soc: qcom: rmtfs: Add support for mmap functionality (8da3daaa) · Commits · 戴 / test

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@linaro.org> Signed-off-by:

Ankit Jain <jankit@codeaurora.org> Signed-off-by:

Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by:

Andy Gross <andy.gross@linaro.org>

drivers/soc/qcom/rmtfs_mem.c

+21 −0

Original line number	Diff line number	Diff line
		@@ -137,6 +137,26 @@ static struct class rmtfs_class = {
		.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 const struct file_operations qcom_rmtfs_mem_fops = {
		.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)

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