On 2/14/20 1:01 PM, Hsin-Yi Wang wrote:
> struct vpu_run *run in vpu_init_ipi_handler() is an ioremapped DTCM (Data
> Tightly Coupled Memory) buffer shared with AP. It's not able to do
> unaligned access. Otherwise kernel would crash due to unable to handle
> kernel paging request.
>
> struct vpu_run {
> u32 signaled;
> char fw_ver[VPU_FW_VER_LEN];
> unsigned int dec_capability;
> unsigned int enc_capability;
> wait_queue_head_t wq;
> };
>
> fw_ver starts at 4 byte boundary. If system enables
> CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, strscpy() will do
> read_word_at_a_time(), which tries to read 8-byte: *(unsigned long *)addr
>
> Copy the string by memcpy_fromio() for this buffer to avoid unaligned
> access.
>
> Fixes: 85709cbf1524 ("media: replace strncpy() by strscpy()")
> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> ---
> Change in v2:
> - fix sparse warnings.
I still get sparse warnings:
drivers/media/platform/mtk-vpu/mtk_vpu.c:710:47: warning: incorrect type in argument 1 (different address spaces)
drivers/media/platform/mtk-mdp/mtk_mdp_vpu.c:66:32: warning: incorrect type in argument 3 (incompatible argument 1 (different address spaces))
drivers/media/platform/mtk-vcodec/vdec_vpu_if.c:111:22: warning: incorrect type in assignment (incompatible argument 1 (different address spaces))
drivers/media/platform/mtk-vcodec/venc_vpu_if.c:96:54: warning: incorrect type in argument 3 (incompatible argument 1 (different address spaces))
Regards,
Hans
> ---
> drivers/media/platform/mtk-vpu/mtk_vpu.c | 17 ++++++++++-------
> drivers/media/platform/mtk-vpu/mtk_vpu.h | 2 +-
> 2 files changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/media/platform/mtk-vpu/mtk_vpu.c b/drivers/media/platform/mtk-vpu/mtk_vpu.c
> index a768707abb94..c59373e84a33 100644
> --- a/drivers/media/platform/mtk-vpu/mtk_vpu.c
> +++ b/drivers/media/platform/mtk-vpu/mtk_vpu.c
> @@ -600,15 +600,18 @@ int vpu_load_firmware(struct platform_device *pdev)
> }
> EXPORT_SYMBOL_GPL(vpu_load_firmware);
>
> -static void vpu_init_ipi_handler(void *data, unsigned int len, void *priv)
> +static void vpu_init_ipi_handler(void __iomem *data, unsigned int len,
> + void *priv)
> {
> struct mtk_vpu *vpu = (struct mtk_vpu *)priv;
> - struct vpu_run *run = (struct vpu_run *)data;
> -
> - vpu->run.signaled = run->signaled;
> - strscpy(vpu->run.fw_ver, run->fw_ver, sizeof(vpu->run.fw_ver));
> - vpu->run.dec_capability = run->dec_capability;
> - vpu->run.enc_capability = run->enc_capability;
> + struct vpu_run __iomem *run = data;
> +
> + vpu->run.signaled = readl(&run->signaled);
> + memcpy_fromio(vpu->run.fw_ver, run->fw_ver, sizeof(vpu->run.fw_ver));
> + /* Make sure the string is NUL-terminated */
> + vpu->run.fw_ver[sizeof(vpu->run.fw_ver) - 1] = '\0';
> + vpu->run.dec_capability = readl(&run->dec_capability);
> + vpu->run.enc_capability = readl(&run->enc_capability);
> wake_up_interruptible(&vpu->run.wq);
> }
>
> diff --git a/drivers/media/platform/mtk-vpu/mtk_vpu.h b/drivers/media/platform/mtk-vpu/mtk_vpu.h
> index d4453b4bcee9..a7ac351b19c1 100644
> --- a/drivers/media/platform/mtk-vpu/mtk_vpu.h
> +++ b/drivers/media/platform/mtk-vpu/mtk_vpu.h
> @@ -15,7 +15,7 @@
> * VPU interfaces with other blocks by share memory and interrupt.
> **/
>
> -typedef void (*ipi_handler_t) (void *data,
> +typedef void (*ipi_handler_t) (void __iomem *data,
> unsigned int len,
> void *priv);
>
>
