[PATCH 1/7] bus: mhi: host: Refactor BHI/BHIe based firmware loading

[Manivannan Sadhasivam]

On Fri, Dec 13, 2024 at 02:33:34PM -0700, Jeffrey Hugo wrote:
> From: Matthew Leung <quic_mattleun at quicinc.com>
> 
> Refactor the firmware loading code to have distinct helper functions for
> BHI and BHIe operations. This lays the foundation for separating the
> firmware loading protocol from the firmware being loaded and the EE it
> is loaded in.
> 
> Signed-off-by: Matthew Leung <quic_mattleun at quicinc.com>
> Reviewed-by: Youssef Samir <quic_yabdulra at quicinc.com>
> Reviewed-by: Jeffrey Hugo <quic_jhugo at quicinc.com>
> Signed-off-by: Jeffrey Hugo <quic_jhugo at quicinc.com>
> ---
>  drivers/bus/mhi/host/boot.c | 155 +++++++++++++++++++++++++-----------
>  1 file changed, 110 insertions(+), 45 deletions(-)
> 
> diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
> index e8c92972f9df..e3f3c07166ad 100644
> --- a/drivers/bus/mhi/host/boot.c
> +++ b/drivers/bus/mhi/host/boot.c
> @@ -177,6 +177,37 @@ int mhi_download_rddm_image(struct mhi_controller *mhi_cntrl, bool in_panic)
>  }
>  EXPORT_SYMBOL_GPL(mhi_download_rddm_image);
>  
> +static inline void mhi_fw_load_error_dump(struct mhi_controller *mhi_cntrl)

No need to add 'inline' keyword in c files. You can trust the compiler.

> +{
> +	struct device *dev = &mhi_cntrl->mhi_dev->dev;
> +	rwlock_t *pm_lock = &mhi_cntrl->pm_lock;
> +	void __iomem *base = mhi_cntrl->bhi;
> +	int ret;
> +	u32 val;
> +	int i;

int ret, i?

> +	struct {
> +		char *name;
> +		u32 offset;
> +	} error_reg[] = {
> +		{ "ERROR_CODE", BHI_ERRCODE },
> +		{ "ERROR_DBG1", BHI_ERRDBG1 },
> +		{ "ERROR_DBG2", BHI_ERRDBG2 },
> +		{ "ERROR_DBG3", BHI_ERRDBG3 },
> +		{ NULL },
> +	};
> +
> +	read_lock_bh(pm_lock);
> +	if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
> +		for (i = 0; error_reg[i].name; i++) {
> +			ret = mhi_read_reg(mhi_cntrl, base, error_reg[i].offset, &val);
> +			if (ret)
> +				break;
> +			dev_err(dev, "Reg: %s value: 0x%x\n", error_reg[i].name, val);
> +		}
> +	}
> +	read_unlock_bh(pm_lock);
> +}
> +

[...]

> +static int mhi_alloc_bhi_buffer(struct mhi_controller *mhi_cntrl,
> +				struct image_info **image_info,
> +				size_t alloc_size)
> +{
> +	struct image_info *img_info;
> +	struct mhi_buf *mhi_buf;
> +	int segments = 1;
> +
> +	img_info = kzalloc(sizeof(*img_info), GFP_KERNEL);
> +	if (!img_info)
> +		return -ENOMEM;
> +
> +	/* Allocate memory for entry */
> +	img_info->mhi_buf = kcalloc(segments, sizeof(*img_info->mhi_buf),
> +				    GFP_KERNEL);

Why do you need kcalloc for only 1 segment?

> +	if (!img_info->mhi_buf)
> +		goto error_alloc_mhi_buf;
> +
> +	/* Allocate and populate vector table */
> +	mhi_buf = img_info->mhi_buf;
> +
> +	mhi_buf->len = alloc_size;
> +	mhi_buf->buf = dma_alloc_coherent(mhi_cntrl->cntrl_dev, mhi_buf->len,
> +					  &mhi_buf->dma_addr, GFP_KERNEL);
> +	if (!mhi_buf->buf)
> +		goto error_alloc_segment;
> +
> +	img_info->bhi_vec = NULL;
> +	img_info->entries = segments;
> +	*image_info = img_info;
> +
> +	return 0;
> +
> +error_alloc_segment:
> +	kfree(mhi_buf);
> +error_alloc_mhi_buf:
> +	kfree(img_info);
> +
> +	return -ENOMEM;
> +}
> +
>  int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
>  			 struct image_info **image_info,
>  			 size_t alloc_size)
> @@ -364,9 +422,18 @@ int mhi_alloc_bhie_table(struct mhi_controller *mhi_cntrl,
>  	return -ENOMEM;
>  }
>  
> -static void mhi_firmware_copy(struct mhi_controller *mhi_cntrl,
> -			      const u8 *buf, size_t remainder,
> -			      struct image_info *img_info)
> +static void mhi_firmware_copy_bhi(struct mhi_controller *mhi_cntrl,
> +				  const u8 *buf, size_t size,
> +				  struct image_info *img_info)
> +{
> +	struct mhi_buf *mhi_buf = img_info->mhi_buf;
> +
> +	memcpy(mhi_buf->buf, buf, size);
> +}
> +
> +static void mhi_firmware_copy_bhie(struct mhi_controller *mhi_cntrl,
> +				   const u8 *buf, size_t remainder,
> +				   struct image_info *img_info)
>  {
>  	size_t to_cpy;
>  	struct mhi_buf *mhi_buf = img_info->mhi_buf;
> @@ -390,10 +457,9 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
>  	const struct firmware *firmware = NULL;
>  	struct device *dev = &mhi_cntrl->mhi_dev->dev;
>  	enum mhi_pm_state new_state;
> +	struct image_info *image;
>  	const char *fw_name;
>  	const u8 *fw_data;
> -	void *buf;
> -	dma_addr_t dma_addr;
>  	size_t size, fw_sz;
>  	int ret;
>  
> @@ -452,17 +518,16 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
>  	fw_sz = firmware->size;
>  
>  skip_req_fw:
> -	buf = dma_alloc_coherent(mhi_cntrl->cntrl_dev, size, &dma_addr,
> -				 GFP_KERNEL);
> -	if (!buf) {
> +	ret = mhi_alloc_bhi_buffer(mhi_cntrl, &image, size);
> +	if (ret) {
>  		release_firmware(firmware);
>  		goto error_fw_load;
>  	}
> +	mhi_firmware_copy_bhi(mhi_cntrl, fw_data, size, image);

Why can't you directly use memcpy here? I know what you want to keep symmetry
with mhi_firmware_copy_bhie(), but it seems unnecessary to me.

Adding a comment like "Load the firmware into BHI vec table" is enough.

- Mani


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