:35 AM > To: Zhang, Tianfei <tianfei.zhang@intel.com>; trix@redhat.com; > mdf@kernel.org; Xu, Yilun <yilun.xu@intel.com>; linux-fpga@vger.kernel.org; > linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org > Cc: corbet@lwn.net > Subject: Re: [PATCH v1 2/7] fpga: dfl: check feature type before parse irq info > > > Subject: [PATCH v1 2/7] fpga: dfl: check feature type before parse irq > > info > > > > From: Tianfei Zhang <tianfei.zhang@intel.com> > > > > The feature ID of "Port User Interrupt" and the "PMCI Subsystem" are > > identical, 0x12, but one is for FME, other is for Port. It should > > check the feature type While parsing the irq info in > > parse_feature_irqs(). > > > > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com> > > --- > > drivers/fpga/dfl.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index > > 599bb21d86af..26f8cf890700 100644 > > --- a/drivers/fpga/dfl.c > > +++ b/drivers/fpga/dfl.c > > @@ -940,9 +940,14 @@ static int parse_feature_irqs(struct > > build_feature_devs_info *binfo, { > > void __iomem *base = binfo->ioaddr + ofst; > > unsigned int i, ibase, inr = 0; > > + enum dfl_id_type type; > > int virq; > > u64 v; > > > > + type = feature_dev_id_type(binfo->feature_dev); > > + if (type >= DFL_ID_MAX) > > + return -EINVAL; > > + > > You don't have to check this, it doesn't allow creating feature dev with type >= > DFL_ID_MAX. I agree, I will fix on next version. > > > /* > > * Ideally DFL framework should only read info from DFL header, but > > * current version DFL only provides mmio resources information for > > @@ -959,16 +964,22 @@ static int parse_feature_irqs(struct > > build_feature_devs_info *binfo, > > */ > > switch (fid) { > > case PORT_FEATURE_ID_UINT: > > + if (type != PORT_ID) > > + break; > > v = readq(base + PORT_UINT_CAP); > > ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); > > inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); > > break; > > case PORT_FEATURE_ID_ERROR: > > + if (type != PORT_ID) > > + break; > > v = readq(base + PORT_ERROR_CAP); > > ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); > > inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); > > break; > > case FME_FEATURE_ID_GLOBAL_ERR: > > + if (type != FME_ID) > > + break; > > v = readq(base + FME_ERROR_CAP); > > ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); > > inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v); > > -- > > 2.17.1
> -----Original Message----- > From: Xu, Yilun <yilun.xu@intel.com> > Sent: Thursday, February 17, 2022 10:38 AM > To: Tom Rix <trix@redhat.com> > Cc: Zhang, Tianfei <tianfei.zhang@intel.com>; Wu, Hao <hao.wu@intel.com>; > mdf@kernel.org; linux-fpga@vger.kernel.org; linux-doc@vger.kernel.org; linux- > kernel@vger.kernel.org; corbet@lwn.net > Subject: Re: [PATCH v1 2/7] fpga: dfl: check feature type before parse irq info > > On Tue, Feb 15, 2022 at 06:49:05AM -0800, Tom Rix wrote: > > > > On 2/14/22 3:26 AM, Tianfei zhang wrote: > > > From: Tianfei Zhang <tianfei.zhang@intel.com> > > > > > > The feature ID of "Port User Interrupt" and the "PMCI Subsystem" are > > > identical, 0x12, but one is for FME, other is for Port. It should > > > check the feature type While parsing the irq info in > > > parse_feature_irqs(). > > > > This seems like a bug fix and not part of iofs feature. > > > > Split this out of the patchset. > > > > This is a workaround a hardware problem, there should be some comments > > to the effect that you can't trust _this_ or _that_ feature id and > > some special handling earlier. > > > > The ambiguity of feature id is a problem, and this sort of bug will > > happen > > Actually this is not the feature id definition problem. The identity of the feature > is determined by the dfl_id_type(FME, PORT) AND feature_id. So the driver > should match the dfl_id_type & feature_id to know what feature it is. In this function