| Message ID | 20210401053656.16065-1-raphael.norwitz@nutanix.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: merge slot and bus reset implementations | expand |
On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > Slot resets are bus resets with additional logic to prevent a device > from being removed during the reset. Currently slot and bus resets have > separate implementations in pci.c, complicating higher level logic. As > discussed on the mailing list, they should be combined into a generic > function which performs an SBR. This change adds a function, > pci_reset_bus_function(), which first attempts a slot reset and then > attempts a bus reset if -ENOTTY is returned, such that there is now a > single device agnostic function to perform an SBR. > > This new function is also needed to add SBR reset quirks and therefore > is exposed in pci.h. > > Link: https://lkml.org/lkml/2021/3/23/911 > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > --- > drivers/pci/pci.c | 17 +++++++++-------- > include/linux/pci.h | 1 + > 2 files changed, 10 insertions(+), 8 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 16a17215f633..12a91af2ade4 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > } > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > +{ > + int rc = pci_dev_reset_slot_function(dev, probe); > + > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; The previous coding style is preferable one in the Linux kernel. int rc = pci_dev_reset_slot_function(dev, probe); if (rc != -ENOTTY) return rc; return pci_parent_bus_reset(dev, probe); > +} > + > static void pci_dev_lock(struct pci_dev *dev) > { > pci_cfg_access_lock(dev); > @@ -5102,10 +5109,7 @@ int __pci_reset_function_locked(struct pci_dev *dev) > rc = pci_pm_reset(dev, 0); > if (rc != -ENOTTY) > return rc; > - rc = pci_dev_reset_slot_function(dev, 0); > - if (rc != -ENOTTY) > - return rc; > - return pci_parent_bus_reset(dev, 0); > + return pci_reset_bus_function(dev, 0); > } > EXPORT_SYMBOL_GPL(__pci_reset_function_locked); > > @@ -5135,13 +5139,10 @@ int pci_probe_reset_function(struct pci_dev *dev) > if (rc != -ENOTTY) > return rc; > rc = pci_pm_reset(dev, 1); > - if (rc != -ENOTTY) > - return rc; > - rc = pci_dev_reset_slot_function(dev, 1); > if (rc != -ENOTTY) > return rc; > > - return pci_parent_bus_reset(dev, 1); > + return pci_reset_bus_function(dev, 1); > } > > /** > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 86c799c97b77..979d54335ac1 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1228,6 +1228,7 @@ int pci_probe_reset_bus(struct pci_bus *bus); > int pci_reset_bus(struct pci_dev *dev); > void pci_reset_secondary_bus(struct pci_dev *dev); > void pcibios_reset_secondary_bus(struct pci_dev *dev); > +int pci_reset_bus_function(struct pci_dev *dev, int probe); > void pci_update_resource(struct pci_dev *dev, int resno); > int __must_check pci_assign_resource(struct pci_dev *dev, int i); > int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align); > -- > 2.20.1
On Thu, 1 Apr 2021 15:27:37 +0300 Leon Romanovsky <leon@kernel.org> wrote: > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > Slot resets are bus resets with additional logic to prevent a device > > from being removed during the reset. Currently slot and bus resets have > > separate implementations in pci.c, complicating higher level logic. As > > discussed on the mailing list, they should be combined into a generic > > function which performs an SBR. This change adds a function, > > pci_reset_bus_function(), which first attempts a slot reset and then > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > single device agnostic function to perform an SBR. > > > > This new function is also needed to add SBR reset quirks and therefore > > is exposed in pci.h. > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > --- > > drivers/pci/pci.c | 17 +++++++++-------- > > include/linux/pci.h | 1 + > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > index 16a17215f633..12a91af2ade4 100644 > > --- a/drivers/pci/pci.c > > +++ b/drivers/pci/pci.c > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > } > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > +{ > > + int rc = pci_dev_reset_slot_function(dev, probe); > > + > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > The previous coding style is preferable one in the Linux kernel. > int rc = pci_dev_reset_slot_function(dev, probe); > if (rc != -ENOTTY) > return rc; > return pci_parent_bus_reset(dev, probe); That'd be news to me, do you have a reference? I've never seen complaints for ternaries previously. Thanks, Alex
