| Message ID | 1507719178-112556-3-git-send-email-liudongdong3@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
From: Dongdong Liu > Sent: 11 October 2017 11:53 > In the AER case, the mask isn't strictly necessary because there are no > higher-order bits above the Interrupt Message Number, but using a #define > will make it possible to grep for it. > > Suggested-by: Bjorn Helgaas <bhelgaas@google.com> > Signed-off-by: Dongdong Liu <liudongdong3@huawei.com> > --- > drivers/pci/pcie/portdrv_core.c | 4 ++-- > include/uapi/linux/pci_regs.h | 2 ++ > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c > index 9692379..2b48297 100644 > --- a/drivers/pci/pcie/portdrv_core.c > +++ b/drivers/pci/pcie/portdrv_core.c > @@ -116,7 +116,7 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) > */ > pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); > pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); > - entry = reg32 >> 27; > + entry = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27; You've still got the hard coded 27 - which is almost more important than the mask. Perhaps define things so this is: entry = PCI_ERR_ROOT_AER_IRQ(reg32); Think I'd shift then mask with 0x1f. David
On Wed, Oct 11, 2017 at 01:01:26PM +0000, David Laight wrote: > From: Dongdong Liu > > Sent: 11 October 2017 11:53 > > In the AER case, the mask isn't strictly necessary because there are no > > higher-order bits above the Interrupt Message Number, but using a #define > > will make it possible to grep for it. > > > > Suggested-by: Bjorn Helgaas <bhelgaas@google.com> > > Signed-off-by: Dongdong Liu <liudongdong3@huawei.com> > > --- > > drivers/pci/pcie/portdrv_core.c | 4 ++-- > > include/uapi/linux/pci_regs.h | 2 ++ > > 2 files changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c > > index 9692379..2b48297 100644 > > --- a/drivers/pci/pcie/portdrv_core.c > > +++ b/drivers/pci/pcie/portdrv_core.c > > @@ -116,7 +116,7 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) > > */ > > pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); > > pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); > > - entry = reg32 >> 27; > > + entry = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27; > > You've still got the hard coded 27 - which is almost more important than the mask. > Perhaps define things so this is: > entry = PCI_ERR_ROOT_AER_IRQ(reg32); > > Think I'd shift then mask with 0x1f. Personally, I prefer to have the mask unshifted so it's easy to see where the fields are in the register and to compare them with the spec, e.g., #define PCI_EXP_DEVCAP_PAYLOAD 0x00000007 /* Max_Payload_Size */ #define PCI_EXP_DEVCAP_PHANTOM 0x00000018 /* Phantom functions */ #define PCI_EXP_DEVCAP_EXT_TAG 0x00000020 /* Extended tags */ Should there be a #define for the shift? Maybe. It doesn't bother me unless it's used in many places. Here I think there'd only be one use, so having it hard-coded along with the symbolic mask is enough for me. Sometimes too many #defines clutter up the include file. Just my personal preferences. Bjorn
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index 9692379..2b48297 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -116,7 +116,7 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) */ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); - entry = reg32 >> 27; + entry = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27; if (entry >= nr_entries) goto out_free_irqs; @@ -142,7 +142,7 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) */ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC); pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, ®16); - entry = reg16 & 0x1f; + entry = reg16 & PCI_EXP_DPC_IRQ; if (entry >= nr_entries) goto out_free_irqs; diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index f8d5804..756e704 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -746,6 +746,7 @@ #define PCI_ERR_ROOT_FIRST_FATAL 0x00000010 /* First UNC is Fatal */ #define PCI_ERR_ROOT_NONFATAL_RCV 0x00000020 /* Non-Fatal Received */ #define PCI_ERR_ROOT_FATAL_RCV 0x00000040 /* Fatal Received */ +#define PCI_ERR_ROOT_AER_IRQ 0xf8000000 /* Advanced Error Interrupt Message Number */ #define PCI_ERR_ROOT_ERR_SRC 52 /* Error Source Identification */ /* Virtual Channel */ @@ -960,6 +961,7 @@ /* Downstream Port Containment */ #define PCI_EXP_DPC_CAP 4 /* DPC Capability */ +#define PCI_EXP_DPC_IRQ 0x1f /* DPC Interrupt message number */ #define PCI_EXP_DPC_CAP_RP_EXT 0x20 /* Root Port Extensions for DPC */ #define PCI_EXP_DPC_CAP_POISONED_TLP 0x40 /* Poisoned TLP Egress Blocking Supported */ #define PCI_EXP_DPC_CAP_SW_TRIGGER 0x80 /* Software Triggering Supported */
In the AER case, the mask isn't strictly necessary because there are no higher-order bits above the Interrupt Message Number, but using a #define will make it possible to grep for it. Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Dongdong Liu <liudongdong3@huawei.com> --- drivers/pci/pcie/portdrv_core.c | 4 ++-- include/uapi/linux/pci_regs.h | 2 ++ 2 files changed, 4 insertions(+), 2 deletions(-)