From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932260AbcHILvS (ORCPT ); Tue, 9 Aug 2016 07:51:18 -0400 Received: from foss.arm.com ([217.140.101.70]:41590 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751596AbcHILvR (ORCPT ); Tue, 9 Aug 2016 07:51:17 -0400 Subject: Re: [PATCH v3] arm64: mm: convert __dma_* routines to use start, size To: Kwangwoo Lee , Russell King - ARM Linux , Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org References: <1470099050-25407-1-git-send-email-kwangwoo.lee@sk.com> Cc: Woosuk Chung , Hyunchul Kim , linux-kernel@vger.kernel.org From: Robin Murphy Message-ID: <80a4602f-8105-fe2e-0f52-ee23f2c0b2e4@arm.com> Date: Tue, 9 Aug 2016 12:51:09 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <1470099050-25407-1-git-send-email-kwangwoo.lee@sk.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/08/16 01:50, Kwangwoo Lee wrote: > __dma_* routines have been converted to use start and size instread of > start and end addresses. The patch was origianlly for adding > __clean_dcache_area_poc() which will be used in pmem driver to clean > dcache to the PoC(Point of Coherency) in arch_wb_cache_pmem(). > > The functionality of __clean_dcache_area_poc() was equivalent to > __dma_clean_range(). The difference was __dma_clean_range() uses the end > address, but __clean_dcache_area_poc() uses the size to clean. > > Thus, __clean_dcache_area_poc() has been revised with a fallthrough > function of __dma_clean_range() after the change that __dma_* routines > use start and size instead of using start and end. > > As a consequence of using start and size, the name of __dma_* routines > has also been altered following the terminology below: > area: takes a start and size > range: takes a start and end This looks pretty nice and tidy now; I don't see anything obviously wrong, and comparing before-and-after disassemblies shows essentially nothing more than the movement of some add instructions as expected, so: Reviewed-by: Robin Murphy > Signed-off-by: Kwangwoo Lee > --- > v3) > clean up in __dma_clean_area() based on 823066d9edcd dcache_by_line_op fix > > v2) > change the names of __dma_* rountines to use area instead of range > fix to use __dma_flush_area() in dma-mapping.c > > v1) > change __dma_* routines to use start, size > add __clean_dcache_area_poc() as a fallthrough of __dma_clean_range() > > arch/arm64/include/asm/cacheflush.h | 3 +- > arch/arm64/mm/cache.S | 82 ++++++++++++++++++------------------- > arch/arm64/mm/dma-mapping.c | 6 +-- > 3 files changed, 44 insertions(+), 47 deletions(-) > > diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h > index c64268d..2e5fb97 100644 > --- a/arch/arm64/include/asm/cacheflush.h > +++ b/arch/arm64/include/asm/cacheflush.h > @@ -68,6 +68,7 @@ > extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end); > extern void flush_icache_range(unsigned long start, unsigned long end); > extern void __flush_dcache_area(void *addr, size_t len); > +extern void __clean_dcache_area_poc(void *addr, size_t len); > extern void __clean_dcache_area_pou(void *addr, size_t len); > extern long __flush_cache_user_range(unsigned long start, unsigned long end); > > @@ -85,7 +86,7 @@ static inline void flush_cache_page(struct vm_area_struct *vma, > */ > extern void __dma_map_area(const void *, size_t, int); > extern void __dma_unmap_area(const void *, size_t, int); > -extern void __dma_flush_range(const void *, const void *); > +extern void __dma_flush_area(const void *, size_t); > > /* > * Copy user data from/to a page which is mapped into a different > diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S > index 07d7352..58b5a90 100644 > --- a/arch/arm64/mm/cache.S > +++ b/arch/arm64/mm/cache.S > @@ -105,19 +105,20 @@ ENTRY(__clean_dcache_area_pou) > ENDPROC(__clean_dcache_area_pou) > > /* > - * __inval_cache_range(start, end) > - * - start - start address of region > - * - end - end address of region > + * __dma_inv_area(start, size) > + * - start - virtual start address of region > + * - size - size in question > */ > -ENTRY(__inval_cache_range) > +__dma_inv_area: > + add x1, x1, x0 > /* FALLTHROUGH */ > > /* > - * __dma_inv_range(start, end) > - * - start - virtual start address of region > - * - end - virtual end address of region > + * __inval_cache_range(start, end) > + * - start - start address of region > + * - end - end address of region > */ > -__dma_inv_range: > +ENTRY(__inval_cache_range) > dcache_line_size x2, x3 > sub x3, x2, #1 > tst x1, x3 // end cache line aligned? > @@ -136,46 +137,43 @@ __dma_inv_range: > dsb sy > ret > ENDPIPROC(__inval_cache_range) > -ENDPROC(__dma_inv_range) > +ENDPROC(__dma_inv_area) > + > +/* > + * __clean_dcache_area_poc(kaddr, size) > + * > + * Ensure that any D-cache lines for the interval [kaddr, kaddr+size) > + * are cleaned to the PoC. > + * > + * - kaddr - kernel address > + * - size - size in question > + */ > +ENTRY(__clean_dcache_area_poc) > + /* FALLTHROUGH */ > > /* > - * __dma_clean_range(start, end) > + * __dma_clean_area(start, size) > * - start - virtual start address of region > - * - end - virtual end address of region > + * - size - size in question > */ > -__dma_clean_range: > - dcache_line_size x2, x3 > - sub x3, x2, #1 > - bic x0, x0, x3 > -1: > -alternative_if_not ARM64_WORKAROUND_CLEAN_CACHE > - dc cvac, x0 > -alternative_else > - dc civac, x0 > -alternative_endif > - add x0, x0, x2 > - cmp x0, x1 > - b.lo 1b > - dsb sy > +__dma_clean_area: > + dcache_by_line_op cvac, sy, x0, x1, x2, x3 > ret > -ENDPROC(__dma_clean_range) > +ENDPIPROC(__clean_dcache_area_poc) > +ENDPROC(__dma_clean_area) > > /* > - * __dma_flush_range(start, end) > + * __dma_flush_area(start, size) > + * > + * clean & invalidate D / U line > + * > * - start - virtual start address of region > - * - end - virtual end address of region > + * - size - size in question > */ > -ENTRY(__dma_flush_range) > - dcache_line_size x2, x3 > - sub x3, x2, #1 > - bic x0, x0, x3 > -1: dc civac, x0 // clean & invalidate D / U line > - add x0, x0, x2 > - cmp x0, x1 > - b.lo 1b > - dsb sy > +ENTRY(__dma_flush_area) > + dcache_by_line_op civac, sy, x0, x1, x2, x3 > ret > -ENDPIPROC(__dma_flush_range) > +ENDPIPROC(__dma_flush_area) > > /* > * __dma_map_area(start, size, dir) > @@ -184,10 +182,9 @@ ENDPIPROC(__dma_flush_range) > * - dir - DMA direction > */ > ENTRY(__dma_map_area) > - add x1, x1, x0 > cmp w2, #DMA_FROM_DEVICE > - b.eq __dma_inv_range > - b __dma_clean_range > + b.eq __dma_inv_area > + b __dma_clean_area > ENDPIPROC(__dma_map_area) > > /* > @@ -197,8 +194,7 @@ ENDPIPROC(__dma_map_area) > * - dir - DMA direction > */ > ENTRY(__dma_unmap_area) > - add x1, x1, x0 > cmp w2, #DMA_TO_DEVICE > - b.ne __dma_inv_range > + b.ne __dma_inv_area > ret > ENDPIPROC(__dma_unmap_area) > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index f6c55af..88922e8 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -168,7 +168,7 @@ static void *__dma_alloc(struct device *dev, size_t size, > return ptr; > > /* remove any dirty cache lines on the kernel alias */ > - __dma_flush_range(ptr, ptr + size); > + __dma_flush_area(ptr, size); > > /* create a coherent mapping */ > page = virt_to_page(ptr); > @@ -387,7 +387,7 @@ static int __init atomic_pool_init(void) > void *page_addr = page_address(page); > > memset(page_addr, 0, atomic_pool_size); > - __dma_flush_range(page_addr, page_addr + atomic_pool_size); > + __dma_flush_area(page_addr, atomic_pool_size); > > atomic_pool = gen_pool_create(PAGE_SHIFT, -1); > if (!atomic_pool) > @@ -548,7 +548,7 @@ fs_initcall(dma_debug_do_init); > /* Thankfully, all cache ops are by VA so we can ignore phys here */ > static void flush_page(struct device *dev, const void *virt, phys_addr_t phys) > { > - __dma_flush_range(virt, virt + PAGE_SIZE); > + __dma_flush_area(virt, PAGE_SIZE); > } > > static void *__iommu_alloc_attrs(struct device *dev, size_t size, >