2024-06-05 08:18:49

by Philipp Stanner

[permalink] [raw]
Subject: [PATCH v7 07/13] PCI: Move dev-enabled status bit to struct pci_dev

The bit describing whether the PCI device is currently enabled is stored
in struct pci_devres. Besides this struct being subject of a cleanup
process, struct pci_device is in general the right place to store this
information, since it is not devres-specific.

Move the 'enabled' boolean bit to struct pci_dev.

Signed-off-by: Philipp Stanner <[email protected]>
---
drivers/pci/devres.c | 11 ++++-------
drivers/pci/pci.c | 17 ++++++++++-------
drivers/pci/pci.h | 1 -
include/linux/pci.h | 1 +
4 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index 572a4e193879..ea590caf8995 100644
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -398,7 +398,7 @@ static void pcim_release(struct device *gendev, void *res)
if (this->restore_intx)
pci_intx(dev, this->orig_intx);

- if (this->enabled && !this->pinned)
+ if (!this->pinned)
pci_disable_device(dev);
}

@@ -441,14 +441,11 @@ int pcim_enable_device(struct pci_dev *pdev)
dr = get_pci_dr(pdev);
if (unlikely(!dr))
return -ENOMEM;
- if (dr->enabled)
- return 0;

rc = pci_enable_device(pdev);
- if (!rc) {
+ if (!rc)
pdev->is_managed = 1;
- dr->enabled = 1;
- }
+
return rc;
}
EXPORT_SYMBOL(pcim_enable_device);
@@ -466,7 +463,7 @@ void pcim_pin_device(struct pci_dev *pdev)
struct pci_devres *dr;

dr = find_pci_dr(pdev);
- WARN_ON(!dr || !dr->enabled);
+ WARN_ON(!dr || !pdev->enabled);
if (dr)
dr->pinned = 1;
}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8dd711b9a291..04accdfab7ce 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2011,6 +2011,9 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
u16 cmd;
u8 pin;

+ if (dev->enabled)
+ return 0;
+
err = pci_set_power_state(dev, PCI_D0);
if (err < 0 && err != -EIO)
return err;
@@ -2025,7 +2028,7 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
pci_fixup_device(pci_fixup_enable, dev);

if (dev->msi_enabled || dev->msix_enabled)
- return 0;
+ goto success_out;

pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
if (pin) {
@@ -2035,6 +2038,8 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
cmd & ~PCI_COMMAND_INTX_DISABLE);
}

+success_out:
+ dev->enabled = true;
return 0;
}

@@ -2193,6 +2198,9 @@ static void do_pci_disable_device(struct pci_dev *dev)
{
u16 pci_command;

+ if (!dev->enabled)
+ return;
+
pci_read_config_word(dev, PCI_COMMAND, &pci_command);
if (pci_command & PCI_COMMAND_MASTER) {
pci_command &= ~PCI_COMMAND_MASTER;
@@ -2200,6 +2208,7 @@ static void do_pci_disable_device(struct pci_dev *dev)
}

pcibios_disable_device(dev);
+ dev->enabled = false;
}

/**
@@ -2227,12 +2236,6 @@ void pci_disable_enabled_device(struct pci_dev *dev)
*/
void pci_disable_device(struct pci_dev *dev)
{
- struct pci_devres *dr;
-
- dr = find_pci_dr(dev);
- if (dr)
- dr->enabled = 0;
-
dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
"disabling already-disabled device");

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9fd50bc99e6b..e223e0f7dada 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -823,7 +823,6 @@ static inline pci_power_t mid_pci_get_power_state(struct pci_dev *pdev)
* then remove them from here.
*/
struct pci_devres {
- unsigned int enabled:1;
unsigned int pinned:1;
unsigned int orig_intx:1;
unsigned int restore_intx:1;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 16493426a04f..110548f00b3b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -367,6 +367,7 @@ struct pci_dev {
this is D0-D3, D0 being fully
functional, and D3 being off. */
u8 pm_cap; /* PM capability offset */
+ unsigned int enabled:1; /* Whether this dev is enabled */
unsigned int imm_ready:1; /* Supports Immediate Readiness */
unsigned int pme_support:5; /* Bitmask of states from which PME#
can be generated */
--
2.45.0



