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authorAnkit Jain <jankit@codeaurora.org>2019-02-04 05:45:43 +0100
committerAndy Gross <andy.gross@linaro.org>2019-03-28 05:32:25 +0100
commit8da3daaa097171edd9658a82bbd3f335bc2e03ad (patch)
tree2232ab6985a2c2ea1a52671772ae7dca4fd5f792 /drivers/soc
parentLinux 5.1-rc1 (diff)
downloadlinux-8da3daaa097171edd9658a82bbd3f335bc2e03ad.tar.xz
linux-8da3daaa097171edd9658a82bbd3f335bc2e03ad.zip
soc: qcom: rmtfs: Add support for mmap functionality
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>
Diffstat (limited to 'drivers/soc')
-rw-r--r--drivers/soc/qcom/rmtfs_mem.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/soc/qcom/rmtfs_mem.c b/drivers/soc/qcom/rmtfs_mem.c
index 7200d762a951..6f5e8be9689c 100644
--- a/drivers/soc/qcom/rmtfs_mem.c
+++ b/drivers/soc/qcom/rmtfs_mem.c
@@ -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)