On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > On Thu, 1 Apr 2021 15:27:37 +0300 > Leon Romanovsky <leon@kernel.org> wrote: > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > > Slot resets are bus resets with additional logic to prevent a device > > > from being removed during the reset. Currently slot and bus resets have > > > separate implementations in pci.c, complicating higher level logic. As > > > discussed on the mailing list, they should be combined into a generic > > > function which performs an SBR. This change adds a function, > > > pci_reset_bus_function(), which first attempts a slot reset and then > > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > > single device agnostic function to perform an SBR. > > > > > > This new function is also needed to add SBR reset quirks and therefore > > > is exposed in pci.h. > > > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > > --- > > > drivers/pci/pci.c | 17 +++++++++-------- > > > include/linux/pci.h | 1 + > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > index 16a17215f633..12a91af2ade4 100644 > > > --- a/drivers/pci/pci.c > > > +++ b/drivers/pci/pci.c > > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > > } > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > +{ > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > + > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > > > The previous coding style is preferable one in the Linux kernel. > > int rc = pci_dev_reset_slot_function(dev, probe); > > if (rc != -ENOTTY) > > return rc; > > return pci_parent_bus_reset(dev, probe); > > > That'd be news to me, do you have a reference? I've never seen > complaints for ternaries previously. Thanks, The complaint is not to ternaries, but to the function call as one of the parameters, that makes it harder to read. Thanks > > Alex >
On Sun, 4 Apr 2021 11:04:32 +0300 Leon Romanovsky <leon@kernel.org> wrote: > On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > > On Thu, 1 Apr 2021 15:27:37 +0300 > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > > > Slot resets are bus resets with additional logic to prevent a device > > > > from being removed during the reset. Currently slot and bus resets have > > > > separate implementations in pci.c, complicating higher level logic. As > > > > discussed on the mailing list, they should be combined into a generic > > > > function which performs an SBR. This change adds a function, > > > > pci_reset_bus_function(), which first attempts a slot reset and then > > > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > > > single device agnostic function to perform an SBR. > > > > > > > > This new function is also needed to add SBR reset quirks and therefore > > > > is exposed in pci.h. > > > > > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > > > --- > > > > drivers/pci/pci.c | 17 +++++++++-------- > > > > include/linux/pci.h | 1 + > > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > index 16a17215f633..12a91af2ade4 100644 > > > > --- a/drivers/pci/pci.c > > > > +++ b/drivers/pci/pci.c > > > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > > > } > > > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > > +{ > > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > > + > > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > > > > > The previous coding style is preferable one in the Linux kernel. > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > if (rc != -ENOTTY) > > > return rc; > > > return pci_parent_bus_reset(dev, probe); > > > > > > That'd be news to me, do you have a reference? I've never seen > > complaints for ternaries previously. Thanks, > > The complaint is not to ternaries, but to the function call as one of > the parameters, that makes it harder to read. Sorry, I don't find a function call as a parameter to a ternary to be extraordinary, nor do I find it to be a discouraged usage model within the kernel. This seems like a pretty low bar for hard to read code.
