On Sun 03 Feb 20:45 PST 2019, Ankit Jain wrote:
> This change adds mmap functionality to rmtfs_mem driver.
> Userspace application can map the address and use this
> mapped address directly as buffer for read/write call to disk.
> and avoid the read/write call to the shared path to copy the
> buffer to userspace application.
>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
And I've picked it up for inclusion in 5.2.
Regards,
Bjorn
> Signed-off-by: Ankit Jain <jankit@xxxxxxxxxxxxxx>
> ---
> drivers/soc/qcom/rmtfs_mem.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/drivers/soc/qcom/rmtfs_mem.c b/drivers/soc/qcom/rmtfs_mem.c
> index 7200d76..6f5e8be 100644
> --- a/drivers/soc/qcom/rmtfs_mem.c
> +++ b/drivers/soc/qcom/rmtfs_mem.c
> @@ -137,6 +137,26 @@ static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp)
> .name = "rmtfs",
> };
>
> +static int qcom_rmtfs_mem_mmap(struct file *filep, struct vm_area_struct *vma)
> +{
> + struct qcom_rmtfs_mem *rmtfs_mem = filep->private_data;
> +
> + if (vma->vm_end - vma->vm_start > rmtfs_mem->size) {
> + dev_dbg(&rmtfs_mem->dev,
> + "vm_end[%lu] - vm_start[%lu] [%lu] > mem->size[%pa]\n",
> + vma->vm_end, vma->vm_start,
> + (vma->vm_end - vma->vm_start), &rmtfs_mem->size);
> + return -EINVAL;
> + }
> +
> + vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
> + return remap_pfn_range(vma,
> + vma->vm_start,
> + rmtfs_mem->addr >> PAGE_SHIFT,
> + vma->vm_end - vma->vm_start,
> + vma->vm_page_prot);
> +}
> +
> static const struct file_operations qcom_rmtfs_mem_fops = {
> .owner = THIS_MODULE,
> .open = qcom_rmtfs_mem_open,
> @@ -144,6 +164,7 @@ static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp)
> .write = qcom_rmtfs_mem_write,
> .release = qcom_rmtfs_mem_release,
> .llseek = default_llseek,
> + .mmap = qcom_rmtfs_mem_mmap,
> };
>
> static void qcom_rmtfs_mem_release_device(struct device *dev)
> --
> Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation collaborative Project.
>
