From mboxrd@z Thu Jan 1 00:00:00 1970 From: Beniamino Galvani Date: Mon, 18 Apr 2016 23:38:40 +0200 Subject: [U-Boot] [PATCH v4 1/3] net: designware: fix descriptor layout and warnings on 64-bit archs In-Reply-To: <5714BFBD.40906@suse.de> References: <1460879338-7671-1-git-send-email-b.galvani@gmail.com> <1460879338-7671-2-git-send-email-b.galvani@gmail.com> <57135DEA.4000609@denx.de> <20160417111422.GA10689@gmail.com> <5713F91F.4040206@denx.de> <20160418105711.GA2286@gmail.com> <5714BFBD.40906@suse.de> Message-ID: <20160418213840.GA3707@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Mon, Apr 18, 2016 at 01:06:37PM +0200, Alexander Graf wrote: > Hmm, this is going to get very interesting with efi_loader support. By > default we allocate memory at the highest possible free address, so payloads > will probably (unless they specify limits) have their buffers above 32bit on > this platform. If we now deny any DMA to them, we basically break I/O > access. I'm not familiar with efi_loader, but on this platform the physical RAM is within the 32bit memory range, so I don't think a workaround is needed. And I guess probably it's the same for the other 64bit ARM SoC using this driver. BTW, I see that another driver (sunxi_mmc) also truncates the upper 32 bits of addresses on 64bit platforms. Maybe this issue should be addresses in a generic way? > Could you by any chance just use a bounce buffer? Do you have any suggestions on how to do it? Are there any primitives in u-boot to request memory from low addresses? Beniamino