If HW IOMMU initialization fails (Intel VT-d often does this,
typically due to BIOS bugs), we fall back to nommu. It doesn't
work for the majority since nowadays we have more than 4GB
memory so we must use swiotlb instead of nommu.
The problem is that it's too late to initialize swiotlb when HW
IOMMU initialization fails. We need to allocate swiotlb memory
earlier from bootmem allocator. Chris explained the issue in
detail:
http://marc.info/?l=linux-kernel&m=125657444317079&w=2
The current x86 IOMMU initialization sequence is too complicated
and handling the above issue makes it more hacky.
This patch changes x86 IOMMU initialization sequence to handle
the above issue cleanly.
The new x86 IOMMU initialization sequence are:
1. we initialize the swiotlb (and setting swiotlb to 1) in the case
of (max_pfn > MAX_DMA32_PFN && !no_iommu). dma_ops is set to
swiotlb_dma_ops or nommu_dma_ops. if swiotlb usage is forced by
the boot option, we finish here.
2. we call the detection functions of all the IOMMUs
3. the detection function sets x86_init.iommu.iommu_init to the
IOMMU initialization function (so we can avoid calling the
initialization functions of all the IOMMUs needlessly).
4. if the IOMMU initialization function doesn't need to swiotlb
then sets swiotlb to zero (e.g. the initialization is
sucessful).
5. if we find that swiotlb is set to zero, we free swiotlb
resource.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: chrisw@sous-sol.org
Cc: dwmw2@infradead.org
Cc: joerg.roedel@amd.com
Cc: muli@il.ibm.com
LKML-Reference: <1257849980-22640-10-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
swiotlb_full() in lib/swiotlb.c throws one of two panic messages
based on whether the direction of transfer is from the device
or to the device. The logic around this is somewhat weird in
the case of bidirectional transfers. It appears to want to
throw both in succession, but since its a panic only the first
makes it.
This patch adds a third, separate error for DMA_BIDIRECTIONAL
to make things a bit clearer.
Signed-off-by: Casey Dahlin <cdahlin@redhat.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Becky Bruce <beckyb@kernel.crashing.org>
[ further fixed the error message ]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <200908202327.n7KNRuqK001504@imap1.linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This converts swiotlb to use phys_to_dma and dma_to_phys instead of
swiotlb_phys_to_bus() and swiotlb_bus_to_phys().
swiotlb_phys_to_bus() and swiotlb_bus_to_phys() are not necessary so
this patch also removes them.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
This converts swiotlb to use dma_capable() instead of
swiotlb_arch_address_needs_mapping() and is_buffer_dma_capable().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
Scatterlists containing HighMem pages do not have a useful virtual
address. Use the physical address instead.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The swiotlb_arch_range_needs_mapping() hook should take a physical
address rather than a virtual address in order to support highmem pages.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: fix rcutorture bug
rcu: eliminate synchronize_rcu_xxx macro
rcu: make treercu safe for suspend and resume
rcu: fix rcutree grace-period-latency bug on small systems
futex: catch certain assymetric (get|put)_futex_key calls
futex: make futex_(get|put)_key() calls symmetric
locking, percpu counters: introduce separate lock classes
swiotlb: clean up EXPORT_SYMBOL usage
swiotlb: remove unnecessary declaration
swiotlb: replace architecture-specific swiotlb.h with linux/swiotlb.h
swiotlb: add support for systems with highmem
swiotlb: store phys address in io_tlb_orig_addr array
swiotlb: add hwdev to swiotlb_phys_to_bus() / swiotlb_sg_to_bus()
This adds swiotlb_map_page and swiotlb_unmap_page to lib/swiotlb.c and
remove IA64 and X86's swiotlb_map_page and swiotlb_unmap_page.
This also removes unnecessary swiotlb_map_single, swiotlb_map_single_attrs,
swiotlb_unmap_single and swiotlb_unmap_single_attrs.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
FUJITA Tomonori
Casey Dahlin
Becky Bruce
Yang Hongyang
Ian Campbell
Ingo Molnar
Linus Torvalds
Kay Sievers