Re: [PATCH v16 10/15] clocksource/drivers/arm_arch_timer: Refactor the timer init code to prepare for GTDT

From: Fu Wei
Date: Wed Nov 23 2016 - 01:10:21 EST

Next message: Al Viro: "Re: sendfile from 9p fs into af_alg"
Previous message: Oliver Hartkopp: "Re: net/can: use-after-free in bcm_rx_thr_flush"
In reply to: Mark Rutland: "Re: [PATCH v16 10/15] clocksource/drivers/arm_arch_timer: Refactor the timer init code to prepare for GTDT"
Next in thread: fu . wei: "[PATCH v16 11/15] acpi/arm64: Add GTDT table parse driver"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Hi Mark,

On 19 November 2016 at 04:03, Mark Rutland <mark.rutland@xxxxxxx> wrote:
> On Wed, Nov 16, 2016 at 09:49:03PM +0800, fu.wei@xxxxxxxxxx wrote:
>> From: Fu Wei <fu.wei@xxxxxxxxxx>
>>
>> The patch refactor original memory-mapped timer init code:
>> (1) Extract a subfunction for detecting a bast time frame:
>> is_best_frame.
>
> Please leave this logic in arch_timer_mem_init(). Pulling it out gains
> us nothing, but makes the patch harder to review.

