linux.git/arch/powerpc/sysdev, branch v3.12.65

powerpc/MSI: Fix race condition in tearing down MSI interrupts

2015-10-05T20:02:56+00:00

commit e297c939b745e420ef0b9dc989cb87bda617b399 upstream.

This fixes a race which can result in the same virtual IRQ number
being assigned to two different MSI interrupts.  The most visible
consequence of that is usually a warning and stack trace from the
sysfs code about an attempt to create a duplicate entry in sysfs.

The race happens when one CPU (say CPU 0) is disposing of an MSI
while another CPU (say CPU 1) is setting up an MSI.  CPU 0 calls
(for example) pnv_teardown_msi_irqs(), which calls
msi_bitmap_free_hwirqs() to indicate that the MSI (i.e. its
hardware IRQ number) is no longer in use.  Then, before CPU 0 gets
to calling irq_dispose_mapping() to free up the virtal IRQ number,
CPU 1 comes in and calls msi_bitmap_alloc_hwirqs() to allocate an
MSI, and gets the same hardware IRQ number that CPU 0 just freed.
CPU 1 then calls irq_create_mapping() to get a virtual IRQ number,
which sees that there is currently a mapping for that hardware IRQ
number and returns the corresponding virtual IRQ number (which is
the same virtual IRQ number that CPU 0 was using).  CPU 0 then
calls irq_dispose_mapping() and frees that virtual IRQ number.
Now, if another CPU comes along and calls irq_create_mapping(), it
is likely to get the virtual IRQ number that was just freed,
resulting in the same virtual IRQ number apparently being used for
two different hardware interrupts.

To fix this race, we just move the call to msi_bitmap_free_hwirqs()
to after the call to irq_dispose_mapping().  Since virq_to_hw()
doesn't work for the virtual IRQ number after irq_dispose_mapping()
has been called, we need to call it before irq_dispose_mapping() and
remember the result for the msi_bitmap_free_hwirqs() call.

The pattern of calling msi_bitmap_free_hwirqs() before
irq_dispose_mapping() appears in 5 places under arch/powerpc, and
appears to have originated in commit 05af7bd2d75e ("[POWERPC] MPIC
U3/U4 MSI backend") from 2007.

Fixes: 05af7bd2d75e ("[POWERPC] MPIC U3/U4 MSI backend")
Reported-by: Alexey Kardashevskiy 
Signed-off-by: Paul Mackerras 
Signed-off-by: Michael Ellerman 
Signed-off-by: Paul Mackerras 
Signed-off-by: Jiri Slaby

axonram: Fix bug in direct_access

2015-03-01T22:34:20+00:00

commit 91117a20245b59f70b563523edbf998a62fc6383 upstream.

The 'pfn' returned by axonram was completely bogus, and has been since
2008.

Signed-off-by: Matthew Wilcox 
Reviewed-by: Jan Kara 
Reviewed-by: Mathieu Desnoyers 
Signed-off-by: Jens Axboe 
Signed-off-by: Jiri Slaby

Merge tag 'iommu-updates-v3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

2013-09-12T18:29:26+00:00

Pull IOMMU Updates from Joerg Roedel:
 "This round the updates contain:

   - A new driver for the Freescale PAMU IOMMU from Varun Sethi.

     This driver has cooked for a while and required changes to the
     IOMMU-API and infrastructure that were already merged before.

   - Updates for the ARM-SMMU driver from Will Deacon

   - Various fixes, the most important one is probably a fix from Alex
     Williamson for a memory leak in the VT-d page-table freeing code

  In summary not all that much.  The biggest part in the diffstat is the
  new PAMU driver"

* tag 'iommu-updates-v3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  intel-iommu: Fix leaks in pagetable freeing
  iommu/amd: Fix resource leak in iommu_init_device()
  iommu/amd: Clean up unnecessary MSI/MSI-X capability find
  iommu/arm-smmu: Simplify VMID and ASID allocation
  iommu/arm-smmu: Don't use VMIDs for stage-1 translations
  iommu/arm-smmu: Tighten up global fault reporting
  iommu/arm-smmu: Remove broken big-endian check
  iommu/fsl: Remove unnecessary 'fsl-pamu' prefixes
  iommu/fsl: Fix whitespace problems noticed by git-am
  iommu/fsl: Freescale PAMU driver and iommu implementation.
  iommu/fsl: Add additional iommu attributes required by the PAMU driver.
  powerpc: Add iommu domain pointer to device archdata
  iommu/exynos: Remove dead code (set_prefbuf)

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2013-09-06T17:49:42+00:00

Pull powerpc updates from Ben Herrenschmidt:
 "Here's the powerpc batch for this merge window.  Some of the
  highlights are:

   - A bunch of endian fixes ! We don't have full LE support yet in that
     release but this contains a lot of fixes all over arch/powerpc to
     use the proper accessors, call the firmware with the right endian
     mode, etc...

   - A few updates to our "powernv" platform (non-virtualized, the one
     to run KVM on), among other, support for bridging the P8 LPC bus
     for UARTs, support and some EEH fixes.

   - Some mpc51xx clock API cleanups in preparation for a clock API
     overhaul

   - A pile of cleanups of our old math emulation code, including better
     support for using it to emulate optional FP instructions on
     embedded chips that otherwise have a HW FPU.

