When domain is related to multiple iommus, need to check if the minimum agaw is sufficient for the mapped memory
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
vm_domid won't be set in context, find available domain id for a device from its iommu.
For a virtual machine domain, a default agaw will be set, and skip top levels of page tables for iommu which has less agaw than default.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
virtual machine domain is different from native DMA-API domain, implement separate allocation and free functions for virtual machine domain.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Because virtual machine domain may have multiple devices from different iommus, it cannot use __iommu_flush_cache.
In some common low level functions, use domain_flush_cache instead of __iommu_flush_cache. On the other hand, in some functions, iommu can is specified or domain cannot be got, still use __iommu_flush_cache
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Add iommu reference count in domain, and add a lock to protect iommu setting including iommu_bmp, iommu_count and iommu_coherency.
virtual machine domain may have multiple devices from different iommus, so it needs to do more things when add/remove domain device info. Thus implement separate these functions for virtual machine domain.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Add this flag for VT-d used in virtual machine, like KVM.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
In dmar_domain, more than one iommus may be included in iommu_bmp. Due to "Coherency" capability may be different across iommus, set this variable to indicate iommu access is coherent or not. Only when all related iommus in a dmar_domain are all coherent, iommu access of this domain is coherent.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
"SAGAW" capability may be different across iommus. Use a default agaw, but if default agaw is not supported in some iommus, choose a less supported agaw.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
In order to support assigning multiple devices from different iommus to a domain, iommu bitmap is used to keep all iommus the domain are related to.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
deferred_flush[] uses the iommu seq_id to index, so its iommu is fixed and can get it from g_iommus.
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
It's random number after the domain is allocated by kmem_cache_alloc
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Some macros were unused, so I just dropped them:
context_fault_disable
context_translation_type
context_address_root
context_address_width
context_domain_id
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
We keep the struct root_entry forward declaration for the
pointer in struct intel_iommu.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
init_dmars() is not used outside of drivers/pci/intel-iommu.c
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The seg, saved_msg and sysdev fields appear to be unused since
before the code was first merged.
linux/msi.h is not needed in linux/intel-iommu.h anymore since
there is no longer a reference to struct msi_msg. The MSI code
in drivers/pci/intel-iommu.c still has linux/msi.h included
via linux/dmar.h.
linux/sysdev.h isn't needed because there is no reference to
struct sys_device.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Impact: cleanup
I got the following warnings on IA64:
linux-2.6/drivers/pci/intel-iommu.c: In function 'init_dmars':
linux-2.6/drivers/pci/intel-iommu.c:1658: warning: format '%Lx' expects type 'long long unsigned int', but argument 2 has type 'u64'
linux-2.6/drivers/pci/intel-iommu.c:1663: warning: format '%Lx' expects type 'long long unsigned int', but argument 2 has type 'u64'
Another victim of int-ll64.h versus int-l64.h confusion between platforms.
->reg_base_addr has a type of u64 - which can only be printed out
consistently if we cast its type up to LL.
[ Eventually reg_base_addr should be converted to phys_addr_t, for which
we have the %pR printk helper - but that is out of the scope of late
-rc's. ]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix for a typo and and replacing incorrect word in the comment.
Signed-off-by: Ameya Palande <2ameya@gmail.com>
Cc: "Ashok Raj" <ashok.raj@intel.com>
Cc: "Shaohua Li" <shaohua.li@intel.com>
Cc: "Anil S Keshavamurthy" <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes intel-iommu to use dev->coherent_dma_mask in
alloc_coherent. Currently, intel-iommu uses dev->dma_mask in
alloc_coherent but alloc_coherent is supposed to use
coherent_dma_mask. It could break drivers that uses smaller
coherent_dma_mask than dma_mask (though the current code works for the
majority that use the same mask for coherent_dma_mask and dma_mask).
[dwmw2: dma_mask can be bigger than 'unsigned long']
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The current Intel IOMMU code assumes that both host page size and Intel
IOMMU page size are 4KiB. The first patch supports variable page size.
