[PATCH v16 14/15] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer
From: mark.rutland@arm.com (Mark Rutland)
Date: 2016-11-18 20:20:46
Also in:
linux-acpi, linux-watchdog, lkml
On Wed, Nov 16, 2016 at 09:49:07PM +0800, fu.wei at linaro.org wrote:
quoted hunk ↗ jump to hunk
From: Fu Wei <redacted> 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 <redacted> --- drivers/clocksource/arm_arch_timer.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-)diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index c494ca8..0aad60a 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c@@ -1067,7 +1067,28 @@ 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(void) +{ + struct arch_timer_mem *timer_mem; + int ret = 0; + int i = 0; + + timer_mem = kzalloc(sizeof(*timer_mem), GFP_KERNEL);
Why do you need it zeroed? You don't clear it between iterations, so either you don't need this, or you have a bug in the loop.
+ if (!timer_mem)
+ return -ENOMEM;
+
+ while (!gtdt_arch_timer_mem_init(timer_mem, i)) {Huh? Why doesn't GTDT expose a function to fill in the entire arch_timer_mem in one go? There shouldn't be multiple instances, as far as I am aware. Am I mistaken?
+ ret = arch_timer_mem_init(timer_mem); + if (ret) + break; + i++; + } + + kfree(timer_mem); + return ret; +}
Regardless, arch_timer_mem is small enough that you don't need dynamic
allocaiton. Just put it on the stack, e.g.
static int __init arch_timer_mem_acpi_init(void)
{
int i = 0;
struct arch_timer_mem timer_mem;
while (!gtdt_arch_timer_mem_init(timer_mem, i)) {
int ret = arch_timer_mem_init();
if (ret)
return ret;
i++
}
return 0;
}
Thanks,
Mark.