Since we started using the generic timekeeping code, we haven't had a
powerpc-specific version of do_gettimeofday, and hence there is now
nothing that reads the do_gtod variable in arch/powerpc/kernel/time.c.
This therefore removes it and the code that sets it.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently the clock_gettime implementation in the VDSO produces a
result with microsecond resolution for the cases that are handled
without a system call, i.e. CLOCK_REALTIME and CLOCK_MONOTONIC. The
nanoseconds field of the result is obtained by computing a
microseconds value and multiplying by 1000.
This changes the code in the VDSO to do the computation for
clock_gettime with nanosecond resolution. That means that the
resolution of the result will ultimately depend on the timebase
frequency.
Because the timestamp in the VDSO datapage (stamp_xsec, the real time
corresponding to the timebase count in tb_orig_stamp) is in units of
2^-20 seconds, it doesn't have sufficient resolution for computing a
result with nanosecond resolution. Therefore this adds a copy of
xtime to the VDSO datapage and updates it in update_gtod() along with
the other time-related fields.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Now that all of the remaining dma_mapping_ops have had their
map_/unmap_single functions updated to become map/unmap_page
functions, there is no need to have the map_/unmap_single function
pointers in the dma_mapping_ops.
So, this removes them and also removes the code that does the checking
for which set of functions to use.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Acked-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This does a few cosmetic cleanups, moving a couple of things around
but without actually changing what the code does.
(There is a minor change in ordering of operations in
pcibios_setup_bus_devices but it should have no impact).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The pseries PCI hotplug code has a number of issues, ranging from
incorrect resource setup to crashes, depending on what is added,
when, whether it contains a bridge, etc etc....
This fixes a whole bunch of these, while actually simplifying the code
a bit, using more generic code in the process and factoring out common
code between adding of a PHB, a slot or a device.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
To properly fix PCI hotplug, it's useful to be able to make the fixup
passes on all devices whether they were just hot plugged or already
there.
However, pcibios_allocate_bus_resources() wouldn't cope well with
being called twice for a given bus. This makes it ignore resources
that have already been allocated, along with adding a bit of debug
output.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
To properly fix PCI hotplug, it's useful to be able to make the fixup
passes on all devices whether they were just hot plugged or already
there.
The EEH code however used to not be very friendly with calling
eeh_add_device_late() multiple time, and not very rebust in the way it
generally tests whether a device is in the expected state vs. the EEH
code.
This improves it, along with cleaning up a couple of debug printk's.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently, our PCI code uses the pcibios_fixup_bus() callback, which
is called by the generic code when probing PCI buses, for two
different things.
One is to set up things related to the bus itself, such as reading
bridge resources for P2P bridges, fixing them up, or setting up the
iommu's associated with bridges on some platforms.
The other is some setup for each individual device under that bridge,
mostly setting up DMA mappings and interrupts.
The problem is that this approach doesn't work well with PCI hotplug
when an existing bus is re-probed for new children. We fix this
problem by splitting pcibios_fixup_bus into two routines:
pcibios_setup_bus_self() is now called to setup the bus itself
pcibios_setup_bus_devices() is now called to setup devices
pcibios_fixup_bus() is then modified to call these two after reading the
bridge bases, and the OF based PCI probe is modified to avoid calling
into the first one when rescanning an existing bridge.
[paulus@samba.org - fixed eeh.h for 32-bit compile now that pci-common.c
is including it unconditionally.]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The function pcibios_do_bus_setup() was used by pcibios_fixup_bus()
to perform setup that is different between the 32-bit and 64-bit
code. This difference no longer exists, thus the function is removed
and the setup now done directly from pci-common.c.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The 32-bit and 64-bit powerpc PCI code used to set up the resource
pointers of the root bus of a given PHB in completely different
places.
This unifies this in large part, by making 32-bit use a routine very
similar to what 64-bit does when initially scanning the PCI busses.
The actual setup of the PHB resources itself is then moved to a
common function in pci-common.c.
