Kernel bugzilla 10273
As reported by Jos van der Ende, ever since commit
5a606b72a4 ("[SPARC64]: Do not ACK an
INO if it is disabled or inprogress.") sun4u interrupts
can get stuck.
What this changset did was add the following conditional to
the various IRQ chip ->enable() handlers on sparc64:
if (unlikely(desc->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
return;
which is correct, however it means that special care is needed
in the ->enable() method.
Specifically we must put the interrupt into IDLE state during
an enable, or else it might never be sent out again.
Setting the INO interrupt state to IDLE resets the state machine,
the interrupt input to the INO is retested by the hardware, and
if an interrupt is being signalled by the device, the INO
moves back into TRANSMIT state, and an interrupt vector is sent
to the cpu.
The two sun4v IRQ chip handlers were already doing this properly,
only sun4u got it wrong.
Signed-off-by: David S. Miller <davem@davemloft.net>
Invoke the desc->handle_irq directly in the top-level dispatch,
just like other sophisticated ports.
This will allow us to decrease the cost of the MSI queue dispatch.
Signed-off-by: David S. Miller <davem@davemloft.net>
Do not use *alloc_bootmem_low*(), because ARCH_LOW_ADDRESS_LIMIT
is 4GB and this results in boot failures if all of the physical
memory in the machine is above 4GB.
Signed-off-by: David S. Miller <davem@davemloft.net>
It no longer translates to "real irqs" (aka. INO buckets)
so reflect that by using a simpler name for it.
Signed-off-by: David S. Miller <davem@davemloft.net>
All the users go through virt_irq_to_bucket() and essentially
want to go from a virt_irq to an INO, but we have a way
to do that already via virt_to_real_irq_table[].dev_ino.
This also allows us to kill both virt_to_real_irq() and
virt_irq_to_bucket().
Signed-off-by: David S. Miller <davem@davemloft.net>
We have a place to stick INO information in the
virt_to_real_irq_table[], which is currently only used for VIRQs.
And that is readily accessible from the one __irq_ino() call site.
Signed-off-by: David S. Miller <davem@davemloft.net>
We were simply concatenating the devhandle and devino and using that
as the cookie, which defeats the entire purpose of the VIRQ hypervisor
interfaces.
Now that we use physical addresses for the INO buckets, we can
allocate them dynamically for VIRQs and encode the cookies as
~__pa(bucket). This allows us to test for and decode the cookie with
a simple:
brlz $reg1, 1f
xnor $reg1, %g0, $reg2
sequence.
This works because bit 64 is never set in traditional
INO vectors, and it is also never set in a physical
address. So xnor'ing the physical address of the bucket
always gives us a negative number, and thus a unique
condition we can test cheaply.
Inspired by ideas from Greg Onufer.
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently we chain IVEC entries using 32-bit "pointers"
because we know that the ivector_table is in the main
kernel image, thus below 4GB.
This uses proper 64-bit pointers instead.
Whilst this bloats up the kernel image size, this sets
the infrastructure necessary to significantly shrink the
kernel size by using physical addresses and dynamically
allocating the ivector table.
Signed-off-by: David S. Miller <davem@davemloft.net>
This also makes us use the MSI queues correctly.
Each MSI queue is serviced by a normal sun4u/sun4v INO interrupt
handler. This handler runs the MSI queue and dispatches the
virtual interrupts indicated by arriving MSIs in that MSI queue.
All of the common logic is placed in pci_msi.c, with callbacks to
handle the PCI controller specific aspects of the operations.
This common infrastructure will make it much easier to add MSG
support.
Signed-off-by: David S. Miller <davem@davemloft.net>
The support code is identical to the hypervisor sun4v stuff,
just replacing the hypervisor calls with register reads and
writes in the Fire controller.
Signed-off-by: David S. Miller <davem@davemloft.net>
1) sun4{u,v}_build_msi() have improper return value handling.
We should always return negative error codes, instead of
using the magic value "0" which could in fact be a valid
MSI number.
2) sun4{u,v}_build_msi() should return -ENOMEM instead of
calling prom_prom() halt with kzalloc() of the interrupt
data fails.
3) We 'remembered' the MSI number using a singleton in the
struct device archdata area, this doesn't work for MSI-X
which can cause multiple MSIs assosciated with one device.
Delete that archdata member, and instead store the MSI
number in the IRQ chip data area.
