This patch implements the kexec support for ppc64 platforms.
A couple of notes:
1) We copy the pages in virtual mode, using the full base kernel
and a statically allocated stack. At kexec_prepare time we
scan the pages and if any overlap our (0, _end[]) range we
return -ETXTBSY.
On PowerPC 64 systems running in LPAR (logical partitioning)
mode, only a small region of memory, referred to as the RMO,
can be accessed in real mode. Since Linux runs with only one
zone of memory in the memory allocator, and it can be orders of
magnitude more memory than the RMO, looping until we allocate
pages in the source region is not feasible. Copying in virtual
means we don't have to write a hash table generation and call
hypervisor to insert translations, instead we rely on the pinned
kernel linear mapping. The kernel already has move to linked
location built in, so there is no requirement to load it at 0.
If we want to load something other than a kernel, then a stub
can be written to copy a linear chunk in real mode.
2) The start entry point gets passed parameters from the kernel.
Slaves are started at a fixed address after copying code from
the entry point.
All CPUs get passed their firmware assigned physical id in r3
(most calling conventions use this register for the first
argument).
This is used to distinguish each CPU from all other CPUs.
Since firmware is not around, there is no other way to obtain
this information other than to pass it somewhere.
A single CPU, referred to here as the master and the one executing
the kexec call, branches to start with the address of start in r4.
While this can be calculated, we have to load it through a gpr to
branch to this point so defining the register this is contained
in is free. A stack of unspecified size is available at r1
(also common calling convention).
All remaining running CPUs are sent to start at absolute address
0x60 after copying the first 0x100 bytes from start to address 0.
This convention was chosen because it matches what the kernel
has been doing itself. (only gpr3 is defined).
Note: This is not quite the convention of the kexec bootblock v2
in the kernel. A stub has been written to convert between them,
and we may adjust the kernel in the future to allow this directly
without any stub.
3) Destination pages can be placed anywhere, even where they
would not be accessible in real mode. This will allow us to
place ram disks above the RMO if we choose.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: R Sharada <sharada@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Implementation of software load support for the BE iommu. This is very
different from other iommu code on ppc64, since we only do a static mapping.
The mapping is currently hardcoded but should really be read from the
firmware, but they don't set up the device nodes yet. There is a single
512MB DMA window for PCI, USB and ethernet at 0x20000000 for our RAM.
The Cell processor can put the I/O page table either in memory like
the hashed page table (hardware load) or have the operating system
write the entries into memory mapped CPU registers (software load).
I use the software load mechanism because I know that all I/O page
table entries for the amount of installed physical memory fit into
the IO TLB cache. At the point when we get machines with more than
4GB of installed memory, we can either use hardware I/O page table
access like the other platforms do or dynamically update the I/O
TLB entries when a page fault occurs in the I/O subsystem.
The software load can then use the macros that I have implemented
for the static mapping in order to do the TLB cache updates.
Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add support for the integrated interrupt controller on BPA
CPUs. There is one of those for each SMT thread.
The mapping of interrupt numbers to HW interrupt sources
is described in arch/ppc64/kernel/bpa_iic.h.
This version hardcodes the 'Spider' chip as the secondary
interrupt controller. That is not really generic for the
architecture, but at the moment it is the only secondary
PIC that exists.
A little more work will be needed on this as soon as
we have boards with multiple external interrupt controllers.
Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds the basic support for running on BPA machines.
So far, this is only the IBM workstation, and it will
not run on others without a little more generalization.
It should be possible to configure a kernel for any
combination of CONFIG_PPC_BPA with any of the other
multiplatform targets.
Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
BPA is using rtas for PCI but should not be confused by
pSeries code. This also avoids some #ifdefs. Other
platforms that want to use rtas_pci.c could create
their own platform_pci.c with platform specific fixups.
Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch allows iSeries to build with CONFIG_PCI=n. This is useful for
partitions that have only virtual I/O.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch just merges XmPciLpEvent.c into iSeries_irq.c (the only caller of
its only external function). XmPciLpEvent.c just contained the lowlevel
iSeries irq code.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Clean up iSeries_VpdInfo.c:
- white space and comment fixes
- make a function static
- the functions here are only called from iSeries_pci.c, so
CONFIG_PCI will be set (so remove check)
- only build when CONFIG_PCI is set
- remove unneeded includes and cast
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The file arch/ppc64/kernel/iSeries_pci_reset contains only one function that
is not use anywhere (any more). Remove it. This function is the only user of
the ReturnCode member of iSeries_Device_Node, so remove that as well.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
