Re: [RFC v3 2/2] vfio/platform: msi: add Broadcom platform devices
From: Auger Eric <eric.auger@redhat.com>
Date: 2021-01-12 09:24:05
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Hi Vikas, On 12/14/20 6:45 PM, Vikas Gupta wrote:
Add msi support for Broadcom 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 | 49 +++++++++++++++++++ 5 files changed, 62 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
what does plt mean?
quoted hunk ↗ jump to hunk
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.odiff --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.odiff --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..a074b5e92d77 --- /dev/null +++ b/drivers/vfio/platform/msi/vfio_platform_bcmplt.c@@ -0,0 +1,49 @@ +// 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
Those 3 defines would not be needed anymore with that implementation option.
+
+static u32 bcm_num_msi(struct vfio_platform_device *vdev)
+{
+ struct vfio_platform_region *reg = &vdev->regions[0];
+
+ return (reg->size / RING_SIZE);
+}
+
+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,
+};
+
+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);One thing I would like to discuss with Alex. As the reset module is mandated (except if reset_required is forced to 0), I am wondering if we shouldn't try to turn the reset module into a "specialization" module and put the msi hooks there. I am afraid we may end up having modules for each and every vfio platform feature specialization. At the moment that's fully bearable but I can't predict what's next. As the mandated feature is the reset capability maybe we could just keep the config/module name terminology, tune the kconfig help message to mention the msi support in case of flex-rm? What do you think? Thanks Eric
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Broadcom");