Hi Hanjun,
On 19 January 2017 at 17:11, Hanjun Guo hanjun.guo@linaro.org wrote:
On 2017/1/18 21:25, fu.wei@linaro.org wrote:
From: Fu Wei fu.wei@linaro.org
This patch adds support for parsing arch timer info in GTDT, provides some kernel APIs to parse all the PPIs and always-on info in GTDT and export them.
By this driver, we can simplify arm_arch_timer drivers, and separate the ACPI GTDT knowledge from it.
Signed-off-by: Fu Wei fu.wei@linaro.org Signed-off-by: Hanjun Guo hanjun.guo@linaro.org Acked-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Tested-by: Xiongfeng Wang wangxiongfeng2@huawei.com
arch/arm64/Kconfig | 1 + drivers/acpi/arm64/Kconfig | 3 + drivers/acpi/arm64/Makefile | 1 + drivers/acpi/arm64/gtdt.c | 157 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 6 ++ 5 files changed, 168 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 1117421..ab1ee10 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2,6 +2,7 @@ config ARM64 def_bool y select ACPI_CCA_REQUIRED if ACPI select ACPI_GENERIC_GSI if ACPI
select ACPI_GTDT if ACPI select ACPI_REDUCED_HARDWARE_ONLY if ACPI select ACPI_MCFG if ACPI select ACPI_SPCR_TABLE if ACPIdiff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig index 4616da4..5a6f80f 100644 --- a/drivers/acpi/arm64/Kconfig +++ b/drivers/acpi/arm64/Kconfig @@ -4,3 +4,6 @@
config ACPI_IORT bool
+config ACPI_GTDT
booldiff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile index 72331f2..1017def 100644 --- a/drivers/acpi/arm64/Makefile +++ b/drivers/acpi/arm64/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_ACPI_IORT) += iort.o +obj-$(CONFIG_ACPI_GTDT) += gtdt.o diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c new file mode 100644 index 0000000..d93a790 --- /dev/null +++ b/drivers/acpi/arm64/gtdt.c @@ -0,0 +1,157 @@
[...]
+/**
- acpi_gtdt_init() - Get the info of GTDT table to prepare for further
init.
- @table: The pointer to GTDT table.
- @platform_timer_count: The pointer of int variate for returning
the
number of platform timers. It can be NULL,if
driver don't need this info.
- Return: 0 if success, -EINVAL if error.
- */
+int __init acpi_gtdt_init(struct acpi_table_header *table,
int *platform_timer_count)+{
int ret = 0;int timer_count = 0;void *platform_timer = NULL;struct acpi_table_gtdt *gtdt;gtdt = container_of(table, struct acpi_table_gtdt, header);acpi_gtdt_desc.gtdt = gtdt;acpi_gtdt_desc.gtdt_end = (void *)table + table->length;if (table->revision < 2)pr_debug("Revision:%d doesn't support Platform Timers.\n",table->revision);GTDT table revision is updated to 2 in ACPI 5.1, we will not support ACPI version under 5.1 and disable ACPI in FADT parse before this code is called, so if we get revision <2 here, I think we need to print warning (we need to keep the firmware stick to the spec on ARM64).
agree, will change pr_debug to pr_warn.
Thanks :-)
else if (!gtdt->platform_timer_count)pr_debug("No Platform Timer.\n");elsetimer_count = gtdt->platform_timer_count;if (timer_count) {platform_timer = (void *)gtdt +gtdt->platform_timer_offset;
if (platform_timer < (void *)table +sizeof(struct acpi_table_gtdt)) {pr_err(FW_BUG "invalid timer data.\n");It's ok but I didn't see other ACPI tables parsing did this check, maybe we can just remove it :)
here, I want to make sure the FW is valid. Once there is a FW bug, we could just return with error. :-)
timer_count = 0;platform_timer = NULL;ret = -EINVAL;}}acpi_gtdt_desc.platform_timer = platform_timer;if (platform_timer_count)*platform_timer_count = timer_count;Then the code will much simple:
if (gtdt->platform_timer_count) { acpi_gtdt_desc.platform_timer = (void *)gtdt + gtdt->platform_timer_offset; if (platform_timer_count) *platform_timer_count = gtdt->platform_timer_count; }
return 0;
and remove ret, timer_count and platform_timer.
yes, this may can simplify the function, but this will be released at the end of init because of "__init" :-) So how about let's just keep this check to make sure the FW is OK. :-)
Thanks Hanjun