From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH] arm64: mm: make CONFIG_ZONE_DMA32 configurable Date: Tue, 28 May 2019 11:43:11 +0100 Message-ID: <814b9bd0-38de-4b8d-92b3-d663931d90bf@arm.com> References: <1558973315-19655-1-git-send-email-miles.chen@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1558973315-19655-1-git-send-email-miles.chen@mediatek.com> Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org To: Miles Chen , Catalin Marinas , Will Deacon Cc: linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, wsd_upstream@mediatek.com List-Id: linux-mediatek@lists.infradead.org On 27/05/2019 17:08, Miles Chen wrote: > This change makes CONFIG_ZONE_DMA32 defuly y and allows users > to overwrite it. > > For the SoCs that do not need CONFIG_ZONE_DMA32, this is the > first step to manage all available memory by a single > zone(normal zone) to reduce the overhead of multiple zones. > > The change also fixes a build error when CONFIG_NUMA=y and > CONFIG_ZONE_DMA32=n. > > arch/arm64/mm/init.c:195:17: error: use of undeclared identifier 'ZONE_DMA32' > max_zone_pfns[ZONE_DMA32] = PFN_DOWN(max_zone_dma_phys()); > > Signed-off-by: Miles Chen > --- > arch/arm64/Kconfig | 3 ++- > arch/arm64/mm/init.c | 2 ++ > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 76f6e4765f49..9d20a736d1d1 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -260,7 +260,8 @@ config GENERIC_CALIBRATE_DELAY > def_bool y > > config ZONE_DMA32 > - def_bool y > + bool "Support DMA32 zone" This probably warrants an "if EMBEDDED" or "if EXPERT", since turning it off produces a kernel which won't work at all on certain systems (I've played around with this before...) > + default y > > config HAVE_GENERIC_GUP > def_bool y > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index d2adffb81b5d..96829ce21f99 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -191,8 +191,10 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) > { > unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; > > +#ifdef CONFIG_ZONE_DMA32 > if (IS_ENABLED(CONFIG_ZONE_DMA32)) There's no point keeping the IS_ENABLED() check when it's entirely redundant with the #ifdefs. Robin. > max_zone_pfns[ZONE_DMA32] = PFN_DOWN(max_zone_dma_phys()); > +#endif > max_zone_pfns[ZONE_NORMAL] = max; > > free_area_init_nodes(max_zone_pfns); >