On 03/03/2012 11:35 AM, Rob Herring wrote:
On 03/02/2012 01:29 PM, David Daney wrote:
On 03/02/2012 11:07 AM, Grant Likely wrote:
+static void __init octeon_irq_set_ciu_mapping(unsigned int irq,
+ unsigned int line,
+ unsigned int bit,
+ struct irq_domain *domain,
struct irq_chip *chip,
irq_flow_handler_t handler)
{
+ struct irq_data *irqd;
union octeon_ciu_chip_data cd;
irq_set_chip_and_handler(irq, chip, handler);
-
cd.l = 0;
cd.s.line = line;
cd.s.bit = bit;
irq_set_chip_data(irq, cd.p);
octeon_irq_ciu_to_irq[line][bit] = irq;
+
+ irqd = irq_get_irq_data(irq);
+ irqd->hwirq = line<< 6 | bit;
+ irqd->domain = domain;
I think the domain code will set these.
It is my understanding that the domain code only does this for:
o irq_domain_add_legacy()
o irq_create_direct_mapping()
o irq_create_mapping()
We use none of those. So I do it here.
If there is a better way, I am open to suggestions.
irq_create_mapping is called by irq_create_of_mapping() which is
in turn called by irq_of_parse_and-map(). irq_domain always
manages the hwirq and domain values. Driver code cannot manipulate
them manually.
I really must be missing something.
Given:
1) I must have a mapping between hwirq and irq that I control so that
non-OF code using the OCTEON_IRQ_* constants continues to work.
Those defines are what you need to work to get rid of.
We are not starting from a blank slate here. There is a lot of in-tree
code using these symbols. We cannot make them disappear with wishful
thinking.
The first step is a switch to irq_domains using the existing mappings.
After we do that, I have patches to transition some drivers to use the
OF mapping via irq_domains. After those are merged, we can work toward
getting rid of OCTEON_IRQ_*. But I think it must be the last step in
the process, not the first.
2) irq_create_mapping() will allocate a random irq value if none is
already assigned to the hwirq.
Therefore: To avoid having random irq values assigned, I must manually
assign them.
So you should be using legacy domain if you need to maintain fixed hwirq
to linux irq numbers. "linear" is a bit confusing as it doesn't mean
linear 1:1 irq number assignment, but linear search.
My reading of Grant's code in linux-next directly contradicts this
statement. There is no code in irqdomain.c, that I can see, that allows
me to have an arbitrary mapping of irq <--> hwirq values.
Ultimately, for DT boot you should use of_irq_init to scan the dts, and
then create a linear domain for each interrupt controller node. You may
need to decide on linear vs. legacy at runtime based on having a DT node
pointer or not.
Perhaps, but we need to take the first step before gradually arriving at
some Ultimate Solution.
We will also need to handle irq controllers with 2^20 sparsely populated
hwirq values, so linear domains will probably be out of the question there.
David Daney
