Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756511Ab3I3PfV (ORCPT ); Mon, 30 Sep 2013 11:35:21 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:50203 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756070Ab3I3PfT (ORCPT ); Mon, 30 Sep 2013 11:35:19 -0400 Date: Mon, 30 Sep 2013 11:34:48 -0400 From: Konrad Rzeszutek Wilk To: Stefano Stabellini Cc: xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Ian.Campbell@citrix.com Subject: Re: [PATCH v6 11/19] swiotlb-xen: use xen_alloc/free_coherent_pages Message-ID: <20130930153448.GR3106@phenom.dumpdata.com> References: <1380298207-29151-11-git-send-email-stefano.stabellini@eu.citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1380298207-29151-11-git-send-email-stefano.stabellini@eu.citrix.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8655 Lines: 225 On Fri, Sep 27, 2013 at 05:09:59PM +0100, Stefano Stabellini wrote: > Use xen_alloc_coherent_pages and xen_free_coherent_pages to allocate or > free coherent pages. > > We need to be careful handling the pointer returned by > xen_alloc_coherent_pages, because on ARM the pointer is not equal to > phys_to_virt(*dma_handle). In fact virt_to_phys only works for kernel > direct mapped RAM memory. > In ARM case the pointer could be an ioremap address, therefore passing > it to virt_to_phys would give you another physical address that doesn't > correspond to it. > > Make xen_create_contiguous_region take a phys_addr_t as start parameter to > avoid the virt_to_phys calls which would be incorrect. > > Changes in v6: > - remove extra spaces. > > Signed-off-by: Stefano Stabellini Reviewed-by: Konrad Rzeszutek Wilk > --- > arch/arm/xen/mm.c | 7 +++---- > arch/x86/xen/mmu.c | 7 +++++-- > drivers/xen/swiotlb-xen.c | 31 +++++++++++++++++++++---------- > include/xen/xen-ops.h | 4 ++-- > 4 files changed, 31 insertions(+), 18 deletions(-) > > diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c > index 4330b15..b305b94 100644 > --- a/arch/arm/xen/mm.c > +++ b/arch/arm/xen/mm.c > @@ -55,11 +55,10 @@ static int xen_exchange_memory(xen_ulong_t extents_in, > return success; > } > > -int xen_create_contiguous_region(unsigned long vstart, unsigned int order, > +int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, > unsigned int address_bits, > dma_addr_t *dma_handle) > { > - phys_addr_t pstart = __pa(vstart); > xen_pfn_t in_frame, out_frame; > int success; > > @@ -78,9 +77,9 @@ int xen_create_contiguous_region(unsigned long vstart, unsigned int order, > } > EXPORT_SYMBOL_GPL(xen_create_contiguous_region); > > -void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order) > +void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) > { > - xen_pfn_t in_frame = __pa(vstart) >> PAGE_SHIFT; > + xen_pfn_t in_frame = pstart >> PAGE_SHIFT; > struct xen_unpin unpin = { > .in = { > .nr_extents = 1, > diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c > index 6c34d7c..8830883 100644 > --- a/arch/x86/xen/mmu.c > +++ b/arch/x86/xen/mmu.c > @@ -2328,13 +2328,14 @@ static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in, > return success; > } > > -int xen_create_contiguous_region(unsigned long vstart, unsigned int order, > +int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, > unsigned int address_bits, > dma_addr_t *dma_handle) > { > unsigned long *in_frames = discontig_frames, out_frame; > unsigned long flags; > int success; > + unsigned long vstart = (unsigned long)phys_to_virt(pstart); > > /* > * Currently an auto-translated guest will not perform I/O, nor will > @@ -2374,11 +2375,12 @@ int xen_create_contiguous_region(unsigned long vstart, unsigned int order, > } > EXPORT_SYMBOL_GPL(xen_create_contiguous_region); > > -void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order) > +void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) > { > unsigned long *out_frames = discontig_frames, in_frame; > unsigned long flags; > int success; > + unsigned long vstart; > > if (xen_feature(XENFEAT_auto_translated_physmap)) > return; > @@ -2386,6 +2388,7 @@ void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order) > if (unlikely(order > MAX_CONTIG_ORDER)) > return; > > + vstart = (unsigned long)phys_to_virt(pstart); > memset((void *) vstart, 0, PAGE_SIZE << order); > > spin_lock_irqsave(&xen_reservation_lock, flags); > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c > index deb9131..96ad316 100644 > --- a/drivers/xen/swiotlb-xen.c > +++ b/drivers/xen/swiotlb-xen.c > @@ -46,6 +46,7 @@ > #include > #include > #include > +#include > > /* > * Used to do a quick range check in swiotlb_tbl_unmap_single and > @@ -244,6 +245,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) > { > int i, j, rc; > int dma_bits; > + phys_addr_t p = virt_to_phys(buf); > > dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT; > > @@ -253,7 +255,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) > > do { > rc = xen_create_contiguous_region( > - (unsigned long)buf + (i << IO_TLB_SHIFT), > + p + (i << IO_TLB_SHIFT), > get_order(slabs << IO_TLB_SHIFT), > dma_bits, &xen_dma_seg[j].dma_addr); > } while (rc && dma_bits++ < max_dma_bits); > @@ -389,7 +391,6 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, > void *ret; > int order = get_order(size); > u64 dma_mask = DMA_BIT_MASK(32); > - unsigned long vstart; > phys_addr_t phys; > dma_addr_t dev_addr; > struct xen_dma_info *dma_info = NULL; > @@ -405,8 +406,12 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, > if (dma_alloc_from_coherent(hwdev, size, dma_handle, &ret)) > return ret; > > - vstart = __get_free_pages(flags, order); > - ret = (void *)vstart; > + /* On ARM this function returns an ioremap'ped virtual address for > + * which virt_to_phys doesn't return the corresponding physical > + * address. In fact on ARM virt_to_phys only works for kernel direct > + * mapped RAM memory. Also see comment below. > + */ > + ret = xen_alloc_coherent_pages(hwdev, size, dma_handle, flags, attrs); > > if (!ret) > return ret; > @@ -414,16 +419,20 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, > if (hwdev && hwdev->coherent_dma_mask) > dma_mask = dma_alloc_coherent_mask(hwdev, flags); > > - phys = virt_to_phys(ret); > + /* At this point dma_handle is the physical address, next we are > + * going to set it to the machine address. > + * Do not use virt_to_phys(ret) because on ARM it doesn't correspond > + * to *dma_handle. */ > + phys = *dma_handle; > dev_addr = xen_phys_to_bus(phys); > if (!xen_feature(XENFEAT_auto_translated_physmap) && > ((dev_addr + size - 1 <= dma_mask)) && > !range_straddles_page_boundary(phys, size)) > *dma_handle = dev_addr; > else { > - if (xen_create_contiguous_region(vstart, order, > + if (xen_create_contiguous_region(phys, order, > fls64(dma_mask), dma_handle) != 0) { > - free_pages(vstart, order); > + xen_free_coherent_pages(hwdev, size, ret, (dma_addr_t)phys, attrs); > return NULL; > } > > @@ -463,18 +472,20 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, > if (hwdev && hwdev->coherent_dma_mask) > dma_mask = hwdev->coherent_dma_mask; > > - phys = virt_to_phys(vaddr); > + /* do not use virt_to_phys because on ARM it doesn't return you the > + * physical address */ > + phys = xen_bus_to_phys(dev_addr); > > if (xen_feature(XENFEAT_auto_translated_physmap) || > (((dev_addr + size - 1 > dma_mask)) || > range_straddles_page_boundary(phys, size))) { > - xen_destroy_contiguous_region((unsigned long)vaddr, order); > + xen_destroy_contiguous_region(phys, order); > dma_info = xen_get_dma_info_from_dma(dev_addr); > rb_erase(&dma_info->rbnode, &bus_to_phys); > kfree(dma_info); > } > > - free_pages((unsigned long)vaddr, order); > + xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs); > } > EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent); > > diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h > index 9ef704d..fb2ea8f 100644 > --- a/include/xen/xen-ops.h > +++ b/include/xen/xen-ops.h > @@ -19,11 +19,11 @@ void xen_arch_resume(void); > int xen_setup_shutdown_event(void); > > extern unsigned long *xen_contiguous_bitmap; > -int xen_create_contiguous_region(unsigned long vstart, unsigned int order, > +int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, > unsigned int address_bits, > dma_addr_t *dma_handle); > > -void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order); > +void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order); > > struct vm_area_struct; > int xen_remap_domain_mfn_range(struct vm_area_struct *vma, > -- > 1.7.2.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/