From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:41476 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932094AbcHIReB (ORCPT ); Tue, 9 Aug 2016 13:34:01 -0400 Date: Tue, 9 Aug 2016 12:33:50 -0500 From: Bjorn Helgaas To: Keith Busch Cc: linux-pci@vger.kernel.org, Bjorn Helgaas , Wei Zhang , Jens Axboe Subject: Re: [PATCH 3/3] pcie/aer: Cache capability position Message-ID: <20160809173350.GE27301@localhost> References: <1470683667-28418-1-git-send-email-keith.busch@intel.com> <1470683667-28418-4-git-send-email-keith.busch@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1470683667-28418-4-git-send-email-keith.busch@intel.com> Sender: linux-pci-owner@vger.kernel.org List-ID: Hi Keith, On Mon, Aug 08, 2016 at 01:14:27PM -0600, Keith Busch wrote: > This saves the postition of the error reporting capability so that it > doesn't need to be rediscovered during error handling. I like the idea of this, and I wonder if we should go even further, and cache aer_pos in the pci_dev. There are a zillion places that look for PCI_EXT_CAP_ID_ERR, and several of them are outside the AER driver, where it would be inconvenient to look up the aer_rpc. That would probably mean adding a hook to pci_init_capabilities(), which would be kind of nice anyway because we already have a call to pci_cleanup_aer_error_status_regs() there, which is sort of dangling and not parallel to the other calls. > Signed-off-by: Keith Busch > --- > drivers/pci/pcie/aer/aerdrv.c | 38 +++++++++++++++++--------------------- > drivers/pci/pcie/aer/aerdrv.h | 1 + > 2 files changed, 18 insertions(+), 21 deletions(-) > > diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c > index 48d21e0..d05c864 100644 > --- a/drivers/pci/pcie/aer/aerdrv.c > +++ b/drivers/pci/pcie/aer/aerdrv.c > @@ -122,7 +122,6 @@ static void set_downstream_devices_error_reporting(struct pci_dev *dev, > static void aer_enable_rootport(struct aer_rpc *rpc) > { > struct pci_dev *pdev = rpc->rpd->port; What if you did this instead: - int aer_pos; + int aer_pos = rpc->pos; Then all the config accesses wouldn't have to change. > u16 reg16; > u32 reg32; > > @@ -134,14 +133,13 @@ static void aer_enable_rootport(struct aer_rpc *rpc) > pcie_capability_clear_word(pdev, PCI_EXP_RTCTL, > SYSTEM_ERROR_INTR_ON_MESG_MASK); > > - aer_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR); > /* Clear error status */ > - pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, ®32); > - pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32); > - pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, ®32); > - pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32); > - pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, ®32); > - pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32); > + pci_read_config_dword(pdev, rpc->pos + PCI_ERR_ROOT_STATUS, ®32); > + pci_write_config_dword(pdev, rpc->pos + PCI_ERR_ROOT_STATUS, reg32); > + pci_read_config_dword(pdev, rpc->pos + PCI_ERR_COR_STATUS, ®32); > + pci_write_config_dword(pdev, rpc->pos + PCI_ERR_COR_STATUS, reg32); > + pci_read_config_dword(pdev, rpc->pos + PCI_ERR_UNCOR_STATUS, ®32); > + pci_write_config_dword(pdev, rpc->pos + PCI_ERR_UNCOR_STATUS, reg32); > > /* > * Enable error reporting for the root port device and downstream port > @@ -150,9 +148,9 @@ static void aer_enable_rootport(struct aer_rpc *rpc) > set_downstream_devices_error_reporting(pdev, true); > > /* Enable Root Port's interrupt in response to error messages */ > - pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, ®32); > + pci_read_config_dword(pdev, rpc->pos + PCI_ERR_ROOT_COMMAND, ®32); > reg32 |= ROOT_PORT_INTR_ON_MESG_MASK; > - pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, reg32); > + pci_write_config_dword(pdev, rpc->pos + PCI_ERR_ROOT_COMMAND, reg32); > } > > /** > @@ -165,7 +163,6 @@ static void aer_disable_rootport(struct aer_rpc *rpc) > { > struct pci_dev *pdev = rpc->rpd->port; > u32 reg32; > - int pos; > > /* > * Disable error reporting for the root port device and downstream port > @@ -173,15 +170,14 @@ static void aer_disable_rootport(struct aer_rpc *rpc) > */ > set_downstream_devices_error_reporting(pdev, false); > > - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR); > /* Disable Root's interrupt in response to error messages */ > - pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, ®32); > + pci_read_config_dword(pdev, rpc->pos + PCI_ERR_ROOT_COMMAND, ®32); > reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK; > - pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, reg32); > + pci_write_config_dword(pdev, rpc->pos + PCI_ERR_ROOT_COMMAND, reg32); > > /* Clear Root's error status reg */ > - pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, ®32); > - pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32); > + pci_read_config_dword(pdev, rpc->pos + PCI_ERR_ROOT_STATUS, ®32); > + pci_write_config_dword(pdev, rpc->pos + PCI_ERR_ROOT_STATUS, reg32); > } > > /** > @@ -198,9 +194,7 @@ irqreturn_t aer_irq(int irq, void *context) > struct aer_rpc *rpc = get_service_data(pdev); > int next_prod_idx; > unsigned long flags; > - int pos; > > - pos = pci_find_ext_capability(pdev->port, PCI_EXT_CAP_ID_ERR); > /* > * Must lock access to Root Error Status Reg, Root Error ID Reg, > * and Root error producer/consumer index > @@ -208,15 +202,15 @@ irqreturn_t aer_irq(int irq, void *context) > spin_lock_irqsave(&rpc->e_lock, flags); > > /* Read error status */ > - pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status); > + pci_read_config_dword(pdev->port, rpc->pos + PCI_ERR_ROOT_STATUS, &status); > if (!(status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV))) { > spin_unlock_irqrestore(&rpc->e_lock, flags); > return IRQ_NONE; > } > > /* Read error source and clear error status */ > - pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id); > - pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status); > + pci_read_config_dword(pdev->port, rpc->pos + PCI_ERR_ROOT_ERR_SRC, &id); > + pci_write_config_dword(pdev->port, rpc->pos + PCI_ERR_ROOT_STATUS, status); > > /* Store error source for later DPC handler */ > next_prod_idx = rpc->prod_idx + 1; > @@ -317,6 +311,8 @@ static int aer_probe(struct pcie_device *dev) > return -ENOMEM; > } > > + rpc->pos = pci_find_ext_capability(dev->port, PCI_EXT_CAP_ID_ERR); > + > /* Request IRQ ISR */ > status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev); > if (status) { > diff --git a/drivers/pci/pcie/aer/aerdrv.h b/drivers/pci/pcie/aer/aerdrv.h > index 945c939..d7c586e 100644 > --- a/drivers/pci/pcie/aer/aerdrv.h > +++ b/drivers/pci/pcie/aer/aerdrv.h > @@ -72,6 +72,7 @@ struct aer_rpc { > * recovery on the same > * root port hierarchy > */ > + int pos; /* position of AER capability */ > }; > > struct aer_broadcast_data { > -- > 2.7.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html