From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Fleming Subject: Re: [PATCH v2 1/2] efi: esrt: use memremap not ioremap to access ESRT table in memory Date: Thu, 18 Feb 2016 10:44:07 +0000 Message-ID: <20160218104407.GC2651@codeblueprint.co.uk> References: <1455535953-5056-1-git-send-email-ard.biesheuvel@linaro.org> <1455535953-5056-2-git-send-email-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1455535953-5056-2-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ard Biesheuvel Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, leif.lindholm-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, tbaicar-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org List-Id: linux-efi@vger.kernel.org On Mon, 15 Feb, at 12:32:32PM, Ard Biesheuvel wrote: > On ARM and arm64, ioremap() and memremap() are not interchangeable like > on x86, and the use of ioremap() on ordinary RAM is typically flagged > as an error if the memory region being mapped is also covered by the > linear mapping, since that would lead to aliases with conflicting > cacheability attributes. > > Since what we are dealing with is not an I/O region with side effects, > using ioremap() here is arguably incorrect anyway, so let's replace > it with memremap instead. Also add a missing unmap on the success path, > and drop a memblock_remove() call which does not belong here, this far > into the boot sequence. > > Cc: Peter Jones > Signed-off-by: Ard Biesheuvel > --- > drivers/firmware/efi/esrt.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > [...] > @@ -432,8 +434,6 @@ static int __init esrt_sysfs_init(void) > if (error) > goto err_cleanup_list; > > - memblock_remove(esrt_data, esrt_data_size); > - > pr_debug("esrt-sysfs: loaded.\n"); > > return 0; Shouldn't we be replacing memblock_remove() with free_bootmem_late()? The original ESRT region is still reserved at this point, so we should do our best to release it to the page allocator.