On Tue, Apr 06, 2021 at 08:16:26AM -0600, Alex Williamson wrote: > On Sun, 4 Apr 2021 11:04:32 +0300 > Leon Romanovsky <leon@kernel.org> wrote: > > > On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > > > On Thu, 1 Apr 2021 15:27:37 +0300 > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > > > > Slot resets are bus resets with additional logic to prevent a device > > > > > from being removed during the reset. Currently slot and bus resets have > > > > > separate implementations in pci.c, complicating higher level logic. As > > > > > discussed on the mailing list, they should be combined into a generic > > > > > function which performs an SBR. This change adds a function, > > > > > pci_reset_bus_function(), which first attempts a slot reset and then > > > > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > > > > single device agnostic function to perform an SBR. > > > > > > > > > > This new function is also needed to add SBR reset quirks and therefore > > > > > is exposed in pci.h. > > > > > > > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > > > > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > > > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > > > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > > > > --- > > > > > drivers/pci/pci.c | 17 +++++++++-------- > > > > > include/linux/pci.h | 1 + > > > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > index 16a17215f633..12a91af2ade4 100644 > > > > > --- a/drivers/pci/pci.c > > > > > +++ b/drivers/pci/pci.c > > > > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > > > > } > > > > > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > > > +{ > > > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > > > + > > > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > > > > > > > The previous coding style is preferable one in the Linux kernel. > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > if (rc != -ENOTTY) > > > > return rc; > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > complaints for ternaries previously. Thanks, > > > > The complaint is not to ternaries, but to the function call as one of > > the parameters, that makes it harder to read. > > Sorry, I don't find a function call as a parameter to a ternary to be > extraordinary, nor do I find it to be a discouraged usage model within > the kernel. This seems like a pretty low bar for hard to read code. It is up to us where this bar is set. Thanks
[+cc Greg for visibility] Hello, [...] > > > > > The previous coding style is preferable one in the Linux kernel. > > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > > if (rc != -ENOTTY) > > > > > return rc; > > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > > complaints for ternaries previously. Thanks, > > > > > > The complaint is not to ternaries, but to the function call as one of > > > the parameters, that makes it harder to read. > > > > Sorry, I don't find a function call as a parameter to a ternary to be > > extraordinary, nor do I find it to be a discouraged usage model within > > the kernel. This seems like a pretty low bar for hard to read code. > > It is up to us where this bar is set. The only person who ever pulled my ear, so to speak, over using ternary was Greg as a bad style where, especially where it does not need to be used. But, I digress. I humbly think that we should move back on track and finish review of Raphael's patch. Would use a ternary here be a show-stopper? Krzysztof
On Wed, Apr 07, 2021 at 09:49:03AM +0200, Krzysztof Wilczyński wrote: > [+cc Greg for visibility] > > Hello, > > [...] > > > > > > The previous coding style is preferable one in the Linux kernel. > > > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > if (rc != -ENOTTY) > > > > > > return rc; > > > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > > > complaints for ternaries previously. Thanks, > > > > > > > > The complaint is not to ternaries, but to the function call as one of > > > > the parameters, that makes it harder to read. > > > > > > Sorry, I don't find a function call as a parameter to a ternary to be > > > extraordinary, nor do I find it to be a discouraged usage model within > > > the kernel. This seems like a pretty low bar for hard to read code. > > > > It is up to us where this bar is set. > > The only person who ever pulled my ear, so to speak, over using ternary > was Greg as a bad style where, especially where it does not need to be > used. Good to hear that I'm not alone. > > But, I digress. I humbly think that we should move back on track and > finish review of Raphael's patch. Would use a ternary here be > a show-stopper? Of course no, I would fix it locally when apply. Thanks > > Krzysztof