This provides support for IA64 which has multiple page sizes.
This patch also adds some other code hooks for IA64 platform including
DMAR_OPERATION_TIMEOUT definition.
[dwmw2: some cleanup]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
If queued invalidation interface is available and enabled, queued invalidation
interface will be used instead of the register based interface.
According to Vt-d2 specification, when queued invalidation is enabled,
invalidation command submit works only through invalidation queue and not
through the command registers interface.
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch extends the VT-d driver to support KVM
[Ben: fixed memory pinning]
[avi: move dma_remapping.h as well]
Signed-off-by: Kay, Allen M <allen.m.kay@intel.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Amit Shah <amit.shah@qumranet.com>
Acked-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (72 commits)
Revert "x86/PCI: ACPI based PCI gap calculation"
PCI: remove unnecessary volatile in PCIe hotplug struct controller
x86/PCI: ACPI based PCI gap calculation
PCI: include linux/pm_wakeup.h for device_set_wakeup_capable
PCI PM: Fix pci_prepare_to_sleep
x86/PCI: Fix PCI config space for domains > 0
Fix acpi_pm_device_sleep_wake() by providing a stub for CONFIG_PM_SLEEP=n
PCI: Simplify PCI device PM code
PCI PM: Introduce pci_prepare_to_sleep and pci_back_from_sleep
PCI ACPI: Rework PCI handling of wake-up
ACPI: Introduce new device wakeup flag 'prepared'
ACPI: Introduce acpi_device_sleep_wake function
PCI: rework pci_set_power_state function to call platform first
PCI: Introduce platform_pci_power_manageable function
ACPI: Introduce acpi_bus_power_manageable function
PCI: make pci_name use dev_name
PCI: handle pci_name() being const
PCI: add stub for pci_set_consistent_dma_mask()
PCI: remove unused arch pcibios_update_resource() functions
PCI: fix pci_setup_device()'s sprinting into a const buffer
...
Fixed up conflicts in various files (arch/x86/kernel/setup_64.c,
arch/x86/pci/irq.c, arch/x86/pci/pci.h, drivers/acpi/sleep/main.c,
drivers/pci/pci.c, drivers/pci/pci.h, include/acpi/acpi_bus.h) from x86
and ACPI updates manually.
Queued invalidation (part of Intel Virtualization Technology for
Directed I/O architecture) infrastructure.
This will be used for invalidating the interrupt entry cache in the
case of Interrupt-remapping and IOTLB invalidation in the case
of DMA-remapping.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Allocate the iommu during the parse of DMA remapping hardware
definition structures. And also, introduce routines for device
scope initialization which will be explicitly called during
dma-remapping initialization.
These will be used for enabling interrupt remapping separately from the
existing DMA-remapping enabling sequence.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Clean up the intel-iommu code related to deferred iommu flush logic. There is
no need to allocate all the iommu's as a sequential array.
This will be used later in the interrupt-remapping patch series to
allocate iommu much early and individually for each device remapping
hardware unit.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
code reorganization of the generic Intel vt-d parsing related routines and linux
iommu routines specific to Intel vt-d.
drivers/pci/dmar.c now contains the generic vt-d parsing related routines
drivers/pci/intel_iommu.c contains the iommu routines specific to vt-d
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
gart.h has only GART-specific stuff. Only GART code needs it. Other
IOMMU stuff should include iommu.h instead of gart.h.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
want to remove arch_get_ram_range, and use early_node_map instead.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The destination of goto error also does a kfree(g_iommus), so it is not
correct to do one here.
This was found using Coccinelle (http://www.emn.fr/x-info/coccinelle/).
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The following patch changes the intel-iommu.c code to use the TSC
instead of jiffies for detecting bad DMAR functionality. Some systems
with bad bios's have been seen to hang in early boot spinning in the
IOMMU_WAIT_IO macro. This patch will replace the infinite loop with a call to
panic.
Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Stephen Rothwell noticed that:
Commit 2be621498d ("x86: dma-ops on highmem
fix") in Linus' tree introduced a new warning (noticed in the x86_64
allmodconfig build of linux-next):
drivers/pci/intel-iommu.c:2240: warning: initialization from incompatible pointer type
Which points at an instance of map_single that needs updating.
Fix it to the new prototype.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The following patch is an update to use an array instead of a list of
IOVA's in the implementation of defered iotlb flushes. It takes
inspiration from sba_iommu.c
I like this implementation better as it encapsulates the batch process
within intel-iommu.c, and no longer touches iova.h (which is shared)
Performance data: Netperf 32byte UDP streaming
2.6.25-rc3-mm1:
IOMMU-strict : 58Mps @ 62% cpu
NO-IOMMU : 71Mbs @ 41% cpu
List-based IOMMU-default-batched-IOTLB flush: 66Mbps @ 57% cpu
with this patch:
IOMMU-strict : 73Mps @ 75% cpu
NO-IOMMU : 74Mbs @ 42% cpu
Array-based IOMMU-default-batched-IOTLB flush: 72Mbps @ 62% cpu
Signed-off-by: <mgross@linux.intel.com>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch is for batching up the flushing of the IOTLB for the DMAR
implementation found in the Intel VT-d hardware. It works by building a list
of to be flushed IOTLB entries and a bitmap list of which DMAR engine they are
from.
After either a high water mark (250 accessible via debugfs) or 10ms the list
of iova's will be reclaimed and the DMAR engines associated are IOTLB-flushed.
This approach recovers 15 to 20% of the performance lost when using the IOMMU
for my netperf udp stream benchmark with small packets. It can be disabled
with a kernel boot parameter "intel_iommu=strict".
Its use does weaken the IOMMU protections a bit.
Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
lockdep goes off on the iova copy_reserved_iova() because it and a function
it calls grabs locks in the from, and the to of the copy operation.
The function grab locks of the same lock classes triggering the warning. The
first lock grabbed is for the constant reserved areas that is never accessed
after early boot. Technically you could do without grabbing the locks for the
"from" structure its copying reserved areas from.
But dropping the from locks to me looks wrong, even though it would be ok.
The affected code only runs in early boot as its setting up the DMAR
engines.
This patch gives the reserved_ioval_list locks special lockdep classes.
Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The following is a clean up and correction of the copyright holding
entities for the files associated with the intel iommu code.
Signed-off-by: <mgross@linux.intel.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix an off by one bug in the fault reason string reporting function, and
clean up some of the code around this buglet.
[akpm@linux-foundation.org: cleanup]
Signed-off-by: mark gross <mgross@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for protected memory enable bits by clearing them if they are
set at startup time. Some future boot loaders or firmware could have this
bit set after it loads the kernel, and it needs to be cleared if DMA's are
going to happen effectively.
Signed-off-by: mark gross <mgross@intel.com>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I would like to potentially move the sparc64 IOMMU code over to using
the nice new drivers/pci/iova.[ch] code for free area management..
In order to do that we have to detach the IOMMU page size assumptions
which only really need to exist in the intel-iommu.[ch] code.
This patch attempts to implement that.
[akpm@linux-foundation.org: build fix]
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch renames the include file asm-x86/iommu.h to asm-x86/gart.h to make
clear to which IOMMU implementation it belongs. The patch also adds "GART" to
the Kconfig line.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
- off by one in dmar_get_fault_reason() (maximal index in array is
ARRAY_SIZE()-1, not ARRAY_SIZE())
- NULL noise removal
- __iomem annotation fix
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86_64 defines ARCH_HAS_SG_CHAIN. So if IOMMU implementations don't
support sg chaining, we will get data corruption.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pci_dev's->sysdata is highly overloaded and currently IOMMU is broken due
to IOMMU code depending on this field.
This patch introduces new field in pci_dev's dev.archdata struct to hold
IOMMU specific per device IOMMU private data.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds PageSelectiveInvalidation support replacing existing
DomainSelectiveInvalidation for intel_{map/unmap}_sg() calls and also
enables to mapping one big contiguous DMA virtual address which is mapped
to discontiguous physical address for SG map/unmap calls.