This should cause no functional change on 64-bit. On 32-bit, the
effect is that the PHB resources are going to be setup a bit earlier,
instead of being setup from pcibios_fixup_bus().
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This removes the various DBG() macro from the powerpc PCI code and
makes it use the standard pr_debug instead.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Update memcpy() to add two new feature sections: one for aligning the
destination before copying and one for copying using aligned load
and store doubles.
These new feature sections will only affect Power6 and Cell because
the CPU feature bit was only added to these two processors.
Power6 gets its best performance in memcpy() when aligning neither the
source nor the destination, while Cell gets its best performance when
just the destination is aligned. But in order to save on CPU feature
bits we can use the previously added CPU_FTR_CP_USE_DCBTZ feature bit
to differentiate between Power6 and Cell (because CPU_FTR_CP_USE_DCBTZ
was added to Cell but not Power6).
The first feature section acts to nop out the branch that takes us to
the code that aligns us to an eight byte boundary for the destination.
We only want to nop out this branch on Power6.
So the ALT_FTR_SECTION_END() for this feature section creates a test
mask of the two feature bits ORed together and provides an expected
result of just CPU_FTR_UNALIGNED_LD_STD, thus we nop out the branch
if we're on a CPU that has CPU_FTR_UNALIGNED_LD_STD set and
CPU_FTR_CP_USE_DCBTZ unset.
For the second feature section added, if we're on a CPU that has the
CPU_FTR_UNALIGNED_LD_STD bit set then we don't want to do the copy
with aligned loads and stores (and the appropriate shifting left and
right instructions), so we want to nop out the branch to
.Lsrc_unaligned.
The andi. used for this branch is moved to just above the branch
because this allows us to nop out both instructions with just one
feature section which gives us better performance and doesn't hurt
readability which two separate feature sections did.
Moving the andi. to just above the branch doesn't have any noticeable
negative effect on the remaining 64bit processors (the ones that
didn't have this feature bit added).
On Cell this simple modification results in an improvement to measured
memcpy() bandwidth of up to 50% in the hot cache case and up to 15% in
the cold cache case.
On Power6 we get memory bandwidth results that are up to three times
faster in the hot cache case and up to 50% faster in the cold cache
case.
Commit 2a9294369b ("powerpc: Add new CPU
feature: CPU_FTR_CP_USE_DCBTZ") was where CPU_FTR_CP_USE_DCBTZ was
added.
To say that Cell gets its best performance in memcpy() with just the
destination aligned is true but only for the reason that the indirect
shift and rotate instructions, sld and srd, are microcoded on Cell.
This means that either the destination or the source can be aligned,
but not both, and seeing as we get better performance with the
destination aligned we choose this option.
While we're at it make a one line change from cmpldi r1,... to
cmpldi cr1,... for consistency.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add a new CPU feature bit, CPU_FTR_UNALIGNED_LD_STD, to be added
to the 64bit powerpc chips that can do unaligned load double and
store double without any performance hit.
This is added to Power6 and Cell and will be used in the next commit
to disable the code that gets the destination address aligned on
those CPUs where doing that doesn't improve performance.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
A new field has been added to the VPA as a method for the client OS to
communicate to firmware the number of page-ins it is performing when
running collaborative memory overcommit. The hypervisor will use this
information to better determine if a partition is experiencing memory
pressure and needs more memory allocated to it.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The 'ibm,interrupt-server#-size' properties are not in the cpu nodes,
which is where we currently look for them, but rather live under the
interrupt source controller nodes (which have "ibm,ppc-xics" in their
compatible property).
This moves the code that looks for the ibm,interrupt-server#-size
properties from xics_update_irq_servers() into xics_init_IRQ().
Also this adds a check for mismatched sizes across the interrupt
source controller nodes. Not sure this is necessary as in this case
the firmware might be seriously busted.
This property only appears on POWER6 boxes and is only used in the
set-indicator(gqirm) call, and apparently firmware currently ignores
the value we pass. Nevertheless we need to fix it in case future
firmware versions use it.
