Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754572Ab3IXUiQ (ORCPT ); Tue, 24 Sep 2013 16:38:16 -0400 Received: from mail-ye0-f174.google.com ([209.85.213.174]:43678 "EHLO mail-ye0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754113Ab3IXUiN (ORCPT ); Tue, 24 Sep 2013 16:38:13 -0400 Date: Tue, 24 Sep 2013 14:38:06 -0600 From: Bjorn Helgaas To: "Marciniszyn, Mike" Cc: Yijing Wang , Chris Metcalf , Greg Kroah-Hartman , David Airlie , infinipath , Roland Dreier , Roland Dreier , "linux-kernel@vger.kernel.org" , Mark Einon , "Hefty, Sean" , Hal Rosenstock , "linux-rdma@vger.kernel.org" , "linux-pci@vger.kernel.org" , Hanjun Guo Subject: Re: [PATCH 4/6] IB/qib: Use pcie_set_mps() and pcie_get_mps() to simplify code Message-ID: <20130924203806.GA9302@google.com> References: <1378732388-4508-1-git-send-email-wangyijing@huawei.com> <1378732388-4508-5-git-send-email-wangyijing@huawei.com> <32E1700B9017364D9B60AED9960492BC2119F081@FMSMSX107.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <32E1700B9017364D9B60AED9960492BC2119F081@FMSMSX107.amr.corp.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6046 Lines: 177 On Mon, Sep 09, 2013 at 02:55:46PM +0000, Marciniszyn, Mike wrote: > > Subject: [PATCH 4/6] IB/qib: Use pcie_set_mps() and pcie_get_mps() to simplify > > code > > > > Refactor qib_tune_pcie_caps() function, use pcie_set_mps() and > > pcie_get_mps() to simply code. Because pci core caches the "PCI-E Max > > Payload Size Supported" in pci_dev->pcie_mpss, so use that instead of > > pcie_capability_read_word(). Remove the unused val2fld() and fld2val(). > > > > I tested this patch as is and saw no issues. > > The only thing I would suggest is that the new use of pcie_get_readrq/pcie_set_readrq() be reflected in the comments with an appropriate adjustment in the subject. Is something like the following what you had in mind? If so, I can just queue it up. Otherwise, I'll wait for Yijing to post a v2 patch. IB/qib: Use pcie_set_mps() and pcie_get_mps() to simplify code From: Yijing Wang Refactor qib_tune_pcie_caps(). Use pcie_get_mps(), pcie_set_mps(), pcie_get_readrq(), and pcie_set_readrq() to simplify the code. The PCI core caches the "PCIe Max Payload Size Supported" in pci_dev->pcie_mpss, so use that instead of pcie_capability_read_word(). Remove the unused val2fld() and fld2val(). Signed-off-by: Yijing Wang Signed-off-by: Bjorn Helgaas --- drivers/infiniband/hw/qib/qib_pcie.c | 96 +++++++++++----------------------- 1 file changed, 30 insertions(+), 66 deletions(-) diff --git a/drivers/infiniband/hw/qib/qib_pcie.c b/drivers/infiniband/hw/qib/qib_pcie.c index 45e55ff..24973c8 100644 --- a/drivers/infiniband/hw/qib/qib_pcie.c +++ b/drivers/infiniband/hw/qib/qib_pcie.c @@ -476,30 +476,6 @@ void qib_pcie_reenable(struct qib_devdata *dd, u16 cmd, u8 iline, u8 cline) "pci_enable_device failed after reset: %d\n", r); } -/* code to adjust PCIe capabilities. */ - -static int fld2val(int wd, int mask) -{ - int lsbmask; - - if (!mask) - return 0; - wd &= mask; - lsbmask = mask ^ (mask & (mask - 1)); - wd /= lsbmask; - return wd; -} - -static int val2fld(int wd, int mask) -{ - int lsbmask; - - if (!mask) - return 0; - lsbmask = mask ^ (mask & (mask - 1)); - wd *= lsbmask; - return wd; -} static int qib_pcie_coalesce; module_param_named(pcie_coalesce, qib_pcie_coalesce, int, S_IRUGO); @@ -584,9 +560,8 @@ static int qib_tune_pcie_caps(struct