Re: [Xen-devel] [PATCH][Linux] gnttab: make dma address conversion logic of gnttab dma arch specific.

[Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>]

I don't spot a sign-off on this specific patch. Apart from that, I'll check
it in when Herbert acks it.

 -- Keir

On 11/6/07 08:35, "Isaku Yamahata" <yamahata@xxxxxxxxxxxxx> wrote:

> This patch is cleaned up of the patch which was sent as
> http://lists.xensource.com/archives/html/xen-devel/2007-06/msg00324.html
> 
> # HG changeset patch
> # User yamahata@xxxxxxxxxxxxx
> # Date 1181545986 -32400
> # Node ID 69e2dd4e06c405a92717c5f1818f5096e1dc0bcd
> # Parent  d5e0eb7dd069c0ffc1854da81aa143ccfb0ad66e
> make dma address conversion logic of gnttab dma arch specific.
> gnttab_dma_map_page() and gnttab_dma_unmap_page() uses machine address
> with dma address interchangebly.
> However it doesn't work with auto translated mode enabled (i.e. on ia64)
> because
> 
> - bus address space(dma_addr_t) is different from machine address
>   space(maddr_t).
>   With the terminology in xen/include/public/mm.h,
>   dma_addr_t is maddr and maddr_t is gmaddr.
>   So they should be handled differently with auto translated physmap mode
>   enabled.
> 
> - dma address conversion depends on dma api implementation and
>   its paravirtualization.
>   "pfn_valid(mfn_to_local_pfn(maddr >> PAGE_SHIFT)" check in
>   gnttab_dma_map_page() doesn't make sense with auto translate physmap
>   mode enabled.
> 
> To address those issues, split those logic from gnttab_dma_map_page() and
> gnttab_dma_unmap_page(), and put it into arch specific files.
> This patch doesn't change the already existing x86 logic.
> 
> PATCHNAME: make_dma_address_conversion_logic_of_gnttab_dma_arch_specific
> 
> diff -r d5e0eb7dd069 -r 69e2dd4e06c4 arch/i386/kernel/pci-dma-xen.c
> --- a/arch/i386/kernel/pci-dma-xen.c Sun Jun 10 19:50:32 2007 +0100
> +++ b/arch/i386/kernel/pci-dma-xen.c Mon Jun 11 16:13:06 2007 +0900
> @@ -19,6 +19,7 @@
>  #include <asm/swiotlb.h>
>  #include <asm/tlbflush.h>
>  #include <asm-i386/mach-xen/asm/swiotlb.h>
> +#include <asm-i386/mach-xen/asm/gnttab_dma.h>
>  #include <asm/bug.h>
>  
>  #ifdef __x86_64__
> @@ -58,6 +59,12 @@ static int __init pci_iommu_init(void)
>  /* Must execute after PCI subsystem */
>  fs_initcall(pci_iommu_init);
>  #endif
> +
> +/* this should be in somewhere appropriate */
> +int gnttab_dma_local_pfn(struct page *page)
> +{
> + return pfn_valid(mfn_to_local_pfn(pfn_to_mfn(page_to_pfn(page))));
> +}
>  
>  struct dma_coherent_mem {
> void  *virt_base;
> diff -r d5e0eb7dd069 -r 69e2dd4e06c4 arch/i386/kernel/swiotlb.c
> --- a/arch/i386/kernel/swiotlb.c Sun Jun 10 19:50:32 2007 +0100
> +++ b/arch/i386/kernel/swiotlb.c Mon Jun 11 16:13:06 2007 +0900
> @@ -27,6 +27,7 @@
>  #include <asm/uaccess.h>
>  #include <xen/gnttab.h>
>  #include <xen/interface/memory.h>
> +#include <asm-i386/mach-xen/asm/gnttab_dma.h>
>  
>  int swiotlb;
>  EXPORT_SYMBOL(swiotlb);
> diff -r d5e0eb7dd069 -r 69e2dd4e06c4 drivers/xen/core/gnttab.c
> --- a/drivers/xen/core/gnttab.c Sun Jun 10 19:50:32 2007 +0100
> +++ b/drivers/xen/core/gnttab.c Mon Jun 11 16:13:06 2007 +0900
> @@ -593,20 +593,18 @@ EXPORT_SYMBOL(gnttab_copy_grant_page);
>   *
>   * All other pages are simply returned as is.
>   */
> -maddr_t gnttab_dma_map_page(struct page *page)
> -{
> - maddr_t maddr = page_to_bus(page);
> +void __gnttab_dma_map_page(struct page *page,
> +      int (*local_pfn)(struct page *page))
> +{
> unsigned int seq;
>  
