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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 {
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