Signed-off-by: David S. Miller <davem@davemloft.net>
Sometimes we were using 32-bit values and the top bits were
getting inadvertantly chopped off. This will matter for the
forthcoming Fire controller MSI support.
Signed-off-by: David S. Miller <davem@davemloft.net>
Every time a cpu is added via hotplug, we allocate the per-cpu MONDO
queues but we never free them up. Freeing isn't easy since the first
cpu gets this memory from bootmem.
Therefore, the simplest thing to do to fix this bug is to allocate the
queues for all possible cpus at boot time.
Signed-off-by: David S. Miller <davem@davemloft.net>
The dev_handle and dev_ino fields don't match up exactly to
the traditional IMAP_IGN and IMAP_INO masks.
So store them away in a table and look them up directly.
Signed-off-by: David S. Miller <davem@davemloft.net>
dr-cpu unconfigure requests will walk throught he enabled
IRQs and trigger ->set_affinity so that the going-down
cpu no longer has INOs targetted to it.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is also a partial workaround for a bug in the LDOM firmware which
double-transmits RX inos during high load. Without this, such an
event causes the kernel to loop forever in the interrupt call chain
ACK'ing but never actually running the IRQ handler (and thus clearing
the interrupt condition in the device).
There is still a bad potential effect when double INOs occur,
not covered by this changeset. Namely, if the INO is already on
the per-cpu INO vector list, we still blindly re-insert it and
thus we can end up losing interrupts already linked in after
it.
We could deal with that by traversing the list before insertion,
but that's too expensive for this edge case.
Signed-off-by: David S. Miller <davem@davemloft.net>
We were doing the wrong call to turn them on, and also
when enabling we need to forcefully set the state to IDLE.
Signed-off-by: David S. Miller <davem@davemloft.net>
Some minor refactoring in the generic code was necessary for
this:
1) This controller requires 8-byte access to the interrupt map
and clear register. They are 64-bits on all the other
SBUS and PCI controllers anyways, so this was easy to cure.
2) The IMAP register has a different layout and some bits that we
need to preserve, so use a read/modify/write when making
changes to the IMAP register in generic code.
3) Flushing the entire IOMMU TLB is best done with a single write
to a register on this PCI controller, add a iommu->iommu_flushinv
for this.
Still lacks MSI support, that will come later.
Signed-off-by: David S. Miller <davem@davemloft.net>
Things were scattered all over the place, split between
SMP and non-SMP.
Unify it all so that dyntick support is easier to add.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is kind of hokey, we could use the hardware provided facilities
much better.
MSIs are assosciated with MSI Queues. MSI Queues generate interrupts
when any MSI assosciated with it is signalled. This suggests a
two-tiered IRQ dispatch scheme:
MSI Queue interrupt --> queue interrupt handler
MSI dispatch --> driver interrupt handler
But we just get one-level under Linux currently. What I'd like to do
is possibly stick the IRQ actions into a per-MSI-Queue data structure,
and dispatch them form there, but the generic IRQ layer doesn't
provide a way to do that right now.
So, the current kludge is to "ACK" the interrupt by processing the
MSI Queue data structures and ACK'ing them, then we run the actual
handler like normal.
We are wasting a lot of useful information, for example the MSI data
and address are provided with ever MSI, as well as a system tick if
available. If we could pass this into the IRQ handler it could help
with certain things, in particular for PCI-Express error messages.
The MSI entries on sparc64 also tell you exactly which bus/device/fn
sent the MSI, which would be great for error handling when no
registered IRQ handler can service the interrupt.
We override the disable/enable IRQ chip methods in sun4v_msi, so we
have to call {mask,unmask}_msi_irq() directly from there. This is
another ugly wart.
Signed-off-by: David S. Miller <davem@davemloft.net>
Otherwise we can't use the generic MSI code.
Furthermore, properly use the {get,set}_irq_foo() abstracted
interfaces instead of direct accesses to irq_desc[]->foo.
Signed-off-by: David S. Miller <davem@davemloft.net>
Consolidation: remove the irq_affinity[NR_IRQS] array and move it into the
irq_desc[NR_IRQS].affinity field.
[akpm@osdl.org: sparc64 build fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch-queue improves the generic IRQ layer to be truly generic, by adding
various abstractions and features to it, without impacting existing
functionality.
While the queue can be best described as "fix and improve everything in the
generic IRQ layer that we could think of", and thus it consists of many
smaller features and lots of cleanups, the one feature that stands out most is
the new 'irq chip' abstraction.
