So we could remove some duplicated calling to irq_desc

v2: make sure irq_desc in  init/main.c is not used without generic_hardirqs
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

remove irq limit checks - nr_irqs is dynamic and we expand anytime.

v2: fix checking about result irq_cfg_without_new, so could use msi again
v3: use irq_desc_without_new to check irq is valid
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Replace another nr_irqs loop to avoid the allocation of all sparse
irq entries - use for_each_irq_desc instead.

v2: make sure arch without GENERIC_HARDIRQS works too
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

There are a handful of loops that go from 0 to nr_irqs and use
get_irq_desc() on them. These would allocate all the irq_desc
entries, regardless of the need for them.

Use the smarter for_each_irq_desc() iterator that will only iterate
over the present ones.

v2: make sure arch without GENERIC_HARDIRQS work too
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

add an irq_desc accessor that will not allocate any sparse entry
but returns failure if there's no entry present.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

based on Eric's patch ...

together mold it with dyn_array for irq_desc, will allcate kstat_irqs for
nr_irq_desc alltogether if needed. -- at that point nr_cpus is known already.

v2: make sure system without generic_hardirqs works they don't have irq_desc
v3: fix merging
v4: [mingo@elte.hu] fix typo

[ mingo@elte.hu ] irq: build fix

fix:

 arch/x86/xen/spinlock.c: In function 'xen_spin_lock_slow':
 arch/x86/xen/spinlock.c:90: error: 'struct kernel_stat' has no member named 'irqs'
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

irq_timer_state[] is a NR_IRQS sized array that is a side-by array to
the real irq_desc[] array.

Integrate that field into the (now dynamic) irq_desc dynamic array and
save some RAM.

v2: keep the old way to support arch not support irq_desc
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

preallocate 32 irq_2_pin entries, and use get_one_free_irq_2_pin() to get
one more and link to irq_cfg if needed.

so don't waste one where no irq is enabled.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

preallocate size is 32, and if it is not enough, irq_cfg will more
via alloc_bootmem() or kzalloc(). (depending on how early we are in
system setup)

v2: fix typo about size of init_one_irq_cfg ... should use sizeof(struct irq_cfg)
v3: according to Eric, change get_irq_cfg() to irq_cfg()
v4: squash add irq_cfg_alloc in
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

fix:

[   10.631533] calling  yenta_socket_init+0x0/0x20
[   10.631533] Yenta: CardBus bridge found at 0000:15:00.0 [17aa:2012]
[   10.631533] Yenta: Using INTVAL to route CSC interrupts to PCI
[   10.631533] Yenta: Routing CardBus interrupts to PCI
[   10.631533] Yenta TI: socket 0000:15:00.0, mfunc 0x01d01002, devctl 0x64
[   10.731599] BUG: unable to handle kernel NULL pointer dereference at 00000040
[   10.731838] IP: [<c0c95b5f>] _spin_lock_irq+0xf/0x20
[   10.732221] *pde = 00000000
[   10.732741] Oops: 0002 [#1] SMP
[   10.733453]
[   10.734253] Pid: 1, comm: swapper Tainted: G        W (2.6.27-rc3-tip-00173-gd7eaa4f-dirty #1)
[   10.735188] EIP: 0060:[<c0c95b5f>] EFLAGS: 00010002 CPU: 0
[   10.735523] EIP is at _spin_lock_irq+0xf/0x20
[   10.735523] EAX: 00000040 EBX: 00000000 ECX: f6e04c90 EDX: 00000100
[   10.735523] ESI: 000000df EDI: f6e04c90 EBP: f7867df0 ESP: f7867df0
[   10.735523]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[   10.735523] Process swapper (pid: 1, ti=f7867000 task=f7870000 task.ti=f7867000)
[   10.735523] Stack: f7867e04 c0155fbd 00000000 00000000 f6e04c90 f7867e5c c0c6e319 c0f6a074
[   10.735523]        f6e04c90 000017aa 00002012 c112b648 f791f240 c112b5e0 f7867e44 c010440b
[   10.735523]        f791f240 f791f29c c112b8ec f791f240 00000000 f7867e5c c048f893 03c0b648
[   10.735523] Call Trace:
[   10.735523]  [<c0155fbd>] ? probe_irq_on+0x3d/0x140
[   10.735523]  [<c0c6e319>] ? yenta_probe+0x529/0x640
[   10.735523]  [<c010440b>] ? mcount_call+0x5/0xa
[   10.735523]  [<c048f893>] ? pci_match_device+0xa3/0xb0
[   10.735523]  [<c048fc1e>] ? pci_device_probe+0x5e/0x80
[   10.735523]  [<c0515423>] ? driver_probe_device+0x83/0x180
[   10.735523]  [<c0515594>] ? __driver_attach+0x74/0x80
[   10.735523]  [<c0514b69>] ? bus_for_each_dev+0x49/0x70
[   10.735523]  [<c051528e>] ? driver_attach+0x1e/0x20
[   10.735523]  [<c0515520>] ? __driver_attach+0x0/0x80
[   10.735523]  [<c05150d3>] ? bus_add_driver+0x1a3/0x220
[   10.735523]  [<c048fb60>] ? pci_device_remove+0x0/0x40
[   10.735523]  [<c05157f4>] ? driver_register+0x54/0x130
[   10.735523]  [<c048fe2f>] ? __pci_register_driver+0x4f/0x90
[   10.735523]  [<c11e9419>] ? yenta_socket_init+0x19/0x20
[   10.735523]  [<c0101125>] ? do_one_initcall+0x35/0x160
[   10.735523]  [<c11e9400>] ? yenta_socket_init+0x0/0x20
[   10.735523]  [<c01391a6>] ? __queue_work+0x36/0x50
[   10.735523]  [<c013922d>] ? queue_work_on+0x3d/0x50
[   10.735523]  [<c11a2758>] ? kernel_init+0x148/0x210
[   10.735523]  [<c11a2610>] ? kernel_init+0x0/0x210
[   10.735523]  [<c01043f3>] ? kernel_thread_helper+0x7/0x10
[   10.735523]  =======================
[   10.735523] Code: 10 38 f2 74 06 f3 90 8a 10 eb f6 5d 89 c8 c3 8d b6 00 00 00 00 8d bc 27 00 00 00 00 55 89 e5 e8 a4 e8 46 ff fa ba 00 01 00 00 90 <66> 0f c1 10 38 f2 74 06 f3 90 8a 10 eb f6 5d c3 90 55 89 e5 53

