This patches enables ACPI support for KVM virtual arch timer. It allows
KVM to parse ACPI table for arch timer PPI when DT table is not present.
Signed-off-by: Alexander Spyridaki <a.spyrida...@virtualopensystems.com>
Signed-off-by: Wei Huang <w...@redhat.com>
---
virt/kvm/arm/arch_timer.c | 64 +++++++++++++++++++++++++++++++++++++----------
1 file changed, 51 insertions(+), 13 deletions(-)
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 98c95f2..7da9eb3 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -21,6 +21,7 @@
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/interrupt.h>
+#include <linux/acpi.h>
#include <clocksource/arm_arch_timer.h>
#include <asm/arch_timer.h>
@@ -274,9 +275,46 @@ static const struct of_device_id arch_timer_of_match[] = {
{},
};
-int kvm_timer_hyp_init(void)
+static int kvm_timer_ppi_dt_parse(unsigned int *ppi)
{
struct device_node *np;
+
+ np = of_find_matching_node(NULL, arch_timer_of_match);
+ if (!np)
+ return -ENODEV;
+
+ *ppi = irq_of_parse_and_map(np, 2);
+ if (*ppi == 0) {
+ of_node_put(np);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_ACPI
+struct acpi_table_gtdt *gtdt_acpi;
+static void arch_timer_acpi_parse(struct acpi_table_header *table)
+{
+ gtdt_acpi = container_of(table, struct acpi_table_gtdt, header);
+}
+
+static int kvm_timer_ppi_acpi_parse(unsigned int *ppi)
+{
+ /* Get the interrupt number from the GTDT table */
+ acpi_table_parse(ACPI_SIG_GTDT,
+ (acpi_tbl_table_handler)arch_timer_acpi_parse);
+
+ if (!gtdt_acpi->virtual_timer_interrupt)
+ return -EINVAL;
+
+ *ppi = gtdt_acpi->virtual_timer_interrupt;
+ return 0;
+}
+#endif
+
+int kvm_timer_hyp_init(void)
+{
unsigned int ppi;
int err;
@@ -284,19 +322,20 @@ int kvm_timer_hyp_init(void)
if (!timecounter)
return -ENODEV;
- np = of_find_matching_node(NULL, arch_timer_of_match);
- if (!np) {
- kvm_err("kvm_arch_timer: can't find DT node\n");
- return -ENODEV;
- }
+ /* PPI parsing: try DT first, then ACPI */
+ err = kvm_timer_ppi_dt_parse(&ppi);
+#ifdef CONFIG_ACPI
+ if (err && !acpi_disabled)
+ err = kvm_timer_ppi_acpi_parse(&ppi);
+#endif
- ppi = irq_of_parse_and_map(np, 2);
- if (!ppi) {
- kvm_err("kvm_arch_timer: no virtual timer interrupt\n");
- err = -EINVAL;
- goto out;
+ if (err) {
+ kvm_err("kvm_arch_timer: can't find virtual timer info or "
+ "config virtual timer interrupt\n");
+ return err;
}
+ /* configure IRQ handler */
err = request_percpu_irq(ppi, kvm_arch_timer_handler,
"kvm guest timer", kvm_get_running_vcpus());
if (err) {
@@ -319,14 +358,13 @@ int kvm_timer_hyp_init(void)
goto out_free;
}
- kvm_info("%s IRQ%d\n", np->name, ppi);
+ kvm_info("timer IRQ%d\n", ppi);
on_each_cpu(kvm_timer_init_interrupt, NULL, 1);
goto out;
out_free:
free_percpu_irq(ppi, kvm_get_running_vcpus());
out:
- of_node_put(np);
return err;
}
--
1.8.3.1
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