The PCI bridge representing the PCIE root complex on Axon, contains
device BARs for a memory range and ROM that define inbound accesses.
This confuses the kernel resource management code -- the resources
need to be hidden when Axon is a host bridge.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The cell IOMMU code to parse the dma-ranges properties, used for the fixed
mapping, was broken in two ways for some devices.
Firstly it didn't cope with empty dma-ranges properties. An empty property
implies no translation so can be safely skipped.
The code also wrongly assumed it would be looking at PCI devices, and hard
coded the number of address and size cells.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
At present, we can hit the BUG_ON in __spu_update_sched_info by reading
the regs file of a context between two calls to spu_run. The
spu_release_saved called by spufs_regs_read() is resulting in the (now
non-runnable) context being placed back on the run queue, so the next
call to spu_run ends up in the bug condition.
This change uses the SPU_SCHED_SPU_RUN flag to only reschedule a context
if it's still in spu_run().
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
commit 4ef11014 introduced a usage of SCHED_IDLE to detect when
a context is within spu_run.
Instead of SCHED_IDLE (which has other meaning), add a flag to
sched_flags to tell if a context should be running.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
The only tricky part is we need to adjust the PTE insertion loop to
cater for holes in the page table. The PTEs for each segment start on
a 4K boundary, so with 16M pages we have 16 PTEs per segment and then
a gap to the next 4K page boundary.
It might be possible to allocate the PTEs for each segment separately,
saving the memory currently filling the gaps. However we'd need to
check that's OK with the hardware, and that it actually saves memory.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Make some preliminary changes to cell_iommu_alloc_ptab() to allow it to
take the page size as a parameter rather than assuming IOMMU_PAGE_SIZE.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
We use n_pte_pages to calculate the stride through the page tables, but
we also use it to set the NPPT value in the segment table entry. That is
defined as the number of 4K pages per segment, so we should calculate
it as such regardless of the IOMMU page size.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Currently the cell IOMMU code allocates the entire IOMMU page table in a
contiguous chunk. This is nice and tidy, but for machines with larger
amounts of RAM the page table allocation can fail due to it simply being
too large.
So split the segment table and page table setup routine, and arrange to
have the dynamic and fixed page tables allocated separately.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
There's no need to allocate the pad page unless we're going to actually
use it - so move the allocation to where we know we're going to use it.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The cell IOMMU code no longer needs to save the pte_offset variable
separately, it is incorporated into tbl->it_offset.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The cell IOMMU tce build and free routines use pte_offset to convert
the index passed from the generic IOMMU code into a page table offset.
This takes into account the SPIDER_DMA_OFFSET which sets the top bit
of every DMA address.
However it doesn't cater for the IOMMU window starting at a non-zero
address, as the base of the window is not incorporated into pte_offset
at all.
As it turns out tbl->it_offset already contains the value we need, it
takes into account the base of the window and also pte_offset. So use
it instead!
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
It's called the fixed mapping, not the static mapping.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Ulrich Weigand has found that the hardware watchpoints on cell were not
working back in November :
http://ozlabs.org/pipermail/linuxppc-dev/2007-November/046135.html
This patch sets them during initialization.
Signed-off-by: Jens Osterkamp <jens@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The spu_runcntl_RW register is restored within spu_restore function.
So, at the end of spu_bind_context, the SPU context is not just loaded,
but running.
This change corrects the state switch to account the time as USER.
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
There is a potential race between flushes of the entire SLB in the MFC
and the point where new entries are being established. The problem is
that we might put a ESID entry into the MFC SLB when the VSID entry has
just been cleared by the global flush.
This can be circumvented by holding the register_lock throughout both
the flushing and the creation of SLB entries.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
When we replace an SLB entry in the MFC after using up all the available
entries, there is a short window in which an incorrect entry is marked
as valid.
The problem is that the 'valid' bit is stored in the ESID, which is
always written after the VSID. Overwriting the VSID first will make the
original ESID entry point to the new VSID, which means that any
concurrent DMA accessing the old ESID ends up being redirected to the
new virtual address. A few cycles later, we write the new ESID and
everything is fine again.
That race can be closed by writing a zero entry to the ESID first, which
makes sure that the VSID is not accessed until we write the new ESID.
