From: hanjun.guo@linaro•org (Hanjun Guo)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v8 17/21] clocksource / arch_timer: Parse GTDT to initialize arch timer
Date: Thu, 05 Feb 2015 18:11:47 +0800 [thread overview]
Message-ID: <54D341E3.9020402@linaro.org> (raw)
In-Reply-To: <20150204185929.GH22035@red-moon>
Hi Lorenzo,
On 2015?02?05? 02:59, Lorenzo Pieralisi wrote:
> On Mon, Feb 02, 2015 at 12:45:45PM +0000, Hanjun Guo wrote:
>> Using the information presented by GTDT (Generic Timer Description Table)
>> to initialize the arch timer (not memory-mapped).
>
> Why are you not initializing the memory mapped timer ?
We left it for later work because no need for that to boot
available ARM64 hardware at now, and we have no hardware to
test unless I missed some of platforms.
>
>> CC: Daniel Lezcano <daniel.lezcano@linaro•org>
>> Originally-by: Amit Daniel Kachhap <amit.daniel@samsung•com>
>> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd•com>
>> Tested-by: Yijing Wang <wangyijing@huawei•com>
>> Tested-by: Mark Langsdorf <mlangsdo@redhat•com>
>> Tested-by: Jon Masters <jcm@redhat•com>
>> Tested-by: Timur Tabi <timur@codeaurora•org>
>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro•org>
>> ---
>> arch/arm64/kernel/time.c | 7 ++
>> drivers/clocksource/arm_arch_timer.c | 132 ++++++++++++++++++++++++++++-------
>> include/linux/clocksource.h | 6 ++
>> 3 files changed, 118 insertions(+), 27 deletions(-)
>>
>> diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
>> index 1a7125c..42f9195 100644
>> --- a/arch/arm64/kernel/time.c
>> +++ b/arch/arm64/kernel/time.c
>> @@ -35,6 +35,7 @@
>> #include <linux/delay.h>
>> #include <linux/clocksource.h>
>> #include <linux/clk-provider.h>
>> +#include <linux/acpi.h>
>>
>> #include <clocksource/arm_arch_timer.h>
>>
>> @@ -72,6 +73,12 @@ void __init time_init(void)
>>
>> tick_setup_hrtimer_broadcast();
>>
>> + /*
>> + * Since ACPI or FDT will only one be available in the system,
>> + * we can use acpi_generic_timer_init() here safely
>> + */
>> + acpi_generic_timer_init();
>> +
>> arch_timer_rate = arch_timer_get_rate();
>> if (!arch_timer_rate)
>> panic("Unable to initialise architected timer.\n");
>> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
>> index 095c177..407aa63 100644
>> --- a/drivers/clocksource/arm_arch_timer.c
>> +++ b/drivers/clocksource/arm_arch_timer.c
>> @@ -21,6 +21,7 @@
>> #include <linux/io.h>
>> #include <linux/slab.h>
>> #include <linux/sched_clock.h>
>> +#include <linux/acpi.h>
>>
>> #include <asm/arch_timer.h>
>> #include <asm/virt.h>
>> @@ -370,8 +371,12 @@ arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np)
>> if (arch_timer_rate)
>> return;
>>
>> - /* Try to determine the frequency from the device tree or CNTFRQ */
>> - if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
>> + /*
>> + * Try to determine the frequency from the device tree or CNTFRQ,
>> + * if ACPI is enabled, get the frequency from CNTFRQ ONLY.
>> + */
>> + if (!acpi_disabled ||
>> + of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
>
> This is getting a mess. cntbase tells you it is a memory mapped timer,
> node pointer that you are probing through DT, and to top it all
> acpi_disabled detects if you are probing in ACPI or DT mode.
>
> I think this function should be simplified, this driver is also
> pending a refactoring to split arch timer and the memory mapped one
> so I think you'd better wait that work to make things simpler.
Does anyone working on this now?
>
> [...]
>
>> +/* Initialize all the generic timers presented in GTDT */
>> +void __init acpi_generic_timer_init(void)
>> +{
>> + if (acpi_disabled)
>> + return;
>
> acpi_disabled used again here, I repeat myself this is going to be
> hard to track. You should try to organize the code something like:
>
> if (acpi_disabled)
> timer_dt_probe();
> else
> timer_acpi_probe();
>
> mixing the code paths is getting unwieldy, see above to see my
> reasoning.
Olof is unhappy with such approach, I think if (acpi_disabled) is
self-contained because we only get DT or ACPI in the system, we
can call this function time_init() without more if (acpi_disabled).