Signed-off-by: Sebastien Dugue <sebastien.dugue@bull.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We don't want to encourage the device_type usage. It isn't used in
the code, so we can simply remove it from the dts files.
Suggested-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When no hardware method is provided to sync the timebase registers
across the machine, and the platform doesn't sync them for us, then we
use a generic software implementation. Currently, the code for that
has many printks, and they don't have log levels. Most of the printks
are only useful for debugging the code, and since we haven't had any
problems with it for years, this turns them into pr_debug.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The code to properly expose domain numbers in /proc is somewhat
bogus on ppc64 as it depends on the "buid" field being non-0,
but that field is really pseries specific.
This removes that code and makes ppc64 use the same code as 32-bit
which effectively decides whether to expose domains based on
ppc_pci_flags set by the platform, and sets the default for 64-bit
to enable domains and enable compatibility for domain 0 (which
strips the domain number for domain 0 to help with X servers).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This gets rid of this build warning:
arch/powerpc/platforms/pseries/pci_dlpar.c: In function 'init_phb_dynamic':
arch/powerpc/platforms/pseries/pci_dlpar.c:192: warning: unused variable 'b'
This is one of the very few warnings left in a ppc64_defconfig build and
getting rid of it will make it easier to see future introduced ones (in
fact this was introduced very recently).
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This fixes this error on Cell when CONFIG_KEXEC = n:
arch/powerpc/platforms/cell/ras.c:299: error: implicit declaration of function 'crash_shutdown_register'
We have to include <asm/kexec.h> because it contains the dummy
definition of crash_shutdown_register that is used when
CONFIG_KEXEC=n, but <linux/kexec.h> doesn't include <asm/kexec.h> in
that case.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Impact: build fix for non-ftrace architectures
Not all archs implement ftrace, and therefore do not have an asm/ftrace.h.
This patch corrects the problem.
The ftrace_nmi_enter/exit now must be defined for all archs that implement
dynamic ftrace. Currently, only x86 does.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Updated the patch to address comments by Michael Ellerman.
Specifically, changed upper limit in for loop to
ARRAY_SIZE() macro and added a check to make sure the
number of events specified by the user, which is used as
the max for indexing various arrays, is no bigger then the
declared size of the arrays.
The size of the pm_signal_local array should be equal to the
number of SPUs being configured in the array. Currently, the
array is of size 4 (NR_PHYS_CTRS) but being indexed by a for
loop from 0 to 7 (NUM_SPUS_PER_NODE).
Signed-off-by: Carl Love <carll@us.ibm.com>
This reverts commit 91a0030295, plus
commit 0dcd440120 ("powerpc: Revert CHRP
boot wrapper to real-base = 12MB on 32-bit") which depended on it.
Commit 91a00302 was causing NVRAM corruption on some pSeries machines,
for as-yet unknown reasons, so this reverts it until the cause is
identified.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This makes sure we don't try to call find_bug or is_warning_bug when
CONFIG_BUG=n and CONFIG_XMON=y. Otherwise we get these errors:
arch/powerpc/xmon/xmon.c: In function ‘print_bug_trap’:
arch/powerpc/xmon/xmon.c:1364: error: implicit declaration of function ‘find_bug’
arch/powerpc/xmon/xmon.c:1364: warning: assignment makes pointer from integer without a cast
arch/powerpc/xmon/xmon.c:1367: error: implicit declaration of function ‘is_warning_bug’
arch/powerpc/xmon/xmon.c:1374: error: dereferencing pointer to incomplete type
make[2]: *** [arch/powerpc/xmon/xmon.o] Error 1
make[1]: *** [arch/powerpc/xmon] Error 2
make: *** [sub-make] Error 2
Signed-off-by: Paul Mackerras <paulus@samba.org>
Impact: cleanup
This patch cleans up the NMI safe code for dynamic ftrace as suggested
by Andrew Morton.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix format string warning in arch/powerpc/boot/main.c. Also correct
a typo ("uncomressed") on the same line.
