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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 3/9] arm: gic: implement IPIs using SGI mechanism
On Tue, 2013-04-09 at 15:51 +0100, Ian Campbell wrote:
>
> > I think that we should leave bit 15 alone.
>
> ... I think this is a good idea.
8<---------------------------------
>From fe8f63c211f6f4a86f99dd72d770524a3816792f Mon Sep 17 00:00:00 2001
From: Ian Campbell <ian.campbell@xxxxxxxxxx>
Date: Wed, 27 Feb 2013 16:34:32 +0000
Subject: [PATCH] arm: gic: implement IPIs using SGI mechanism
Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
v2: Drop GROUP1 bit, it has no meaning unless you are in secure mode.
---
xen/arch/arm/arm32/mode_switch.S | 2 +-
xen/arch/arm/gic.c | 85 +++++++++++++++++++++++++++++++++++---
xen/arch/arm/smp.c | 14 ++----
xen/include/asm-arm/gic.h | 22 +++++++++-
4 files changed, 105 insertions(+), 18 deletions(-)
diff --git a/xen/arch/arm/arm32/mode_switch.S b/xen/arch/arm/arm32/mode_switch.S
index bc2be74..d6741d0 100644
--- a/xen/arch/arm/arm32/mode_switch.S
+++ b/xen/arch/arm/arm32/mode_switch.S
@@ -43,7 +43,7 @@ kick_cpus:
mov r2, #0x1
str r2, [r0, #(GICD_CTLR * 4)] /* enable distributor */
mov r2, #0xfe0000
- str r2, [r0, #(GICD_SGIR * 4)] /* send IPI to everybody */
+ str r2, [r0, #(GICD_SGIR * 4)] /* send IPI to everybody, SGI0 =
Event check */
dsb
str r2, [r0, #(GICD_CTLR * 4)] /* disable distributor */
mov pc, lr
diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 12f2e7f..07c816b 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -356,10 +356,52 @@ void __init gic_init(void)
spin_unlock(&gic.lock);
}
+void send_SGI_mask(const cpumask_t *cpumask, enum gic_sgi sgi)
+{
+ unsigned long mask = cpumask_bits(cpumask)[0];
+
+ ASSERT(sgi < 16); /* There are only 16 SGIs */
+
+ mask &= cpumask_bits(&cpu_online_map)[0];
+
+ ASSERT(mask < 0x100); /* The target bitmap only supports 8 CPUs */
+
+ dsb();
+
+ GICD[GICD_SGIR] = GICD_SGI_TARGET_LIST
+ | (mask<<GICD_SGI_TARGET_SHIFT)
+ | sgi;
+}
+
+void send_SGI_one(unsigned int cpu, enum gic_sgi sgi)
+{
+ ASSERT(cpu < 7); /* Targets bitmap only supports 8 CPUs */
+ send_SGI_mask(cpumask_of(cpu), sgi);
+}
+
+void send_SGI_self(enum gic_sgi sgi)
+{
+ ASSERT(sgi < 16); /* There are only 16 SGIs */
+
+ dsb();
+
+ GICD[GICD_SGIR] = GICD_SGI_TARGET_SELF
+ | sgi;
+}
+
+void send_SGI_allbutself(enum gic_sgi sgi)
+{
+ ASSERT(sgi < 16); /* There are only 16 SGIs */
+
+ dsb();
+
+ GICD[GICD_SGIR] = GICD_SGI_TARGET_OTHERS
+ | sgi;
+}
+
void smp_send_state_dump(unsigned int cpu)
{
- printk("WARNING: unable to send state dump request to CPU%d\n", cpu);
- /* XXX TODO -- send an SGI */
+ send_SGI_one(cpu, GIC_SGI_DUMP_STATE);
}
/* Set up the per-CPU parts of the GIC for a secondary CPU */
@@ -592,6 +634,28 @@ out:
return retval;
}
+static void do_sgi(struct cpu_user_regs *regs, int othercpu, enum gic_sgi sgi)
+{
+ /* Lower the priority */
+ GICC[GICC_EOIR] = sgi;
+
+ switch (sgi)
+ {
+ case GIC_SGI_EVENT_CHECK:
+ /* Nothing to do, will check for events on return path */
+ break;
+ case GIC_SGI_DUMP_STATE:
+ dump_execstate(regs);
+ break;
+ default:
+ panic("Unhandled SGI %d on CPU%d\n", sgi, smp_processor_id());
