linux-kernel - Re: [PATCH] mtd: sh_flctl: pass FIFO as physical address

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20151219022737.GC109450@google.com>
Date:	Fri, 18 Dec 2015 18:27:37 -0800
From:	Brian Norris <computersforpeace@...il.com>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	linux-mtd@...ts.infradead.org,
	David Woodhouse <dwmw2@...radead.org>,
	Boris BREZILLON <boris.brezillon@...e-electrons.com>,
	Frans Klaver <fransklaver@...il.com>,
	Kuninori Morimoto <kuninori.morimoto.gx@...esas.com>,
	linux-kernel@...r.kernel.org, linux-sh@...r.kernel.org,
	Simon Horman <horms@...ge.net.au>,
	Magnus Damm <magnus.damm@...il.com>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH] mtd: sh_flctl: pass FIFO as physical address

On Tue, Dec 08, 2015 at 04:38:12PM +0100, Arnd Bergmann wrote:
> By convention, the FIFO address we pass using dmaengine_slave_config
> is a physical address in the form that is understood by the DMA
> engine, as a dma_addr_t, phys_addr_t or resource_size_t.
> 
> The sh_flctl driver however passes a virtual __iomem address that
> gets cast to dma_addr_t in the slave driver. This happens to work
> on shmobile because that platform sets up an identity mapping for
> its MMIO regions, but such code is not portable to other platforms,
> and prevents us from ever changing the platform mapping or reusing
> the driver on other architectures like ARM64 that might not have the
> mapping.
> 
> We also get a warning about a type mismatch for the case that
> dma_addr_t is wider than a pointer, i.e. when CONFIG_LPAE is set:
> 
> drivers/mtd/nand/sh_flctl.c: In function 'flctl_setup_dma':
> drivers/mtd/nand/sh_flctl.c:163:17: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
>   cfg.dst_addr = (dma_addr_t)FLDTFIFO(flctl);
> 
> This changes the driver to instead pass the physical address of
> the FIFO that is extracted from the MMIO resource, making the
> code more portable and avoiding the warning.
> 
> Signed-off-by: Arnd Bergmann <arnd@...db.de>

Applied
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/