BOOTCC arch/powerpc/boot/main.o
arch/powerpc/boot/main.c: In function 'prep_kernel':
arch/powerpc/boot/main.c:65: warning: format '%08x' expects type
'unsigned int', but argument 3 has type 'long unsigned int'
Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There's currently an off-by-one bug in fdt_subnode_offset_namelen()
which causes it to keep searching after it's finished the subnodes of
the given parent, and into the subnodes of siblings of the original
node which come after it in the tree. This bug was introduced in
commit ed95d7450d ("powerpc: Update
in-kernel dtc and libfdt to version 1.2.0").
A patch has already been submitted to dtc/libfdt mainline. We don't
really want to pull in a new upstream version during the 2.6.28 cycle,
but we should still fix this bug, hence this standalone version of the
fix for the in-kernel libfdt.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The size of the pm_signal_local array should be equal to the
number of SPUs being configured in the array. Currently, the
array is of size 4 (NR_PHYS_CTRS) but being indexed by a for
loop from 0 to 7 (NUM_SPUS_PER_NODE). This could potentially
cause an oops or random memory corruption since the pm_signal_local
array is on the stack. This fixes it.
Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The Freescale implementation of MPIC only allows a single CPU destination
for non-IPI interrupts. We add a flag to the mpic_init to distinquish
these variants of MPIC. We pull in the irq_choose_cpu from sparc64 to
select a single CPU as the destination of the interrupt.
This is to deal with the fact that the default smp affinity was
changed by commit 1840475676 ("genirq:
Expose default irq affinity mask (take 3)") to be all CPUs.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
After the merge of the 32 and 64bit DMA code, dma_direct_ops lost
their map/unmap_single() functions but gained map/unmap_page(). This
caused a problem for Cell because Cell's dma_iommu_fixed_ops called
the dma_direct_ops if the fixed linear mapping was to be used or the
iommu ops if the dynamic window was to be used. So in order to fix
this problem we need to update the 64bit DMA code to use
map/unmap_page.
First, we update the generic IOMMU code so that iommu_map_single()
becomes iommu_map_page() and iommu_unmap_single() becomes
iommu_unmap_page(). Then we propagate these changes up through all
the callers of these two functions and in the process update all the
dma_mapping_ops so that they have map/unmap_page rahter than
map/unmap_single. We can do this because on 64bit there is no HIGHMEM
memory so map/unmap_page ends up performing exactly the same function
as map/unmap_single, just taking different arguments.
This has no affect on drivers because the dma_map_single_attrs() just
ends up calling the map_page() function of the appropriate
dma_mapping_ops and similarly the dma_unmap_single_attrs() calls
unmap_page().
This fixes an oops on Cell blades, which oops on boot without this
because they call dma_direct_ops.map_single, which is NULL.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
A typo/thinko made us pass the wrong argument to __flush_hash_table_range
when unplugging bridges, thus not flushing all the translations for
the IO space on unplug. The third parameter to __flush_hash_table_range
is `end', not `size'.
This causes the hypervisor to refuse unplugging slots.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Resources for PHB's that are dynamically added to a system are not
properly allocated in the resource tree.
Not having these resources allocated causes an oops when removing
the PHB when we try to release them.
The diff appears a bit messy, this is mainly due to moving everything
one tab to the left in the pcibios_allocate_bus_resources routine.
The functionality change in this routine is only that the
list_for_each_entry() loop is pulled out and moved to the necessary
calling routine.
Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently, the numa_node of OF-devices will be overwritten during
device_register, which simply sets the node to -1. On cell machines,
this means that devices can't find their IOMMU, which is referenced
through the device's numa node.
Set the numa node for OF devices with no parent, and use the
lower-level device_initialize and device_add functions, so that the
node is preserved.
We can remove the call to set_dev_node in of_device_alloc, as it
will be overwritten during register.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Since VSX support was added, we now have two sizes of ucontext_t;
the older, smaller size without the extra VSX state, and the new
larger size with the extra VSX state. A program using the
sys_swapcontext system call and supplying smaller ucontext_t
structures will currently get an EINVAL error if the task has
used VSX (e.g. because of calling library code that uses VSX) and
the old_ctx argument is non-NULL (i.e. the program is asking for
its current context to be saved). Thus the program will start
getting EINVAL errors on calls that previously worked.
