diff mbox

[v12,7/8] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer

Message ID 1473763144-5653-8-git-send-email-fu.wei@linaro.org (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

fu.wei@linaro.org Sept. 13, 2016, 10:39 a.m. UTC
From: Fu Wei <fu.wei@linaro.org>

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@linaro.org>
---
 drivers/clocksource/arm_arch_timer.c | 127 ++++++++++++++++++++++++++++++++++-
 1 file changed, 124 insertions(+), 3 deletions(-)

Comments

Marc Zyngier Sept. 13, 2016, 11 a.m. UTC | #1
Argh, new version...

On 13/09/16 11:39, fu.wei@linaro.org wrote:
> From: Fu Wei <fu.wei@linaro.org>
> 
> 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@linaro.org>
> ---
>  drivers/clocksource/arm_arch_timer.c | 127 ++++++++++++++++++++++++++++++++++-
>  1 file changed, 124 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index 0197ef9..d33802b 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -888,7 +888,128 @@ CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
>  		       arch_timer_mem_init);
>  
>  #ifdef CONFIG_ACPI_GTDT
> -/* Initialize per-processor generic timer */
> +static struct gt_timer_data __init *arch_timer_mem_get_timer(
> +						struct gt_block_data *gt_blocks)
> +{
> +	struct gt_block_data *gt_block = gt_blocks;
> +	struct gt_timer_data *best_frame = NULL;
> +	void __iomem *cntctlbase;
> +	u32 cnttidr;
> +	int i;
> +
> +	/*
> +	 * According to ARMv8 Architecture Reference Manual(ARM),
> +	 * the size of CNTCTLBase frame of memory-mapped timer
> +	 * is SZ_4K(Offset 0x000 – 0xFFF).
> +	 */
> +	cntctlbase = ioremap(gt_block->cntctlbase_phy, SZ_4K);
> +	if (!cntctlbase) {
> +		pr_err("Failed to map mem timer control frame base address\n");
> +		return NULL;
> +	}
> +	cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
> +
> +	/*
> +	 * Try to find a virtual capable frame. Otherwise fall back to a
> +	 * physical capable frame.
> +	 */
> +	for (i = 0; i < gt_block->timer_count; i++) {
> +		int n;
> +		u32 cntacr;
> +
> +		n = gt_block->timer[i].frame_nr;
> +
> +		/* Try enabling everything, and see what sticks */
> +		cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT |
> +			 CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT;
> +		writel_relaxed(cntacr, cntctlbase + CNTACR(n));
> +		cntacr = readl_relaxed(cntctlbase + CNTACR(n));
> +
> +		if ((cnttidr & CNTTIDR_VIRT(n)) &&
> +		    !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) {
> +			best_frame = &gt_block->timer[i];
> +			arch_timer_mem_use_virtual = true;
> +			break;
> +		}
> +
> +		if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
> +			continue;
> +
> +		best_frame = &gt_block->timer[i];
> +	}
> +	iounmap(cntctlbase);

As I just said in my reply to the same patch in v11, all of this is
duplicating existing infrastructure that already exists for DT. Please
consider decoupling the core driver code from the firmware side and make
this reusable.

Thanks,

	M.
fu.wei@linaro.org Sept. 13, 2016, 11:31 a.m. UTC | #2
Hi Marc,


On 09/13/2016 07:00 PM, Marc Zyngier wrote:
> Argh, new version...
>
> On 13/09/16 11:39, fu.wei@linaro.org wrote:
>> From: Fu Wei <fu.wei@linaro.org>
>>
>> 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@linaro.org>
>> ---
>>  drivers/clocksource/arm_arch_timer.c | 127 ++++++++++++++++++++++++++++++++++-
>>  1 file changed, 124 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
>> index 0197ef9..d33802b 100644
>> --- a/drivers/clocksource/arm_arch_timer.c
>> +++ b/drivers/clocksource/arm_arch_timer.c
>> @@ -888,7 +888,128 @@ CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
>>  		       arch_timer_mem_init);
>>  
>>  #ifdef CONFIG_ACPI_GTDT
>> -/* Initialize per-processor generic timer */
>> +static struct gt_timer_data __init *arch_timer_mem_get_timer(
>> +						struct gt_block_data *gt_blocks)
>> +{
>> +	struct gt_block_data *gt_block = gt_blocks;
>> +	struct gt_timer_data *best_frame = NULL;
>> +	void __iomem *cntctlbase;
>> +	u32 cnttidr;
>> +	int i;
>> +
>> +	/*
>> +	 * According to ARMv8 Architecture Reference Manual(ARM),
>> +	 * the size of CNTCTLBase frame of memory-mapped timer
>> +	 * is SZ_4K(Offset 0x000 – 0xFFF).
>> +	 */
>> +	cntctlbase = ioremap(gt_block->cntctlbase_phy, SZ_4K);
>> +	if (!cntctlbase) {
>> +		pr_err("Failed to map mem timer control frame base address\n");
>> +		return NULL;
>> +	}
>> +	cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
>> +
>> +	/*
>> +	 * Try to find a virtual capable frame. Otherwise fall back to a
>> +	 * physical capable frame.
>> +	 */
>> +	for (i = 0; i < gt_block->timer_count; i++) {
>> +		int n;
>> +		u32 cntacr;
>> +
>> +		n = gt_block->timer[i].frame_nr;
>> +
>> +		/* Try enabling everything, and see what sticks */
>> +		cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT |
>> +			 CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT;
>> +		writel_relaxed(cntacr, cntctlbase + CNTACR(n));
>> +		cntacr = readl_relaxed(cntctlbase + CNTACR(n));
>> +
>> +		if ((cnttidr & CNTTIDR_VIRT(n)) &&
>> +		    !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) {
>> +			best_frame = &gt_block->timer[i];
>> +			arch_timer_mem_use_virtual = true;
>> +			break;
>> +		}
>> +
>> +		if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
>> +			continue;
>> +
>> +		best_frame = &gt_block->timer[i];
>> +	}
>> +	iounmap(cntctlbase);
> As I just said in my reply to the same patch in v11, all of this is
> duplicating existing infrastructure that already exists for DT. Please
> consider decoupling the core driver code from the firmware side and make
> this reusable.