OK, I have put it back to arch_timer_mem_init() in next version: v17

>
>> (2) Refactor "arch_timer_mem_init", make it become a common code for
>> memory-mapped timer init.
>> (3) Add a new function "arch_timer_mem_of_init" for DT init.
>
> These generally look fine.
>
> Thanks,
> Mark.
>
>> Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
>> ---
>> drivers/clocksource/arm_arch_timer.c | 162 +++++++++++++++++++++++------------
>> 1 file changed, 107 insertions(+), 55 deletions(-)
>>
>> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
>> index 9ddc091..0836bb9 100644
>> --- a/drivers/clocksource/arm_arch_timer.c
>> +++ b/drivers/clocksource/arm_arch_timer.c
>> @@ -923,17 +923,35 @@ 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 bool __init is_best_frame(void __iomem *cntctlbase, 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 arch_timer_mem *timer_mem)
>> {
>> - struct device_node *frame, *best_frame = NULL;
>> void __iomem *cntctlbase, *base;
>> - unsigned int irq, ret = -EINVAL;
>> + struct arch_timer_mem_frame *best_frame = NULL;
>> + unsigned int irq;
>> u32 cnttidr;
>> + int i, ret;
>>
>> - arch_timers_present |= ARCH_TIMER_TYPE_MEM;
>> - cntctlbase = of_iomap(np, 0);
>> + cntctlbase = ioremap(timer_mem->cntctlbase, timer_mem->size);
>> if (!cntctlbase) {
>> - pr_err("Can't find CNTCTLBase\n");
>> + pr_err("Can't map CNTCTLBase.\n");
>> return -ENXIO;
>> }
>>
>> @@ -943,76 +961,110 @@ static int __init arch_timer_mem_init(struct device_node *np)
>> * Try to find a virtual capable frame. Otherwise fall back to a
>> * physical capable frame.
>> */
>> - 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");
>> - 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))) {
>> - of_node_put(best_frame);
>> - best_frame = frame;
>> - arch_timer_mem_use_virtual = true;
>> - break;
>> + for (i = 0; i < timer_mem->num_frames; i++) {
>> + if (is_best_frame(cntctlbase, cnttidr,
>> + timer_mem->frame[i].frame_nr)) {
>> + best_frame = &timer_mem->frame[i];
>> + 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);
>> }
>> + iounmap(cntctlbase);
>>
>> - 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 (!best_frame) {
>> + pr_err("Can't find frame for register\n");
>> + return -EINVAL;
>> }
>>
>> if (arch_timer_mem_use_virtual)
>> - irq = irq_of_parse_and_map(best_frame, ARCH_TIMER_VIRT_SPI);
>> + irq = best_frame->virt_irq;
>> else
>> - irq = irq_of_parse_and_map(best_frame, ARCH_TIMER_PHYS_SPI);
>> + irq = best_frame->phys_irq;
>>
>> - ret = -EINVAL;
>> if (!irq) {
>> pr_err("Frame missing %s irq",
>> arch_timer_mem_use_virtual ? "virt" : "phys");
>> - goto out;
>> + return -EINVAL;
>> }
>>
>> - /*
>> - * Try to determine the frequency from the device tree,
>> - * if fail, get the frequency from CNTFRQ.
>> - */
>> - if (!arch_timer_rate &&
>> - of_property_read_u32(np, "clock-frequency", &arch_timer_rate))
>> - arch_timer_detect_rate(base);
>> + base = ioremap(best_frame->cntbase, best_frame->size);
>> + if (!base) {
>> + pr_err("Can't map frame's registers\n");
>> + return -ENXIO;
>> + }
>> +
>> + arch_timer_detect_rate(base);
>>
>> ret = arch_timer_mem_register(base, irq);
>> - if (ret)
>> + if (ret) {
>> + iounmap(base);
>> + return ret;
>> + }
>> +
>> + arch_counter_base = base;
>> + arch_timers_present |= ARCH_TIMER_TYPE_MEM;
>> +
>> + return 0;
>> +}
>> +
>> +static int __init arch_timer_mem_of_init(struct device_node *np)
>> +{
>> + struct arch_timer_mem *timer_mem;
>> + struct device_node *frame_node;
>> + struct resource res;
>> + int i, ret = -EINVAL;
>> +
>> + timer_mem = kzalloc(sizeof(*timer_mem), GFP_KERNEL);
>> + if (!timer_mem)
>> + return -ENOMEM;
>> +
>> + if (of_address_to_resource(np, 0, &res))
>> goto out;
>> + timer_mem->cntctlbase = res.start;
>> + timer_mem->size = resource_size(&res);
>>
>> - return arch_timer_common_init();
>> + i = 0;
>> + for_each_available_child_of_node(np, frame_node) {
>> + int n;
>> + struct arch_timer_mem_frame *frame = &timer_mem->frame[i];
>> +
>> + if (of_property_read_u32(frame_node, "frame-number", &n)) {
>> + pr_err("Missing frame-number\n");
>> + of_node_put(frame_node);
>> + goto out;
>> + }
>> + frame->frame_nr = n;
>> +
>> + if (of_address_to_resource(frame_node, 0, &res)) {
>> + of_node_put(frame_node);
>> + goto out;
>> + }
>> + frame->cntbase = res.start;
>> + frame->size = resource_size(&res);
>> +
>> + frame->virt_irq = irq_of_parse_and_map(frame_node,
>> + ARCH_TIMER_VIRT_SPI);
>> + frame->phys_irq = irq_of_parse_and_map(frame_node,
>> + ARCH_TIMER_PHYS_SPI);
>> +
>> + if (++i >= ARCH_TIMER_MEM_MAX_FRAMES)
>> + break;
>> + }
>> + timer_mem->num_frames = i;
>> +
>> + /* Try to determine the frequency from the device tree */
>> + if (!arch_timer_rate)
>> + of_property_read_u32(np, "clock-frequency", &arch_timer_rate);
>> +
>> + ret = arch_timer_mem_init(timer_mem);
>> + if (!ret)
>> + ret = arch_timer_common_init();
>> out:
>> - iounmap(cntctlbase);
>> - of_node_put(best_frame);
>> + kfree(timer_mem);
>> return ret;
>> }
>> CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
>> - arch_timer_mem_init);
>> + arch_timer_mem_of_init);
>>
>> #ifdef CONFIG_ACPI
>> static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags)
>> --
>> 2.7.4
>>

--
Best regards,

Fu Wei
Software Engineer
Red Hat

Next message: Al Viro: "Re: sendfile from 9p fs into af_alg"
Previous message: Oliver Hartkopp: "Re: net/can: use-after-free in bcm_rx_thr_flush"
In reply to: Mark Rutland: "Re: [PATCH v16 10/15] clocksource/drivers/arm_arch_timer: Refactor the timer init code to prepare for GTDT"
Next in thread: fu . wei: "[PATCH v16 11/15] acpi/arm64: Add GTDT table parse driver"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]