2024-06-05 21:11:25

by Bjorn Helgaas

[permalink] [raw]
Subject: Re: [PATCH v7 07/13] PCI: Move dev-enabled status bit to struct pci_dev

On Wed, Jun 05, 2024 at 10:15:59AM +0200, Philipp Stanner wrote:
> The bit describing whether the PCI device is currently enabled is stored
> in struct pci_devres. Besides this struct being subject of a cleanup
> process, struct pci_device is in general the right place to store this
> information, since it is not devres-specific.
>
> Move the 'enabled' boolean bit to struct pci_dev.

I think this (and the similar 'pinned' patch) appeared in v6.

It sounds plausible to have this in struct pci_dev, but it's confusing
to have both:

pci_dev.enabled
pci_dev.enable_cnt, used by pci_is_enabled()

I haven't looked hard enough to see whether both are required. If
they are, I think we should rename "enabled" to something descriptive
enough to make it obviously different from "enable_cnt".

> Signed-off-by: Philipp Stanner <[email protected]>
> ---
> drivers/pci/devres.c | 11 ++++-------
> drivers/pci/pci.c | 17 ++++++++++-------
> drivers/pci/pci.h | 1 -
> include/linux/pci.h | 1 +
> 4 files changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
> index 572a4e193879..ea590caf8995 100644
> --- a/drivers/pci/devres.c
> +++ b/drivers/pci/devres.c
> @@ -398,7 +398,7 @@ static void pcim_release(struct device *gendev, void *res)
> if (this->restore_intx)
> pci_intx(dev, this->orig_intx);
>
> - if (this->enabled && !this->pinned)
> + if (!this->pinned)
> pci_disable_device(dev);
> }
>
> @@ -441,14 +441,11 @@ int pcim_enable_device(struct pci_dev *pdev)
> dr = get_pci_dr(pdev);
> if (unlikely(!dr))
> return -ENOMEM;
> - if (dr->enabled)
> - return 0;
>
> rc = pci_enable_device(pdev);
> - if (!rc) {
> + if (!rc)
> pdev->is_managed = 1;
> - dr->enabled = 1;
> - }
> +
> return rc;
> }
> EXPORT_SYMBOL(pcim_enable_device);
> @@ -466,7 +463,7 @@ void pcim_pin_device(struct pci_dev *pdev)
> struct pci_devres *dr;
>
> dr = find_pci_dr(pdev);
> - WARN_ON(!dr || !dr->enabled);
> + WARN_ON(!dr || !pdev->enabled);
> if (dr)
> dr->pinned = 1;
> }
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 8dd711b9a291..04accdfab7ce 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2011,6 +2011,9 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
> u16 cmd;
> u8 pin;
>
> + if (dev->enabled)
> + return 0;
> +
> err = pci_set_power_state(dev, PCI_D0);
> if (err < 0 && err != -EIO)
> return err;
> @@ -2025,7 +2028,7 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
> pci_fixup_device(pci_fixup_enable, dev);
>
> if (dev->msi_enabled || dev->msix_enabled)
> - return 0;
> + goto success_out;
>
> pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
> if (pin) {
> @@ -2035,6 +2038,8 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
> cmd & ~PCI_COMMAND_INTX_DISABLE);
> }
>
> +success_out:
> + dev->enabled = true;
> return 0;
> }
>
> @@ -2193,6 +2198,9 @@ static void do_pci_disable_device(struct pci_dev *dev)
> {
> u16 pci_command;
>
> + if (!dev->enabled)
> + return;
> +
> pci_read_config_word(dev, PCI_COMMAND, &pci_command);
> if (pci_command & PCI_COMMAND_MASTER) {
> pci_command &= ~PCI_COMMAND_MASTER;
> @@ -2200,6 +2208,7 @@ static void do_pci_disable_device(struct pci_dev *dev)
> }
>
> pcibios_disable_device(dev);
> + dev->enabled = false;
> }
>
> /**
> @@ -2227,12 +2236,6 @@ void pci_disable_enabled_device(struct pci_dev *dev)
> */
> void pci_disable_device(struct pci_dev *dev)
> {
> - struct pci_devres *dr;
> -
> - dr = find_pci_dr(dev);
> - if (dr)
> - dr->enabled = 0;
> -
> dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
> "disabling already-disabled device");
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 9fd50bc99e6b..e223e0f7dada 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -823,7 +823,6 @@ static inline pci_power_t mid_pci_get_power_state(struct pci_dev *pdev)
> * then remove them from here.
> */
> struct pci_devres {
> - unsigned int enabled:1;
> unsigned int pinned:1;
> unsigned int orig_intx:1;
> unsigned int restore_intx:1;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 16493426a04f..110548f00b3b 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -367,6 +367,7 @@ struct pci_dev {
> this is D0-D3, D0 being fully
> functional, and D3 being off. */
> u8 pm_cap; /* PM capability offset */
> + unsigned int enabled:1; /* Whether this dev is enabled */
> unsigned int imm_ready:1; /* Supports Immediate Readiness */
> unsigned int pme_support:5; /* Bitmask of states from which PME#
> can be generated */
> --
> 2.45.0
>

