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authorStephen Rothwell <sfr@canb.auug.org.au>2006-04-04 14:49:48 +1000
committerStephen Rothwell <sfr@canb.auug.org.au>2006-04-04 14:49:48 +1000
commit7d01c880856bae31502095bc68784c1518a680cb (patch)
tree8bc0a1b072d9fdf2bc15288e7ce712ff636a7cf8
parent6246b6128bbe34d0752f119cf7c5111c85fe481d (diff)
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powerpc: iSeries has only 256 IRQs
The iSeries Hypervisor only allows us to specify IRQ numbers up to 255 (it has a u8 field to pass it in). This patch allows platforms to specify a maximum to the virtual IRQ numbers we will use and has iSeries set that to 255. If not set, the maximum is NR_IRQS - 1 (as before). Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
-rw-r--r--arch/powerpc/kernel/irq.c36
-rw-r--r--arch/powerpc/platforms/iseries/setup.c7
-rw-r--r--include/asm-powerpc/irq.h7
3 files changed, 36 insertions, 14 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index bb5c950..57d560c 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -272,18 +272,26 @@ unsigned int virt_irq_to_real_map[NR_IRQS];
* Don't use virtual irqs 0, 1, 2 for devices.
* The pcnet32 driver considers interrupt numbers < 2 to be invalid,
* and 2 is the XICS IPI interrupt.
- * We limit virtual irqs to 17 less than NR_IRQS so that when we
- * offset them by 16 (to reserve the first 16 for ISA interrupts)
- * we don't end up with an interrupt number >= NR_IRQS.
+ * We limit virtual irqs to __irq_offet_value less than virt_irq_max so
+ * that when we offset them we don't end up with an interrupt
+ * number >= virt_irq_max.
*/
#define MIN_VIRT_IRQ 3
-#define MAX_VIRT_IRQ (NR_IRQS - NUM_ISA_INTERRUPTS - 1)
-#define NR_VIRT_IRQS (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)
+
+unsigned int virt_irq_max;
+static unsigned int max_virt_irq;
+static unsigned int nr_virt_irqs;
void
virt_irq_init(void)
{
int i;
+
+ if ((virt_irq_max == 0) || (virt_irq_max > (NR_IRQS - 1)))
+ virt_irq_max = NR_IRQS - 1;
+ max_virt_irq = virt_irq_max - __irq_offset_value;
+ nr_virt_irqs = max_virt_irq - MIN_VIRT_IRQ + 1;
+
for (i = 0; i < NR_IRQS; i++)
virt_irq_to_real_map[i] = UNDEFINED_IRQ;
}
@@ -308,17 +316,17 @@ int virt_irq_create_mapping(unsigned int real_irq)
return real_irq;
}
- /* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
+ /* map to a number between MIN_VIRT_IRQ and max_virt_irq */
virq = real_irq;
- if (virq > MAX_VIRT_IRQ)
- virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
+ if (virq > max_virt_irq)
+ virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ;
/* search for this number or a free slot */
first_virq = virq;
while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
if (virt_irq_to_real_map[virq] == real_irq)
return virq;
- if (++virq > MAX_VIRT_IRQ)
+ if (++virq > max_virt_irq)
virq = MIN_VIRT_IRQ;
if (virq == first_virq)
goto nospace; /* oops, no free slots */
@@ -330,8 +338,8 @@ int virt_irq_create_mapping(unsigned int real_irq)
nospace:
if (!warned) {
printk(KERN_CRIT "Interrupt table is full\n");
- printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
- "in your kernel sources and rebuild.\n", NR_IRQS);
+ printk(KERN_CRIT "Increase virt_irq_max (currently %d) "
+ "in your kernel sources and rebuild.\n", virt_irq_max);
warned = 1;
}
return NO_IRQ;
@@ -349,8 +357,8 @@ unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
virq = real_irq;
- if (virq > MAX_VIRT_IRQ)
- virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
+ if (virq > max_virt_irq)
+ virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ;
first_virq = virq;
@@ -360,7 +368,7 @@ unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
virq++;
- if (virq >= MAX_VIRT_IRQ)
+ if (virq >= max_virt_irq)
virq = 0;
} while (first_virq != virq);
diff --git a/arch/powerpc/platforms/iseries/setup.c b/arch/powerpc/platforms/iseries/setup.c
index 6ce8a40..a6fd9be 100644
--- a/arch/powerpc/platforms/iseries/setup.c
+++ b/arch/powerpc/platforms/iseries/setup.c
@@ -54,6 +54,7 @@
#include <asm/iseries/hv_lp_event.h>
#include <asm/iseries/lpar_map.h>
#include <asm/udbg.h>
+#include <asm/irq.h>
#include "naca.h"
#include "setup.h"
@@ -684,6 +685,12 @@ static int __init iseries_probe(void)
powerpc_firmware_features |= FW_FEATURE_ISERIES;
powerpc_firmware_features |= FW_FEATURE_LPAR;
+ /*
+ * The Hypervisor only allows us up to 256 interrupt
+ * sources (the irq number is passed in a u8).
+ */
+ virt_irq_max = 255;
+
return 1;
}
diff --git a/include/asm-powerpc/irq.h b/include/asm-powerpc/irq.h
index 51f87d9..7bc6d73 100644
--- a/include/asm-powerpc/irq.h
+++ b/include/asm-powerpc/irq.h
@@ -54,6 +54,13 @@
*/
extern unsigned int virt_irq_to_real_map[NR_IRQS];
+/* The maximum virtual IRQ number that we support. This
+ * can be set by the platform and will be reduced by the
+ * value of __irq_offset_value. It defaults to and is
+ * capped by (NR_IRQS - 1).
+ */
+extern unsigned int virt_irq_max;
+
/* Create a mapping for a real_irq if it doesn't already exist.
* Return the virtual irq as a convenience.
*/