"Doamin selective invalidations" wipes out the IOMMU address translation
cache based on domain ID where as "Page selective invalidations" wipes out
the IOMMU address translation cache for that address mask range which is
more cache friendly when compared to Domain selective invalidations.
Here is how it is done.
1) changes to iova.c
alloc_iova() now takes a bool size_aligned argument, which
when when set, returns the io virtual address that is
naturally aligned to 2 ^ x, where x is the order
of the size requested.
Returning this io vitual address which is naturally
aligned helps iommu to do the "page selective
invalidations" which is IOMMU cache friendly
over "domain selective invalidations".
2) Changes to driver/pci/intel-iommu.c
Clean up intel_{map/unmap}_{single/sg} () calls so that
s/g map/unamp calls is no more dependent on
intel_{map/unmap}_single()
intel_map_sg() now computes the total DMA virtual address
required and allocates the size aligned total DMA virtual address
and maps the discontiguous physical address to the allocated
contiguous DMA virtual address.
In the intel_unmap_sg() case since the DMA virtual address
is contiguous and size_aligned, PageSelectiveInvalidation
is used replacing earlier DomainSelectiveInvalidations.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Greg KH <greg@kroah.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Suresh B <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This config option (DMAR_FLPY_WA) sets up 1:1 mapping for the floppy device so
that the floppy device which does not use DMA api's will continue to work.
Once the floppy driver starts using DMA api's this config option can be turn
off or this patch can be yanked out of kernel at that time.
[akpm@linux-foundation.org: cleanups, rename things, build fix]
[jengelh@computergmbh.de: Kconfig fixes]
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we fix all the opensource gfx drivers to use the DMA api's, at that time
we can yank this config options out.
[jengelh@computergmbh.de: Kconfig fixes]
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MSI interrupt handler registrations and fault handling support for Intel-IOMMU
hadrware.
This patch enables the MSI interrupts for the DMA remapping units and in the
interrupt handler read the fault cause and outputs the same on to the console.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Intel IOMMU driver needs memory during DMA map calls to setup its internal
page tables and for other data structures. As we all know that these DMA map
calls are mostly called in the interrupt context or with the spinlock held by
the upper level drivers(network/storage drivers), so in order to avoid any
memory allocation failure due to low memory issues, this patch makes memory
allocation by temporarily setting PF_MEMALLOC flags for the current task
before making memory allocation calls.
We evaluated mempools as a backup when kmem_cache_alloc() fails
and found that mempools are really not useful here because
1) We don't know for sure how much to reserve in advance
2) And mempools are not useful for GFP_ATOMIC case (as we call
memory alloc functions with GFP_ATOMIC)
(akpm: point 2 is wrong...)
With PF_MEMALLOC flag set in the current->flags, the VM subsystem avoids any
watermark checks before allocating memory thus guarantee'ing the memory till
the last free page. Further, looking at the code in mm/page_alloc.c in
__alloc_pages() function, looks like this flag is useful only in the
non-interrupt context.
If we are in the interrupt context and memory allocation in IOMMU driver fails
for some reason, then the DMA map api's will return failure and it is up to
the higher level drivers to retry. Suppose, if upper level driver programs
the controller with the buggy DMA virtual address, the IOMMU will block that
DMA transaction when that happens thus preventing any corruption to main
memory.
So far in our test scenario, we were unable to create any memory allocation
failure inside dma map api calls.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Actual intel IOMMU driver. Hardware spec can be found at:
http://www.intel.com/technology/virtualization
This driver sets X86_64 'dma_ops', so hook into standard DMA APIs. In this
way, PCI driver will get virtual DMA address. This change is transparent to
PCI drivers.
[akpm@linux-foundation.org: remove unneeded cast]
[akpm@linux-foundation.org: build fix]
[bunk@stusta.de: fix duplicate CONFIG_DMAR Makefile line]
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