Note that we don't actually need to invalidate the SLB entry using the
invalidation register, which would also flush any ERAT entries for that
segment, because the segment translation does not become invalid but is
only removed from the SLB cache.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
There is a small race between the context save procedure
and the SPU interrupt handling, where we expect all interrupt
processing to have finished after disabling them, while
an interrupt is still being processed on another CPU.
The obvious fix is to call synchronize_irq() after disabling
the interrupts at the start of the context save procedure
to make sure we never access the SPU any more during an
ongoing save or even after that.
Thanks to Benjamin Herrenschmidt for pointing this out.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Currently, we get the following output from sputrace:
[5.097935954] 1606: spufs_ps_nopfn__enter (thread = 1605, spu = -1)
[5.097958164] 1606: spufs_ps_nopfn__insert (thread = 1605, spu = 15)
[5.097973529] 1607: spufs_ps_nopfn__enter (thread = 1605, spu = -1)
[5.097989174] 1607: spufs_ps_nopfn__insert (thread = 1605, spu = 14)
Which leads me to believe that 160[67] is the current thread ID, and
1605 is the context backing the psmap.
However, the 'current' and 'owner' tids are reversed - the 'current'
tid is on the right. This change puts the current thread ID in the
left-hand column instead, and renames the right to 'ctxthread'.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
At present, we have a situation where a context with no owner is
re-scheduled by spu_forget:
Thread 1: reading regs file Thread 2: context owner
spu_forget()
- ctx->owner = NULL
- set SPU_SCHED_WAS_ACTIVE
spu_acquire_saved()
- context is in saved state
spu_release_saved()
- SPU_SCHED_WAS_ACTIVE is set,
so spu_activate() the context,
which now has no owner
In spu_forget(), we shouldn't be requesting a re-schedule by setting
SPU_SCHED_WAS_ACTIVE. This change removes the set_bit in spu_forget(),
so that spu_release_saved() doesn't reinsert this destroyed context on
to the run queue.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
We have a small window where a spu context may be destroyed while
we're servicing a page fault (from another thread) to the context's
problem state mapping.
After we up_read() the mmap_sem, it's possible that the context is
destroyed by its owning thread, and so the later references to ctx
are invalid. This can maifest as a deadlock on the (now free()-ed)
context state mutex.
This change adds a reference to the context before we release the
mmap_sem, so that the context cannot be destroyed.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
At present, the __spufs_trap_data_map and __spu_trap_data_seq functions
exit if spu->flags has the SPU_CONTEXT_SWITCH_ACTIVE set. This was
resulting in suprious returns from these functions, as they may be
legitimately called when we have this bit set.
We only use it in these two sanity checks, so this change removes the
flag completely. This fixes hangs in the page-fault path of SPE apps.
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
2.6.25 has a regression where we can starve the scheduler by creating
(N_SPES+1) contexts, then running them one at a time.
The final context will never be run, as the other contexts are loaded on
the SPEs, none of which are repoted as free (ie, spu->alloc_state !=
SPU_FREE), so spu_get_idle() doesn't give us a spu to run on. Because
all of the contexts are stopped, none are descheduled by the scheduler
tick, as spusched_tick returns if spu_stopped(ctx).
This change replaces the spu_stopped() check with checking for SCHED_IDLE
in ctx->policy. We set a context's policy to SCHED_IDLE when we're not
in spu_run(). We also favour SCHED_IDLE contexts when looking for contexts
to unbind, but leave their timeslice intact for later resumption.
This patch fixes the following test in the spufs-testsuite:
tests/20-scheduler/02-yield-starvation
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
[POWERPC] Remove unused CONFIG_WANT_DEVICE_TREE
[POWERPC] Cell RAS: Remove DEBUG, and add license and copyright
[POWERPC] hvc_rtas_init() must be __init
[POWERPC] free_property() must not be __init
[POWERPC] vdso_do_func_patch{32,64}() must be __init
[POWERPC] Remove generated files on make clean
[POWERPC] Fix arch/ppc compilation - add typedef for pgtable_t
[POWERPC] Wire up new timerfd syscalls
[POWERPC] PS3: Update sys-manager button events
[POWERPC] PS3: Sys-manager code cleanup
[POWERPC] PS3: Use system reboot on restart
[POWERPC] PS3: Fix bootwrapper hang bug
[POWERPC] PS3: Fix reading pm interval in logical performance monitor
[POWERPC] PS3: Fix setting bookmark in logical performance monitor
[POWERPC] Fix DEBUG_PREEMPT warning when warning
* Add path_put() functions for releasing a reference to the dentry and
vfsmount of a struct path in the right order
* Switch from path_release(nd) to path_put(&nd->path)
* Rename dput_path() to path_put_conditional()
[akpm@linux-foundation.org: fix cifs]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.
Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
<dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
struct path in every place where the stack can be traversed
- it reduces the overall code size:
without patch series:
text data bss dec hex filename
5321639 858418 715768 6895825 6938d1 vmlinux
with patch series:
text data bss dec hex filename
5320026 858418 715768 6894212 693284 vmlinux
This patch:
Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/powerpc/platforms/cell/ras.c still has DEBUG #defined, which is no
longer necessary. Disable it - this disables two pr_debugs().
While we're there this file should have a copyright notice and license,
so add both.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
RCU style multiple probes support for the Linux Kernel Markers. Common case
(one probe) is still fast and does not require dynamic allocation or a
supplementary pointer dereference on the fast path.
- Move preempt disable from the marker site to the callback.
Since we now have an internal callback, move the preempt disable/enable to the
callback instead of the marker site.
Since the callback change is done asynchronously (passing from a handler that
supports arguments to a handler that does not setup the arguments is no
arguments are passed), we can safely update it even if it is outside the
preempt disable section.
- Move probe arm to probe connection. Now, a connected probe is automatically
armed.
Remove MARK_MAX_FORMAT_LEN, unused.
This patch modifies the Linux Kernel Markers API : it removes the probe
"arm/disarm" and changes the probe function prototype : it now expects a
va_list * instead of a "...".
If we want to have more than one probe connected to a marker at a given
time (LTTng, or blktrace, ssytemtap) then we need this patch. Without it,
connecting a second probe handler to a marker will fail.
It allow us, for instance, to do interesting combinations :
Do standard tracing with LTTng and, eventually, to compute statistics
with SystemTAP, or to have a special trigger on an event that would call
a systemtap script which would stop flight recorder tracing.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Mason <mmlnx@us.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: David Smith <dsmith@redhat.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-2.6.25' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
[POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpc
[POWERPC] Enable hotplug memory remove for 64-bit powerpc
[POWERPC] Add remove_memory() for 64-bit powerpc
[POWERPC] Make cell IOMMU fixed mapping printk more useful
[POWERPC] Fix potential cell IOMMU bug when switching back to default DMA ops
[POWERPC] Don't enable cell IOMMU fixed mapping if there are no dma-ranges
[POWERPC] Fix cell IOMMU null pointer explosion on old firmwares
[POWERPC] spufs: Fix timing dependent false return from spufs_run_spu
[POWERPC] spufs: No need to have a runnable SPU for libassist update
[POWERPC] spufs: Update SPU_Status[CISHP] in backing runcntl write
[POWERPC] spufs: Fix state_mutex leaks
[POWERPC] Disable G5 NAP mode during SMU commands on U3
Add a .show_options super operation to spufs.
Use generic_show_options() and save the complete option string in
spufs_fill_super().
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
simple_attr_close implementes ->release so it should be named accordingly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: <stefano.brivio@polimi.it>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg KH <greg@kroah.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sometimes simple attributes might need to return an error, e.g. for
acquiring a mutex interruptibly. In fact we have that situation in
spufs already which is the original user of the simple attributes. This
patch merged the temporarily forked attributes in spufs back into the
main ones and allows to return errors.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: <stefano.brivio@polimi.it>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg KH <greg@kroah.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the cell IOMMU fixed mapping just printks that it's been setup,
which is not particularly useful. Much more interesting is the address
ranges for the different windows. This adds one line to dmesg on a blade.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
If we get a 64-bit dma mask we switch to the fixed ops and call
cell_dma_dev_setup(). If the driver then switches back to a 32-bit dma
mask for any reason we don't call cell_dma_dev_setup() again, which
has the potential to leave bogus data in dev->archdata.dma_data.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
In order for the cell IOMMU fixed mapping to work we need "dma-ranges"
properties in the device tree. If there are none then there's no point
enabling the fixed mapping support.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The cell IOMMU fixed mapping support has a null pointer bug if you run
it on older firmwares that don't contain the "dma-ranges" properties.
