vfio: platform: reset: Add Broadcom FlexRM reset module

This patch adds Broadcom FlexRM low-level reset for
VFIO platform.

It will do the following:
1. Disable/Deactivate each FlexRM ring
2. Flush each FlexRM ring

The cleanup sequence for FlexRM rings is adapted from
Broadcom FlexRM mailbox driver.

Signed-off-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Oza Oza <oza.oza@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig
index 70cccc5..392e3c0 100644 (file)
--- 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_BCMFLEXRM_RESET
+       tristate "VFIO support for Broadcom FlexRM reset"
+       depends on VFIO_PLATFORM && (ARCH_BCM_IPROC || COMPILE_TEST)
+       default ARCH_BCM_IPROC
+       help
+         Enables the VFIO platform driver to handle reset for Broadcom FlexRM
+
+         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..8d9874b 100644 (file)
--- a/drivers/vfio/platform/reset/Makefile
+++ b/drivers/vfio/platform/reset/Makefile
@@ -5,3 +5,4 @@ ccflags-y += -Idrivers/vfio/platform
 
 obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC_RESET) += vfio-platform-calxedaxgmac.o
 obj-$(CONFIG_VFIO_PLATFORM_AMDXGBE_RESET) += vfio-platform-amdxgbe.o
+obj-$(CONFIG_VFIO_PLATFORM_BCMFLEXRM_RESET) += vfio_platform_bcmflexrm.o

diff --git a/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
new file mode 100644 (file)
index 0000000..d45c3be
--- /dev/null
+++ b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2017 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * 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];
+
+       /* Map FlexRM ring registers if not mapped */
+       if (!reg->ioaddr) {
+               reg->ioaddr = ioremap_nocache(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");