On 2017/1/18 21:25, fu.wei@xxxxxxxxxx wrote:
From: Fu Wei <fu.wei@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Tested-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
---
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 ACPI
diff --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
+ bool
diff --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).
+ else if (!gtdt->platform_timer_count)
+ pr_debug("No Platform Timer.\n");
+ else
+ timer_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 :)
+ 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.
Thanks
Hanjun
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