From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH 07/28] 53c700: improve non-coherent DMA handling Date: Tue, 01 Sep 2020 07:52:40 -0700 Message-ID: <1598971960.4238.5.camel@HansenPartnership.com> References: <20200819065555.1802761-1-hch@lst.de> <20200819065555.1802761-8-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200819065555.1802761-8-hch-jcswGhMUV9g@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Sender: "iommu" To: Christoph Hellwig , Mauro Carvalho Chehab , Thomas Bogendoerfer , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , Ben Skeggs , Pawel Osciak , Marek Szyprowski , Matt Porter , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Cc: Tom Lendacky , alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org, linux-samsung-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ia64-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-parisc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-mips-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: nouveau.vger.kernel.org On Wed, 2020-08-19 at 08:55 +0200, Christoph Hellwig wrote: > Switch the 53c700 driver to only use non-coherent descriptor memory > if it really has to because dma_alloc_coherent fails. This doesn't > matter for any of the platforms it runs on currently, but that will > change soon. > > To help with this two new helpers to transfer ownership to and from > the device are added that abstract the syncing of the non-coherent > memory. The two current bidirectional cases are mapped to transfers > to the device, as that appears to what they are used for. Note that > for parisc, which is the only architecture this driver needs to use > non-coherent memory on, the direction argument of dma_cache_sync is > ignored, so this will not change behavior in any way. I think this looks mostly OK, except for one misnamed parameter below. Unfortunately, the last non-coherent parisc was the 700 series and I no longer own a box, so I can't test that part of it (I can fire up the C360 to test it on a coherent arch). [...] > diff --git a/drivers/scsi/53c700.h b/drivers/scsi/53c700.h > index 05fe439b66afe5..0f545b05fe611d 100644 > --- a/drivers/scsi/53c700.h > +++ b/drivers/scsi/53c700.h > @@ -209,6 +209,7 @@ struct NCR_700_Host_Parameters { > #endif > __u32 chip710:1; /* set if really a 710 not > 700 */ > __u32 burst_length:4; /* set to 0 to disable > 710 bursting */ > + __u32 noncoherent:1; /* needs to use non- > coherent DMA */ > > /* NOTHING BELOW HERE NEEDS ALTERING */ > __u32 fast:1; /* if we can alter the > SCSI bus clock > @@ -429,7 +430,7 @@ struct NCR_700_Host_Parameters { > for(i=0; i< (sizeof(A_##symbol##_used) / sizeof(__u32)); > i++) { \ > __u32 val = > bS_to_cpu((script)[A_##symbol##_used[i]]) + da; \ > (script)[A_##symbol##_used[i]] = bS_to_host(val); \ > - dma_cache_sync((dev), > &(script)[A_##symbol##_used[i]], 4, DMA_TO_DEVICE); \ > + dma_sync_to_dev((dev), > &(script)[A_##symbol##_used[i]], 4); \ > DEBUG((" script, patching %s at %d to %pad\n", \ > #symbol, A_##symbol##_used[i], &da)); \ > } \ > @@ -441,7 +442,7 @@ struct NCR_700_Host_Parameters { > dma_addr_t da = value; \ > for(i=0; i< (sizeof(A_##symbol##_used) / sizeof(__u32)); > i++) { \ > (script)[A_##symbol##_used[i]] = bS_to_host(da); \ > - dma_cache_sync((dev), > &(script)[A_##symbol##_used[i]], 4, DMA_TO_DEVICE); \ > + dma_sync_to_dev((dev), > &(script)[A_##symbol##_used[i]], 4); \ > DEBUG((" script, patching %s at %d to %pad\n", \ > #symbol, A_##symbol##_used[i], &da)); \ > } \ > @@ -456,7 +457,7 @@ struct NCR_700_Host_Parameters { > val &= 0xff00ffff; \ > val |= ((value) & 0xff) << 16; \ > (script)[A_##symbol##_used[i]] = bS_to_host(val); \ > - dma_cache_sync((dev), > &(script)[A_##symbol##_used[i]], 4, DMA_TO_DEVICE); \ > + dma_sync_to_dev((dev), > &(script)[A_##symbol##_used[i]], 4); \ > DEBUG((" script, patching ID field %s at %d to > 0x%x\n", \ > #symbol, A_##symbol##_used[i], val)); \ > } \ > @@ -470,7 +471,7 @@ struct NCR_700_Host_Parameters { > val &= 0xffff0000; \ > val |= ((value) & 0xffff); \ > (script)[A_##symbol##_used[i]] = bS_to_host(val); \ > - dma_cache_sync((dev), > &(script)[A_##symbol##_used[i]], 4, DMA_TO_DEVICE); \ > + dma_sync_to_dev((dev), > &(script)[A_##symbol##_used[i]], 4); \ > DEBUG((" script, patching short field %s at %d to > 0x%x\n", \ > #symbol, A_##symbol##_used[i], val)); \ > } \ These macro arguments need updating. Since you changed the input from hostdata->dev to hostdata, leaving the macro argument as dev is simply misleading. It needs to become hostdata or h. James