This commit changes this behaviour so that we don't send an EINVAL in
this case. It will now return the smaller context but the VSX MSR bit
will always be cleared to indicate that the ucontext_t doesn't include
the extra VSX state, even if the task has executed VSX instructions.
Both 32 and 64 bit cases are updated.
[paulus@samba.org - also fix some access_ok() and get_user() calls]
Thanks to Ben Herrenschmidt for noticing this problem.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Fixes this warning:
arch/powerpc/kernel/setup_64.c:447:5: warning: "kernstart_addr" is not defined
which arises because PHYSICAL_START is no longer a constant when
CONFIG_RELOCATABLE=y.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Commit 549e8152de ("powerpc: Make the
64-bit kernel as a position-independent executable") added lines to
vmlinux.lds.S to add the extra sections needed to implement a
relocatable kernel. However, those lines seem to trigger a bug in
older versions of GNU ld (such as 2.16.1) when building a
non-relocatable kernel. Since ld 2.16.1 is still a popular choice for
cross-toolchains, this adds an #ifdef to vmlinux.lds.S so the added
lines are only included when building a relocatable kernel.
Signed-off-by: Paul Mackerras <paulus@samba.org>
The __kdump_flag ABI is overly constraining for future development.
As of 2.6.27, the kernel entry point has 4 constraints: Offset 0 is
the starting point for the master (boot) cpu (entered with r3 pointing
to the device tree structure), offset 0x60 is code for the slave cpus
(entered with r3 set to their device tree physical id), offset 0x20 is
used by the iseries hypervisor, and secondary cpus must be well behaved
when the first 256 bytes are copied to address 0.
Placing the __kdump_flag at 0x18 is bad because:
- It was taking the last 8 bytes before the iseries hypervisor data.
- It was 8 bytes for a boolean flag
- It had no way of identifying that the flag was present
- It does leave any room for the master to add any additional code
before branching, which hurts debug.
- It will be unnecessarily hard for 32 bit code to be common (8 bytes)
Now that we have eliminated the use of __kdump_flag in favor of
the standard is_kdump_kernel(), this flag only controls run without
relocating the kernel to PHYSICAL_START (0), so rename it __run_at_load.
Move the flag to 0x5c, 1 word before the secondary cpu entry point at
0x60. Initialize it with "run0" to say it will run at 0 unless it is
set to 1. It only exists if we are relocatable.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
linux/crash_dump.h defines is_kdump_kernel() to be used by code that
needs to know if the previous kernel crashed instead of a (clean) boot
or reboot.
This updates the just added powerpc code to use it. This is needed
for the next commit, which will remove __kdump_flag.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Commit 54622f10a6 ("powerpc: Support for
relocatable kdump kernel") added a magic flag value in a register to
tell purgatory that it should be a panic kernel. This part is wrong
and is reverted by this commit.
The kernel gets a list of memory blocks and a entry point from user space.
Its job is to copy the blocks into place and then branch to the designated
entry point (after turning "off" the mmu).
The user space tool inserts a trampoline, called purgatory, that runs
before the user supplied code. Its job is to establish the entry
environment for the new kernel or other application based on the contents
of memory. The purgatory code is compiled and embedded in the tool,
where it is later patched using the elf symbol table using elf symbols.
Since the tool knows it is creating a purgatory that will run after a
kernel crash, it should just patch purgatory (or the kernel directly)
if something needs to happen.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The init_phy() function attaches to the PHY, then configures the
SerDes<->TBI link (in SGMII mode). The TBI is on the MDIO bus with the PHY
(sort of) and is accessed via the gianfar's MDIO registers, using the
functions gfar_local_mdio_read/write(), which don't do any locking.
The previously attached PHY will start a work-queue on a timer, and
probably an irq handler as well, which will talk to the PHY and thus use
the MDIO bus. This uses phy_read/write(), which have locking, but not
against the gfar_local_mdio versions.
