kernel-fxtec-pro1x/arch/powerpc/sysdev/mpic_msi.c
Kyle Moffett 5019609fce powerpc/mpic: Remove MPIC_BROKEN_FRR_NIRQS and duplicate irq_count
The mpic->irq_count variable is only used as a software error-checking
limit to determine whether or not an IRQ number is valid.  In board code
which does not manually specify an IRQ count to mpic_alloc(), i.e. 0, it
is automatically detected from the number of ISUs and the ISU size.

In practice, all hardware ends up with irq_count == num_sources, so all
of the runtime checks on mpic->irq_count should just check the value of
mpic->num_sources instead.

When platform hardware does not correctly report the number of IRQs,
which only happens on the MPC85xx/MPC86xx, the MPIC_BROKEN_FRR_NIRQS
flag is used to override the detected value of num_sources with the
manual irq_count parameter.  Since there's no need to manually specify
the number of IRQs except in this case, the extra flag can be eliminated
and the test changed to "irq_count != 0".

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-02-23 10:49:59 +11:00

103 lines
2.4 KiB
C

/*
* Copyright 2006-2007, Michael Ellerman, IBM Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2 of the
* License.
*
*/
#include <linux/irq.h>
#include <linux/bitmap.h>
#include <linux/msi.h>
#include <asm/mpic.h>
#include <asm/prom.h>
#include <asm/hw_irq.h>
#include <asm/ppc-pci.h>
#include <asm/msi_bitmap.h>
#include <sysdev/mpic.h>
void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
{
/* The mpic calls this even when there is no allocator setup */
if (!mpic->msi_bitmap.bitmap)
return;
msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
}
#ifdef CONFIG_MPIC_U3_HT_IRQS
static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
{
irq_hw_number_t hwirq;
struct irq_host_ops *ops = mpic->irqhost->ops;
struct device_node *np;
int flags, index, i;
struct of_irq oirq;
pr_debug("mpic: found U3, guessing msi allocator setup\n");
/* Reserve source numbers we know are reserved in the HW.
*
* This is a bit of a mix of U3 and U4 reserves but that's going
* to work fine, we have plenty enugh numbers left so let's just
* mark anything we don't like reserved.
*/
for (i = 0; i < 8; i++)
msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
for (i = 42; i < 46; i++)
msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
for (i = 100; i < 105; i++)
msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
for (i = 124; i < mpic->num_sources; i++)
msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
np = NULL;
while ((np = of_find_all_nodes(np))) {
pr_debug("mpic: mapping hwirqs for %s\n", np->full_name);
index = 0;
while (of_irq_map_one(np, index++, &oirq) == 0) {
ops->xlate(mpic->irqhost, NULL, oirq.specifier,
oirq.size, &hwirq, &flags);
msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
}
}
return 0;
}
#else
static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
{
return -1;
}
#endif
int mpic_msi_init_allocator(struct mpic *mpic)
{
int rc;
rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->num_sources,
mpic->irqhost->of_node);
if (rc)
return rc;
rc = msi_bitmap_reserve_dt_hwirqs(&mpic->msi_bitmap);
if (rc > 0) {
if (mpic->flags & MPIC_U3_HT_IRQS)
rc = mpic_msi_reserve_u3_hwirqs(mpic);
if (rc) {
msi_bitmap_free(&mpic->msi_bitmap);
return rc;
}
}
return 0;
}