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dmarc=none action=none header.from=microchip.com; Received-SPF: SoftFail (protection.outlook.com: domain of transitioning microchip.com discourages use of 208.19.100.22 as permitted sender) Received: from AVMBX2.microsemi.net (208.19.100.22) by BL2FFO11FD006.mail.protection.outlook.com (10.173.161.2) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.20.1339.12 via Frontend Transport; Thu, 15 Nov 2018 03:16:29 +0000 Received: from AVMBX3.microsemi.net (10.100.34.33) by AVMBX2.microsemi.net (10.100.34.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1531.3; Wed, 14 Nov 2018 18:46:14 -0800 Received: from server1.microsemi.net (10.188.116.185) by avmbx3.microsemi.net (10.100.34.33) with Microsoft SMTP Server id 15.1.1531.3 via Frontend Transport; Wed, 14 Nov 2018 18:46:12 -0800 From: Wesley Sheng To: , , , , CC: , Subject: [PATCH 4/5] switchtec: Improve MRPC efficiency by leveraging write combining Date: Thu, 15 Nov 2018 17:44:03 +0800 Message-ID: <1542275044-10970-5-git-send-email-wesley.sheng@microchip.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1542275044-10970-1-git-send-email-wesley.sheng@microchip.com> References: <1542275044-10970-1-git-send-email-wesley.sheng@microchip.com> MIME-Version: 1.0 Content-Type: text/plain X-EOPAttributedMessage: 0 X-Matching-Connectors: 131867253894595531;(5a93feec-e11d-4f7b-166a-08d09f1f276b);() X-Forefront-Antispam-Report: CIP:208.19.100.22;IPV:NLI;CTRY:US;EFV:NLI;SFV:NSPM;SFS:(10009020)(136003)(346002)(396003)(376002)(39860400002)(2980300002)(199004)(189003)(8936002)(2201001)(68736007)(14444005)(6666004)(305945005)(2906002)(498600001)(107886003)(4326008)(8676002)(48376002)(50466002)(53416004)(356004)(105596002)(81156014)(81166006)(106466001)(36756003)(5660300001)(53936002)(50226002)(450100002)(76176011)(47776003)(44832011)(51416003)(86362001)(16586007)(2616005)(316002)(446003)(476003)(11346002)(69596002)(126002)(336012)(26005)(54906003)(110136005)(486006)(77096007)(97736004);DIR:OUT;SFP:1101;SCL:1;SRVR:SN2PR19MB0735;H:AVMBX2.microsemi.net;FPR:;SPF:SoftFail;LANG:en;PTR:InfoDomainNonexistent;A:1;MX:1; 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In a few places, we still need to flush the WC buffer. To do this, we simply read from the Outbound Doorbell register seeing reads to this register are processed by low latency hardware. Signed-off-by: Kelvin Cao Signed-off-by: Wesley Sheng --- drivers/pci/switch/switchtec.c | 41 +++++++++++++++++++++++++++++++++++------ 1 file changed, 35 insertions(+), 6 deletions(-) diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c index a908670..0b8862b 100644 --- a/drivers/pci/switch/switchtec.c +++ b/drivers/pci/switch/switchtec.c @@ -113,6 +113,19 @@ static void stuser_set_state(struct switchtec_user *stuser, static void mrpc_complete_cmd(struct switchtec_dev *stdev); +static void flush_wc_buf(struct switchtec_dev *stdev) +{ + struct ntb_dbmsg_regs __iomem *mmio_dbmsg; + + /* + * odb (outbound doorbell) register is processed by low latency + * hardware and w/o side effect + */ + mmio_dbmsg = (void __iomem *)stdev->mmio_ntb + + SWITCHTEC_NTB_REG_DBMSG_OFFSET; + ioread32(&mmio_dbmsg->odb); +} + static void mrpc_cmd_submit(struct switchtec_dev *stdev) { /* requires the mrpc_mutex to already be held when called */ @@ -132,6 +145,7 @@ static void mrpc_cmd_submit(struct switchtec_dev *stdev) stdev->mrpc_busy = 1; memcpy_toio(&stdev->mmio_mrpc->input_data, stuser->data, stuser->data_len); + flush_wc_buf(stdev); iowrite32(stuser->cmd, &stdev->mmio_mrpc->cmd); schedule_delayed_work(&stdev->mrpc_timeout, @@ -1231,23 +1245,38 @@ static int switchtec_init_pci(struct switchtec_dev *stdev, struct pci_dev *pdev) { int rc; + void __iomem *map; + unsigned long res_start, res_len; rc = pcim_enable_device(pdev); if (rc) return rc; - rc = pcim_iomap_regions(pdev, 0x1, KBUILD_MODNAME); - if (rc) - return rc; - rc = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64)); if (rc) return rc; pci_set_master(pdev); - stdev->mmio = pcim_iomap_table(pdev)[0]; - stdev->mmio_mrpc = stdev->mmio + SWITCHTEC_GAS_MRPC_OFFSET; + res_start = pci_resource_start(pdev, 0); + res_len = pci_resource_len(pdev, 0); + + if (!devm_request_mem_region(&pdev->dev, res_start, + res_len, KBUILD_MODNAME)) + return -EBUSY; + + stdev->mmio_mrpc = devm_ioremap_wc(&pdev->dev, res_start, + SWITCHTEC_GAS_TOP_CFG_OFFSET); + if (!stdev->mmio_mrpc) + return -ENOMEM; + + map = devm_ioremap(&pdev->dev, + res_start + SWITCHTEC_GAS_TOP_CFG_OFFSET, + res_len - SWITCHTEC_GAS_TOP_CFG_OFFSET); + if (!map) + return -ENOMEM; + + stdev->mmio = map - SWITCHTEC_GAS_TOP_CFG_OFFSET; stdev->mmio_sw_event = stdev->mmio + SWITCHTEC_GAS_SW_EVENT_OFFSET; stdev->mmio_sys_info = stdev->mmio + SWITCHTEC_GAS_SYS_INFO_OFFSET; stdev->mmio_flash_info = stdev->mmio + SWITCHTEC_GAS_FLASH_INFO_OFFSET; -- 2.7.4