From: Sebastien Dugue <sebastien.dugue@xxxxxxxx>
Date: Tue, 22 Jul 2008 13:05:24 +0200
Subject: [PATCH][RT] powerpc - XICS: move the call to irq_radix_revmap from xics_startup to xics_host_map
This patch moves the insertion of an irq into the reverse mapping radix tree
from xics_startup() into xics_host_map().
The reason for this change is that xics_startup() is called with preemption
disabled (which is not the case for xics_host_map()) which is a problem under a
preempt-rt kernel as we cannot even allocate GFP_ATOMIC memory for the radix tree
nodes.
Signed-off-by: Sebastien Dugue <sebastien.dugue@xxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <michael@xxxxxxxxxxxxxx>
---
arch/powerpc/platforms/pseries/xics.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
Index: linux-2.6.25.8-rt7/arch/powerpc/platforms/pseries/xics.c
===================================================================
--- linux-2.6.25.8-rt7.orig/arch/powerpc/platforms/pseries/xics.c
+++ linux-2.6.25.8-rt7/arch/powerpc/platforms/pseries/xics.c
@@ -311,12 +311,6 @@ static void xics_mask_irq(unsigned int v
static unsigned int xics_startup(unsigned int virq)
{
- unsigned int irq;
-
- /* force a reverse mapping of the interrupt so it gets in the cache */
- irq = (unsigned int)irq_map[virq].hwirq;
- irq_radix_revmap(xics_host, irq);
-
/* unmask it */
xics_unmask_irq(virq);
return 0;
@@ -529,8 +523,14 @@ static int xics_host_match(struct irq_ho
static int xics_host_map_direct(struct irq_host *h, unsigned int virq,
irq_hw_number_t hw)
{
+ unsigned int irq;
+
pr_debug("xics: map_direct virq %d, hwirq 0x%lx\n", virq, hw);
+ /* force a reverse mapping of the interrupt so it gets in the cache */
+ irq = (unsigned int)irq_map[virq].hwirq;
+ irq_radix_revmap(xics_host, irq);
+
get_irq_desc(virq)->status |= IRQ_LEVEL;
set_irq_chip_and_handler(virq, &xics_pic_direct, handle_fasteoi_irq);
return 0;
@@ -539,8 +539,14 @@ static int xics_host_map_direct(struct i
static int xics_host_map_lpar(struct irq_host *h, unsigned int virq,
irq_hw_number_t hw)
{
+ unsigned int irq;
+
pr_debug("xics: map_direct virq %d, hwirq 0x%lx\n", virq, hw);
+ /* force a reverse mapping of the interrupt so it gets in the cache */
+ irq = (unsigned int)irq_map[virq].hwirq;
+ irq_radix_revmap(xics_host, irq);
+
get_irq_desc(virq)->status |= IRQ_LEVEL;
set_irq_chip_and_handler(virq, &xics_pic_lpar, handle_fasteoi_irq);
return 0;
--
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