1 files changed, 107 insertions, 0 deletions
diff --git a/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
new file mode 100644
index 000000000000..51c9d156f307
--- /dev/null
+++ b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 Broadcom
+ */
+
+/*
+ * This driver provides reset support for Broadcom FlexRM ring manager
+ * to VFIO platform.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "../vfio_platform_private.h"
+
+/* FlexRM configuration */
+#define RING_REGS_SIZE					0x10000
+#define RING_VER_MAGIC					0x76303031
+
+/* Per-Ring register offsets */
+#define RING_VER					0x000
+#define RING_CONTROL					0x034
+#define RING_FLUSH_DONE					0x038
+
+/* Register RING_CONTROL fields */
+#define CONTROL_FLUSH_SHIFT				5
+
+/* Register RING_FLUSH_DONE fields */
+#define FLUSH_DONE_MASK					0x1
+
+static int vfio_platform_bcmflexrm_shutdown(void __iomem *ring)
+{
+	unsigned int timeout;
+
+	/* Disable/inactivate ring */
+	writel_relaxed(0x0, ring + RING_CONTROL);
+
+	/* Set ring flush state */
+	timeout = 1000; /* timeout of 1s */
+	writel_relaxed(BIT(CONTROL_FLUSH_SHIFT), ring + RING_CONTROL);
+	do {
+		if (readl_relaxed(ring + RING_FLUSH_DONE) &
+		    FLUSH_DONE_MASK)
+			break;
+		mdelay(1);
+	} while (--timeout);
+	if (!timeout)
+		return -ETIMEDOUT;
+
+	/* Clear ring flush state */
+	timeout = 1000; /* timeout of 1s */
+	writel_relaxed(0x0, ring + RING_CONTROL);
+	do {
+		if (!(readl_relaxed(ring + RING_FLUSH_DONE) &
+		      FLUSH_DONE_MASK))
+			break;
+		mdelay(1);
+	} while (--timeout);
+	if (!timeout)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static int vfio_platform_bcmflexrm_reset(struct vfio_platform_device *vdev)
+{
+	void __iomem *ring;
+	int rc = 0, ret = 0, ring_num = 0;
+	struct vfio_platform_region *reg = &vdev->regions[0];
+
+	dev_err_once(vdev->device, "DEPRECATION: VFIO Broadcom FlexRM platform reset is deprecated and will be removed in a future kernel release\n");
+
+	/* Map FlexRM ring registers if not mapped */
+	if (!reg->ioaddr) {
+		reg->ioaddr = ioremap(reg->addr, reg->size);
+		if (!reg->ioaddr)
+			return -ENOMEM;
+	}
+
+	/* Discover and shutdown each FlexRM ring */
+	for (ring = reg->ioaddr;
+	     ring < (reg->ioaddr + reg->size); ring += RING_REGS_SIZE) {
+		if (readl_relaxed(ring + RING_VER) == RING_VER_MAGIC) {
+			rc = vfio_platform_bcmflexrm_shutdown(ring);
+			if (rc) {
+				dev_warn(vdev->device,
+					 "FlexRM ring%d shutdown error %d\n",
+					 ring_num, rc);
+				ret |= rc;
+			}
+			ring_num++;
+		}
+	}
+
+	return ret;
+}
+
+module_vfio_reset_handler("brcm,iproc-flexrm-mbox",
+			  vfio_platform_bcmflexrm_reset);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>");
+MODULE_DESCRIPTION("Reset support for Broadcom FlexRM VFIO platform device");