flow, create_feature_instance() -> parse_feature_irqs(), the DFL driver has not check the dfl_id_type yet. > > Thanks, > Yilun > > > again. > > > > What can be done to prevent this in the future ? > > > > > > > > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com> > > > --- > > > drivers/fpga/dfl.c | 11 +++++++++++ > > > 1 file changed, 11 insertions(+) > > > > > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index > > > 599bb21d86af..26f8cf890700 100644 > > > --- a/drivers/fpga/dfl.c > > > +++ b/drivers/fpga/dfl.c > > > @@ -940,9 +940,14 @@ static int parse_feature_irqs(struct > build_feature_devs_info *binfo, > > > { > > > void __iomem *base = binfo->ioaddr + ofst; > > > unsigned int i, ibase, inr = 0; > > > + enum dfl_id_type type; > > > int virq; > > > u64 v; > > > + type = feature_dev_id_type(binfo->feature_dev); > > > + if (type >= DFL_ID_MAX) > > > + return -EINVAL; > > > + > > > /* > > > * Ideally DFL framework should only read info from DFL header, but > > > * current version DFL only provides mmio resources information > > > for @@ -959,16 +964,22 @@ static int parse_feature_irqs(struct > build_feature_devs_info *binfo, > > > */ > > > switch (fid) { > > > case PORT_FEATURE_ID_UINT: > > > + if (type != PORT_ID) > > > + break; > > > > Instead of embedding a break in the switch, break the switch into fme > > switch and port switch > > > > if (type == PORT_ID) > > > > port-switch > > > > else if (type == FME_ID > > > > fme-switch > > > > Tom > > > > > v = readq(base + PORT_UINT_CAP); > > > ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); > > > inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); > > > break; > > > case PORT_FEATURE_ID_ERROR: > > > + if (type != PORT_ID) > > > + break; > > > v = readq(base + PORT_ERROR_CAP); > > > ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); > > > inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); > > > break; > > > case FME_FEATURE_ID_GLOBAL_ERR: > > > + if (type != FME_ID) > > > + break; > > > v = readq(base + FME_ERROR_CAP); > > > ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); > > > inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v);
> -----Original Message----- > From: Tom Rix <trix@redhat.com> > Sent: Friday, February 18, 2022 10:30 PM > To: Zhang, Tianfei <tianfei.zhang@intel.com>; Wu, Hao <hao.wu@intel.com>; > mdf@kernel.org; Xu, Yilun <yilun.xu@intel.com>; linux-fpga@vger.kernel.org; > linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org > Cc: corbet@lwn.net > Subject: Re: [PATCH v1 2/7] fpga: dfl: check feature type before parse irq info > > > On 2/17/22 10:53 PM, Zhang, Tianfei wrote: > > > >> -----Original Message----- > >> From: Tom Rix <trix@redhat.com> > >> Sent: Tuesday, February 15, 2022 10:49 PM > >> To: Zhang, Tianfei <tianfei.zhang@intel.com>; Wu, Hao > >> <hao.wu@intel.com>; mdf@kernel.org; Xu, Yilun <yilun.xu@intel.com>; > >> linux-fpga@vger.kernel.org; linux-doc@vger.kernel.org; > >> linux-kernel@vger.kernel.org > >> Cc: corbet@lwn.net > >> Subject: Re: [PATCH v1 2/7] fpga: dfl: check feature type before > >> parse irq info > >> > >> > >> On 2/14/22 3:26 AM, Tianfei zhang wrote: > >>> From: Tianfei Zhang <tianfei.zhang@intel.com> > >>> > >>> The feature ID of "Port User Interrupt" and the "PMCI Subsystem" are > >>> identical, 0x12, but one is for FME, other is for Port. It should > >>> check the feature type While parsing the irq info in > >>> parse_feature_irqs(). > >> This seems like a bug fix and not part of iofs feature. > >> > >> Split this out of the patchset. > > ? I agree, I will send this patch as a bug fix. > > >> > >> This is a workaround a hardware problem, there should be some > >> comments to the effect that you can't trust _this_ or _that_ feature > >> id and some special handling earlier. > >> > >> The ambiguity of feature id is a problem, and this sort of bug will happen > again. > >> > >> What can be done to prevent this