>
>> +
>> + acpi_table_parse(ACPI_SIG_GTDT, arch_timer_acpi_init);
>> +}
>> +#endif
>> diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
>> index abcafaa..af6155a 100644
>> --- a/include/linux/clocksource.h
>> +++ b/include/linux/clocksource.h
>> @@ -346,4 +346,10 @@ extern void clocksource_of_init(void);
>> static inline void clocksource_of_init(void) {}
>> #endif
>>
>> +#ifdef CONFIG_ACPI
>> +void acpi_generic_timer_init(void);
>> +#else
>> +static inline void acpi_generic_timer_init(void) { }
>> +#endif
>> +
>
> That's not nice, it is a generic header, arch specific stuff should be
> avoided. I think you should have an ACPI generic layer similar to
> clocksource_of_init(), and probe from there when matching the respective
> timers.
I think I'm OK with it, but do we really need to introduce a heavy
framework to init just arm arch timer (memory mapped or not) ?
Thanks
Hanjun
next prev parent reply other threads:[~2015-02-05 10:11 UTC|newest]
Thread overview: 123+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-02 12:45 [PATCH v8 00/21] Introduce ACPI for ARM64 based on ACPI 5.1 Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 01/21] acpi: add arm64 to the platforms that use ioremap Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 02/21] acpi: fix acpi_os_ioremap for arm64 Hanjun Guo
2015-02-02 22:14 ` Rafael J. Wysocki
2015-02-03 9:08 ` Hanjun Guo
2015-02-03 11:37 ` Catalin Marinas
2015-02-03 11:41 ` Ard Biesheuvel
2015-02-03 17:29 ` Mark Salter
2015-02-03 22:04 ` Rafael J. Wysocki
2015-02-04 10:48 ` Russell King - ARM Linux
2015-02-04 13:22 ` Rafael J. Wysocki
2015-02-04 15:53 ` Bjorn Helgaas
2015-02-04 16:25 ` Russell King - ARM Linux
2015-02-04 16:38 ` David Woodhouse
2015-02-04 16:41 ` Bjorn Helgaas
2015-02-04 11:25 ` Catalin Marinas
2015-02-04 16:08 ` Mark Salter
2015-02-04 16:16 ` Timur Tabi
2015-02-04 17:52 ` Catalin Marinas
2015-02-04 17:57 ` Catalin Marinas
2015-02-04 18:58 ` Mark Salter
2015-02-05 10:41 ` Catalin Marinas
2015-02-05 10:47 ` Ard Biesheuvel
2015-02-05 10:59 ` Catalin Marinas
2015-02-05 11:14 ` Graeme Gregory
2015-02-05 12:07 ` Catalin Marinas
2015-02-05 12:52 ` Graeme Gregory
2015-02-05 14:50 ` Catalin Marinas
2015-02-05 12:55 ` Ard Biesheuvel
2015-02-05 13:54 ` Mark Salter
2015-02-05 16:42 ` [Linaro-acpi] " Al Stone
2015-02-05 17:48 ` Catalin Marinas
2015-02-05 22:16 ` Ard Biesheuvel
2015-02-06 10:36 ` Catalin Marinas
2015-02-06 11:08 ` Ard Biesheuvel
2015-02-06 14:16 ` Catalin Marinas
2015-02-07 1:44 ` Ard Biesheuvel
2015-02-05 1:24 ` Rafael J. Wysocki
2015-02-02 12:45 ` [PATCH v8 03/21] arm64: allow late use of early_ioremap Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 04/21] ARM64 / ACPI: Get RSDP and ACPI boot-time tables Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 05/21] ACPI / sleep: Introduce sleep_arm.c Hanjun Guo
2015-02-02 22:18 ` Rafael J. Wysocki
2015-02-03 16:18 ` Graeme Gregory
2015-02-02 12:45 ` [PATCH v8 06/21] ARM64 / ACPI: Introduce PCI stub functions for ACPI Hanjun Guo
2015-02-03 12:15 ` Catalin Marinas
2015-02-03 13:30 ` Hanjun Guo
2015-02-03 14:55 ` Rafael J. Wysocki
2015-02-04 9:06 ` Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 07/21] ARM64 / ACPI: Introduce early_param for "acpi" and pass acpi=force to enable ACPI Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 08/21] dt / chosen: Add linux, uefi-stub-generated-dtb property Hanjun Guo
2015-02-02 13:40 ` [PATCH v8 08/21] dt / chosen: Add linux,uefi-stub-generated-dtb property Leif Lindholm
2015-02-02 13:50 ` Graeme Gregory
2015-02-02 16:32 ` Mark Rutland
2015-02-06 10:34 ` [PATCH v8 08/21] dt / chosen: Add linux, uefi-stub-generated-dtb property G Gregory
2015-02-07 3:36 ` [PATCH v8 08/21] dt / chosen: Add linux,uefi-stub-generated-dtb property Hanjun Guo
2015-02-07 5:03 ` [PATCH v8 08/21] dt / chosen: Add linux, uefi-stub-generated-dtb property Ard Biesheuvel
