RE: [PATCH] swiotlb: manipulate orig_addr when tlb_addr has offset

From: "Chanho Park" <chanho61.park@samsung.com>
To: "'Christoph Hellwig'" <hch@lst.de>
Cc: 'Konrad Rzeszutek Wilk' <konrad.wilk@oracle.com>,
	linux-kernel@vger.kernel.org,
	'Bumyong Lee' <bumyong.lee@samsung.com>,
	iommu@lists.linux-foundation.org,
	'Robin Murphy' <robin.murphy@arm.com>
Subject: RE: [PATCH] swiotlb: manipulate orig_addr when tlb_addr has offset
Date: Mon, 10 May 2021 18:04:17 +0900	[thread overview]
Message-ID: <002401d7457b$75171560$5f454020$@samsung.com> (raw)
In-Reply-To: <20210510084406.GA1093@lst.de>

(RESEND due to wrong encrypted message setting)

Hi,

> On Mon, May 10, 2021 at 05:30:57PM +0900, Chanho Park wrote:
> > +static unsigned int swiotlb_align_offset(struct device *dev, u64
> > +addr);
> 
> Please just move swiotlb_align_offset up to avoid the forward declaration.

Okay. I'll move the position of the function next patch.

> 
> >  /*
> >   * Bounce: copy the swiotlb buffer from or back to the original dma
> location
> >   */
> > @@ -346,10 +347,17 @@ static void swiotlb_bounce(struct device *dev,
> phys_addr_t tlb_addr, size_t size
> >  	size_t alloc_size = mem->slots[index].alloc_size;
> >  	unsigned long pfn = PFN_DOWN(orig_addr);
> >  	unsigned char *vaddr = phys_to_virt(tlb_addr);
> > +	unsigned int tlb_offset;
> >
> >  	if (orig_addr == INVALID_PHYS_ADDR)
> >  		return;
> >
> > +	tlb_offset = (unsigned int)tlb_addr & (IO_TLB_SIZE - 1);
> > +	tlb_offset -= swiotlb_align_offset(dev, orig_addr);
> 
> Nit: I'd write this as:
> 
> 	tlb_offset = (tlb_addr & (IO_TLB_SIZE - 1)) -
> 			swiotlb_align_offset(dev, orig_addr);
> 
> as there is no need for the cast, and just having a single assignment is
> easier to follow.

Great. It can be a single assignment as you suggested.

Best Regards,
Chanho Park

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu