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Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in GTDT driver

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Hi,

I tried to fix the issue that Lornzo raised, such that I could queue
these patches. From looking at this patch in more detail however, I
think there are further issues that need to be addressed.

On Sat, Apr 01, 2017 at 01:51:03AM +0800, fu.wei@linaro.org wrote:
> +	/*
> +	 * Get the GT timer Frame data for every GT Block Timer
> +	 */
> +	for (i = 0; i < block->timer_count; i++, gtdt_frame++) {
> +		if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER)
> +			continue;
> +
> +		if (!gtdt_frame->base_address || !gtdt_frame->timer_interrupt)
> +			goto error;
> +
> +		frame = &timer_mem->frame[gtdt_frame->frame_number];
> +		frame->phys_irq = map_gt_gsi(gtdt_frame->timer_interrupt,
> +					     gtdt_frame->timer_flags);
> +		if (frame->phys_irq <= 0) {
> +			pr_warn("failed to map physical timer irq in frame %d.\n",
> +				gtdt_frame->frame_number);
> +			goto error;
> +		}
> +
> +		if (gtdt_frame->virtual_timer_interrupt) {
> +			frame->virt_irq =
> +				map_gt_gsi(gtdt_frame->virtual_timer_interrupt,
> +					   gtdt_frame->virtual_timer_flags);
> +			if (frame->virt_irq <= 0) {
> +				pr_warn("failed to map virtual timer irq in frame %d.\n",
> +					gtdt_frame->frame_number);
> +				acpi_unregister_gsi(gtdt_frame->timer_interrupt);
> +				goto error;
> +			}
> +		} else {
> +			frame->virt_irq = 0;
> +			pr_debug("virtual timer in frame %d not implemented.\n",
> +				 gtdt_frame->frame_number);
> +		}
> +
> +		frame->cntbase = gtdt_frame->base_address;
> +		/*
> +		 * The CNTBaseN frame is 4KB (register offsets 0x000 - 0xFFC).
> +		 * See ARM DDI 0487A.k_iss10775, page I1-5130, Table I1-4
> +		 * "CNTBaseN memory map".
> +		 */
> +		frame->size = SZ_4K;
> +		frame->valid = true;
> +	}
> +
> +	return 0;
> +
> +error:
> +	for (i = 0; i < ARCH_TIMER_MEM_MAX_FRAMES; i++) {
> +		frame = &timer_mem->frame[i];
> +		if (!frame->valid)
> +			continue;
> +		irq_dispose_mapping(frame->phys_irq);
> +		if (frame->virt_irq)
> +			irq_dispose_mapping(frame->virt_irq);
> +	}

We assign interrupts and may goto error before setting valid, so here we
won't free the interrupts of the last frame we parsed.

> +	return -EINVAL;
> +}
> +
> +/**
> + * acpi_arch_timer_mem_init() - Get the info of all GT blocks in GTDT table.
> + * @timer_mem:	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).
> + * @timer_count: It points to a integer variable which is used for storing 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 *timer_mem,
> +				    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, timer_mem);
> +			if (ret)
> +				return ret;
> +			timer_mem++;
> +			(*timer_count)++;
> +		}
> +	}

If we were to have multiple GT blocks, this would leave timer_mem in an
inconsistent state. In gtdt_parse_timer_block we'll blat any existing
timer_mem->cntctlbase, and blat some arbitrary set of frames. however,
*some* frames may have been held over from a previous iteration.

My understanding was that the system level timer had a single CNTCTLBase
frame, and hence we should only have a single GT block.

Judging by ARM DDI 0487A.k_iss10775, I1.3 "Memory-mapped timer
components" and I3.4 "Generic Timer memory-mapped registers overview",
it does appear that the system should only have one CNTCTLBase frame.

What's going on here?

Thanks,
Mark.

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[PATCH v23 00/11] acpi, clocksource: add GTDT driver and GTDT support in arm_arch_timer fu.wei@linaro.org - 2017-03-31 20:00 +0200
  [PATCH v23 06/11] clocksource: arm_arch_timer: refactor MMIO timer probing. fu.wei@linaro.org - 2017-03-31 20:00 +0200
    Re: [PATCH v23 06/11] clocksource: arm_arch_timer: refactor MMIO  timer probing. Mark Rutland <mark.rutland@arm.com> - 2017-04-05 20:50 +0200
      Re: [PATCH v23 06/11] clocksource: arm_arch_timer: refactor MMIO  timer probing. Fu Wei <fu.wei@linaro.org> - 2017-04-06 12:50 +0200
  [PATCH v23 04/11] clocksource: arm_arch_timer: move arch_timer_needs_of_probing into DT init call fu.wei@linaro.org - 2017-03-31 20:00 +0200
  [PATCH v23 08/11] clocksource: arm_arch_timer: simplify ACPI support code. fu.wei@linaro.org - 2017-03-31 20:00 +0200
  [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in GTDT driver fu.wei@linaro.org - 2017-03-31 20:00 +0200
    Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Will Deacon <will.deacon@arm.com> - 2017-04-03 11:50 +0200
    Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-03 12:50 +0200
      Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Fu Wei <fu.wei@linaro.org> - 2017-04-06 19:20 +0200
    Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Mark Rutland <mark.rutland@arm.com> - 2017-04-05 20:40 +0200
      Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Mark Rutland <mark.rutland@arm.com> - 2017-04-06 12:10 +0200
      Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Fu Wei <fu.wei@linaro.org> - 2017-04-06 18:50 +0200
        Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Mark Rutland <mark.rutland@arm.com> - 2017-04-06 19:30 +0200
          Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Fu Wei <fu.wei@linaro.org> - 2017-04-06 19:50 +0200
            Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Mark Rutland <mark.rutland@arm.com> - 2017-04-06 20:00 +0200
              Re: [PATCH v23 09/11] acpi/arm64: Add memory-mapped timer support in  GTDT driver Fu Wei <fu.wei@linaro.org> - 2017-04-06 20:10 +0200
  [PATCH v23 07/11] acpi/arm64: Add GTDT table parse driver fu.wei@linaro.org - 2017-03-31 20:00 +0200
  [PATCH v23 05/11] clocksource: arm_arch_timer: add structs to describe MMIO timer fu.wei@linaro.org - 2017-03-31 20:00 +0200
  [PATCH v23 01/11] clocksource: arm_arch_timer: add MMIO CNTFRQ helper fu.wei@linaro.org - 2017-03-31 20:00 +0200
  [PATCH v23 11/11] acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver fu.wei@linaro.org - 2017-03-31 20:00 +0200
  [PATCH v23 02/11] clocksource: arm_arch_timer: split dt-only rate handling fu.wei@linaro.org - 2017-03-31 20:00 +0200
  [PATCH v23 03/11] clocksource: arm_arch_timer: refactor arch_timer_needs_probing fu.wei@linaro.org - 2017-03-31 20:00 +0200
  Re: [PATCH v23 00/11] acpi, clocksource: add GTDT driver and GTDT  support in arm_arch_timer Xiongfeng Wang <wangxiongfeng2@huawei.com> - 2017-04-01 04:20 +0200
    Re: [PATCH v23 00/11] acpi, clocksource: add GTDT driver and GTDT  support in arm_arch_timer Fu Wei <fu.wei@linaro.org> - 2017-04-01 05:50 +0200
  Re: [PATCH v23 00/11] acpi, clocksource: add GTDT driver and GTDT  support in arm_arch_timer Timur Tabi <timur@codeaurora.org> - 2017-04-04 22:40 +0200

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