Fix it and convert to using of_get_next_parent() while we're there.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Stop bits are only valid when the running bit is not set. Status bits
carry over from one invocation of spufs_run_spu() to another, so the
RUNNING bit gets added to the previous state of the register which may
have been a remote library call. In this case, it looks like another
library routine should be invoked, but the spe is actually running.
This fixes a problem with a testcase that exercises the scheduler.
Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We don't need to update the libassist statistic with the context in a
runnable state, so do it after spu_disable_spu().
Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently, the kernel may fail to restart a SPE context which
has stopped and been swapped out.
This changes spu_backing_runcntl_write to emulate the real
SPU_Status register exactly. When the SPU Run Control register
is written with SPU_RunCntl[Run] set to '1', the physical SPU
automatically sets SPU_Status[R] and clears SPU_Status[CISHP].
Signed-off-by: Masato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Fix various state_mutex leaks. The worst one was introduced by the
interrutible state_mutex conversion but there've been a few before
too. Notably spufs_wait now returns without the state_mutex held
when returning an error, which actually cleans up some code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
I got this warning from gcc:
arch/powerpc/platforms/cell/axon_msi.c:118: warning: 'tmp' may be used uninitialized in this function
Which turns out to be a false positive, but pointed out that it was
possible for the error path in find_msi_translator() to do an extra
of_node_put on a node. This fixes it by localising the ref counting
a bit. As a side effect, the warning goes away.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There's a brown-paper-bag bug in axon_msi, we pass the address of our
FIFO directly to the hardware, without DMA mapping it. This leads to
DMA exceptions if you enable MSI & the IOMMU.
The fix is to correctly DMA map the fifo, dma_alloc_coherent() does
what we want - and we need to track the virt & phys addresses.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Now that we create of_platform devices earlier on cell, we can make the
axon_msi driver an of_platform driver. This makes the code cleaner in
several ways, and most importantly means we have a struct device.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently cell publishes OF devices at device_initcall() time, which
means the earliest a driver can bind to a device is also device_initcall()
time. We have a driver we want to register before other devices, so
publish the devices at subsys_initcall() time.
This should not cause any behaviour change for existing drivers, as they
are still bound at device_initcall() time.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Reference count for the "neighbor" spu context was not
being correctly decremented after usage.
So, contexts used as reference during SPU affinity setup
were not being deallocated, leading to a memory leak.
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently we only catch debug events through the 0x3fff status;
spufs_run_spu doesn't handle single-step SPE events.
This change adds a handler for conditions where the SPE is stopped due
to single-step-mode.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds markers two important points in the spufs code and a new
module (sputrace.ko) that allows reading these out through a proc file.
Long-term I'd rather see something like lttng extended to use the spufs
instrumentation, but for now I think this is a good enough quick
solution. We'll probably want to add various addition event in addition
to that ones I have already.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds support for setting up a fixed IOMMU mapping on certain
cell machines. For 64-bit devices this avoids the performance overhead of
mapping and unmapping pages at runtime. 32-bit devices are unable to use
the fixed mapping.
The fixed mapping is established at boot, and maps all of physical memory
1:1 into device space at some offset. On machines with < 30 GB of memory
we setup the fixed mapping immediately above the normal IOMMU window.
For example a machine with 4GB of memory would end up with the normal
IOMMU window from 0-2GB and the fixed mapping window from 2GB to 6GB. In
this case a 64-bit device wishing to DMA to 1GB would be told to DMA to
3GB, plus any offset required by firmware. The firmware offset is encoded
in the "dma-ranges" property.
On machines with 30GB or more of memory, we are unable to place the fixed
mapping above the normal IOMMU window as we would run out of address space.
Instead we move the normal IOMMU window to coincide with the hash page
table, this region does not need to be part of the fixed mapping as no
device should ever be DMA'ing to it. We then setup the fixed mapping
from 0 to 32GB.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Split out the ioid fetching and checking logic so we can use it elsewhere
in a subsequent patch.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add support to cell_iommu_setup_page_tables() for handling two windows,
the dynamic window and the fixed window. A fixed window size of 0
indicates that there is no fixed window at all.
Currently there are no callers who pass a non-zero fixed window, but the
upcoming fixed IOMMU mapping patch will change that.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
