[PATCH v13 7/8] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer
Fu Wei
fu.wei at linaro.org
Thu Sep 15 03:49:30 PDT 2016
HI
On 15 September 2016 at 04:09, <fu.wei at linaro.org> wrote:
> From: Fu Wei <fu.wei at linaro.org>
>
> The patch add memory-mapped timer register support by using the information
> provided by the new GTDT driver of ACPI.
> Also refactor original memory-mapped timer dt support for reusing some common
> code.
>
> Signed-off-by: Fu Wei <fu.wei at linaro.org>
> ---
> drivers/clocksource/arm_arch_timer.c | 238 +++++++++++++++++++++++++----------
> 1 file changed, 172 insertions(+), 66 deletions(-)
>
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index 0197ef9..ddca6e3 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -57,6 +57,7 @@
> static unsigned arch_timers_present __initdata;
>
> static void __iomem *arch_counter_base;
> +static void __iomem *cntctlbase __initdata;
>
> struct arch_timer {
> void __iomem *base;
> @@ -656,15 +657,56 @@ out:
> return err;
> }
>
> -static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
> +static int __init arch_timer_mem_register(struct device_node *np, void *frame)
> {
> - int ret;
> - irq_handler_t func;
> + struct device_node *frame_node = NULL;
> + struct gt_timer_data *frame_data = NULL;
> struct arch_timer *t;
> + void __iomem *base;
> + irq_handler_t func;
> + unsigned int irq;
> + int ret;
> +
> + if (np) {
> + frame_node = (struct device_node *)frame;
> + base = of_iomap(frame_node, 0);
> + arch_timer_detect_rate(base, np);
> + if (arch_timer_mem_use_virtual)
> + irq = irq_of_parse_and_map(frame_node, VIRT_SPI);
> + else
> + irq = irq_of_parse_and_map(frame_node, PHYS_SPI);
> + } else {
> + frame_data = (struct gt_timer_data *)frame;
> + /*
> + * According to ARMv8 Architecture Reference Manual(ARM),
> + * the size of CNTBaseN frames of memory-mapped timer
> + * is SZ_4K(Offset 0x000 – 0xFFF).
> + */
> + base = ioremap(frame_data->cntbase_phy, SZ_4K);
> + if (arch_timer_mem_use_virtual)
> + irq = frame_data->virtual_irq;
> + else
> + irq = frame_data->irq;
> + }
> +
> + if (!base) {
> + pr_err("Can't map frame's registers\n");
> + return -ENXIO;
> + }
> + if (!irq) {
> + pr_err("Frame missing %s irq",
> + arch_timer_mem_use_virtual ? "virt" : "phys");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + arch_counter_base = base;
>
> t = kzalloc(sizeof(*t), GFP_KERNEL);
> - if (!t)
> + if (!t) {
> return -ENOMEM;
^
my bad, it should be "ret = "
> + goto out;
> + }
>
> t->base = base;
> t->evt.irq = irq;
> @@ -676,11 +718,13 @@ static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
> func = arch_timer_handler_phys_mem;
>
> ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &t->evt);
> - if (ret) {
> - pr_err("Failed to request mem timer irq\n");
> - kfree(t);
> - }
> + if (!ret)
> + return 0;
>
> + pr_err("Failed to request mem timer irq\n");
> + kfree(t);
> +out:
> + iounmap(base);
> return ret;
> }
>
> @@ -769,7 +813,7 @@ static int __init arch_timer_init(void)
> return ret;
>
> arch_timer_kvm_info.virtual_irq = arch_timer_ppi[VIRT_PPI];
> -
> +
> return 0;
> }
>
> @@ -803,21 +847,56 @@ static int __init arch_timer_of_init(struct device_node *np)
> CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
> CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
>
> -static int __init arch_timer_mem_init(struct device_node *np)
> +static int __init get_cnttidr(struct device_node *np,
> + struct gt_block_data *gt_block, u32 *cnttidr)
> {
> - struct device_node *frame, *best_frame = NULL;
> - void __iomem *cntctlbase, *base;
> - unsigned int irq, ret = -EINVAL;
> - u32 cnttidr;
> + if (np)
> + cntctlbase = of_iomap(np, 0);
> + else
> + cntctlbase = ioremap(gt_block->cntctlbase_phy, SZ_4K);
> + /*
> + * According to ARMv8 Architecture Reference Manual(ARM),
> + * the size of CNTCTLBase frame of memory-mapped timer
> + * is SZ_4K(Offset 0x000 – 0xFFF).