2024-06-06 08:00:22

by Philipp Stanner

[permalink] [raw]
Subject: Re: [PATCH v7 07/13] PCI: Move dev-enabled status bit to struct pci_dev

On Wed, 2024-06-05 at 16:11 -0500, Bjorn Helgaas wrote:
> On Wed, Jun 05, 2024 at 10:15:59AM +0200, Philipp Stanner wrote:
> > The bit describing whether the PCI device is currently enabled is
> > stored
> > in struct pci_devres. Besides this struct being subject of a
> > cleanup
> > process, struct pci_device is in general the right place to store
> > this
> > information, since it is not devres-specific.
> >
> > Move the 'enabled' boolean bit to struct pci_dev.
>
> I think this (and the similar 'pinned' patch) appeared in v6.

Yes. This patch and its brothers serve to remove members from
struct pci_devres step by step, so it can ultimately be removed, so
that we won't have a generic devres struct anymore, but actual
resource-specific structs.

>
> It sounds plausible to have this in struct pci_dev, but it's
> confusing
> to have both:
>
>   pci_dev.enabled
>   pci_dev.enable_cnt, used by pci_is_enabled()
>
> I haven't looked hard enough to see whether both are required.  If
> they are, I think we should rename "enabled" to something descriptive
> enough to make it obviously different from "enable_cnt".

I took a look at it and I think we can actually drop "enabled" and use
"enable_cnt" for everything. That would even simplify things more, I'd
say.

Let me provide that in v8.


P.

