RE: [PATCH v8 5/8] PCI: endpoint: Add support to handle multiple base for mapping outbound memory

[Yoshihiro Shimoda]

Hi Prabhakar-san,

Thank you for the patch!

> From: Lad Prabhakar, Sent: Sunday, April 19, 2020 10:27 PM
<snip>
> @@ -109,11 +137,22 @@ EXPORT_SYMBOL_GPL(pci_epc_mem_init);
>   */
>  void pci_epc_mem_exit(struct pci_epc *epc)
>  {
> -	struct pci_epc_mem *mem = epc->mem;
> +	struct pci_epc_mem *mem;
> +	int i;
> 
> +	if (!epc->num_windows)
> +		return;
> +
> +	for (i = 0; i <= epc->num_windows; i++) {

I'm sorry, I overlooked when I reviewed before.
This condition should be "i < epc->num_windows".

> +		mem = epc->windows[i];
> +		kfree(mem->bitmap);
> +		kfree(mem);
> +	}
> +	kfree(epc->windows);
> +
> +	epc->windows = NULL;
>  	epc->mem = NULL;
> -	kfree(mem->bitmap);
> -	kfree(mem);
> +	epc->num_windows = 0;
>  }
>  EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
> 
> @@ -129,31 +168,57 @@ EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
>  void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
>  				     phys_addr_t *phys_addr, size_t size)
>  {
> -	int pageno;
>  	void __iomem *virt_addr = NULL;
> -	struct pci_epc_mem *mem = epc->mem;
> -	unsigned int page_shift = ilog2(mem->page_size);
> +	struct pci_epc_mem *mem;
> +	unsigned int page_shift;
> +	size_t align_size;
> +	int pageno;
>  	int order;
> +	int i;
> 
> -	size = ALIGN(size, mem->page_size);
> -	order = pci_epc_mem_get_order(mem, size);
> -
> -	mutex_lock(&mem->lock);
> -	pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order);
> -	if (pageno < 0)
> -		goto ret;
> +	for (i = 0; i < epc->num_windows; i++) {
> +		mem = epc->windows[i];
> +		mutex_lock(&mem->lock);
> +		align_size = ALIGN(size, mem->window.page_size);
> +		order = pci_epc_mem_get_order(mem, align_size);
> 
> -	*phys_addr = mem->phys_base + ((phys_addr_t)pageno << page_shift);
> -	virt_addr = ioremap(*phys_addr, size);
> -	if (!virt_addr)
> -		bitmap_release_region(mem->bitmap, pageno, order);
> +		pageno = bitmap_find_free_region(mem->bitmap, mem->pages,
> +						 order);
> +		if (pageno >= 0) {
> +			page_shift = ilog2(mem->window.page_size);
> +			*phys_addr = mem->window.phys_base +
> +				((phys_addr_t)pageno << page_shift);
> +			virt_addr = ioremap(*phys_addr, align_size);
> +			if (!virt_addr)
> +				bitmap_release_region(mem->bitmap,
> +						      pageno, order);

I'm sorry here again. But, I think we should call mutex_unlock() and "continue;"
here if ioremap() failed for trying remaining windows. What do you think?

> +			mutex_unlock(&mem->lock);
> +			return virt_addr;
> +		}
> +		mutex_unlock(&mem->lock);
> +	}
> 
> -ret:
> -	mutex_unlock(&mem->lock);
>  	return virt_addr;
>  }
>  EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);

Best regards,
Yoshihiro Shimoda