[openwrt/staging/ynezz.git] /

From c4fbb93e85b13edc174fa6fc3105341f646305e4 Mon Sep 17 00:00:00 2001
From: Diana Craciun <diana.craciun@nxp.com>
Date: Wed, 2 Oct 2019 11:14:52 +0300
Subject: [PATCH] vfio/fsl-mc: Add read/write support for fsl-mc devices

This patch adds support to read and write ioctls for
fsl-mc devices. Only read-write to DPRC/DPMCP devices
are supported while read writes on other fsl-mc devices
is not supported by this patch.

Also current patch limits userspace to write complete
64byte command once and read 64byte response by one ioctl.

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
---
 drivers/vfio/fsl-mc/vfio_fsl_mc.c         | 125 +++++++++++++++++++++++++++++-
 drivers/vfio/fsl-mc/vfio_fsl_mc_private.h |   1 +
 2 files changed, 124 insertions(+), 2 deletions(-)

--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -12,6 +12,7 @@
 #include <linux/types.h>
 #include <linux/vfio.h>
 #include <linux/fsl/mc.h>
+#include <linux/delay.h>
 
 #include "vfio_fsl_mc_private.h"
 
@@ -112,6 +113,11 @@ static int vfio_fsl_mc_regions_init(stru
 }
 static void vfio_fsl_mc_regions_cleanup(struct vfio_fsl_mc_device *vdev)
 {
+       int i;
+
+       for (i = 0; i < vdev->num_regions; i++)
+               iounmap(vdev->regions[i].ioaddr);
+
        vdev->num_regions = 0;
        kfree(vdev->regions);
 }
@@ -308,13 +314,128 @@ static long vfio_fsl_mc_ioctl(void *devi
 static ssize_t vfio_fsl_mc_read(void *device_data, char __user *buf,
                                size_t count, loff_t *ppos)
 {
-       return -EINVAL;
+       struct vfio_fsl_mc_device *vdev = device_data;
+       unsigned int index = VFIO_FSL_MC_OFFSET_TO_INDEX(*ppos);
+       loff_t off = *ppos & VFIO_FSL_MC_OFFSET_MASK;
+       struct vfio_fsl_mc_region *region;
+       uint64_t data[8];
+       int i;
+
+       /* Read ioctl supported only for DPRC and DPMCP device */
+       if (strcmp(vdev->mc_dev->obj_desc.type, "dprc") &&
+           strcmp(vdev->mc_dev->obj_desc.type, "dpmcp"))
+               return -EINVAL;
+
+       if (index >= vdev->num_regions)
+               return -EINVAL;
+
+       region = &vdev->regions[index];
+
+       if (!(region->flags & VFIO_REGION_INFO_FLAG_READ))
+               return -EINVAL;
+
+
+       if (!region->ioaddr) {
+               region->ioaddr = ioremap_nocache(region->addr, region->size);
+               if (!region->ioaddr)
+                       return -ENOMEM;
+       }
+
+       if (count != 64 || off != 0)
+               return -EINVAL;
+
+       for (i = 7; i >= 0; i--)
+               data[i] = readq(region->ioaddr + i * sizeof(uint64_t));
+
+       if (copy_to_user(buf, data, 64))
+               return -EFAULT;
+
+       return count;
 }
 
+#define MC_CMD_COMPLETION_TIMEOUT_MS    5000
+#define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500
+
+static int vfio_fsl_mc_send_command(void __iomem *ioaddr, uint64_t *cmd_data)
+{
+       int i;
+       enum mc_cmd_status status;
+       unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;
+
+       /* Write at command parameter into portal */
+       for (i = 7; i >= 1; i--)
+               writeq_relaxed(cmd_data[i], ioaddr + i * sizeof(uint64_t));
+
+       /* Write command header in the end */
+       writeq(cmd_data[0], ioaddr);
+
+       /* Wait for response before returning to user-space
+        * This can be optimized in future to even prepare response
+        * before returning to user-space and avoid read ioctl.
+        */
+       for (;;) {
+               u64 header;
+               struct mc_cmd_header *resp_hdr;
+
+               header = cpu_to_le64(readq_relaxed(ioaddr));
+
+               resp_hdr = (struct mc_cmd_header *)&header;
+               status = (enum mc_cmd_status)resp_hdr->status;
+               if (status != MC_CMD_STATUS_READY)
+                       break;
+
+               udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
+               timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
+               if (timeout_usecs == 0)
+                       return -ETIMEDOUT;
+       }
+
+       return 0;
+}
+
+
 static ssize_t vfio_fsl_mc_write(void *device_data, const char __user *buf,
                                 size_t count, loff_t *ppos)
 {
-       return -EINVAL;
+       struct vfio_fsl_mc_device *vdev = device_data;
+       unsigned int index = VFIO_FSL_MC_OFFSET_TO_INDEX(*ppos);
+       loff_t off = *ppos & VFIO_FSL_MC_OFFSET_MASK;
+       struct vfio_fsl_mc_region *region;
+       uint64_t data[8];
+       int ret;
+
+
+       /* Write ioctl supported only for DPRC and DPMCP device */
+       if (strcmp(vdev->mc_dev->obj_desc.type, "dprc") &&
+           strcmp(vdev->mc_dev->obj_desc.type, "dpmcp"))
+               return -EINVAL;
+
+       if (index >= vdev->num_regions)
+               return -EINVAL;
+
+       region = &vdev->regions[index];
+
+       if (!(region->flags & VFIO_REGION_INFO_FLAG_WRITE))
+               return -EINVAL;
+
+       if (!region->ioaddr) {
+               region->ioaddr = ioremap_nocache(region->addr, region->size);
+               if (!region->ioaddr)
+                       return -ENOMEM;
+       }
+
+       if (count != 64 || off != 0)
+               return -EINVAL;
+
+       if (copy_from_user(&data, buf, 64))
+               return -EFAULT;
+
+       ret = vfio_fsl_mc_send_command(region->ioaddr, data);
+       if (ret)
+               return ret;
+
+       return count;
+
 }
 
 static int vfio_fsl_mc_mmap_mmio(struct vfio_fsl_mc_region region,
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
@@ -32,6 +32,7 @@ struct vfio_fsl_mc_region {
        u32                     type;
        u64                     addr;
        resource_size_t         size;
+       void __iomem            *ioaddr;
 };
 
 struct vfio_fsl_mc_device {