> + */
>
> - arch_timers_present |= ARCH_MEM_TIMER;
> - cntctlbase = of_iomap(np, 0);
> if (!cntctlbase) {
> pr_err("Can't find CNTCTLBase\n");
> return -ENXIO;
> }
>
> - cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
> + *cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
> + return 0;
> +}
> +
> +static bool __init is_best_frame(u32 cnttidr, int n)
> +{
> + u32 cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT | CNTACR_RWVT |
> + CNTACR_RVOFF | CNTACR_RVCT;
> +
> + /* Try enabling everything, and see what sticks */
> + writel_relaxed(cntacr, cntctlbase + CNTACR(n));
> + cntacr = readl_relaxed(cntctlbase + CNTACR(n));
> +
> + if ((cnttidr & CNTTIDR_VIRT(n)) &&
> + !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT)))
> + arch_timer_mem_use_virtual = true;
> + else if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
> + return false;
> +
> + return true;
> +}
> +
> +static int __init arch_timer_mem_init(struct device_node *np)
> +{
> + struct device_node *frame, *best_frame = NULL;
> + unsigned int ret = -EINVAL;
> + u32 cnttidr;
> +
> + arch_timers_present |= ARCH_MEM_TIMER;
> +
> + if (get_cnttidr(np, NULL, &cnttidr))
> + return -ENXIO;
>
> /*
> * Try to find a virtual capable frame. Otherwise fall back to a
> @@ -825,60 +904,22 @@ static int __init arch_timer_mem_init(struct device_node *np)
> */
> for_each_available_child_of_node(np, frame) {
> int n;
> - u32 cntacr;
> -
> if (of_property_read_u32(frame, "frame-number", &n)) {
> - pr_err("Missing frame-number\n");
> + pr_err("Missing frame-number.\n");
> of_node_put(frame);
> goto out;
> }
> -
> - /* 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))) {
> + if (is_best_frame(cnttidr, n)) {
> of_node_put(best_frame);
> - best_frame = frame;
> - arch_timer_mem_use_virtual = true;
> - break;
> + best_frame = of_node_get(frame);
> + if (arch_timer_mem_use_virtual)
> + break;
> }
> -
> - if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
> - continue;
> -
> - of_node_put(best_frame);
> - best_frame = of_node_get(frame);
> - }
> -
> - ret= -ENXIO;
> - base = arch_counter_base = of_iomap(best_frame, 0);
> - if (!base) {
> - pr_err("Can't map frame's registers\n");
> - goto out;
> - }
> -
> - if (arch_timer_mem_use_virtual)
> - irq = irq_of_parse_and_map(best_frame, VIRT_SPI);
> - else
> - irq = irq_of_parse_and_map(best_frame, PHYS_SPI);
> -
> - ret = -EINVAL;
> - if (!irq) {
> - pr_err("Frame missing %s irq",
> - arch_timer_mem_use_virtual ? "virt" : "phys");
> - goto out;
> }
>
> - arch_timer_detect_rate(base, np);
> - ret = arch_timer_mem_register(base, irq);
> - if (ret)
> - goto out;
> -
> - return arch_timer_common_init();
> + ret = arch_timer_mem_register(np, best_frame);
> + if (!ret)
> + ret = arch_timer_common_init();
> out:
> iounmap(cntctlbase);
> of_node_put(best_frame);
> @@ -888,7 +929,72 @@ 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;
> + u32 cnttidr;
> + int i;
> +
> + if (get_cnttidr(NULL, gt_block, &cnttidr))
> + return NULL;
> + /*
> + * Try to find a virtual capable frame. Otherwise fall back to a
> + * physical capable frame.
> + */
> + for (i = 0; i < gt_block->timer_count; i++) {
> + if (is_best_frame(cnttidr, gt_block->timer[i].frame_nr)) {
> + best_frame = >_block->timer[i];
> + if (arch_timer_mem_use_virtual)
> + break;
> + }
> + }
> + 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;
> + int ret = -EINVAL;
> +
> + /*
> + * 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;
> + }
> + ret = arch_timer_mem_register(NULL, gt_timer);
> + if (ret) {
> + pr_err("Failed to register mem timer.\n");
> + goto error;
> + }
> + }
> + 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 +1018,8 @@ 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();
> }
> --
> 2.7.4
>
--
Best regards,
Fu Wei
Software Engineer
Red Hat
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