Hi Bjorn
May you please help to understand if the patch requires any further improvements?
Thanks
Mayur
>
> On Wed, Aug 07, 2019 at 04:03:52PM +0000, Patel, Mayurkumar wrote:
> > This patch provides AER config save and restore capabilities. After system
> > resume AER config registers settings are lost. Not restoring AER root error
> > command register bits on root port if they were set, disables generation
> > of an AER interrupt reported by function as described in PCIe spec r4.0,
> > sec 7.8.4.9. Moreover, AER config mask, severity and ECRC registers are
> > also required to maintain same state prior to system suspend to maintain
> > AER interrupts behavior.
> >
>
> FWIW,
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
>
>
> > Signed-off-by: Mayurkumar Patel <mayurkumar.patel@xxxxxxxxx>
> > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> > ---
> > drivers/pci/pci.c | 2 ++
> > drivers/pci/pcie/aer.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++
> > include/linux/aer.h | 4 +++
> > 3 files changed, 76 insertions(+)
> >
> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > index 8abc843..40d5507 100644
> > --- a/drivers/pci/pci.c
> > +++ b/drivers/pci/pci.c
> > @@ -1340,6 +1340,7 @@ int pci_save_state(struct pci_dev *dev)
> >
> > pci_save_ltr_state(dev);
> > pci_save_dpc_state(dev);
> > + pci_save_aer_state(dev);
> > return pci_save_vc_state(dev);
> > }
> > EXPORT_SYMBOL(pci_save_state);
> > @@ -1453,6 +1454,7 @@ void pci_restore_state(struct pci_dev *dev)
> > pci_restore_dpc_state(dev);
> >
> > pci_cleanup_aer_error_status_regs(dev);
> > + pci_restore_aer_state(dev);
> >
> > pci_restore_config_space(dev);
> >
> > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> > index b45bc47..fb067dc 100644
> > --- a/drivers/pci/pcie/aer.c
> > +++ b/drivers/pci/pcie/aer.c
> > @@ -448,6 +448,64 @@ int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
> > return 0;
> > }
> >
> > +static inline bool pcie_aer_cap_has_root_command(struct pci_dev *dev)
> > +{
> > + return pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
> > + pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC;
> > +}
> > +
> > +void pci_save_aer_state(struct pci_dev *dev)
> > +{
> > + struct pci_cap_saved_state *save_state;
> > + u32 *cap;
> > + int pos;
> > +
> > + if (!pci_is_pcie(dev))
> > + return;
> > +
> > + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
> > + if (!save_state)
> > + return;
> > +
> > + pos = dev->aer_cap;
> > + if (!pos)
> > + return;
> > +
> > + cap = &save_state->cap.data[0];
> > + pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, cap++);
> > + pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, cap++);
> > + pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, cap++);
> > + pci_read_config_dword(dev, pos + PCI_ERR_CAP, cap++);
> > + if (pcie_aer_cap_has_root_command(dev))
> > + pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, cap++);
> > +}
> > +
> > +void pci_restore_aer_state(struct pci_dev *dev)
> > +{
> > + struct pci_cap_saved_state *save_state;
> > + u32 *cap;
> > + int pos;
> > +
> > + if (!pci_is_pcie(dev))
> > + return;
> > +
> > + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
> > + if (!save_state)
> > + return;
> > +
> > + pos = dev->aer_cap;
> > + if (!pos)
> > + return;
> > +
> > + cap = &save_state->cap.data[0];
> > + pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, *cap++);
> > + pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, *cap++);
> > + pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, *cap++);
> > + pci_write_config_dword(dev, pos + PCI_ERR_CAP, *cap++);
> > + if (pcie_aer_cap_has_root_command(dev))
> > + pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, *cap++);
> > +}
> > +
> > void pci_aer_init(struct pci_dev *dev)
> > {
> > dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
> > @@ -455,6 +513,18 @@ void pci_aer_init(struct pci_dev *dev)
> > if (dev->aer_cap)
> > dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
> >
> > + /*
> > + * Since PCI_ERR_ROOT_COMMAND is only valid for root port and root
> > + * complex event collector, as per PCIe 4.0 section 7.8.4, interpret
> > + * the device/port type to determine the availability of additional
> > + * root port and root complex event collector register.
> > + */
> > + if (pcie_aer_cap_has_root_command(dev))
> > + pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR,
> > + sizeof(u32) * 5);
> > + else
> > + pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR,
> > + sizeof(u32) * 4);
> > pci_cleanup_aer_error_status_regs(dev);
> > }
> >
> > diff --git a/include/linux/aer.h b/include/linux/aer.h
> > index 514bffa..fa19e01 100644
> > --- a/include/linux/aer.h
> > +++ b/include/linux/aer.h
> > @@ -46,6 +46,8 @@ int pci_enable_pcie_error_reporting(struct pci_dev *dev);
> > int pci_disable_pcie_error_reporting(struct pci_dev *dev);
> > int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev);
> > int pci_cleanup_aer_error_status_regs(struct pci_dev *dev);
> > +void pci_save_aer_state(struct pci_dev *dev);
> > +void pci_restore_aer_state(struct pci_dev *dev);
> > #else
> > static inline int pci_enable_pcie_error_reporting(struct pci_dev *dev)
> > {
> > @@ -63,6 +65,8 @@ static inline int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
> > {
> > return -EINVAL;
> > }
> > +static inline void pci_save_aer_state(struct pci_dev *dev) {}
> > +static inline void pci_restore_aer_state(struct pci_dev *dev) {}
> > #endif
> >
> > void cper_print_aer(struct pci_dev *dev, int aer_severity,
> > --
> > 2.7.4
> >
> >
>
> --
> With Best Regards,
> Andy Shevchenko
>
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