From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:48283 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753967AbbG0OAy (ORCPT ); Mon, 27 Jul 2015 10:00:54 -0400 Message-ID: <55B63995.8000808@redhat.com> Date: Mon, 27 Jul 2015 10:00:53 -0400 From: Don Dutile MIME-Version: 1.0 To: Bjorn Helgaas , linux-pci@vger.kernel.org, Joerg Roedel , David Woodhouse CC: iommu@lists.linux-foundation.org, Gregor Dick Subject: Re: [PATCH v2 10/11] PCI: Stop caching ATS Invalidate Queue Depth References: <20150721001243.28145.81610.stgit@bhelgaas-glaptop2.roam.corp.google.com> <20150721001511.28145.29144.stgit@bhelgaas-glaptop2.roam.corp.google.com> In-Reply-To: <20150721001511.28145.29144.stgit@bhelgaas-glaptop2.roam.corp.google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: On 07/20/2015 08:15 PM, Bjorn Helgaas wrote: > Stop caching the Invalidate Queue Depth in struct pci_dev. > pci_ats_queue_depth() is typically called only once per device, and it > returns a fixed value per-device, so callers who need the value frequently > can cache it themselves. > > Signed-off-by: Bjorn Helgaas > --- > drivers/pci/ats.c | 9 ++++----- > include/linux/pci.h | 1 - > 2 files changed, 4 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c > index 67524a7..bdb1383 100644 > --- a/drivers/pci/ats.c > +++ b/drivers/pci/ats.c > @@ -20,16 +20,12 @@ > void pci_ats_init(struct pci_dev *dev) > { > int pos; > - u16 cap; > > pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS); > if (!pos) > return; > > dev->ats_cap = pos; > - pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap); > - dev->ats_qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) : > - PCI_ATS_MAX_QDEP; > } > > /** > @@ -131,13 +127,16 @@ EXPORT_SYMBOL_GPL(pci_restore_ats_state); > */ > int pci_ats_queue_depth(struct pci_dev *dev) > { > + u16 cap; > + > if (!dev->ats_cap) > return -EINVAL; > > if (dev->is_virtfn) > return 0; > hmmm, isn't one of the fixes in this patch set to change the caching of ats queue depth ? won't above make it 0 for all VF's ? is that correct, or desired (virtual) value? > - return dev->ats_qdep; > + pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap); > + return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) : PCI_ATS_MAX_QDEP; > } > EXPORT_SYMBOL_GPL(pci_ats_queue_depth); > > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 307f96a..4b484fd 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -378,7 +378,6 @@ struct pci_dev { > }; > u16 ats_cap; /* ATS Capability offset */ > u8 ats_stu; /* ATS Smallest Translation Unit */ > - u8 ats_qdep; /* ATS Invalidate Queue Depth */ > atomic_t ats_ref_cnt; /* number of VFs with ATS enabled */ > #endif > phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */ > > -- > 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 >