   - Some infrastructure in selftest, for powerpc now, but could be
     generalized, initially used by some tests for our perf instruction
     counting code.

   - A pile of fixes for hotplug on pseries (that was seriously
     bitrotting)

   - The usual slew of freescale embedded updates, new boards, 64-bit
     hiberation support, e6500 core PMU support, etc..."

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (146 commits)
  powerpc: Correct FSCR bit definitions
  powerpc/xmon: Fix printing of set of CPUs in xmon
  powerpc/pseries: Move lparcfg.c to platforms/pseries
  powerpc/powernv: Return secondary CPUs to firmware on kexec
  powerpc/btext: Fix CONFIG_PPC_EARLY_DEBUG_BOOTX on ppc32
  powerpc: Cleanup handling of the DSCR bit in the FSCR register
  powerpc/pseries: Child nodes are not detached by dlpar_detach_node
  powerpc/pseries: Add mising of_node_put in delete_dt_node
  powerpc/pseries: Make dlpar_configure_connector parent node aware
  powerpc/pseries: Do all node initialization in dlpar_parse_cc_node
  powerpc/pseries: Fix parsing of initial node path in update_dt_node
  powerpc/pseries: Pack update_props_workarea to map correctly to rtas buffer header
  powerpc/pseries: Fix over writing of rtas return code in update_dt_node
  powerpc/pseries: Fix creation of loop in device node property list
  powerpc: Skip emulating & leave interrupts off for kernel program checks
  powerpc: Add more exception trampolines for hypervisor exceptions
  powerpc: Fix location and rename exception trampolines
  powerpc: Add more trap names to xmon
  powerpc/pseries: Add a warning in the case of cross-cpu VPA registration
  powerpc: Update the 00-Index in Documentation/powerpc
  ...

iommu/fsl: Freescale PAMU driver and iommu implementation.

2013-08-14T09:38:34+00:00

Following is a brief description of the PAMU hardware:
PAMU determines what action to take and whether to authorize the action on
the basis of the memory address, a Logical IO Device Number (LIODN), and
PAACT table (logically) indexed by LIODN and address. Hardware devices which
need to access memory must provide an LIODN in addition to the memory address.

Peripheral Access Authorization and Control Tables (PAACTs) are the primary
data structures used by PAMU. A PAACT is a table of peripheral access
authorization and control entries (PAACE).Each PAACE defines the range of
I/O bus address space that is accessible by the LIOD and the associated access
capabilities.

There are two types of PAACTs: primary PAACT (PPAACT) and secondary PAACT
(SPAACT).A given physical I/O device may be able to act as one or more
independent logical I/O devices (LIODs). Each such logical I/O device is
assigned an identifier called logical I/O device number (LIODN). A LIODN is
allocated a contiguous portion of the I/O bus address space called the DSA window
for performing DSA operations. The DSA window may optionally be divided into
multiple sub-windows, each of which may be used to map to a region in system
storage space. The first sub-window is referred to as the primary sub-window
and the remaining are called secondary sub-windows.

This patch provides the PAMU driver (fsl_pamu.c) and the corresponding IOMMU
API implementation (fsl_pamu_domain.c). The PAMU hardware driver (fsl_pamu.c)
has been derived from the work done by Ashish Kalra and Timur Tabi.

[For iommu group support]
Acked-by: Alex Williamson 

Signed-off-by: Timur Tabi 
Signed-off-by: Varun Sethi 
Signed-off-by: Joerg Roedel

powerpc: Fix some endian issues in xics code

2013-08-14T05:33:25+00:00

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Add some endian annotations to time and xics code

2013-08-14T05:33:24+00:00

Fix a couple of sparse warnings.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

powerpc/pci: fix PCI-e check link issue

2013-08-07T23:38:08+00:00

For Freescale powerpc platform, the PCI-e bus number uses the reassign mode
by default. It means the second PCI-e controller's hose->first_busno is the
first controller's last bus number adding 1. For some hotpluged device(or
controlled by FPGA), the device is linked to PCI-e slot at linux runtime.
It needs rescan for the system to add it and driver it to work. It successes
to rescan the device linked to the first PCI-e controller's slot, but fails to
rescan the device linked to the second PCI-e controller's slot. The cause is
that the bus->number is reset to 0, which isn't equal to the hose->first_busno
for the second controller checking PCI-e link. So it doesn't really check the
PCI-e link status, the link status is always no_link. The device won't be
really rescaned. Reset the bus->number to hose->first_busno in the function
fsl_pcie_check_link(), it will do the real checking PCI-e link status for the
second controller, the device will be rescaned.

Signed-off-by: Yuanquan Chen 
Tested-by: Rojhalat Ibrahim 
Signed-off-by: Scott Wood

powerpc/fsl-pci: enable SWIOTLB in function setup_pci_atmu

2013-08-07T23:38:08+00:00

This function contains all the stuff we need to check if SWIOTLB
should be enabled or not. So it is more convenient to enable
the SWIOTLB here than later.

Signed-off-by: Kevin Hao 
Signed-off-by: Scott Wood

powerpc/fsl-pci: fix the unreachable warning message

2013-08-07T23:38:07+00:00

The (1ull << mem_log) is never greater than mem unless mem_log++;

Signed-off-by: Kevin Hao 
Signed-off-by: Scott Wood