On 21/04/07 10:23AM, Leon Romanovsky wrote: > On Tue, Apr 06, 2021 at 08:16:26AM -0600, Alex Williamson wrote: > > On Sun, 4 Apr 2021 11:04:32 +0300 > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > > > > On Thu, 1 Apr 2021 15:27:37 +0300 > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > > > > > Slot resets are bus resets with additional logic to prevent a device > > > > > > from being removed during the reset. Currently slot and bus resets have > > > > > > separate implementations in pci.c, complicating higher level logic. As > > > > > > discussed on the mailing list, they should be combined into a generic > > > > > > function which performs an SBR. This change adds a function, > > > > > > pci_reset_bus_function(), which first attempts a slot reset and then > > > > > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > > > > > single device agnostic function to perform an SBR. > > > > > > > > > > > > This new function is also needed to add SBR reset quirks and therefore > > > > > > is exposed in pci.h. > > > > > > > > > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > > > > > > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > > > > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > > > > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > > > > > --- > > > > > > drivers/pci/pci.c | 17 +++++++++-------- > > > > > > include/linux/pci.h | 1 + > > > > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > > index 16a17215f633..12a91af2ade4 100644 > > > > > > --- a/drivers/pci/pci.c > > > > > > +++ b/drivers/pci/pci.c > > > > > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > > > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > > > > > } > > > > > > > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > > > > +{ > > > > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > + > > > > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > > > > > > > > > The previous coding style is preferable one in the Linux kernel. > > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > > if (rc != -ENOTTY) > > > > > return rc; > > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > > complaints for ternaries previously. Thanks, > > > > > > The complaint is not to ternaries, but to the function call as one of > > > the parameters, that makes it harder to read. > > > > Sorry, I don't find a function call as a parameter to a ternary to be > > extraordinary, nor do I find it to be a discouraged usage model within > > the kernel. This seems like a pretty low bar for hard to read code. > > It is up to us where this bar is set. > > Thanks On the side note there are plenty of places where this pattern is used though for example - kernel/time/clockevents.c:328: return force ? clockevents_program_min_delta(dev) : -ETIME; kernel/trace/trace_kprobe.c:233: return tk ? within_error_injection_list(trace_kprobe_address(tk)) : false; kernel/signal.c:3104: return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0; etc Thanks, Amey
On Wed, Apr 07, 2021 at 01:53:56PM +0530, ameynarkhede03@gmail.com wrote: > On 21/04/07 10:23AM, Leon Romanovsky wrote: > > On Tue, Apr 06, 2021 at 08:16:26AM -0600, Alex Williamson wrote: > > > On Sun, 4 Apr 2021 11:04:32 +0300 > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > > > > > On Thu, 1 Apr 2021 15:27:37 +0300 > > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > > > > > > Slot resets are bus resets with additional logic to prevent a device > > > > > > > from being removed during the reset. Currently slot and bus resets have > > > > > > > separate implementations in pci.c, complicating higher level logic. As > > > > > > > discussed on the mailing list, they should be combined into a generic > > > > > > > function which performs an SBR. This change adds a function, > > > > > > > pci_reset_bus_function(), which first attempts a slot reset and then > > > > > > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > > > > > > single device agnostic function to perform an SBR. > > > > > > > > > > > > > > This new function is also needed to add SBR reset quirks and therefore > > > > > > > is exposed in pci.h. > > > > > > > > > > > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > > > > > > > > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > > > > > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > > > > > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > > > > > > --- > > > > > > > drivers/pci/pci.c | 17 +++++++++-------- > > > > > > > include/linux/pci.h | 1 + > > > > > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > > > index 16a17215f633..12a91af2ade4 100644 > > > > > > > --- a/drivers/pci/pci.c > > > > > > > +++ b/drivers/pci/pci.c > > > > > > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > > > > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > > > > > > } > > > > > > > > > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > > > > > +{ > > > > > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > + > > > > > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > > > > > > > > > > > The previous coding style is preferable one in the Linux kernel. > > > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > if (rc != -ENOTTY) > > > > > > return rc; > > > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > > > complaints for ternaries