From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH/RFC 4/6] mm: Add NO_DMA dummies for DMA pool API Date: Tue, 6 Feb 2018 12:47:56 +0000 Message-ID: <61f0970a-c0aa-9b6f-74c7-d63be1e477ac@arm.com> References: <1517912092-15470-1-git-send-email-geert@linux-m68k.org> <1517912092-15470-5-git-send-email-geert@linux-m68k.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1517912092-15470-5-git-send-email-geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org> Content-Language: en-GB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Geert Uytterhoeven , Christoph Hellwig , Marek Szyprowski , Arnd Bergmann , Mark Brown , Richard Weinberger Cc: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Felipe Balbi , "James E . J . Bottomley" , linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Martin K . Petersen" , Greg Kroah-Hartman , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: iommu@lists.linux-foundation.org Hi Geert, On 06/02/18 10:14, Geert Uytterhoeven wrote: > Add dummies for dma{,m}_pool_{create,destroy,alloc,free}(), to allow > compile-testing if NO_DMA=y. > > This prevents the following from showing up later: > > ERROR: "dma_pool_destroy" [drivers/usb/mtu3/mtu3.ko] undefined! > ERROR: "dma_pool_free" [drivers/usb/mtu3/mtu3.ko] undefined! > ERROR: "dma_pool_alloc" [drivers/usb/mtu3/mtu3.ko] undefined! > ERROR: "dma_pool_create" [drivers/usb/mtu3/mtu3.ko] undefined! > ERROR: "dma_pool_destroy" [drivers/scsi/hisi_sas/hisi_sas_main.ko] undefined! > ERROR: "dma_pool_free" [drivers/scsi/hisi_sas/hisi_sas_main.ko] undefined! > ERROR: "dma_pool_alloc" [drivers/scsi/hisi_sas/hisi_sas_main.ko] undefined! > ERROR: "dma_pool_create" [drivers/scsi/hisi_sas/hisi_sas_main.ko] undefined! > ERROR: "dma_pool_alloc" [drivers/mailbox/bcm-pdc-mailbox.ko] undefined! > ERROR: "dma_pool_free" [drivers/mailbox/bcm-pdc-mailbox.ko] undefined! > ERROR: "dma_pool_create" [drivers/mailbox/bcm-pdc-mailbox.ko] undefined! > ERROR: "dma_pool_destroy" [drivers/mailbox/bcm-pdc-mailbox.ko] undefined! > > Signed-off-by: Geert Uytterhoeven > --- > include/linux/dmapool.h | 21 +++++++++++++++++++-- > 1 file changed, 19 insertions(+), 2 deletions(-) > > diff --git a/include/linux/dmapool.h b/include/linux/dmapool.h > index 53ba737505df31c7..adeb5e56c3ad73a8 100644 > --- a/include/linux/dmapool.h > +++ b/include/linux/dmapool.h > @@ -16,6 +16,7 @@ > > struct device; > > +#ifdef CONFIG_HAS_DMA > struct dma_pool *dma_pool_create(const char *name, struct device *dev, > size_t size, size_t align, size_t allocation); > > @@ -23,6 +24,17 @@ void dma_pool_destroy(struct dma_pool *pool); > > void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, > dma_addr_t *handle); > +void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t addr); > +#else /* !CONFIG_HAS_DMA */ > +static inline struct dma_pool *dma_pool_create(const char *name, > + struct device *dev, size_t size, size_t align, size_t allocation) > +{ return NULL; } > +static inline void dma_pool_destroy(struct dma_pool *pool) { } > +static inline void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, > + dma_addr_t *handle) { return NULL; } > +static inline void dma_pool_free(struct dma_pool *pool, void *vaddr, > + dma_addr_t addr) { } > +#endif /* !CONFIG_HAS_DMA */ > > static inline void *dma_pool_zalloc(struct dma_pool *pool, gfp_t mem_flags, > dma_addr_t *handle) > @@ -30,14 +42,19 @@ static inline void *dma_pool_zalloc(struct dma_pool *pool, gfp_t mem_flags, > return dma_pool_alloc(pool, mem_flags | __GFP_ZERO, handle); > } > > -void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t addr); > - > /* > * Managed DMA pool > */ > +#ifdef CONFIG_HAS_DMA > struct dma_pool *dmam_pool_create(const char *name, struct device *dev, > size_t size, size_t align, size_t allocation); > void dmam_pool_destroy(struct dma_pool *pool); > +#else /* !CONFIG_HAS_DMA */ > +static inline struct dma_pool *dmam_pool_create(const char *name, > + struct device *dev, size_t size, size_t align, size_t allocation) > +{ return NULL; } > +static inline void dmam_pool_destroy(struct dma_pool *pool) { } > +#endif /* !CONFIG_HAS_DMA */ Nit: It might be tidier to add *all* the stubs down here so that there only need be a single #ifdef, then move the dma_pool_zalloc definition outside at the end (where we might eventually get rid of it anyway). Other than that, though, I think I agree with the series in general - more COMPILE_TEST is always good from the point of view of weeding out drivers using architecture-specific DMA API internals which aren't part of the proper generic interface. Robin. > > #endif > >