as auto-probing wants to iterate over existing irqs.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

add CONFIG_HAVE_SPARSE_IRQ to for use condensed array.
Get rid of irq_desc[] array assumptions.

Preallocate 32 irq_desc, and irq_desc() will try to get more.

( No change in functionality is expected anywhere, except the odd build
  failure where we missed a code site or where a crossing commit itroduces
  new irq_desc[] usage. )

v2: according to Eric, change get_irq_desc() to irq_desc()
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

remove unused defines derived from the (now obsolete) NR_IRQS define.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Until now, NR_IRQS was derived from black magic defines that had to
be "large enough" to both accomodate NR_CPUS and MAX_NR_IO_APICs.

This resulted in a way too large irq_desc[] array on most x86 systems.
Especially with larger CPU masks, the size of irq_desc can spiral out
of control quickly.

So be smarter about it and use precise allocation instead: determine the
default maximum possible IRQ number from the ACPI MADT. Use a minimum limit
of at least 32 IRQs for broken BIOSes.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

fix non-APIC UP build:

 arch/x86/kernel/built-in.o: In function `setup_arch':
 : undefined reference to `pin_map_size'
 arch/x86/kernel/built-in.o: In function `setup_arch':
 : undefined reference to `first_free_entry'
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

fix:

  Building modules, stage 2.
  MODPOST 458 modules
  ERROR: "nr_irqs" [drivers/serial/8250.ko] undefined!
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

convert them to nr_irqs.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

also add first_free_entry and pin_map_size, which were NR_IRQS derived
constants.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

at this point nr_irqs is equal NR_IRQS

convert a few easy users from NR_IRQS to dynamic nr_irqs.

v2: according to Eric, we need to take care of arch without generic_hardirqs
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

so could spare some memory with small alignment in bootmem

also tighten the alignment checking, and make print out less debug info.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

allow dyn-array in per_cpu area, allocated dynamically.

usage:

|  /* in .h */
| struct kernel_stat {
|        struct cpu_usage_stat   cpustat;
|        unsigned int *irqs;
| };
|
|  /* in .c */
| DEFINE_PER_CPU(struct kernel_stat, kstat);
|
| DEFINE_PER_CPU_DYN_ARRAY_ADDR(per_cpu__kstat_irqs, per_cpu__kstat.irqs, sizeof(unsigned int), nr_irqs, sizeof(unsigned long), NULL);

after setup_percpu()/per_cpu_alloc_dyn_array(), the dyn_array in
per_cpu area is ready to use.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Allow crazy big arrays via bootmem at init stage.
Architectures use CONFIG_HAVE_DYN_ARRAY to enable it.

usage:

| static struct irq_desc irq_desc_init __initdata = {
|        .status = IRQ_DISABLED,
|        .chip = &no_irq_chip,
|        .handle_irq = handle_bad_irq,
|        .depth = 1,
|        .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
| #ifdef CONFIG_SMP
|        .affinity = CPU_MASK_ALL
| #endif
| };
|
| static void __init init_work(void *data)
| {
|        struct dyn_array *da = data;
|        struct  irq_desc *desc;
|        int i;
|
|        desc = *da->name;
|
|        for (i = 0; i < *da->nr; i++)
|                memcpy(&desc[i], &irq_desc_init, sizeof(struct irq_desc));
| }
|
| struct irq_desc *irq_desc;
| DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work);

after pre_alloc_dyn_array() after setup_arch(), the array is ready to be
used.

Via this facility we can replace irq_desc[NR_IRQS] array with dyn_array
irq_desc[nr_irqs].

v2: remove _nopanic in pre_alloc_dyn_array()
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

there's no user left.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

to prepare to use dyn_array support etc.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Works on my test box with a quick test.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>