diff mbox

[v21,11/13] acpi/arm64: Add memory-mapped timer support in GTDT driver

Message ID 20170206185015.12296-12-fu.wei@linaro.org (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

fu.wei@linaro.org Feb. 6, 2017, 6:50 p.m. UTC 
From: Fu Wei <fu.wei@linaro.org>

On platforms booting with ACPI, architected memory-mapped timers'
configuration data is provided by firmware through the ACPI GTDT
static table.

The clocksource architected timer kernel driver requires a firmware
interface to collect timer configuration and configure its driver.
this infrastructure is present for device tree systems, but it is
missing on systems booting with ACPI.

Implement the kernel infrastructure required to parse the static
ACPI GTDT table so that the architected timer clocksource driver can
make use of it on systems booting with ACPI, therefore enabling
the corresponding timers configuration.

Signed-off-by: Fu Wei <fu.wei@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 drivers/acpi/arm64/gtdt.c | 128 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/acpi.h      |   1 +
 2 files changed, 129 insertions(+)

Comments

Mark Rutland March 17, 2017, 7:40 p.m. UTC | #1 
Hi,

On Tue, Feb 07, 2017 at 02:50:13AM +0800, fu.wei@linaro.org wrote:
> +static int __init gtdt_parse_timer_block(struct acpi_gtdt_timer_block *block,
> +					 struct arch_timer_mem *data)

Please s/data/timer_mem/ here, to match the rest of the timer code.

> +{
> +	int i, j;
> +	struct acpi_gtdt_timer_entry *frame;

So as to make it clear what this is, and to make things a litlte simpler
below, please s/frame/gtdt_frame/ here.

> +
> +	if (!block->timer_count) {
> +		pr_err(FW_BUG "GT block present, but frame count is zero.");
> +		return -ENODEV;
> +	}
> +
> +	if (block->timer_count > ARCH_TIMER_MEM_MAX_FRAMES) {
> +		pr_err(FW_BUG "GT block lists %d frames, ACPI spec only allows 8\n",
> +		       block->timer_count);
> +		return -EINVAL;
> +	}
> +
> +	data->cntctlbase = (phys_addr_t)block->block_address;
> +	/*
> +	 * According to "Table * CNTCTLBase memory map" of
> +	 * <ARM Architecture Reference Manual> for ARMv8,
> +	 * The size of the CNTCTLBase frame is 4KB(Offset 0x000 – 0xFFC).
> +	 */

As a general thing, please cite the version of the ARM ARM you're
referring to, as over time the internal numbering (and the headings)
change.

e.g.
	/*
	 * The CNTCTLBase frame is 4KB (register offsets 0x000 - 0xFFC).
	 * See ARM DDI 0487A.k_iss10775, page I1-5129, Table I1-3
	 * "CNTCTLBase memory map".
	 */

> +	data->size = SZ_4K;
> +
> +	frame = (void *)block + block->timer_offset;
> +	if (frame + block->timer_count != (void *)block + block->header.length)
> +		return -EINVAL;
> +
> +	/*
> +	 * Get the GT timer Frame data for every GT Block Timer
> +	 */
> +	for (i = 0, j = 0; i < block->timer_count; i++, frame++) {

With the gtdt_frame rename as above, here we can do:

	struct arch_timer_mem_frame *frame = &timer_mem->frame[j];

> +		if (frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER)
> +			continue;
> +
> +		if (!frame->base_address || !frame->timer_interrupt)
> +			return -EINVAL;
> +
> +		data->frame[j].phys_irq = map_gt_gsi(frame->timer_interrupt,
> +						     frame->timer_flags);

... allowing us to simplify lines like this.