The irq-chip abstraction is about describing and coding and IRQ controller
driver by mapping its raw hardware capabilities [and quirks, if needed] in a
straightforward way, without having to think about "IRQ flow"
(level/edge/etc.) type of details.
This stands in contrast with the current 'irq-type' model of genirq
architectures, which 'mixes' raw hardware capabilities with 'flow' details.
The patchset supports both types of irq controller designs at once, and
converts i386 and x86_64 to the new irq-chip design.
As a bonus side-effect of the irq-chip approach, chained interrupt controllers
(master/slave PIC constructs, etc.) are now supported by design as well.
The end result of this patchset intends to be simpler architecture-level code
and more consolidation between architectures.
We reused many bits of code and many concepts from Russell King's ARM IRQ
layer, the merging of which was one of the motivations for this patchset.
This patch:
rename desc->handler to desc->chip.
Originally i did not want to do this, because it's a big patch. But having
both "desc->handler", "desc->handle_irq" and "action->handler" caused a
large degree of confusion and made the code appear alot less clean than it
truly is.
I have also attempted a dual approach as well by introducing a
desc->chip alias - but that just wasnt robust enough and broke
frequently.
So lets get over with this quickly. The conversion was done automatically
via scripts and converts all the code in the kernel.
This renaming patch is the first one amongst the patches, so that the
remaining patches can stay flexible and can be merged and split up
without having some big monolithic patch act as a merge barrier.
[akpm@osdl.org: build fix]
[akpm@osdl.org: another build fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is the long overdue conversion of sparc64 over to
the generic IRQ layer.
The kernel image is slightly larger, but the BSS is ~60K
smaller due to the reduced size of struct ino_bucket.
A lot of IRQ implementation details, including ino_bucket,
were moved out of asm-sparc64/irq.h and are now private to
arch/sparc64/kernel/irq.c, and most of the code in irq.c
totally disappeared.
One thing that's different at the moment is IRQ distribution,
we do it at enable_irq() time. If the cpu mask is ALL then
we round-robin using a global rotating cpu counter, else
we pick the first cpu in the mask to support single cpu
targetting. This is similar to what powerpc's XICS IRQ
support code does.
This works fine on my UP SB1000, and the SMP build goes
fine and runs on that machine, but lots of testing on
different setups is needed.
Signed-off-by: David S. Miller <davem@davemloft.net>
Inspired by PowerPC XICS interrupt support code.
All IRQs are virtualized in order to keep NR_IRQS from needing
to be too large. Interrupts on sparc64 are arbitrary 11-bit
values, but we don't need to define NR_IRQS to 2048 if we
virtualize the IRQs.
As PCI and SBUS controller drivers build device IRQs, we divy
out virtual IRQ numbers incrementally starting at 1. Zero is
a special virtual IRQ used for the timer interrupt.
So device drivers all see virtual IRQs, and all the normal
interfaces such as request_irq(), enable_irq(), etc. translate
that into a real IRQ number in order to configure the IRQ.
At this point knowledge of the struct ino_bucket is almost
entirely contained within arch/sparc64/kernel/irq.c There are
a few small bits in the PCI controller drivers that need to
be swept away before we can remove ino_bucket's definition
out of asm-sparc64/irq.h and privately into kernel/irq.c
Signed-off-by: David S. Miller <davem@davemloft.net>
And reuse that struct member for virt_irq, which will
be used in future changesets for the implementation of
mapping between real and virtual IRQ numbers.
This nicely kills off a ton of SBUS and PCI controller
PIL assignment code which is no longer necessary.
Signed-off-by: David S. Miller <davem@davemloft.net>
Only pil0_dummy_bucket had a pil of zero and we just killed that
off, so we can delete all special case code that used bp->pil==0
as a way to identify a dummy bucket.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the first in a series of cleanups that will hopefully
allow a seamless attempt at using the generic IRQ handling
infrastructure in the Linux kernel.
Define PIL_DEVICE_IRQ and vector all device interrupts through
there.
Get rid of the ugly pil0_dummy_{bucket,desc}, instead vector
the timer interrupt directly to a specific handler since the
timer interrupt is the only event that will be signaled on
PIL 14.
The irq_worklist is now in the per-cpu trap_block[].
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller
Harvey Harrison
David S. Miller
Stephen Rothwell
Al Viro
Al Viro
Jörn Engel
Ingo Molnar