in the future ? > > This patch is not workaround, this is a bug fix for DFL driver. > > The root cause is that DLF driver miss check the feature type while > > parsing the interrupt information, because some Feature IDs are identical > between FME and Port, like PMCI in FME and "Port User Interrupt" > > in Port. > > The definition of Feature ID is here: > > https://github.com/OPAE/linux-dfl-feature-id/blob/master/dfl-feature-i > > ds.rst > Helpful but hidden. At least a link to this should be added to > Documentation/fpga/dfl.rst. > >>> Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com> > >>> --- > >>> drivers/fpga/dfl.c | 11 +++++++++++ > >>> 1 file changed, 11 insertions(+) > >>> > >>> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index > >>> 599bb21d86af..26f8cf890700 100644 > >>> --- a/drivers/fpga/dfl.c > >>> +++ b/drivers/fpga/dfl.c > >>> @@ -940,9 +940,14 @@ static int parse_feature_irqs(struct > >> build_feature_devs_info *binfo, > >>> { > >>> void __iomem *base = binfo->ioaddr + ofst; > >>> unsigned int i, ibase, inr = 0; > >>> + enum dfl_id_type type; > >>> int virq; > >>> u64 v; > >>> > >>> + type = feature_dev_id_type(binfo->feature_dev); > >>> + if (type >= DFL_ID_MAX) > >>> + return -EINVAL; > >>> + > >>> /* > >>> * Ideally DFL framework should only read info from DFL header, but > >>> * current version DFL only provides mmio resources information > >>> for @@ -959,16 +964,22 @@ static int parse_feature_irqs(struct > >> build_feature_devs_info *binfo, > >>> */ > >>> switch (fid) { > >>> case PORT_FEATURE_ID_UINT: > >>> + if (type != PORT_ID) > >>> + break; > >> Instead of embedding a break in the switch, break the switch into fme > >> switch and port switch > >> > >> if (type == PORT_ID) > >> > >> port-switch > >> > >> else if (type == FME_ID > >> > >> fme-switch > > Your suggestion is looks good for me, I will change on next version. > > > >> Tom > >> > >>> v = readq(base + PORT_UINT_CAP); > >>> ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); > >>> inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); > >>> break; > >>> case PORT_FEATURE_ID_ERROR: > >>> + if (type != PORT_ID) > >>> + break; > >>> v = readq(base + PORT_ERROR_CAP); > >>> ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); > >>> inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); > >>> break; > >>> case FME_FEATURE_ID_GLOBAL_ERR: > >>> + if (type != FME_ID) > >>> + break; > >>> v = readq(base + FME_ERROR_CAP); > >>> ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); > >>> inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v);
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index 599bb21d86af..26f8cf890700 100644 --- a/drivers/fpga/dfl.c +++ b/drivers/fpga/dfl.c @@ -940,9 +940,14 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo, { void __iomem *base = binfo->ioaddr + ofst; unsigned int i, ibase, inr = 0; + enum dfl_id_type type; int virq; u64 v; + type = feature_dev_id_type(binfo->feature_dev); + if (type >= DFL_ID_MAX) + return -EINVAL; + /* * Ideally DFL framework should only read info from DFL header, but * current version DFL only provides mmio resources information for @@ -959,16 +964,22 @@ static int parse_feature_irqs(struct build_feature_devs_info *binfo, */ switch (fid) { case PORT_FEATURE_ID_UINT: + if (type != PORT_ID) + break; v = readq(base + PORT_UINT_CAP); ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v); inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v); break; case PORT_FEATURE_ID_ERROR: + if (type != PORT_ID) + break; v = readq(base + PORT_ERROR_CAP); ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v); inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v); break; case FME_FEATURE_ID_GLOBAL_ERR: + if (type != FME_ID) + break; v = readq(base + FME_ERROR_CAP); ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v); inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v);