previously. Thanks, > > > > > > > > The complaint is not to ternaries, but to the function call as one of > > > > the parameters, that makes it harder to read. > > > > > > Sorry, I don't find a function call as a parameter to a ternary to be > > > extraordinary, nor do I find it to be a discouraged usage model within > > > the kernel. This seems like a pretty low bar for hard to read code. > > > > It is up to us where this bar is set. > > > > Thanks > On the side note there are plenty of places where this pattern is used > though > for example - > kernel/time/clockevents.c:328: > return force ? clockevents_program_min_delta(dev) : -ETIME; > > kernel/trace/trace_kprobe.c:233: > return tk ? within_error_injection_list(trace_kprobe_address(tk)) : > false; > > kernel/signal.c:3104: > return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0; > etc Did you look when they were introduced? Thanks > > Thanks, > Amey
On 21/04/07 03:30PM, Leon Romanovsky wrote: > On Wed, Apr 07, 2021 at 01:53:56PM +0530, ameynarkhede03@gmail.com wrote: > > On 21/04/07 10:23AM, Leon Romanovsky wrote: > > > On Tue, Apr 06, 2021 at 08:16:26AM -0600, Alex Williamson wrote: > > > > On Sun, 4 Apr 2021 11:04:32 +0300 > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > > > > > > On Thu, 1 Apr 2021 15:27:37 +0300 > > > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > > > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > > > > > > > Slot resets are bus resets with additional logic to prevent a device > > > > > > > > from being removed during the reset. Currently slot and bus resets have > > > > > > > > separate implementations in pci.c, complicating higher level logic. As > > > > > > > > discussed on the mailing list, they should be combined into a generic > > > > > > > > function which performs an SBR. This change adds a function, > > > > > > > > pci_reset_bus_function(), which first attempts a slot reset and then > > > > > > > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > > > > > > > single device agnostic function to perform an SBR. > > > > > > > > > > > > > > > > This new function is also needed to add SBR reset quirks and therefore > > > > > > > > is exposed in pci.h. > > > > > > > > > > > > > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > > > > > > > > > > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > > > > > > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > > > > > > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > > > > > > > --- > > > > > > > > drivers/pci/pci.c | 17 +++++++++-------- > > > > > > > > include/linux/pci.h | 1 + > > > > > > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > > > > index 16a17215f633..12a91af2ade4 100644 > > > > > > > > --- a/drivers/pci/pci.c > > > > > > > > +++ b/drivers/pci/pci.c > > > > > > > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > > > > > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > > > > > > > } > > > > > > > > > > > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > > > > > > +{ > > > > > > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > > + > > > > > > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > > > > > > > > > > > > > The previous coding style is preferable one in the Linux kernel. > > > > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > if (rc != -ENOTTY) > > > > > > > return rc; > > > > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > > > > complaints for ternaries previously. Thanks, > > > > > > > > > > The complaint is not to ternaries, but to the function call as one of > > > > > the parameters, that makes it harder to read. > > > > > > > > Sorry, I don't find a function call as a parameter to a ternary to be > > > > extraordinary, nor do I find it to be a discouraged usage model within > > > > the kernel. This seems like a pretty low bar for hard to read code. > > > > > > It is up to us where this bar is set. > > > > > > Thanks > > On the side note there are plenty of places where this pattern is used > > though > > for example - > > kernel/time/clockevents.c:328: > > return force ? clockevents_program_min_delta(dev) : -ETIME; > > > > kernel/trace/trace_kprobe.c:233: > > return tk ? within_error_injection_list(trace_kprobe_address(tk)) : > > false; > > > > kernel/signal.c:3104: > > return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0; > > etc > > Did you look when they were introduced? > > Thanks > that code trace_kprobe in 2 years old. If you want more recent example checkout drivers/pci/controller/pcie-brcmstb.c:1112,1117: return pcie->rescal ? brcm_phy_cntl(pcie, 1) : 0; which was introduced 7 months ago. There are lot of examples in pci.c also. Thanks, Amey
