From patchwork Mon Sep 8 16:58:34 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Murali Karicheri X-Patchwork-Id: 4863931 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id CD0F19F32F for ; Mon, 8 Sep 2014 17:01:31 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8F10820149 for ; Mon, 8 Sep 2014 17:01:30 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6ABA2200F3 for ; Mon, 8 Sep 2014 17:01:29 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XR2Gx-0007Ht-Hq; Mon, 08 Sep 2014 16:58:35 +0000 Received: from devils.ext.ti.com ([198.47.26.153]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XR2Gu-0007D6-SB for linux-arm-kernel@lists.infradead.org; Mon, 08 Sep 2014 16:58:33 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id s88GwAgH013054; Mon, 8 Sep 2014 11:58:10 -0500 Received: from DLEE70.ent.ti.com (dlee70.ent.ti.com [157.170.170.113]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id s88GwASx019878; Mon, 8 Sep 2014 11:58:10 -0500 Received: from dlep33.itg.ti.com (157.170.170.75) by DLEE70.ent.ti.com (157.170.170.113) with Microsoft SMTP Server id 14.3.174.1; Mon, 8 Sep 2014 11:58:09 -0500 Received: from localhost.localdomain (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep33.itg.ti.com (8.14.3/8.13.8) with ESMTP id s88Gw9G6004206; Mon, 8 Sep 2014 11:58:09 -0500 From: Murali Karicheri To: , , , , Subject: [PATCH - v3] PCI: keystone: add a pci quirk to limit mrrs Date: Mon, 8 Sep 2014 12:58:34 -0400 Message-ID: <1410195514-29945-1-git-send-email-m-karicheri2@ti.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140908_095833_002209_8B50A6DA X-CRM114-Status: GOOD ( 12.61 ) X-Spam-Score: -7.5 (-------) Cc: Murali Karicheri X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Keystone PCI controller has a limitation that memory read request size must not exceed 256 bytes. This is a hardware limitation and add a quirk to force this limit on all downstream devices by updating mrrs. Signed-off-by: Murali Karicheri --- -v3: added check for vendor id and use pci_matc_id() to do matching -v2: made the quirk happens after tuning -v1: changed printk to indicate PCI bdf drivers/pci/host/pci-keystone.c | 47 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c index c1cfaef..0a477e5 100644 --- a/drivers/pci/host/pci-keystone.c +++ b/drivers/pci/host/pci-keystone.c @@ -42,8 +42,55 @@ /* DEV_STAT_CTRL */ #define PCIE_CAP_BASE 0x70 +/* PCIE controller device IDs */ +#define PCIE_RC_K2HK 0xb008 +#define PCIE_RC_K2E 0xb009 +#define PCIE_RC_K2L 0xb00a + #define to_keystone_pcie(x) container_of(x, struct keystone_pcie, pp) + + +static void quirk_limit_mrrs(struct pci_dev *dev) +{ + struct pci_bus *bus = dev->bus; + struct pci_dev *bridge = bus->self; + static const struct pci_device_id rc_pci_devids[] = { + { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2HK), + .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, }, + { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2E), + .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, }, + { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2L), + .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, }, + { 0, }, + }; + + if (pci_is_root_bus(bus)) + return; + + /* look for the host bridge */ + while (!pci_is_root_bus(bus)) { + bridge = bus->self; + bus = bus->parent; + } + + if (bridge) { + /* + * Keystone PCI controller has a h/w limitation of + * 256 bytes maximum read request size. It can't handle + * anything higher than this. So force this limit on + * all downstream devices + */ + if (pci_match_id(rc_pci_devids, bridge)) { + if (pcie_get_readrq(dev) > 256) { + dev_info(&dev->dev, "limiting mrrs to 256\n"); + pcie_set_readrq(dev, 256); + } + } + } +} +DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, quirk_limit_mrrs); + static int ks_pcie_establish_link(struct keystone_pcie *ks_pcie) { struct pcie_port *pp = &ks_pcie->pp;