Thanks,
Mark.
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fu.wei@linaro.org March 20, 2017, 1:38 p.m. UTC | #2 
Hi Mark,

On 18 March 2017 at 03:40, Mark Rutland <mark.rutland@arm.com> wrote:
> Hi,
>
> On Tue, Feb 07, 2017 at 02:50:13AM +0800, fu.wei@linaro.org wrote:
>> +static int __init gtdt_parse_timer_block(struct acpi_gtdt_timer_block *block,
>> +                                      struct arch_timer_mem *data)
>
> Please s/data/timer_mem/ here, to match the rest of the timer code.
>
>> +{
>> +     int i, j;
>> +     struct acpi_gtdt_timer_entry *frame;
>
> So as to make it clear what this is, and to make things a litlte simpler
> below, please s/frame/gtdt_frame/ here.
>
>> +
>> +     if (!block->timer_count) {
>> +             pr_err(FW_BUG "GT block present, but frame count is zero.");
>> +             return -ENODEV;
>> +     }
>> +
>> +     if (block->timer_count > ARCH_TIMER_MEM_MAX_FRAMES) {
>> +             pr_err(FW_BUG "GT block lists %d frames, ACPI spec only allows 8\n",
>> +                    block->timer_count);
>> +             return -EINVAL;
>> +     }
>> +
>> +     data->cntctlbase = (phys_addr_t)block->block_address;
>> +     /*
>> +      * According to "Table * CNTCTLBase memory map" of
>> +      * <ARM Architecture Reference Manual> for ARMv8,
>> +      * The size of the CNTCTLBase frame is 4KB(Offset 0x000 – 0xFFC).
>> +      */
>
> As a general thing, please cite the version of the ARM ARM you're
> referring to, as over time the internal numbering (and the headings)
> change.
>
> e.g.
>         /*
>          * The CNTCTLBase frame is 4KB (register offsets 0x000 - 0xFFC).
>          * See ARM DDI 0487A.k_iss10775, page I1-5129, Table I1-3
>          * "CNTCTLBase memory map".
>          */
>
>> +     data->size = SZ_4K;
>> +
>> +     frame = (void *)block + block->timer_offset;
>> +     if (frame + block->timer_count != (void *)block + block->header.length)
>> +             return -EINVAL;
>> +
>> +     /*
>> +      * Get the GT timer Frame data for every GT Block Timer
>> +      */
>> +     for (i = 0, j = 0; i < block->timer_count; i++, frame++) {
>
> With the gtdt_frame rename as above, here we can do:
>
>         struct arch_timer_mem_frame *frame = &timer_mem->frame[j];
>
>> +             if (frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER)
>> +                     continue;
>> +
>> +             if (!frame->base_address || !frame->timer_interrupt)
>> +                     return -EINVAL;
>> +
>> +             data->frame[j].phys_irq = map_gt_gsi(frame->timer_interrupt,
>> +                                                  frame->timer_flags);
>
> ... allowing us to simplify lines like this.

Thanks, will follow all the suggestion above.
:-)

>
> Thanks,
> Mark.
diff mbox

Patch

diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c
index 8a03b4b..29b9acc 100644
--- a/drivers/acpi/arm64/gtdt.c
+++ b/drivers/acpi/arm64/gtdt.c
@@ -37,6 +37,28 @@  struct acpi_gtdt_descriptor {
 
 static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata;
 
+static inline void *next_platform_timer(void *platform_timer)
+{
+	struct acpi_gtdt_header *gh = platform_timer;
+
+	platform_timer += gh->length;
+	if (platform_timer < acpi_gtdt_desc.gtdt_end)
+		return platform_timer;
+
+	return NULL;
+}
+
+#define for_each_platform_timer(_g)				\
+	for (_g = acpi_gtdt_desc.platform_timer; _g;	\
+	     _g = next_platform_timer(_g))
+
+static inline bool is_timer_block(void *platform_timer)
+{
+	struct acpi_gtdt_header *gh = platform_timer;
+
+	return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK;
+}
+
 static int __init map_gt_gsi(u32 interrupt, u32 flags)
 {
 	int trigger, polarity;
@@ -155,3 +177,109 @@  int __init acpi_gtdt_init(struct acpi_table_header *table,
 
