Re: [PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer

From: Hanjun Guo
Date: Thu Jan 19 2017 - 07:43:25 EST


On 2017/1/19 18:02, Fu Wei wrote:
Hi Hanjun,

On 19 January 2017 at 17:16, Hanjun Guo <hanjun.guo@xxxxxxxxxx> wrote:
On 2017/1/18 21:25, fu.wei@xxxxxxxxxx wrote:

From: Fu Wei <fu.wei@xxxxxxxxxx>

The patch add memory-mapped timer register support by using the
information provided by the new GTDT driver of ACPI.

Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
---
drivers/clocksource/arm_arch_timer.c | 35
++++++++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c
b/drivers/clocksource/arm_arch_timer.c
index 79dc004..7ca2da7 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -1077,10 +1077,36 @@ CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem,
"arm,armv7-timer-mem",
arch_timer_mem_of_init);

#ifdef CONFIG_ACPI_GTDT
-/* Initialize per-processor generic timer */
+static int __init arch_timer_mem_acpi_init(int platform_timer_count)
+{
+ struct arch_timer_mem *timer_mem;
+ int timer_count, i, ret;
+


if (!platform_timer_count)
return 0;

Did I miss something?

Ah, thanks, I guess I miss this check below.


Thanks
Hanjun


+ timer_mem = kcalloc(platform_timer_count, sizeof(*timer_mem),
+ GFP_KERNEL);
+ if (!timer_mem)
+ return -ENOMEM;
+
+ ret = acpi_arch_timer_mem_init(timer_mem, &timer_count);
+ if (ret || !timer_count)
+ goto error;
+
+ for (i = 0; i < timer_count; i++) {
+ ret = arch_timer_mem_init(timer_mem);
+ if (!ret)
+ break;
+ timer_mem++;
+ }
+
+error:
+ kfree(timer_mem);
+ return ret;
+}
+
+/* Initialize per-processor generic timer and memory-mapped timer(if
present) */
static int __init arch_timer_acpi_init(struct acpi_table_header *table)
{
- int ret;
+ int ret, platform_timer_count;

if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
pr_warn("already initialized, skipping\n");
@@ -1089,7 +1115,7 @@ static int __init arch_timer_acpi_init(struct
acpi_table_header *table)

arch_timers_present |= ARCH_TIMER_TYPE_CP15;

- ret = acpi_gtdt_init(table, NULL);
+ ret = acpi_gtdt_init(table, &platform_timer_count);
if (ret) {
pr_err("Failed to init GTDT table.\n");
return ret;
@@ -1122,6 +1148,9 @@ static int __init arch_timer_acpi_init(struct
acpi_table_header *table)
if (ret)
return ret;

+ if (arch_timer_mem_acpi_init(platform_timer_count))

+ if (platform_timer_count &&
+ arch_timer_mem_acpi_init(platform_timer_count))

It's better.

Thanks
Hanjun