From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751671AbcBEEfh (ORCPT ); Thu, 4 Feb 2016 23:35:37 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:40758 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751495AbcBEEfc (ORCPT ); Thu, 4 Feb 2016 23:35:32 -0500 From: Sinan Kaya To: dmaengine@vger.kernel.org, marc.zyngier@arm.com, mark.rutland@arm.com, timur@codeaurora.org, devicetree@vger.kernel.org, cov@codeaurora.org, vinod.koul@intel.com, jcm@redhat.com Cc: shankerd@codeaurora.org, vikrams@codeaurora.org, eric.auger@linaro.org, agross@codeaurora.org, arnd@arndb.de, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , linux-kernel@vger.kernel.org Subject: [PATCH V14 9/9] vfio, platform: add QTI HIDMA reset driver Date: Thu, 4 Feb 2016 23:34:40 -0500 Message-Id: <1454646882-24369-10-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1454646882-24369-1-git-send-email-okaya@codeaurora.org> References: <1454646882-24369-1-git-send-email-okaya@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In situations where the userspace driver is stopped abnormally and the VFIO platform device is released, the assigned HW device currently is left running. As a consequence the HW device might continue issuing IRQs and performing DMA accesses. This patch is implementing a reset driver for HIDMA platform driver. This gets called by the VFIO platform reset interface. Signed-off-by: Sinan Kaya --- drivers/vfio/platform/reset/Kconfig | 9 ++ drivers/vfio/platform/reset/Makefile | 2 + .../vfio/platform/reset/vfio_platform_qcomhidma.c | 99 ++++++++++++++++++++++ 3 files changed, 110 insertions(+) create mode 100644 drivers/vfio/platform/reset/vfio_platform_qcomhidma.c diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig index 70cccc5..d02b3b5 100644 --- a/drivers/vfio/platform/reset/Kconfig +++ b/drivers/vfio/platform/reset/Kconfig @@ -13,3 +13,12 @@ config VFIO_PLATFORM_AMDXGBE_RESET Enables the VFIO platform driver to handle reset for AMD XGBE If you don't know what to do here, say N. + +config VFIO_PLATFORM_QCOMHIDMA_RESET + tristate "VFIO support for Qualcomm Technologies HIDMA reset" + depends on VFIO_PLATFORM + help + Enables the VFIO platform driver to handle reset for Qualcomm Technologies + HIDMA Channel. + + If you don't know what to do here, say N. diff --git a/drivers/vfio/platform/reset/Makefile b/drivers/vfio/platform/reset/Makefile index 93f4e23..ec7748a 100644 --- a/drivers/vfio/platform/reset/Makefile +++ b/drivers/vfio/platform/reset/Makefile @@ -1,7 +1,9 @@ vfio-platform-calxedaxgmac-y := vfio_platform_calxedaxgmac.o vfio-platform-amdxgbe-y := vfio_platform_amdxgbe.o +vfio-platform-qcomhidma-y := vfio_platform_qcomhidma.o ccflags-y += -Idrivers/vfio/platform obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC_RESET) += vfio-platform-calxedaxgmac.o +obj-$(CONFIG_VFIO_PLATFORM_QCOMHIDMA_RESET) += vfio-platform-qcomhidma.o obj-$(CONFIG_VFIO_PLATFORM_AMDXGBE_RESET) += vfio-platform-amdxgbe.o diff --git a/drivers/vfio/platform/reset/vfio_platform_qcomhidma.c b/drivers/vfio/platform/reset/vfio_platform_qcomhidma.c new file mode 100644 index 0000000..70d7eed --- /dev/null +++ b/drivers/vfio/platform/reset/vfio_platform_qcomhidma.c @@ -0,0 +1,99 @@ +/* + * Qualcomm Technologies HIDMA VFIO Reset Driver + * + * Copyright (c) 2016, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include + +#include "vfio_platform_private.h" + +#define TRCA_CTRLSTS_OFFSET 0x000 +#define EVCA_CTRLSTS_OFFSET 0x000 + +#define CH_CONTROL_MASK GENMASK(7, 0) +#define CH_STATE_MASK GENMASK(7, 0) +#define CH_STATE_BIT_POS 0x8 + +#define HIDMA_CH_STATE(val) \ + ((val >> CH_STATE_BIT_POS) & CH_STATE_MASK) + +#define EVCA_IRQ_EN_OFFSET 0x110 + +#define CH_RESET 9 +#define CH_DISABLED 0 + +int vfio_platform_qcomhidma_reset(struct vfio_platform_device *vdev) +{ + struct vfio_platform_region *trreg; + struct vfio_platform_region *evreg; + u32 val; + int ret; + + if (vdev->num_regions != 2) + return -ENODEV; + + trreg = &vdev->regions[0]; + if (!trreg->ioaddr) { + trreg->ioaddr = + ioremap_nocache(trreg->addr, trreg->size); + if (!trreg->ioaddr) + return -ENOMEM; + } + + evreg = &vdev->regions[1]; + if (!evreg->ioaddr) { + evreg->ioaddr = + ioremap_nocache(evreg->addr, evreg->size); + if (!evreg->ioaddr) + return -ENOMEM; + } + + /* disable IRQ */ + writel(0, evreg->ioaddr + EVCA_IRQ_EN_OFFSET); + + /* reset both transfer and event channels */ + val = readl(trreg->ioaddr + TRCA_CTRLSTS_OFFSET); + val &= ~(CH_CONTROL_MASK << 16); + val |= CH_RESET << 16; + writel(val, trreg->ioaddr + TRCA_CTRLSTS_OFFSET); + + ret = readl_poll_timeout(trreg->ioaddr + TRCA_CTRLSTS_OFFSET, val, + HIDMA_CH_STATE(val) == CH_DISABLED, 1000, + 10000); + if (ret) + return ret; + + val = readl(evreg->ioaddr + EVCA_CTRLSTS_OFFSET); + val &= ~(CH_CONTROL_MASK << 16); + val |= CH_RESET << 16; + writel(val, evreg->ioaddr + EVCA_CTRLSTS_OFFSET); + + ret = readl_poll_timeout(evreg->ioaddr + EVCA_CTRLSTS_OFFSET, val, + HIDMA_CH_STATE(val) == CH_DISABLED, 1000, + 10000); + if (ret) + return ret; + + pr_info("HIDMA channel reset\n"); + return 0; +} +module_vfio_reset_handler("qcom,hidma-1.0", "QCOM8061", + vfio_platform_qcomhidma_reset); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Reset support for Qualcomm Technologies HIDMA device"); -- 1.8.2.1