> - if (!PageForeign(page))
> -  return maddr;
> + if (!is_running_on_xen() || !PageForeign(page))
> +  return;
>  
> do {
> seq = read_seqbegin(&gnttab_dma_lock);
> -  maddr = page_to_bus(page);
> -
> -  /* Has it become a local MFN? */
> -  if (pfn_valid(mfn_to_local_pfn(maddr >> PAGE_SHIFT)))
> +
> +  if (local_pfn && (*local_pfn)(page))
> break;
>  
> atomic_set(&page->_mapcount, 0);
> @@ -614,8 +612,6 @@ maddr_t gnttab_dma_map_page(struct page
> /* Make _mapcount visible before read_seqretry. */
> smp_mb();
> } while (unlikely(read_seqretry(&gnttab_dma_lock, seq)));
> -
> - return maddr;
>  }
>  
>  int gnttab_resume(void)
> diff -r d5e0eb7dd069 -r 69e2dd4e06c4
> include/asm-i386/mach-xen/asm/gnttab_dma.h
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/include/asm-i386/mach-xen/asm/gnttab_dma.h Mon Jun 11 16:13:06 2007
> +0900
> @@ -0,0 +1,37 @@
> +/*
> + * Copyright (c) 2007 Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> + * Copyright (c) 2007 Isaku Yamahata <yamahata at valinux co jp>
> + *                    VA Linux Systems Japan K.K.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> + */
> +
> +#ifndef _ASM_I386_GNTTAB_DMA_H
> +#define _ASM_I386_GNTTAB_DMA_H
> +
> +int gnttab_dma_local_pfn(struct page *page);
> +
> +static inline maddr_t gnttab_dma_map_page(struct page *page)
> +{
> + __gnttab_dma_map_page(page, &gnttab_dma_local_pfn);
> + return page_to_bus(page);
> +}
> +
> +static inline void gnttab_dma_unmap_page(maddr_t maddr)
> +{
> + __gnttab_dma_unmap_page(virt_to_page(bus_to_virt(maddr)));
> +}
> +
> +#endif /* _ASM_I386_GNTTAB_DMA_H */
> diff -r d5e0eb7dd069 -r 69e2dd4e06c4 include/asm-ia64/gnttab_dma.h
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/include/asm-ia64/gnttab_dma.h Mon Jun 11 16:13:06 2007 +0900
> @@ -0,0 +1,46 @@
> +/*
> + * Copyright (c) 2007 Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> + * Copyright (c) 2007 Isaku Yamahata <yamahata at valinux co jp>
> + *                    VA Linux Systems Japan K.K.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> + */
> +
> +#ifndef _ASM_IA64_GNTTAB_DMA_H
> +#define _ASM_IA64_GNTTAB_DMA_H
> +
> +/* caller must get dma address after calling this function */
> +static inline void gnttab_dma_use_page(struct page *page)
> +{
> + __gnttab_dma_map_page(page, NULL);
> +}
> +
> +static inline dma_addr_t gnttab_dma_map_page(struct page *page)
> +{
> + gnttab_dma_use_page(page);
> + return page_to_bus(page);
> +}
> +
> +static inline dma_addr_t gnttab_dma_map_virt(void *ptr)
> +{
> + return gnttab_dma_map_page(virt_to_page(ptr)) + offset_in_page(ptr);
> +}
> +
> +static inline void gnttab_dma_unmap_page(dma_addr_t dma_address)
> +{
> + __gnttab_dma_unmap_page(virt_to_page(bus_to_virt(dma_address)));
> +}
> +
> +#endif /* _ASM_IA64_GNTTAB_DMA_H */
> diff -r d5e0eb7dd069 -r 69e2dd4e06c4 include/xen/gnttab.h
> --- a/include/xen/gnttab.h Sun Jun 10 19:50:32 2007 +0100
> +++ b/include/xen/gnttab.h Mon Jun 11 16:13:06 2007 +0900
> @@ -103,9 +103,9 @@ void gnttab_grant_foreign_transfer_ref(g
>       unsigned long pfn);
>  
>  int gnttab_copy_grant_page(grant_ref_t ref, struct page **pagep);
> -maddr_t gnttab_dma_map_page(struct page *page);
> -
> -static inline void gnttab_dma_unmap_page(maddr_t mfn)
> +void __gnttab_dma_map_page(struct page *page,
> +      int (*local_pfn)(struct page *page));
> +static inline void __gnttab_dma_unmap_page(struct page *page)
>  {
>  }
>  
> 



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