From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx179.postini.com [74.125.245.179]) by kanga.kvack.org (Postfix) with SMTP id 9D6AC6B0034 for ; Thu, 27 Jun 2013 07:42:47 -0400 (EDT) Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MP1004A5V70JG10@mailout3.w1.samsung.com> for linux-mm@kvack.org; Thu, 27 Jun 2013 12:42:45 +0100 (BST) Message-id: <51CC2530.2060605@samsung.com> Date: Thu, 27 Jun 2013 13:42:40 +0200 From: Marek Szyprowski MIME-version: 1.0 Subject: Re: [RFC PATCH 1/3] mm/cma: Move dma contiguous changes into a seperate config References: <1372062327-7028-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> In-reply-to: <1372062327-7028-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Content-type: text/plain; charset=UTF-8; format=flowed Content-transfer-encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, benh@kernel.crashing.org, paulus@samba.org, linuxppc-dev@lists.ozlabs.org, Michal Nazarewicz Hello, On 6/24/2013 10:25 AM, Aneesh Kumar K.V wrote: > From: "Aneesh Kumar K.V" > > We want to use CMA for allocating hash page table and real mode area for > PPC64. Hence move DMA contiguous related changes into a seperate config > so that ppc64 can enable CMA without requiring DMA contiguous. > > Signed-off-by: Aneesh Kumar K.V It's nice to see that CMA is gaining another client in mainline Linux kernel. I also like the idea of adding CONFIG_DMA_CMA for DMA-mapping related CMA use to let others to use alloc_contig_range() interface. However I noticed that You have almost copied the whole drivers/base.c for separate use with PPC64 KVM. Is this really necessary? I think it should be possible to isolate some common code, which plays with contiguous region management and use it for both alloc_contig_range() clients (dma-mapping and ppc64 kvm). > --- > arch/arm/configs/omap2plus_defconfig | 2 +- > arch/arm/configs/tegra_defconfig | 2 +- > arch/arm/include/asm/dma-contiguous.h | 2 +- > arch/arm/mm/dma-mapping.c | 6 +++--- > drivers/base/Kconfig | 21 +++++---------------- > drivers/base/Makefile | 2 +- > include/linux/dma-contiguous.h | 2 +- > mm/Kconfig | 20 ++++++++++++++++++++ > 8 files changed, 33 insertions(+), 24 deletions(-) > > diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig > index abbe319..098268f 100644 > --- a/arch/arm/configs/omap2plus_defconfig > +++ b/arch/arm/configs/omap2plus_defconfig > @@ -71,7 +71,7 @@ CONFIG_MAC80211=m > CONFIG_MAC80211_RC_PID=y > CONFIG_MAC80211_RC_DEFAULT_PID=y > CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug" > -CONFIG_CMA=y > +CONFIG_DMA_CMA=y > CONFIG_CONNECTOR=y > CONFIG_DEVTMPFS=y > CONFIG_DEVTMPFS_MOUNT=y > diff --git a/arch/arm/configs/tegra_defconfig b/arch/arm/configs/tegra_defconfig > index f7ba3161..34ae8f2 100644 > --- a/arch/arm/configs/tegra_defconfig > +++ b/arch/arm/configs/tegra_defconfig > @@ -79,7 +79,7 @@ CONFIG_RFKILL_GPIO=y > CONFIG_DEVTMPFS=y > CONFIG_DEVTMPFS_MOUNT=y > # CONFIG_FIRMWARE_IN_KERNEL is not set > -CONFIG_CMA=y > +CONFIG_DMA_CMA=y > CONFIG_MTD=y > CONFIG_MTD_CHAR=y > CONFIG_MTD_M25P80=y > diff --git a/arch/arm/include/asm/dma-contiguous.h b/arch/arm/include/asm/dma-contiguous.h > index 3ed37b4..e072bb2 100644 > --- a/arch/arm/include/asm/dma-contiguous.h > +++ b/arch/arm/include/asm/dma-contiguous.h > @@ -2,7 +2,7 @@ > #define ASMARM_DMA_CONTIGUOUS_H > > #ifdef __KERNEL__ > -#ifdef CONFIG_CMA > +#ifdef CONFIG_DMA_CMA > > #include > #include > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index ef3e0f3..1fb40dc 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -358,7 +358,7 @@ static int __init atomic_pool_init(void) > if (!pages) > goto no_pages; > > - if (IS_ENABLED(CONFIG_CMA)) > + if (IS_ENABLED(CONFIG_DMA_CMA)) > ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page, > atomic_pool_init); > else > @@ -670,7 +670,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, > addr = __alloc_simple_buffer(dev, size, gfp, &page); > else if (!