>
> > Signed-off-by: Philipp Stanner <[email protected]>
> > ---
> >  drivers/pci/devres.c | 11 ++++-------
> >  drivers/pci/pci.c    | 17 ++++++++++-------
> >  drivers/pci/pci.h    |  1 -
> >  include/linux/pci.h  |  1 +
> >  4 files changed, 15 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
> > index 572a4e193879..ea590caf8995 100644
> > --- a/drivers/pci/devres.c
> > +++ b/drivers/pci/devres.c
> > @@ -398,7 +398,7 @@ static void pcim_release(struct device *gendev,
> > void *res)
> >         if (this->restore_intx)
> >                 pci_intx(dev, this->orig_intx);
> >  
> > -       if (this->enabled && !this->pinned)
> > +       if (!this->pinned)
> >                 pci_disable_device(dev);
> >  }
> >  
> > @@ -441,14 +441,11 @@ int pcim_enable_device(struct pci_dev *pdev)
> >         dr = get_pci_dr(pdev);
> >         if (unlikely(!dr))
> >                 return -ENOMEM;
> > -       if (dr->enabled)
> > -               return 0;
> >  
> >         rc = pci_enable_device(pdev);
> > -       if (!rc) {
> > +       if (!rc)
> >                 pdev->is_managed = 1;
> > -               dr->enabled = 1;
> > -       }
> > +
> >         return rc;
> >  }
> >  EXPORT_SYMBOL(pcim_enable_device);
> > @@ -466,7 +463,7 @@ void pcim_pin_device(struct pci_dev *pdev)
> >         struct pci_devres *dr;
> >  
> >         dr = find_pci_dr(pdev);
> > -       WARN_ON(!dr || !dr->enabled);
> > +       WARN_ON(!dr || !pdev->enabled);
> >         if (dr)
> >                 dr->pinned = 1;
> >  }
> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > index 8dd711b9a291..04accdfab7ce 100644
> > --- a/drivers/pci/pci.c
> > +++ b/drivers/pci/pci.c
> > @@ -2011,6 +2011,9 @@ static int do_pci_enable_device(struct
> > pci_dev *dev, int bars)
> >         u16 cmd;
> >         u8 pin;
> >  
> > +       if (dev->enabled)
> > +               return 0;
> > +
> >         err = pci_set_power_state(dev, PCI_D0);
> >         if (err < 0 && err != -EIO)
> >                 return err;
> > @@ -2025,7 +2028,7 @@ static int do_pci_enable_device(struct
> > pci_dev *dev, int bars)
> >         pci_fixup_device(pci_fixup_enable, dev);
> >  
> >         if (dev->msi_enabled || dev->msix_enabled)
> > -               return 0;
> > +               goto success_out;
> >  
> >         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
> >         if (pin) {
> > @@ -2035,6 +2038,8 @@ static int do_pci_enable_device(struct
> > pci_dev *dev, int bars)
> >                                               cmd &
> > ~PCI_COMMAND_INTX_DISABLE);
> >         }
> >  
> > +success_out:
> > +       dev->enabled = true;
> >         return 0;
> >  }
> >  
> > @@ -2193,6 +2198,9 @@ static void do_pci_disable_device(struct
> > pci_dev *dev)
> >  {
> >         u16 pci_command;
> >  
> > +       if (!dev->enabled)
> > +               return;
> > +
> >         pci_read_config_word(dev, PCI_COMMAND, &pci_command);
> >         if (pci_command & PCI_COMMAND_MASTER) {
> >                 pci_command &= ~PCI_COMMAND_MASTER;
> > @@ -2200,6 +2208,7 @@ static void do_pci_disable_device(struct
> > pci_dev *dev)
> >         }
> >  
> >         pcibios_disable_device(dev);
> > +       dev->enabled = false;
> >  }
> >  
> >  /**
> > @@ -2227,12 +2236,6 @@ void pci_disable_enabled_device(struct
> > pci_dev *dev)
> >   */
> >  void pci_disable_device(struct pci_dev *dev)
> >  {
> > -       struct pci_devres *dr;
> > -
> > -       dr = find_pci_dr(dev);
> > -       if (dr)
> > -               dr->enabled = 0;
> > -
> >         dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <=
> > 0,
> >                       "disabling already-disabled device");
> >  
> > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> > index 9fd50bc99e6b..e223e0f7dada 100644
> > --- a/drivers/pci/pci.h
> > +++ b/drivers/pci/pci.h
> > @@ -823,7 +823,6 @@ static inline pci_power_t
> > mid_pci_get_power_state(struct pci_dev *pdev)
> >   * then remove them from here.
> >   */
> >  struct pci_devres {
> > -       unsigned int enabled:1;
> >         unsigned int pinned:1;
> >         unsigned int orig_intx:1;
> >         unsigned int restore_intx:1;
> > diff --git a/include/linux/pci.h b/include/linux/pci.h
> > index 16493426a04f..110548f00b3b 100644
> > --- a/include/linux/pci.h
> > +++ b/include/linux/pci.h
> > @@ -367,6 +367,7 @@ struct pci_dev {
> >                                            this is D0-D3, D0 being
> > fully
> >                                            functional, and D3 being
> > off. */
> >         u8              pm_cap;         /* PM capability offset */
> > +       unsigned int    enabled:1;      /* Whether this dev is
> > enabled */
> >         unsigned int    imm_ready:1;    /* Supports Immediate
> > Readiness */
> >         unsigned int    pme_support:5;  /* Bitmask of states from
> > which PME#
> >                                            can be generated */
> > --
> > 2.45.0
> >
>