[RFC, v0 3/3] vfio/platform: add Broadcom msi module

[Vikas Gupta <vikas.gupta@broadcom.com>]

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Add Broadcom msi module for platform devices.

Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
---
 drivers/vfio/platform/Kconfig                 |  1 +
 drivers/vfio/platform/Makefile                |  1 +
 drivers/vfio/platform/msi/Kconfig             |  9 +++
 drivers/vfio/platform/msi/Makefile            |  2 +
 .../vfio/platform/msi/vfio_platform_bcmplt.c  | 74 +++++++++++++++++++
 5 files changed, 87 insertions(+)
 create mode 100644 drivers/vfio/platform/msi/Kconfig
 create mode 100644 drivers/vfio/platform/msi/Makefile
 create mode 100644 drivers/vfio/platform/msi/vfio_platform_bcmplt.c

diff --git a/drivers/vfio/platform/Kconfig b/drivers/vfio/platform/Kconfig
index dc1a3c44f2c6..7b8696febe61 100644
--- a/drivers/vfio/platform/Kconfig
+++ b/drivers/vfio/platform/Kconfig
@@ -21,3 +21,4 @@ config VFIO_AMBA
 	  If you don't know what to do here, say N.
 
 source "drivers/vfio/platform/reset/Kconfig"
+source "drivers/vfio/platform/msi/Kconfig"
diff --git a/drivers/vfio/platform/Makefile b/drivers/vfio/platform/Makefile
index 3f3a24e7c4ef..9ccdcdbf0e7e 100644
--- a/drivers/vfio/platform/Makefile
+++ b/drivers/vfio/platform/Makefile
@@ -5,6 +5,7 @@ vfio-platform-y := vfio_platform.o
 obj-$(CONFIG_VFIO_PLATFORM) += vfio-platform.o
 obj-$(CONFIG_VFIO_PLATFORM) += vfio-platform-base.o
 obj-$(CONFIG_VFIO_PLATFORM) += reset/
+obj-$(CONFIG_VFIO_PLATFORM) += msi/
 
 vfio-amba-y := vfio_amba.o
 
diff --git a/drivers/vfio/platform/msi/Kconfig b/drivers/vfio/platform/msi/Kconfig
new file mode 100644
index 000000000000..54d6b70e1e32
--- /dev/null
+++ b/drivers/vfio/platform/msi/Kconfig
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config VFIO_PLATFORM_BCMPLT_MSI
+	tristate "MSI support for Broadcom platform devices"
+	depends on VFIO_PLATFORM && (ARCH_BCM_IPROC || COMPILE_TEST)
+	default ARCH_BCM_IPROC
+	help
+	  Enables the VFIO platform driver to handle msi for Broadcom devices
+
+	  If you don't know what to do here, say N.
diff --git a/drivers/vfio/platform/msi/Makefile b/drivers/vfio/platform/msi/Makefile
new file mode 100644
index 000000000000..27422d45cecb
--- /dev/null
+++ b/drivers/vfio/platform/msi/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_VFIO_PLATFORM_BCMPLT_MSI) += vfio_platform_bcmplt.o
diff --git a/drivers/vfio/platform/msi/vfio_platform_bcmplt.c b/drivers/vfio/platform/msi/vfio_platform_bcmplt.c
new file mode 100644
index 000000000000..b97a571e90a9
--- /dev/null
+++ b/drivers/vfio/platform/msi/vfio_platform_bcmplt.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Broadcom.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/msi.h>
+#include <linux/vfio.h>
+
+#include "../vfio_platform_private.h"
+
+#define RING_SIZE	(64 << 10)
+
+#define RING_MSI_ADDR_LS	0x03c
+#define RING_MSI_ADDR_MS	0x040
+#define RING_MSI_DATA_VALUE	0x064
+
+static u32 bcm_num_msi(struct vfio_platform_device *vdev)
+{
+	struct vfio_platform_region *reg = &vdev->regions[0];
+
+	return (reg->size / RING_SIZE);
+}
+
+static int bcm_write_msi(struct vfio_platform_device *vdev,
+			 struct msi_desc *desc,
+			 struct msi_msg *msg)
+{
+	void __iomem *ring;
+	u32 msi_off = vdev->num_irqs - vdev->num_msis;
+	int ring_num = desc->irq - vdev->irqs[msi_off].hwirq;
+	struct vfio_platform_region *reg = &vdev->regions[0];
+
+	if (!reg->ioaddr) {
+		reg->ioaddr = ioremap(reg->addr, reg->size);
+		if (!reg->ioaddr)
+			return -ENOMEM;
+	}
+
+	ring = reg->ioaddr + ring_num * RING_SIZE;
+
+	writel_relaxed(msg->address_lo, ring + RING_MSI_ADDR_LS);
+	writel_relaxed(msg->address_hi, ring + RING_MSI_ADDR_MS);
+	writel_relaxed(msg->data, ring + RING_MSI_DATA_VALUE);
+
+	return 0;
+}
+
+static struct vfio_platform_msi_node vfio_platform_bcmflexrm_msi_node = {
+	.owner = THIS_MODULE,
+	.compat = "brcm,iproc-flexrm-mbox",
+	.of_get_msi = bcm_num_msi,
+	.of_msi_write = bcm_write_msi
+};
+
+static int __init vfio_platform_bcmflexrm_msi_module_init(void)
+{
+	__vfio_platform_register_msi(&vfio_platform_bcmflexrm_msi_node);
+
+	return 0;
+}
+
+static void __exit vfio_platform_bcmflexrm_msi_module_exit(void)
+{
+	vfio_platform_unregister_msi("brcm,iproc-flexrm-mbox");
+}
+
+module_init(vfio_platform_bcmflexrm_msi_module_init);
+module_exit(vfio_platform_bcmflexrm_msi_module_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Broadcom");
-- 
2.17.1


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