(gfp & __GFP_WAIT)) > addr = __alloc_from_pool(size, &page); > - else if (!IS_ENABLED(CONFIG_CMA)) > + else if (!IS_ENABLED(CONFIG_DMA_CMA)) > addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller); > else > addr = __alloc_from_contiguous(dev, size, prot, &page, caller); > @@ -759,7 +759,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, > __dma_free_buffer(page, size); > } else if (__free_from_pool(cpu_addr, size)) { > return; > - } else if (!IS_ENABLED(CONFIG_CMA)) { > + } else if (!IS_ENABLED(CONFIG_DMA_CMA)) { > __dma_free_remap(cpu_addr, size); > __dma_free_buffer(page, size); > } else { > diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig > index 07abd9d..74b7c98 100644 > --- a/drivers/base/Kconfig > +++ b/drivers/base/Kconfig > @@ -202,11 +202,10 @@ config DMA_SHARED_BUFFER > APIs extension; the file's descriptor can then be passed on to other > driver. > > -config CMA > - bool "Contiguous Memory Allocator" > - depends on HAVE_DMA_CONTIGUOUS && HAVE_MEMBLOCK > - select MIGRATION > - select MEMORY_ISOLATION > +config DMA_CMA > + bool "DMA Contiguous Memory Allocator" > + depends on HAVE_DMA_CONTIGUOUS > + select CMA > help > This enables the Contiguous Memory Allocator which allows drivers > to allocate big physically-contiguous blocks of memory for use with > @@ -215,17 +214,7 @@ config CMA > For more information see . > If unsure, say "n". > > -if CMA > - > -config CMA_DEBUG > - bool "CMA debug messages (DEVELOPMENT)" > - depends on DEBUG_KERNEL > - help > - Turns on debug messages in CMA. This produces KERN_DEBUG > - messages for every CMA call as well as various messages while > - processing calls such as dma_alloc_from_contiguous(). > - This option does not affect warning and error messages. > - > +if DMA_CMA > comment "Default contiguous memory area size:" > > config CMA_SIZE_MBYTES > diff --git a/drivers/base/Makefile b/drivers/base/Makefile > index 4e22ce3..5d93bb5 100644 > --- a/drivers/base/Makefile > +++ b/drivers/base/Makefile > @@ -6,7 +6,7 @@ obj-y := core.o bus.o dd.o syscore.o \ > attribute_container.o transport_class.o \ > topology.o > obj-$(CONFIG_DEVTMPFS) += devtmpfs.o > -obj-$(CONFIG_CMA) += dma-contiguous.o > +obj-$(CONFIG_DMA_CMA) += dma-contiguous.o > obj-y += power/ > obj-$(CONFIG_HAS_DMA) += dma-mapping.o > obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o > diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h > index 01b5c84..00141d3 100644 > --- a/include/linux/dma-contiguous.h > +++ b/include/linux/dma-contiguous.h > @@ -57,7 +57,7 @@ struct cma; > struct page; > struct device; > > -#ifdef CONFIG_CMA > +#ifdef CONFIG_DMA_CMA > > /* > * There is always at least global CMA area and a few optional device > diff --git a/mm/Kconfig b/mm/Kconfig > index e742d06..b362369 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -477,3 +477,23 @@ config FRONTSWAP > and swap data is stored as normal on the matching swap device. > > If unsure, say Y to enable frontswap. > + > +config CMA > + bool "Contiguous Memory Allocator" > + depends on HAVE_MEMBLOCK > + select MIGRATION > + select MEMORY_ISOLATION > + help > + This enables the Contiguous Memory Allocator which allows other > + subsystem to allocate big physically-contiguous blocks of memory > + > + If unsure, say "n". > + > +config CMA_DEBUG > + bool "CMA debug messages (DEVELOPMENT)" > + depends on DEBUG_KERNEL && CMA > + help > + Turns on debug messages in CMA. This produces KERN_DEBUG > + messages for every CMA call as well as various messages while > + processing calls such as dma_alloc_from_contiguous(). > + This option does not affect warning and error messages. Best regards -- Marek Szyprowski Samsung R&D Institute Poland -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org