+ break;
+ }
+
+ /* Deactivate */
+ GICC[GICC_DIR] = sgi;
+}
+
/* Accept an interrupt from the GIC and dispatch its handler */
void gic_interrupt(struct cpu_user_regs *regs, int is_fiq)
{
@@ -602,14 +666,23 @@ void gic_interrupt(struct cpu_user_regs *regs, int is_fiq)
do {
intack = GICC[GICC_IAR];
irq = intack & GICC_IA_IRQ;
- local_irq_enable();
- if (likely(irq < 1021))
+ if ( likely(irq >= 16 && irq < 1021) )
+ {
+ local_irq_enable();
do_IRQ(regs, irq, is_fiq);
+ local_irq_disable();
+ }
+ else if (unlikely(irq < 16))
+ {
+ unsigned int cpu = (intack & GICC_IA_CPU_MASK) >>
GICC_IA_CPU_SHIFT;
+ do_sgi(regs, cpu, irq);
+ }
else
+ {
+ local_irq_disable();
break;
-
- local_irq_disable();
+ }
} while (1);
}
diff --git a/xen/arch/arm/smp.c b/xen/arch/arm/smp.c
index 12260f4..a902d84 100644
--- a/xen/arch/arm/smp.c
+++ b/xen/arch/arm/smp.c
@@ -3,10 +3,11 @@
#include <asm/smp.h>
#include <asm/cpregs.h>
#include <asm/page.h>
+#include <asm/gic.h>
void flush_tlb_mask(const cpumask_t *mask)
{
- /* XXX IPI other processors */
+ /* No need to IPI other processors on ARM, the processor takes care of it.
*/
flush_xen_data_tlb();
}
@@ -15,17 +16,12 @@ void smp_call_function(
void *info,
int wait)
{
- /* TODO: No SMP just now, does not include self so nothing to do.
- cpumask_t allbutself = cpu_online_map;
- cpu_clear(smp_processor_id(), allbutself);
- on_selected_cpus(&allbutself, func, info, wait);
- */
+ panic("%s not implmented\n", __func__);
}
+
void smp_send_event_check_mask(const cpumask_t *mask)
{
- /* TODO: No SMP just now, does not include self so nothing to do.
- send_IPI_mask(mask, EVENT_CHECK_VECTOR);
- */
+ send_SGI_mask(mask, GIC_SGI_EVENT_CHECK);
}
/*
diff --git a/xen/include/asm-arm/gic.h b/xen/include/asm-arm/gic.h
index 6bf50bb..24c0d5c 100644
--- a/xen/include/asm-arm/gic.h
+++ b/xen/include/asm-arm/gic.h
@@ -51,6 +51,13 @@
#define GICD_SPENDSGIRN (0xF2C/4)
#define GICD_ICPIDR2 (0xFE8/4)
+#define GICD_SGI_TARGET_LIST (0UL<<24)
+#define GICD_SGI_TARGET_OTHERS (1UL<<24)
+#define GICD_SGI_TARGET_SELF (2UL<<24)
+#define GICD_SGI_TARGET_SHIFT (16)
+#define GICD_SGI_TARGET_MASK (0xFFUL<<GICD_SGI_TARGET_SHIFT)
+#define GICD_SGI_GROUP1 (1UL<<15)
+
#define GICC_CTLR (0x0000/4)
#define GICC_PMR (0x0004/4)
#define GICC_BPR (0x0008/4)
@@ -83,8 +90,9 @@
#define GICC_CTL_ENABLE 0x1
#define GICC_CTL_EOI (0x1 << 9)
-#define GICC_IA_IRQ 0x03ff
-#define GICC_IA_CPU 0x1c00
+#define GICC_IA_IRQ 0x03ff
+#define GICC_IA_CPU_MASK 0x1c00
+#define GICC_IA_CPU_SHIFT 10
#define GICH_HCR_EN (1 << 0)
#define GICH_HCR_UIE (1 << 1)
@@ -157,6 +165,16 @@ extern int gicv_setup(struct domain *d);
extern void gic_save_state(struct vcpu *v);
extern void gic_restore_state(struct vcpu *v);
+/* SGI (AKA IPIs) */
+enum gic_sgi {
+ GIC_SGI_EVENT_CHECK = 0,
+ GIC_SGI_DUMP_STATE = 1,
+};
+extern void send_SGI_mask(const cpumask_t *cpumask, enum gic_sgi sgi);
+extern void send_SGI_one(unsigned int cpu, enum gic_sgi sgi);
+extern void send_SGI_self(enum gic_sgi sgi);
+extern void send_SGI_allbutself(enum gic_sgi sgi);
+
/* print useful debug info */
extern void gic_dump_info(struct vcpu *v);
--
1.7.2.5
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