linux-toradex.git/arch/powerpc/sysdev/xics/xics-common.c, branch v4.8

powerpc/xics: Properly set Edge/Level type and enable resend

2016-08-09T04:50:18+00:00

This sets the type of the interrupt appropriately. We set it as follow:

 - If not mapped from the device-tree, we use edge. This is the case
of the virtual interrupts and PCI MSIs for example.

 - If mapped from the device-tree and #interrupt-cells is 2 (PAPR
compliant), we use the second cell to set the appropriate type

 - If mapped from the device-tree and #interrupt-cells is 1 (current
OPAL on P8 does that), we assume level sensitive since those are
typically going to be the PSI LSIs which are level sensitive.

Additionally, we mark the interrupts requested via the opal_interrupts
property all level. This is a bit fishy but the best we can do until we
fix OPAL to properly expose them with a complete descriptor. It is also
correct for the current HW anyway as OPAL interrupts are currently PCI
error and PSI interrupts which are level.

Finally now that edge interrupts are properly identified, we can enable
CONFIG_HARDIRQS_SW_RESEND which will make the core re-send them if
they occur while masked, which some drivers rely upon.

This fixes issues with lost interrupts on some Mellanox adapters.

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Michael Ellerman

powerpc/xics: Add ICP OPAL backend

2016-07-17T06:42:45+00:00

This adds a new XICS backend that uses OPAL calls, which can be
used when we don't have native support for the platform interrupt
controller.

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Michael Ellerman

genirq/irqdomain: Allow irq domain aliasing

2015-07-29T22:14:36+00:00

It is not uncommon (at least with the ARM stuff) to have a piece
of hardware that implements different flavours of "interrupts".
A typical example of this is the GICv3 ITS, which implements
standard PCI/MSI support, but also some form of "generic MSI".

So far, the PCI/MSI domain is registered using the ITS device_node,
so that irq_find_host can return it. On the contrary, the raw MSI
domain is not registered with an device_node, making it impossible
to be looked up by another subsystem (obviously, using the same
device_node twice would only result in confusion, as it is not
defined which one irq_find_host would return).

A solution to this is to "type" domains that may be aliasing, and
to be able to lookup an device_node that matches a given type.
For this, we introduce irq_find_matching_host() as a superset
of irq_find_host:

struct irq_domain *irq_find_matching_host(struct device_node *node,
                                enum irq_domain_bus_token bus_token);

where bus_token is the "type" we want to match the domain against
(so far, only DOMAIN_BUS_ANY is defined). This result in some
moderately invasive changes on the PPC side (which is the only
user of the .match method).

This has otherwise no functionnal change.

Reviewed-by: Hanjun Guo 
Signed-off-by: Marc Zyngier 
Cc: 
Cc: Yijing Wang 
Cc: Ma Jun 
Cc: Lorenzo Pieralisi 
Cc: Duc Dang 
Cc: Bjorn Helgaas 
Cc: Jiang Liu 
Cc: Jason Cooper 
Link: http://lkml.kernel.org/r/1438091186-10244-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner

powerpc: Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc

2015-06-02T06:54:44+00:00

Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc while we
already have a pointer to corresponding irq_desc.

Signed-off-by: Jiang Liu 
Signed-off-by: Michael Ellerman

powerpc: Constify irq_domain_ops

2015-05-11T06:58:20+00:00

The irq_domain_ops are not modified by the driver and the irqdomain core
code accepts pointer to a const data.

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Michael Ellerman

powerpc: Drop return value of smp_ops->probe()

2015-04-10T10:02:49+00:00

smp_ops->probe() is currently supposed to return the number of cpus in
the system.

The last actual usage of the value was removed in May 2007 in e147ec8f1808
"[POWERPC] Simplify smp_space_timers". We still passed the value around
until June 2010 when even that was finally removed in c1aa687d499a
"powerpc: Clean up obsolete code relating to decrementer and timebase".

So drop that requirement, probe() now returns void, and update all
implementations.

Signed-off-by: Michael Ellerman

powerpc: Replace cpumask_weight(cpu_possible_mask) with num_possible_cpus()

2015-01-23T03:02:51+00:00

num_possible_cpus() is just a shorthand for it.

Signed-off-by: Emil Medve 
Signed-off-by: Michael Ellerman

powerpc: Replace __get_cpu_var uses

2014-11-03T01:12:32+00:00

This still has not been merged and now powerpc is the only arch that does
not have this change. Sorry about missing linuxppc-dev before.

V2->V2
  - Fix up to work against 3.18-rc1

__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Cc: Benjamin Herrenschmidt 
CC: Paul Mackerras 
Signed-off-by: Christoph Lameter 
[mpe: Fix build errors caused by set/or_softirq_pending(), and rework
      assignment in __set_breakpoint() to use memcpy().]
Signed-off-by: Michael Ellerman

powerpc: Fix some endian issues in xics code

2013-08-14T05:33:25+00:00

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

irqdomain: Always update revmap when setting up a virq

2012-07-11T15:15:34+00:00

At irq_setup_virq() time all of the data needed to update the reverse
map is available, but the current code ignores it and relies upon the
slow path to insert revmap records.  This patch adds revmap updating
to the setup path so the slow path will no longer be necessary.

Signed-off-by: Grant Likely 
Cc: Paul Mundt 
Cc: Benjamin Herrenschmidt 
Cc: Thomas Gleixner 
Cc: Rob Herring