The result is that PHY code will try to use the MDIO bus at the same time
as the SerDes setup code, corrupting the transfers.
Setting up the SerDes before attaching to the PHY will insure that there is
no race between the SerDes code and *our* PHY, but doesn't fix everything.
Typically the PHYs for all gianfar devices are on the same MDIO bus, which
is associated with the first gianfar device. This means that the first
gianfar's SerDes code could corrupt the MDIO transfers for a different
gianfar's PHY.
The lock used by phy_read/write() is contained in the mii_bus structure,
which is pointed to by the PHY. This is difficult to access from the
gianfar drivers, as there is no link between a gianfar device and the
mii_bus which shares the same MDIO registers. As far as the device layer
and drivers are concerned they are two unrelated devices (which happen to
share registers).
Generally all gianfar devices' PHYs will be on the bus associated with the
first gianfar. But this might not be the case, so simply locking the
gianfar's PHY's mii bus might not lock the mii bus that the SerDes setup
code is going to use.
We solve this by having the code that creates the gianfar platform device
look in the device tree for an mdio device that shares the gianfar's
registers. If one is found the ID of its platform device is saved in the
gianfar's platform data.
A new function in the gianfar mii code, gfar_get_miibus(), can use the bus
ID to search through the platform devices for a gianfar_mdio device with
the right ID. The platform device's driver data is the mii_bus structure,
which the SerDes setup code can use to lock the current bus.
Signed-off-by: Trent Piepho <tpiepho@freescale.com>
CC: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Impact: fix crashes that can occur in NMI handlers, if their code is modified
Modifying code is something that needs special care. On SMP boxes,
if code that is being modified is also being executed on another CPU,
that CPU will have undefined results.
The dynamic ftrace uses kstop_machine to make the system act like a
uniprocessor system. But this does not address NMIs, that can still
run on other CPUs.
One approach to handle this is to make all code that are used by NMIs
not be traced. But NMIs can call notifiers that spread throughout the
kernel and this will be very hard to maintain, and the chance of missing
a function is very high.
The approach that this patch takes is to have the NMIs modify the code
if the modification is taking place. The way this works is that just
writing to code executing on another CPU is not harmful if what is
written is the same as what exists.
Two buffers are used: an IP buffer and a "code" buffer.
The steps that the patcher takes are:
1) Put in the instruction pointer into the IP buffer
and the new code into the "code" buffer.
2) Set a flag that says we are modifying code
3) Wait for any running NMIs to finish.
4) Write the code
5) clear the flag.
6) Wait for any running NMIs to finish.
If an NMI is executed, it will also write the pending code.
Multiple writes are OK, because what is being written is the same.
Then the patcher must wait for all running NMIs to finish before
going to the next line that must be patched.
This is basically the RCU approach to code modification.
Thanks to Ingo Molnar for suggesting the idea, and to Arjan van de Ven
for his guidence on what is safe and what is not.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The current defconfig for Linkstation/Kuroboxes has the "Disable Heap
Randomization" option enabled.
Since some of these machines are facing the internet, it helps to have
heap randomization enabled. This patch enables it.
Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Since Linkstations and Kuroboxes often have *very* little memory (as
they are embedded systems), it is desirable to get their kernels
compiled optimized for size.
Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
The i2c bus defn is broken on linkstation / kurobox machines since at
least 2.6.27. Fix it. Also remove CONFIG_SERIAL_OF_PLATFORM, which, if
enabled, breaks the serial console after the
"console handover: boot [udbg0] -> real [ttyS1]" message.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Fix the HCU4 Kconfig option to 'default n'. We don't want the
board to always be enabled for other board defconfigs.
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
The size of the pm_signal_local array should be equal to the
number of SPUs being configured in the call. Currently, the
array is of size 4 (NR_PHYS_CTRS) but being indexed by a for
loop from 0 to 7 (NUM_SPUS_PER_NODE).
Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Paul Mackerras