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Subject[PATCH V14 9/9] vfio, platform: add QTI HIDMA reset driver
Date
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 <okaya@codeaurora.org>
---
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 <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/iopoll.h>
+
+#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
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