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

[Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>]

Hi,

On 12/13/2024 10:33 PM, Jeffrey Hugo wrote:
> From: Matthew Leung <quic_mattleun@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@quicinc.com>
> Reviewed-by: Youssef Samir <quic_yabdulra@quicinc.com>
> Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
> Signed-off-by: Jeffrey Hugo <quic_jhugo@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)
> +{
> +	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;
> +	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_fw_load_bhie(struct mhi_controller *mhi_cntrl,
>  			    const struct mhi_buf *mhi_buf)
>  {
> @@ -226,24 +257,13 @@ static int mhi_fw_load_bhie(struct mhi_controller *mhi_cntrl,
>  }
>  
>  static int mhi_fw_load_bhi(struct mhi_controller *mhi_cntrl,
> -			   dma_addr_t dma_addr,
> -			   size_t size)
> +			    const struct mhi_buf *mhi_buf)
>  {
> -	u32 tx_status, val, session_id;
> -	int i, ret;
> -	void __iomem *base = mhi_cntrl->bhi;
> -	rwlock_t *pm_lock = &mhi_cntrl->pm_lock;
>  	struct device *dev = &mhi_cntrl->mhi_dev->dev;
> -	struct {
> -		char *name;
> -		u32 offset;
> -	} error_reg[] = {
> -		{ "ERROR_CODE", BHI_ERRCODE },
> -		{ "ERROR_DBG1", BHI_ERRDBG1 },
> -		{ "ERROR_DBG2", BHI_ERRDBG2 },
> -		{ "ERROR_DBG3", BHI_ERRDBG3 },
> -		{ NULL },
> -	};
> +	rwlock_t *pm_lock = &mhi_cntrl->pm_lock;
> +	void __iomem *base = mhi_cntrl->bhi;
> +	u32 tx_status, session_id;
> +	int ret;
>  
>  	read_lock_bh(pm_lock);
>  	if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
> @@ -255,11 +275,9 @@ static int mhi_fw_load_bhi(struct mhi_controller *mhi_cntrl,
>  	dev_dbg(dev, "Starting image download via BHI. Session ID: %u\n",
>  		session_id);
>  	mhi_write_reg(mhi_cntrl, base, BHI_STATUS, 0);
> -	mhi_write_reg(mhi_cntrl, base, BHI_IMGADDR_HIGH,
> -		      upper_32_bits(dma_addr));
> -	mhi_write_reg(mhi_cntrl, base, BHI_IMGADDR_LOW,
> -		      lower_32_bits(dma_addr));
> -	mhi_write_reg(mhi_cntrl, base, BHI_IMGSIZE, size);
> +	mhi_write_reg(mhi_cntrl, base, BHI_IMGADDR_HIGH, upper_32_bits(mhi_buf->dma_addr));
> +	mhi_write_reg(mhi_cntrl, base, BHI_IMGADDR_LOW, lower_32_bits(mhi_buf->dma_addr));
> +	mhi_write_reg(mhi_cntrl, base, BHI_IMGSIZE, mhi_buf->len);
>  	mhi_write_reg(mhi_cntrl, base, BHI_IMGTXDB, session_id);
>  	read_unlock_bh(pm_lock);
>  
> @@ -274,18 +292,7 @@ static int mhi_fw_load_bhi(struct mhi_controller *mhi_cntrl,
>  
>  	if (tx_status == BHI_STATUS_ERROR) {
>  		dev_err(dev, "Image transfer failed\n");
> -		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);
> +		mhi_fw_load_error_dump(mhi_cntrl);
>  		goto invalid_pm_state;
>  	}
>  
> @@ -296,6 +303,16 @@ static int mhi_fw_load_bhi(struct mhi_controller *mhi_cntrl,
>  	return -EIO;
>  }
>  
> +static void mhi_free_bhi_buffer(struct mhi_controller *mhi_cntrl,
> +				struct image_info *image_info)
> +{
> +	struct mhi_buf *mhi_buf = image_info->mhi_buf;
> +
> +	dma_free_coherent(mhi_cntrl->cntrl_dev, mhi_buf->len, mhi_buf->buf, mhi_buf->dma_addr);
> +	kfree(image_info->mhi_buf);
> +	kfree(image_info);
> +}
> +
>  void mhi_free_bhie_table(struct mhi_controller *mhi_cntrl,
>  			 struct image_info *image_info)
>  {
> @@ -310,6 +327,47 @@ void mhi_free_bhie_table(struct mhi_controller *mhi_cntrl,
>  	kfree(image_info);
>  }
>  
> +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;Are you planning for variable segment count in future?

> +	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);
> +	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);
> +}
I'm not sure this function improves readablity.

> +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);
>  
>  	/* Download image using BHI */
> -	memcpy(buf, fw_data, size);
> -	ret = mhi_fw_load_bhi(mhi_cntrl, dma_addr, size);
> -	dma_free_coherent(mhi_cntrl->cntrl_dev, size, buf, dma_addr);
> +	ret = mhi_fw_load_bhi(mhi_cntrl, image->mhi_buf);
> +	mhi_free_bhi_buffer(mhi_cntrl, image);
>  
>  	/* Error or in EDL mode, we're done */
>  	if (ret) {
> @@ -493,7 +558,7 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
>  		}
>  
>  		/* Load the firmware into BHIE vec table */
> -		mhi_firmware_copy(mhi_cntrl, fw_data, fw_sz, mhi_cntrl->fbc_image);
> +		mhi_firmware_copy_bhie(mhi_cntrl, fw_data, fw_sz, mhi_cntrl->fbc_image);
>  	}
>  
>  	release_firmware(firmware);

Regards,
Jacek