Great thanks for your help, I am working on it now.
Any suggestion for other arm_arch_timer patches?

> Thanks,
>
> 	M.
diff mbox

Patch

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 0197ef9..d33802b 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -888,7 +888,128 @@  CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
 		       arch_timer_mem_init);
 
 #ifdef CONFIG_ACPI_GTDT
-/* Initialize per-processor generic timer */
+static struct gt_timer_data __init *arch_timer_mem_get_timer(
+						struct gt_block_data *gt_blocks)
+{
+	struct gt_block_data *gt_block = gt_blocks;
+	struct gt_timer_data *best_frame = NULL;
+	void __iomem *cntctlbase;
+	u32 cnttidr;
+	int i;
+
+	/*
+	 * According to ARMv8 Architecture Reference Manual(ARM),
+	 * the size of CNTCTLBase frame of memory-mapped timer
+	 * is SZ_4K(Offset 0x000 – 0xFFF).
+	 */
+	cntctlbase = ioremap(gt_block->cntctlbase_phy, SZ_4K);
+	if (!cntctlbase) {
+		pr_err("Failed to map mem timer control frame base address\n");
+		return NULL;
+	}
+	cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
+
+	/*
+	 * Try to find a virtual capable frame. Otherwise fall back to a
+	 * physical capable frame.
+	 */
+	for (i = 0; i < gt_block->timer_count; i++) {
+		int n;
+		u32 cntacr;
+
+		n = gt_block->timer[i].frame_nr;
+
+		/* Try enabling everything, and see what sticks */
+		cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT |
+			 CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT;
+		writel_relaxed(cntacr, cntctlbase + CNTACR(n));
+		cntacr = readl_relaxed(cntctlbase + CNTACR(n));
+
+		if ((cnttidr & CNTTIDR_VIRT(n)) &&
+		    !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) {
+			best_frame = &gt_block->timer[i];
+			arch_timer_mem_use_virtual = true;
+			break;
+		}
+
+		if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
+			continue;
+
+		best_frame = &gt_block->timer[i];
+	}
+	iounmap(cntctlbase);
+
+	return best_frame;
+}
+
+static int __init arch_timer_mem_acpi_init(size_t timer_count)
+{
+	struct gt_block_data *gt_blocks;
+	struct gt_timer_data *gt_timer;
+	void __iomem *timer_cntbase;
+	int ret = -EINVAL;
+	int timer_irq;
+
+	/*
+	 * If we don't have any Platform Timer Structures, just return.
+	 */
+	if (!timer_count)
+		return 0;
+
+	/*
+	 * before really check all the Platform Timer Structures,
+	 * we assume they are GT block, and allocate memory for them.
+	 * We will free these memory once we finish the initialization.
+	 */
+	gt_blocks = kcalloc(timer_count, sizeof(*gt_blocks), GFP_KERNEL);
+	if (!gt_blocks)
+		return -ENOMEM;
+
+	if (gtdt_arch_timer_mem_init(gt_blocks) > 0) {
+		gt_timer = arch_timer_mem_get_timer(gt_blocks);
+		if (!gt_timer) {
+			pr_err("Failed to get mem timer info.\n");
+			goto error;
+		}
+
+		if (arch_timer_mem_use_virtual)
+			timer_irq = gt_timer->virtual_irq;
+		else
+			timer_irq = gt_timer->irq;
+		if (!timer_irq) {
+			pr_err("Failed to get %s irq for mem timer.",
+			       arch_timer_mem_use_virtual ? "virt" : "phys");
+			goto error;
+		}
+
+		/*
+		 * According to ARMv8 Architecture Reference Manual(ARM),
+		 * the size of CNTBaseN frames of memory-mapped timer
+		 * is SZ_4K(Offset 0x000 – 0xFFF).
+		 */
+		timer_cntbase = ioremap(gt_timer->cntbase_phy, SZ_4K);
+		if (!timer_cntbase) {
+			pr_err("Failed to map mem timer base address.\n");
+			goto error;
+		}
+
+		ret = arch_timer_mem_register(timer_cntbase, timer_irq);
+		if (ret) {
+			iounmap(timer_cntbase);
+			pr_err("Failed to register mem timer.\n");
+			goto error;
+		}
+
+		arch_counter_base = timer_cntbase;
+		arch_timers_present |= ARCH_MEM_TIMER;
+	}
+
+error:
+	kfree(gt_blocks);
+	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 timer_count;
@@ -912,8 +1033,8 @@  static int __init arch_timer_acpi_init(struct acpi_table_header *table)
 	/* Get the frequency from CNTFRQ */
 	arch_timer_detect_rate(NULL, NULL);
 
-	if (timer_count < 0)
-		pr_err("Failed to get platform timer info.\n");
+	if (timer_count < 0 || arch_timer_mem_acpi_init((size_t)timer_count))
+		pr_err("Failed to initialize memory-mapped timer.\n");
 
 	return arch_timer_init();
 }