On Wed, Apr 07, 2021 at 06:36:01PM +0530, ameynarkhede03@gmail.com wrote: > On 21/04/07 03:30PM, Leon Romanovsky wrote: > > On Wed, Apr 07, 2021 at 01:53:56PM +0530, ameynarkhede03@gmail.com wrote: > > > On 21/04/07 10:23AM, Leon Romanovsky wrote: > > > > On Tue, Apr 06, 2021 at 08:16:26AM -0600, Alex Williamson wrote: > > > > > On Sun, 4 Apr 2021 11:04:32 +0300 > > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > > > On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > > > > > > > On Thu, 1 Apr 2021 15:27:37 +0300 > > > > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > > > > > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > > > > > > > > Slot resets are bus resets with additional logic to prevent a device > > > > > > > > > from being removed during the reset. Currently slot and bus resets have > > > > > > > > > separate implementations in pci.c, complicating higher level logic. As > > > > > > > > > discussed on the mailing list, they should be combined into a generic > > > > > > > > > function which performs an SBR. This change adds a function, > > > > > > > > > pci_reset_bus_function(), which first attempts a slot reset and then > > > > > > > > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > > > > > > > > single device agnostic function to perform an SBR. > > > > > > > > > > > > > > > > > > This new function is also needed to add SBR reset quirks and therefore > > > > > > > > > is exposed in pci.h. > > > > > > > > > > > > > > > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > > > > > > > > > > > > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > > > > > > > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > > > > > > > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > > > > > > > > --- > > > > > > > > > drivers/pci/pci.c | 17 +++++++++-------- > > > > > > > > > include/linux/pci.h | 1 + > > > > > > > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > > > > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > > > > > index 16a17215f633..12a91af2ade4 100644 > > > > > > > > > --- a/drivers/pci/pci.c > > > > > > > > > +++ b/drivers/pci/pci.c > > > > > > > > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > > > > > > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > > > > > > > > } > > > > > > > > > > > > > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > > > > > > > +{ > > > > > > > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > > > + > > > > > > > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > > > > > > > > > > > > > > > The previous coding style is preferable one in the Linux kernel. > > > > > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > > if (rc != -ENOTTY) > > > > > > > > return rc; > > > > > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > > > > > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > > > > > complaints for ternaries previously. Thanks, > > > > > > > > > > > > The complaint is not to ternaries, but to the function call as one of > > > > > > the parameters, that makes it harder to read. > > > > > > > > > > Sorry, I don't find a function call as a parameter to a ternary to be > > > > > extraordinary, nor do I find it to be a discouraged usage model within > > > > > the kernel. This seems like a pretty low bar for hard to read code. > > > > > > > > It is up to us where this bar is set. > > > > > > > > Thanks > > > On the side note there are plenty of places where this pattern is used > > > though > > > for example - > > > kernel/time/clockevents.c:328: > > > return force ? clockevents_program_min_delta(dev) : -ETIME; > > > > > > kernel/trace/trace_kprobe.c:233: > > > return tk ? within_error_injection_list(trace_kprobe_address(tk)) : > > > false; > > > > > > kernel/signal.c:3104: > > > return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0; > > > etc > > > > Did you look when they were introduced? > > > > Thanks > > > that code trace_kprobe in 2 years old. > If you want more recent example checkout > drivers/pci/controller/pcie-brcmstb.c:1112,1117: > return pcie->rescal ? brcm_phy_cntl(pcie, 1) : 0; > which was introduced 7 months ago. > There are lot of examples in pci.c also. Yeah, I know, copy-paste is a powerful tool. Can we please progress with this patch instead of doing archaeological research? Thanks > > Thanks, > Amey
On 21/04/07 04:37PM, Leon Romanovsky wrote: > On Wed, Apr 07, 2021 at 06:36:01PM +0530, ameynarkhede03@gmail.com wrote: > > On 21/04/07 03:30PM, Leon Romanovsky wrote: > > > On Wed, Apr 07, 2021 at 01:53:56PM +0530, ameynarkhede03@gmail.com wrote: > > > > On 21/04/07 10:23AM, Leon Romanovsky wrote: > > > > > On Tue, Apr 06, 2021 at 08:16:26AM -0600, Alex Williamson wrote: > > > > > > On Sun, 4 Apr 2021 11:04:32 +0300 > > > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > > > > > On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > > > > > > > > On Thu, 1 Apr 2021 15:27:37 +0300 > > > > > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > > > > > > > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > > > > > > > > > Slot resets are bus resets with additional logic to prevent a device > > > > > > > > > > from being removed during the reset. Currently slot and bus resets have > > > > > > > > > > separate implementations in pci.c, complicating higher level logic. As > > > > > > > > > > discussed on the mailing list, they