qib_devdata *dd) { int ret = 1; /* Assume the worst */ struct pci_dev *parent; - u16 pcaps, pctl, ecaps, ectl; - int rc_sup, ep_sup; - int rc_cur, ep_cur; + u16 rc_mpss, rc_mps, ep_mpss, ep_mps; + u16 rc_mrrs, ep_mrrs, max_mrrs; /* Find out supported and configured values for parent (root) */ parent = dd->pcidev->bus->self; @@ -597,38 +572,29 @@ static int qib_tune_pcie_caps(struct qib_devdata *dd) if (!pci_is_pcie(parent) || !pci_is_pcie(dd->pcidev)) goto bail; - pcie_capability_read_word(parent, PCI_EXP_DEVCAP, &pcaps); - pcie_capability_read_word(parent, PCI_EXP_DEVCTL, &pctl); + rc_mpss = parent->pcie_mpss; + rc_mps = ffs(pcie_get_mps(parent)) - 8; /* Find out supported and configured values for endpoint (us) */ - pcie_capability_read_word(dd->pcidev, PCI_EXP_DEVCAP, &ecaps); - pcie_capability_read_word(dd->pcidev, PCI_EXP_DEVCTL, &ectl); + ep_mpss = dd->pcidev->pcie_mpss; + ep_mps = ffs(pcie_get_mps(dd->pcidev)) - 8; ret = 0; /* Find max payload supported by root, endpoint */ - rc_sup = fld2val(pcaps, PCI_EXP_DEVCAP_PAYLOAD); - ep_sup = fld2val(ecaps, PCI_EXP_DEVCAP_PAYLOAD); - if (rc_sup > ep_sup) - rc_sup = ep_sup; - - rc_cur = fld2val(pctl, PCI_EXP_DEVCTL_PAYLOAD); - ep_cur = fld2val(ectl, PCI_EXP_DEVCTL_PAYLOAD); + if (rc_mpss > ep_mpss) + rc_mpss = ep_mpss; /* If Supported greater than limit in module param, limit it */ - if (rc_sup > (qib_pcie_caps & 7)) - rc_sup = qib_pcie_caps & 7; + if (rc_mpss > (qib_pcie_caps & 7)) + rc_mpss = qib_pcie_caps & 7; /* If less than (allowed, supported), bump root payload */ - if (rc_sup > rc_cur) { - rc_cur = rc_sup; - pctl = (pctl & ~PCI_EXP_DEVCTL_PAYLOAD) | - val2fld(rc_cur, PCI_EXP_DEVCTL_PAYLOAD); - pcie_capability_write_word(parent, PCI_EXP_DEVCTL, pctl); + if (rc_mpss > rc_mps) { + rc_mps = rc_mpss; + pcie_set_mps(parent, 128 << rc_mps); } /* If less than (allowed, supported), bump endpoint payload */ - if (rc_sup > ep_cur) { - ep_cur = rc_sup; - ectl = (ectl & ~PCI_EXP_DEVCTL_PAYLOAD) | - val2fld(ep_cur, PCI_EXP_DEVCTL_PAYLOAD); - pcie_capability_write_word(dd->pcidev, PCI_EXP_DEVCTL, ectl); + if (rc_mpss > ep_mps) { + ep_mps = rc_mpss; + pcie_set_mps(dd->pcidev, 128 << ep_mps); } /* @@ -636,23 +602,21 @@ static int qib_tune_pcie_caps(struct qib_devdata *dd) * No field for max supported, but PCIe spec limits it to 4096, * which is code '5' (log2(4096) - 7) */ - rc_sup = 5; - if (rc_sup > ((qib_pcie_caps >> 4) & 7)) - rc_sup = (qib_pcie_caps >> 4) & 7; - rc_cur = fld2val(pctl, PCI_EXP_DEVCTL_READRQ); - ep_cur = fld2val(ectl, PCI_EXP_DEVCTL_READRQ); - - if (rc_sup > rc_cur) { - rc_cur = rc_sup; - pctl = (pctl & ~PCI_EXP_DEVCTL_READRQ) | - val2fld(rc_cur, PCI_EXP_DEVCTL_READRQ); - pcie_capability_write_word(parent, PCI_EXP_DEVCTL, pctl); + max_mrrs = 5; + if (max_mrrs > ((qib_pcie_caps >> 4) & 7)) + max_mrrs = (qib_pcie_caps >> 4) & 7; + + max_mrrs = 128 << max_mrrs; + rc_mrrs = pcie_get_readrq(parent); + ep_mrrs = pcie_get_readrq(dd->pcidev); + + if (max_mrrs > rc_mrrs) { + rc_mrrs = max_mrrs; + pcie_set_readrq(parent, rc_mrrs); } - if (rc_sup > ep_cur) { - ep_cur = rc_sup; - ectl = (ectl & ~PCI_EXP_DEVCTL_READRQ) | - val2fld(ep_cur, PCI_EXP_DEVCTL_READRQ); - pcie_capability_write_word(dd->pcidev, PCI_EXP_DEVCTL, ectl); + if (max_mrrs > ep_mrrs) { + ep_mrrs = max_mrrs; + pcie_set_readrq(dd->pcidev, ep_mrrs); } bail: return ret; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/