 	return ret;
 }
+
+static int __init gtdt_parse_timer_block(struct acpi_gtdt_timer_block *block,
+					 struct arch_timer_mem *data)
+{
+	int i, j;
+	struct acpi_gtdt_timer_entry *frame;
+
+	if (!block->timer_count) {
+		pr_err(FW_BUG "GT block present, but frame count is zero.");
+		return -ENODEV;
+	}
+
+	if (block->timer_count > ARCH_TIMER_MEM_MAX_FRAMES) {
+		pr_err(FW_BUG "GT block lists %d frames, ACPI spec only allows 8\n",
+		       block->timer_count);
+		return -EINVAL;
+	}
+
+	data->cntctlbase = (phys_addr_t)block->block_address;
+	/*
+	 * According to "Table * CNTCTLBase memory map" of
+	 * <ARM Architecture Reference Manual> for ARMv8,
+	 * The size of the CNTCTLBase frame is 4KB(Offset 0x000 – 0xFFC).
+	 */
+	data->size = SZ_4K;
+
+	frame = (void *)block + block->timer_offset;
+	if (frame + block->timer_count != (void *)block + block->header.length)
+		return -EINVAL;
+
+	/*
+	 * Get the GT timer Frame data for every GT Block Timer
+	 */
+	for (i = 0, j = 0; i < block->timer_count; i++, frame++) {
+		if (frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER)
+			continue;
+
+		if (!frame->base_address || !frame->timer_interrupt)
+			return -EINVAL;
+
+		data->frame[j].phys_irq = map_gt_gsi(frame->timer_interrupt,
+						     frame->timer_flags);
+		if (data->frame[j].phys_irq <= 0) {
+			pr_warn("failed to map physical timer irq in frame %d.\n",
+				i);
+			return -EINVAL;
+		}
+
+		data->frame[j].virt_irq =
+			map_gt_gsi(frame->virtual_timer_interrupt,
+				   frame->virtual_timer_flags);
+		if (data->frame[j].virt_irq <= 0) {
+			pr_warn("failed to map virtual timer irq in frame %d.\n",
+				i);
+			acpi_unregister_gsi(frame->timer_interrupt);
+			return -EINVAL;
+		}
+
+		data->frame[j].frame_nr = frame->frame_number;
+		data->frame[j].cntbase = frame->base_address;
+		/*
+		 * According to "Table * CNTBaseN memory map" of
+		 * <ARM Architecture Reference Manual> for ARMv8,
+		 * The size of the CNTBaseN frame is 4KB(Offset 0x000 – 0xFFC).
+		 */
+		data->frame[j].size = SZ_4K;
+		j++;
+	}
+	data->num_frames = j;
+
+	return 0;
+}
+
+/**
+ * acpi_arch_timer_mem_init() - Get the info of all GT blocks in GTDT table.
+ * @data:	the pointer to the array of struct arch_timer_mem for returning
+ *		the result of parsing. The element number of this array should
+ *		be platform_timer_count(the total number of platform timers).
+ * @count:	The pointer of int variate for returning the number of GT
+ *		blocks we have parsed.
+ *
+ * Return: 0 if success, -EINVAL/-ENODEV if error.
+ */
+int __init acpi_arch_timer_mem_init(struct arch_timer_mem *data,
+				    int *timer_count)
+{
+	int ret;
+	void *platform_timer;
+
+	*timer_count = 0;
+	for_each_platform_timer(platform_timer) {
+		if (is_timer_block(platform_timer)) {
+			ret = gtdt_parse_timer_block(platform_timer, data);
+			if (ret)
+				return ret;
+			data++;
+			(*timer_count)++;
+		}
+	}
+
+	if (*timer_count)
+		pr_info("found %d memory-mapped timer block(s).\n",
+			*timer_count);
+
+	return 0;
+}
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index d0b271e..51e85b9 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -601,6 +601,7 @@  int acpi_reconfig_notifier_unregister(struct notifier_block *nb);
 int acpi_gtdt_init(struct acpi_table_header *table, int *platform_timer_count);
 int acpi_gtdt_map_ppi(int type);
 bool acpi_gtdt_c3stop(int type);
+int acpi_arch_timer_mem_init(struct arch_timer_mem *data, int *timer_count);
 #endif
 
 #else	/* !CONFIG_ACPI */