should be combined into a generic > > > > > > > > > > function which performs an SBR. This change adds a function, > > > > > > > > > > pci_reset_bus_function(), which first attempts a slot reset and then > > > > > > > > > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > > > > > > > > > single device agnostic function to perform an SBR. > > > > > > > > > > > > > > > > > > > > This new function is also needed to add SBR reset quirks and therefore > > > > > > > > > > is exposed in pci.h. > > > > > > > > > > > > > > > > > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > > > > > > > > > > > > > > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > > > > > > > > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > > > > > > > > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > > > > > > > > > --- > > > > > > > > > > drivers/pci/pci.c | 17 +++++++++-------- > > > > > > > > > > include/linux/pci.h | 1 + > > > > > > > > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > > > > > > index 16a17215f633..12a91af2ade4 100644 > > > > > > > > > > --- a/drivers/pci/pci.c > > > > > > > > > > +++ b/drivers/pci/pci.c > > > > > > > > > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > > > > > > > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > > > > > > > > +{ > > > > > > > > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > > > > + > > > > > > > > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > > > > > > > > > > > > > > > > > The previous coding style is preferable one in the Linux kernel. > > > > > > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > > > if (rc != -ENOTTY) > > > > > > > > > return rc; > > > > > > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > > > > > > > > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > > > > > > complaints for ternaries previously. Thanks, > > > > > > > > > > > > > > The complaint is not to ternaries, but to the function call as one of > > > > > > > the parameters, that makes it harder to read. > > > > > > > > > > > > Sorry, I don't find a function call as a parameter to a ternary to be > > > > > > extraordinary, nor do I find it to be a discouraged usage model within > > > > > > the kernel. This seems like a pretty low bar for hard to read code. > > > > > > > > > > It is up to us where this bar is set. > > > > > > > > > > Thanks > > > > On the side note there are plenty of places where this pattern is used > > > > though > > > > for example - > > > > kernel/time/clockevents.c:328: > > > > return force ? clockevents_program_min_delta(dev) : -ETIME; > > > > > > > > kernel/trace/trace_kprobe.c:233: > > > > return tk ? within_error_injection_list(trace_kprobe_address(tk)) : > > > > false; > > > > > > > > kernel/signal.c:3104: > > > > return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0; > > > > etc > > > > > > Did you look when they were introduced? > > > > > > Thanks > > > > > that code trace_kprobe in 2 years old. > > If you want more recent example checkout > > drivers/pci/controller/pcie-brcmstb.c:1112,1117: > > return pcie->rescal ? brcm_phy_cntl(pcie, 1) : 0; > > which was introduced 7 months ago. > > There are lot of examples in pci.c also. > > Yeah, I know, copy-paste is a powerful tool. > > Can we please progress with this patch instead of doing > archaeological research? > > Thanks > Sorry I didn't understand what you said. Thanks, Amey
On Wed, Apr 07, 2021 at 04:37:23PM +0300, Leon Romanovsky wrote: > On Wed, Apr 07, 2021 at 06:36:01PM +0530, ameynarkhede03@gmail.com wrote: > > On 21/04/07 03:30PM, Leon Romanovsky wrote: > > > On Wed, Apr 07, 2021 at 01:53:56PM +0530, ameynarkhede03@gmail.com wrote: > > > > On 21/04/07 10:23AM, Leon Romanovsky wrote: > > > > > On Tue, Apr 06, 2021 at 08:16:26AM -0600, Alex Williamson wrote: > > > > > > On Sun, 4 Apr 2021 11:04:32 +0300 > > > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > > > > > On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > > > > > > > > On Thu, 1 Apr 2021 15:27:37 +0300 > > > > > > > > Leon Romanovsky <leon@kernel.org> wrote: > > > > > > > > > > > > > > > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz wrote: > > > > > > > > > > Slot resets are bus resets with additional logic to prevent a device > > > > > > > > > > from being removed during the reset. Currently slot and bus resets have > > > > > > > > > > separate implementations in pci.c, complicating higher level logic. As > > > > > > > > > > discussed on the mailing list, they should be combined into a generic > > > > > > > > > > function which performs an SBR. This change adds a function, > > > > > > > > > > pci_reset_bus_function(), which first attempts a slot reset and then > > > > > > > > > > attempts a bus reset if -ENOTTY is returned, such that there is now a > > > > > > > > > > single device agnostic function to perform an SBR. > > > > > > > > > > > > > > > > > > > > This new function is also needed to add SBR reset quirks and therefore > > > > > > > > > > is exposed in pci.h. > > > > > > > > > > > > > > > > > > > > Link: https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2021_3_23_911&d=DwIBAg&c=s883GpUCOChKOHiocYtGcg&r=In4gmR1pGzKB8G5p6LUrWqkSMec2L5EtXZow_FZNJZk&m=dn12ruIb9lwgcFMNKBZzri1m3zoTBFlkHnrF48PChs4&s=iEm1FGjLlWUpKJQYMwCHc1crraEzAgN10pCzyEzbrWI&e= > > > > > > > > > > > > > > > > > > > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > > > > > > > > > > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > > > > > > > > > > Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > > > > > > > > > > --- > > > > > > > > > > drivers/pci/pci.c | 17 +++++++++-------- > > > > > > > > > > include/linux/pci.h | 1 + > > > > > > > > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > > > > > > index 16a17215f633..12a91af2ade4 100644 > > > > > > > > > > --- a/drivers/pci/pci.c > > > > > > > > > > +++ b/drivers/pci/pci.c > > > > > > > > > > @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > > > > > > > > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > > > > > > > > +{ > > > > > > > > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > > > > + > > > > > > > > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; > > > > > > > > > > > > > > > > > > The previous coding style is preferable one in the Linux kernel. > > > > > > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > > > if (rc != -ENOTTY) > > > > > > > > > return rc; > > > > > > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > > > > > > > > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > > > > > > complaints for ternaries previously. Thanks, > > > > > > > > > > > > > > The complaint is not to ternaries, but to the function call as one of > > > > > > > the parameters, that makes it harder to read. > > > > > > > > > > > > Sorry, I don't find a function call as a parameter to a ternary to be > > > > > > extraordinary, nor do I find it to be a discouraged usage model within > > > > > > the kernel. This seems like a pretty low bar for hard to read code. > > > > > > > > > > It is up to us where this bar is set. > > > > > > > > > > Thanks > > > > On the side note there are plenty of places where this pattern is used > > > > though > > > > for example - > > > > kernel/time/clockevents.c:328: > > > > return force ? clockevents_program_min_delta(dev) : -ETIME; > > > > > > > > kernel/trace/trace_kprobe.c:233: > > > > return tk ? within_error_injection_list(trace_kprobe_address(tk)) : > > > > false; > > > > > > > > kernel/signal.c:3104: > > > > return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0; > > > > etc > > > > > > Did you look when they were introduced? > > > > > > Thanks > > > > > that code trace_kprobe in 2 years old. > > If you want more recent example checkout > > drivers/pci/controller/pcie-brcmstb.c:1112,1117: > > return pcie->rescal ? brcm_phy_cntl(pcie, 1) : 0; > > which was introduced 7 months ago. > > There are lot of examples in pci.c also. > > Yeah, I know, copy-paste is a powerful tool. > > Can we please progress with this patch instead of doing > archaeological research? > > Thanks > I don't have a strong view on the style guidelines being discussed here. I just sent a V2 replacing the ternary function parameter with your suggestion. > > > > Thanks, > > Amey
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 16a17215f633..12a91af2ade4 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4982,6 +4982,13 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) return pci_reset_hotplug_slot(dev->slot->hotplug, probe); } +int pci_reset_bus_function(struct pci_dev *dev, int probe) +{ + int rc = pci_dev_reset_slot_function(dev, probe); + + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, probe) : rc; +} + static void pci_dev_lock(struct pci_dev *dev) { pci_cfg_access_lock(dev); @@ -5102,10 +5109,7 @@ int __pci_reset_function_locked(struct pci_dev *dev) rc = pci_pm_reset(dev, 0); if (rc != -ENOTTY) return rc; - rc = pci_dev_reset_slot_function(dev, 0); - if (rc != -ENOTTY) - return rc; - return pci_parent_bus_reset(dev, 0); + return pci_reset_bus_function(dev, 0); } EXPORT_SYMBOL_GPL(__pci_reset_function_locked); @@ -5135,13 +5139,10 @@ int pci_probe_reset_function(struct pci_dev *dev) if (rc != -ENOTTY) return rc; rc = pci_pm_reset(dev, 1); - if (rc != -ENOTTY) - return rc; - rc = pci_dev_reset_slot_function(dev, 1); if (rc != -ENOTTY) return rc; - return pci_parent_bus_reset(dev, 1); + return pci_reset_bus_function(dev, 1); } /** diff --git a/include/linux/pci.h b/include/linux/pci.h index 86c799c97b77..979d54335ac1 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1228,6 +1228,7 @@ int pci_probe_reset_bus(struct pci_bus *bus); int pci_reset_bus(struct pci_dev *dev); void pci_reset_secondary_bus(struct pci_dev *dev); void pcibios_reset_secondary_bus(struct pci_dev *dev); +int pci_reset_bus_function(struct pci_dev *dev, int probe); void pci_update_resource(struct pci_dev *dev, int resno); int __must_check pci_assign_resource(struct pci_dev *dev, int i); int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align);