2015-02-07 6:51 ` [PATCH v8 08/21] dt / chosen: Add linux,uefi-stub-generated-dtb property Hanjun Guo
2015-02-09 11:46 ` Mark Rutland
2015-02-11 2:44 ` [PATCH v8 08/21] dt / chosen: Add linux, uefi-stub-generated-dtb property Ard Biesheuvel
2015-02-11 6:33 ` [PATCH v8 08/21] dt / chosen: Add linux,uefi-stub-generated-dtb property Stefano Stabellini
2015-02-11 6:53 ` [PATCH v8 08/21] dt / chosen: Add linux, uefi-stub-generated-dtb property Ard Biesheuvel
2015-02-11 7:07 ` [PATCH v8 08/21] dt / chosen: Add linux,uefi-stub-generated-dtb property Stefano Stabellini
2015-02-02 12:45 ` [PATCH v8 09/21] ARM64 / ACPI: Disable ACPI if FADT revision is less than 5.1 Hanjun Guo
2015-02-03 17:20 ` Catalin Marinas
2015-02-04 9:38 ` Hanjun Guo
2015-02-04 13:06 ` Lorenzo Pieralisi
2015-02-05 9:45 ` Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 10/21] ARM64 / ACPI: If we chose to boot from acpi then disable FDT Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 11/21] ARM64 / ACPI: Get PSCI flags in FADT for PSCI init Hanjun Guo
2015-02-04 16:43 ` Lorenzo Pieralisi
2015-02-05 9:48 ` Hanjun Guo
2015-02-05 17:11 ` [Linaro-acpi] " Al Stone
2015-02-05 17:49 ` Lorenzo Pieralisi
2015-02-05 19:03 ` Al Stone
2015-02-06 7:56 ` Hanjun Guo
2015-02-06 16:21 ` Lorenzo Pieralisi
2015-02-02 12:45 ` [PATCH v8 12/21] ACPI / table: Print GIC information when MADT is parsed Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 13/21] ARM64 / ACPI: Parse MADT for SMP initialization Hanjun Guo
2015-02-03 13:53 ` Mark Rutland
2015-02-04 9:05 ` Hanjun Guo
2015-02-04 10:30 ` Mark Rutland
2015-02-05 9:20 ` Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 14/21] ACPI / processor: Make it possible to get CPU hardware ID via GICC Hanjun Guo
2015-02-03 14:17 ` Mark Rutland
2015-02-03 20:09 ` Catalin Marinas
2015-02-04 9:48 ` Hanjun Guo
2015-02-04 11:21 ` Catalin Marinas
2015-02-05 9:27 ` Hanjun Guo
2015-02-05 10:52 ` Catalin Marinas
2015-02-09 6:55 ` Will Deacon
2015-02-09 9:52 ` Catalin Marinas
2015-02-02 12:45 ` [PATCH v8 15/21] ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi Hanjun Guo
2015-02-09 6:34 ` Will Deacon
2015-02-09 6:53 ` Hanjun Guo
2015-02-09 7:07 ` Will Deacon
2015-02-02 12:45 ` [PATCH v8 16/21] irqchip: Add GICv2 specific ACPI boot support Hanjun Guo
2015-02-02 22:23 ` Rafael J. Wysocki
2015-02-03 15:38 ` Tomasz Nowicki
2015-02-02 12:45 ` [PATCH v8 17/21] clocksource / arch_timer: Parse GTDT to initialize arch timer Hanjun Guo
2015-02-02 22:23 ` Rafael J. Wysocki
2015-02-03 13:28 ` Hanjun Guo
2015-02-04 18:59 ` Lorenzo Pieralisi
2015-02-05 10:11 ` Hanjun Guo [this message]
2015-02-02 12:45 ` [PATCH v8 18/21] ARM64 / ACPI: Select ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64 Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 19/21] ARM64 / ACPI: Enable ARM64 in Kconfig Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 20/21] Documentation: ACPI for ARM64 Hanjun Guo
2015-02-02 19:01 ` Timur Tabi
2015-02-03 8:44 ` Hanjun Guo
2015-02-02 12:45 ` [PATCH v8 21/21] arm64: ACPI: additions of ACPI documentation for arm64 Hanjun Guo
2015-02-04 0:40 ` Al Stone
2015-02-04 18:12 ` Mark Brown
2015-02-04 19:06 ` Al Stone
2015-02-05 2:02 ` Mark Brown
2015-02-03 16:47 ` [PATCH v8 00/21] Introduce ACPI for ARM64 based on ACPI 5.1 Mark Rutland
2015-02-03 17:43 ` [Linaro-acpi] " Al Stone
2015-02-04 9:41 ` Hanjun Guo
2015-02-04 20:29 ` Timur Tabi
2015-02-05 10:16 ` Hanjun Guo
2015-02-12 10:02 ` Robert Richter
2015-02-13 2:48 ` Hanjun Guo
2015-02-19 16:10 ` Robert Richter
[not found] ` <a314cdbbefb349acbb8f47d6e806989f@NASANEXM01D.na.qualcomm.com>
2015-02-13 0:50 ` Jonathan (Zhixiong) Zhang
2015-02-13 7:50 ` Hanjun Guo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=54D341E3.9020402@linaro.org \
--to=hanjun.guo@linaro$(echo .)org \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox