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

[Jeffrey Hugo <quic_jhugo@quicinc.com>]

On 1/7/2025 10:24 PM, Manivannan Sadhasivam wrote:
> On Fri, Dec 13, 2024 at 02:33:34PM -0700, 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)
> 
> No need to add 'inline' keyword in c files. You can trust the compiler.

Done.

> 
>> +{
>> +	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?

Done.

> 
>> +	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?

Symmetry with mhi_alloc_bhie_table().  Will change.

> 
>> +	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.

Just symmetry.  Jarek had the same comment.  Will inline.