Since "Factor out cpu joining/unjoining the GIQ"
(b4963255ad) the WARN_ON in
xics_set_cpu_giq() is being triggered during boot on JS20 because the
GIQ indicator is not available on that platform. While the warning is
harmless and the system runs normally, it's nicer to check for the
existence of the indicator before trying to manipulate it.
Implement rtas_indicator_present(), which searches the
/rtas/rtas-indicators property for the given indicator token, and use
this function in xics_set_cpu_giq().
Also use a WARN statement in xics_set_cpu_giq to get better
information on failure.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Acked-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
smp_hw_index isn't used on 64-bit, so move it from smp.c to
setup_32.c.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The `have_of' variable is a relic from the arch/ppc time, it isn't
useful nowadays.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
An example calling sequence which we did see:
copy_user_highpage -> kmap_atomic -> flush_tlb_page -> _tlbil_va
We got interrupted after setting up the MAS registers before the
tlbwe and the interrupt handler that caused the interrupt also did
a kmap_atomic (ide code) and thus on returning from the interrupt
the MAS registers no longer contained the proper values.
Since we dont save/restore MAS registers for normal interrupts we
need to disable interrupts in _tlbil_va to ensure atomicity.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
The 440x5 core in the Virtex5 uses the 440A type machine check
(ie, they have MCSRR0/MCSRR1). They thus need to call the
appropriate fixup function to hook the right variant of the
exception.
Without this, all machine checks become fatal due to loss
of context when entering the exception handler.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Added 85xx specifc smp_ops structure. We use ePAPR style boot release
and the MPIC for IPIs at this point.
Additionally added routines for secondary cpu entry and initializtion.
Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Trent Piepho <tpiepho@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
The initial TLB mapping for the kernel boot didn't set the memory coherent
attribute, MAS2[M], in SMP mode.
If this code supported booting a secondary processor, which it doesn't yet,
but if it did, then when a secondary processor boots, it would probably signal
the primary processor by setting a variable called something like
__secondary_hold_acknowledge. However, due to the lack of the M bit, the
primary processor would not snoop the transaction (even if a transaction were
broadcast). If primary CPU's L1 D-cache had a copy, it would not be flushed
and the CPU would never see the ack. Which would have resulted in the primary
CPU spinning for a long time, perhaps a full second before it gives up, while
it would have waited for the ack from the secondary CPU that it wouldn't have
been able to see because of the stale cache.
The value of MAS2 for the boot page TLB1 entry is a compile time constant,
so there is no need to calculate it in powerpc assembly language.
Also, from the MPC8572 manual section 6.12.5.3, "Bits that represent
offsets within a page are ignored and should be cleared." Existing code
didn't clear them, this code does.
The same when the page of KERNELBASE is found; we don't need to use asm to
mask the lower 12 bits off.
In the code that computes the address to rfi from, don't hard code the
offset to 24 bytes, but have the assembler figure that out for us.
Signed-off-by: Trent Piepho <tpiepho@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This patch add the handlers of SPE/EFP exceptions.
The code is used to emulate float point arithmetic,
when MSR(SPE) is enabled and receive EFP data interrupt or EFP round interrupt.
This patch has no conflict with or dependence on FP math-emu.
The code has been tested by TestFloat.
Now the code doesn't support SPE/EFP instructions emulation
(it won't be called when receive program interrupt),
but it could be easily added.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
ibmebus_free_irq() frees the IRQ but does not remove its mapping, which
results in stale entries in the map.
This fixes it by adding a call to irq_dispose_mapping() in
ibmebus_free_irq().
Signed-off-by: Sebastien Dugue <sebastien.dugue@bull.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
As noted by Akinobu Mita in commit b1fceac2 ("x86: remove unnecessary
memset and NULL check after alloc_bootmem()"), alloc_bootmem and
related functions never return NULL and always return a zeroed region
of memory. Thus a NULL test or memset after calls to these functions
is unnecessary.
This was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
expression E;
statement S;
@@
E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\|alloc_bootmem_node\|alloc_bootmem_low_pages_node\|alloc_bootmem_pages_node\)(...)
... when != E
(
- BUG_ON (E == NULL);
|
- if (E == NULL) S
)
@@
expression E,E1;
@@
E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\|alloc_bootmem_node\|alloc_bootmem_low_pages_node\|alloc_bootmem_pages_node\)(...)
... when != E
- memset(E,0,E1);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We need to swap these out once we start using swiotlb, so add
them to dma_ops. Create CONFIG_PPC_NEED_DMA_SYNC_OPS Kconfig
option; this is currently enabled automatically if we're
CONFIG_NOT_COHERENT_CACHE. In the future, this will also
be enabled for builds that need swiotlb. If PPC_NEED_DMA_SYNC_OPS
is not defined, the dma_sync_*_for_* ops compile to nothing.
