lkml.org 
[lkml]   [2008]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 03/10] x86: add initialization code for DMA-API debugging
    On Sat, Nov 22, 2008 at 12:27:41PM +0900, FUJITA Tomonori wrote:
    > On Fri, 21 Nov 2008 17:26:03 +0100
    > Joerg Roedel <joerg.roedel@amd.com> wrote:
    >
    > > Impact: creates necessary data structures for DMA-API debugging
    > >
    > > Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
    > > ---
    > > arch/x86/include/asm/dma-mapping.h | 1 +
    > > arch/x86/include/asm/dma_debug.h | 14 +++++
    > > arch/x86/kernel/Makefile | 2 +
    > > arch/x86/kernel/pci-dma-debug.c | 111 ++++++++++++++++++++++++++++++++++++
    > > arch/x86/kernel/pci-dma.c | 2 +
    > > 5 files changed, 130 insertions(+), 0 deletions(-)
    > > create mode 100644 arch/x86/kernel/pci-dma-debug.c
    > >
    > > diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
    > > index 7f225a4..83d7b7d 100644
    > > --- a/arch/x86/include/asm/dma-mapping.h
    > > +++ b/arch/x86/include/asm/dma-mapping.h
    > > @@ -9,6 +9,7 @@
    > > #include <linux/scatterlist.h>
    > > #include <asm/io.h>
    > > #include <asm/swiotlb.h>
    > > +#include <asm/dma_debug.h>
    > > #include <asm-generic/dma-coherent.h>
    > >
    > > extern dma_addr_t bad_dma_address;
    > > diff --git a/arch/x86/include/asm/dma_debug.h b/arch/x86/include/asm/dma_debug.h
    > > index d79f024..f2c3d53 100644
    > > --- a/arch/x86/include/asm/dma_debug.h
    > > +++ b/arch/x86/include/asm/dma_debug.h
    > > @@ -38,4 +38,18 @@ struct dma_debug_entry {
    > > int direction;
    > > };
    > >
    > > +#ifdef CONFIG_DMA_API_DEBUG
    > > +
    > > +extern
    > > +void dma_debug_init(void);
    > > +
    > > +#else /* CONFIG_DMA_API_DEBUG */
    > > +
    > > +static inline
    > > +void dma_debug_init(void)
    > > +{
    > > +}
    > > +
    > > +#endif /* CONFIG_DMA_API_DEBUG */
    > > +
    > > #endif /* __ASM_X86_DMA_DEBUG */
    > > diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
    > > index e489ff9..6271cd2 100644
    > > --- a/arch/x86/kernel/Makefile
    > > +++ b/arch/x86/kernel/Makefile
    > > @@ -105,6 +105,8 @@ microcode-$(CONFIG_MICROCODE_INTEL) += microcode_intel.o
    > > microcode-$(CONFIG_MICROCODE_AMD) += microcode_amd.o
    > > obj-$(CONFIG_MICROCODE) += microcode.o
    > >
    > > +obj-$(CONFIG_DMA_API_DEBUG) += pci-dma-debug.o
    > > +
    > > ###
    > > # 64 bit specific files
    > > ifeq ($(CONFIG_X86_64),y)
    > > diff --git a/arch/x86/kernel/pci-dma-debug.c b/arch/x86/kernel/pci-dma-debug.c
    > > new file mode 100644
    > > index 0000000..c2d3408
    > > --- /dev/null
    > > +++ b/arch/x86/kernel/pci-dma-debug.c
    > > @@ -0,0 +1,111 @@
    > > +/*
    > > + * Copyright (C) 2008 Advanced Micro Devices, Inc.
    > > + *
    > > + * Author: Joerg Roedel <joerg.roedel@amd.com>
    > > + *
    > > + * This program is free software; you can redistribute it and/or modify it
    > > + * under the terms of the GNU General Public License version 2 as published
    > > + * by the Free Software Foundation.
    > > + *
    > > + * 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
    > > + */
    > > +
    > > +#include <linux/types.h>
    > > +#include <linux/scatterlist.h>
    > > +#include <linux/list.h>
    > > +#include <linux/slab.h>
    > > +#include <linux/spinlock.h>
    > > +#include <linux/module.h>
    > > +#include <linux/hardirq.h>
    > > +#include <linux/dma-mapping.h>
    > > +#include <asm/bug.h>
    > > +#include <asm/dma-mapping.h>
    > > +#include <asm/dma_debug.h>
    > > +
    > > +#define HASH_SIZE 256
    > > +#define HASH_FN_SHIFT 20
    > > +#define HASH_FN_MASK 0xffULL
    > > +
    > > +/* Hash list to save the allocated dma addresses */
    > > +static struct list_head dma_entry_hash[HASH_SIZE];
    > > +
    > > +/* A slab cache to allocate dma_map_entries fast */
    > > +static struct kmem_cache *dma_entry_cache;
    > > +
    > > +/* lock to protect the data structures */
    > > +static DEFINE_SPINLOCK(dma_lock);
    > > +
    > > +static int hash_fn(struct dma_debug_entry *entry)
    > > +{
    > > + /*
    > > + * Hash function is based on the dma address.
    > > + * We use bits 20-27 here as the index into the hash
    > > + */
    > > + BUG_ON(entry->dev_addr == bad_dma_address);
    >
    > 'bad_dma_address' is x86 specific. You already found it though.

    Interesting. Is there another value for dma_addr_t which drivers can
    check for to find out if a dma-api operation failed?

    Joerg


    \
     
     \ /
      Last update: 2008-11-22 10:43    [W:0.031 / U:0.340 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site