Otherwise, they access the dma_ops pointers for the sync ops.
This patch also changes dma_sync_single_range_* to actually
sync the range - previously it was using a generous
dma_sync_single. dma_sync_single_* is now implemented
as a dma_sync_single_range with an offset of 0.
Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On my screen, when something crashes, I only have space for maybe 16
functions of the stack trace before the information above it scrolls
off the screen. It's easy to hack the kernel to print out only that
much, but it's harder to remember to do it. This introduces a config
option for it so that I can keep the setting in my config.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On PowerPC 4xx or other non cache-coherent platforms, we lost the
appropriate cache flushing in dma_map_sg() when merging the 32 and
64-bit DMA code (commit 4fc665b88a,
"powerpc: Merge 32 and 64-bit dma code"). This restores it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
attr_smt_snooze_delay is only defined for CONFIG_PPC64, so protect the
attribute removal with the same condition. This fixes this build error
on 32-bit SMP configurations:
/data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c: In function ‘unregister_cpu_online’:
/data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c:722: error: ‘attr_smt_snooze_delay’ undeclared (first use in this function)
/data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c:722: error: (Each undeclared identifier is reported only once
/data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c:722: error: for each function it appears in.)
Signed-off-by: Paul Mackerras <paulus@samba.org>
It turns out that on Cell, on a kernel with CONFIG_VIRT_CPU_ACCOUNTING
= y, if a program sets the SO (summary overflow) bit in the XER and
then does a system call, the SO bit in CR0 will be set on return
regardless of whether the system call detected an error. Since CR0.SO
is used as the error indication from the system call, this means that
all system calls appear to fail.
The reason is that the workaround for the timebase bug on Cell uses a
compare instruction. With CONFIG_VIRT_CPU_ACCOUNTING = y, the
ACCOUNT_CPU_USER_ENTRY macro reads the timebase, so we end up doing a
compare instruction, which copies XER.SO to CR0.SO. Since we were
doing this in the system call entry patch after clearing CR0.SO but
before saving the CR, this meant that the saved CR image had CR0.SO
set if XER.SO was set on entry.
This fixes it by moving the clearing of CR0.SO to after the
ACCOUNT_CPU_USER_ENTRY call in the system call entry path.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently, some PCIe devices on POWER6 machines do not get interrupts
assigned correctly. The problem is that OF doesn't create an
"interrupt" property for them. The fix is for of_irq_map_pci to fall
back to using the value in the PCI interrupt-pin register in config
space, as we do when there is no OF device-tree node for the device.
I have verified that this works fine with a pair of Squib-E SAS
adapter on a P6-570.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
With the new generic smp call function helpers, I noticed the code in
smp_message_recv was a single function call in many cases. While
getting the message number from the ipi data is easy, we can reduce
the path length by a function and data-dependent switch by registering
seperate IPI actions for these simple calls.
Originally I left the ipi action array exposed, but then I realized the
registration code should be common too.
The three users each had their own name array, so I made a fourth
to convert all users to use a common one.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Those cores use the 440A type machine check (ie, they have
MCSRR0/MCSRR1). They thus need to call the appropriate fixup
function to hook the right variant of the exception.
Without this, all machine checks become fatal due to loss
of context when entering the exception handler.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
The new context may not be 16-byte aligned, so the real address of the
mcontext structure should be read from the uc_regs pointer instead of
directly using the (unaligned) uc_mcontext field.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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>
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>
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>
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>
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>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (23 commits)
Revert "powerpc: Sync RPA note in zImage with kernel's RPA note"
powerpc: Fix compile errors with CONFIG_BUG=n
powerpc: Fix format string warning in arch/powerpc/boot/main.c
powerpc: Fix bug in kernel copy of libfdt's fdt_subnode_offset_namelen()
powerpc: Remove duplicate DMA entry from mpc8313erdb device tree
powerpc/cell/OProfile: Fix on-stack array size in activate spu profiling function
powerpc/mpic: Fix regression caused by change of default IRQ affinity
powerpc: Update remaining dma_mapping_ops to use map/unmap_page
powerpc/pci: Fix unmapping of IO space on 64-bit
powerpc/pci: Properly allocate bus resources for hotplug PHBs
OF-device: Don't overwrite numa_node in device registration
powerpc: Fix swapcontext system for VSX + old ucontext size
powerpc: Fix compiler warning for the relocatable kernel
powerpc: Work around ld bug in older binutils
powerpc/ppc64/kdump: Better flag for running relocatable
powerpc: Use is_kdump_kernel()
powerpc: Kexec exit should not use magic numbers
powerpc/44x: Update 44x defconfigs
powerpc/40x: Update 40x defconfigs
powerpc: enable heap randomization for linkstations
...
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>
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>
