[2/2] arch_timer: acpi: add hisi timer erratum data

From: Marc Zyngier <marc.zyngier@arm.com>

On Tue, Feb 21 2017 at 11:56:31 am GMT, Hanjun Guo <guohanjun@huawei.com> wrote:
> Hi Marc,

[...]

> Thank you very much! I prepared an ACPI patch based on your branch, I was
> trying to reuse the "const void *id" for ACPI as well but we need to match the
> oem_id, oem_table_id and oem_revision in GTDT table, so I introduced new
> matching information for ACPI, please take a look if it's OK.
>
> commit 02d531ae4a88c483db849a611bd9bf7c39d2e1bf
> Author: Hanjun Guo <hanjun.guo@linaro.org>
> Date:   Tue Feb 21 15:17:14 2017 +0800
>
>     arm64: arch_timer: enable the erratums in ACPI way
>    
>     Match OEM information which are oem_id, oem_table_id and oem_revision
>     to enable the erratum for specific platforms.
>    
>     Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
>  arch/arm64/include/asm/arch_timer.h  |  7 +++++++
>  drivers/clocksource/arm_arch_timer.c | 31 +++++++++++++++++++++++++++++++
>  2 files changed, 38 insertions(+)
>
> diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
> index 1595134..79d033c 100644
> --- a/arch/arm64/include/asm/arch_timer.h
> +++ b/arch/arm64/include/asm/arch_timer.h
> @@ -22,6 +22,7 @@
>  #include <asm/barrier.h>
>  #include <asm/sysreg.h>
>  
> +#include <linux/acpi.h>
>  #include <linux/bug.h>
>  #include <linux/init.h>
>  #include <linux/jump_label.h>
> @@ -42,6 +43,7 @@ enum arch_timer_erratum_match_type {
>         ate_match_dt,
>         ate_match_global_cap_id,
>         ate_match_local_cap_id,
> + ate_match_acpi,
>  };
>  
>  struct clock_event_device;
> @@ -49,6 +51,11 @@ enum arch_timer_erratum_match_type {
>  struct arch_timer_erratum_workaround {
>         enum arch_timer_erratum_match_type match_type;
>         const void *id;         /* Indicate the Erratum ID */
> +#ifdef CONFIG_ACPI
> + char oem_id[ACPI_OEM_ID_SIZE + 1];
> + char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
> + u32 oem_revision;
> +#endif
>         const char *desc_str;
>         u32 (*read_cntp_tval_el0)(void);
>         u32 (*read_cntv_tval_el0)(void);
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index bbd9361..82ff6e4 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -363,6 +363,32 @@ bool arch_timer_check_dt_erratum(const struct arch_timer_erratum_workaround
> *wa,
>         return of_property_read_bool(np, wa->id);
>  }
>  
> +#ifdef CONFIG_ACPI
> +static bool
> +arch_timer_check_acpi_erratum(const struct arch_timer_erratum_workaround *wa,
> +                       const void *arg)
> +{
> + const struct acpi_table_header *table = arg;
> +
> + if (!wa->oem_id || !wa->oem_table_id)
> +         return false;
> +
> + if (!memcmp(wa->oem_id, table->oem_id, ACPI_OEM_ID_SIZE) &&
> +     !memcmp(wa->oem_table_id, table->oem_table_id,
> +             ACPI_OEM_TABLE_ID_SIZE) &&
> +     wa->oem_revision == table->oem_revision) {
> +         return true;
> + }
> +
> + return false;
> +}
> +#else
> +static inline bool
> +arch_timer_check_acpi_erratum(const struct arch_timer_erratum_workaround *wa,
> +                       const void *arg)
> +{ return false; }
> +#endif
> +
>  static
>  bool arch_timer_check_global_cap_erratum(const struct arch_timer_erratum_workaround *wa,
>                                          const void *arg)
> @@ -440,6 +466,9 @@ static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_typ
> e t
>                 match_fn = arch_timer_check_local_cap_erratum;
>                 local = true;
>                 break;
> + case ate_match_acpi:
> +         match_fn = arch_timer_check_acpi_erratum;
> +         break;
>         }
>
>         wa = arch_timer_iterate_errata(type, match_fn, arg);
> @@ -1284,6 +1313,8 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table)
>         /* Check for globally applicable workarounds */
>         arch_timer_check_ool_workaround(ate_match_global_cap_id, NULL);
>  
> + arch_timer_check_ool_workaround(ate_match_acpi, table);
> +
>         arch_timer_init();
>         return 0;
>  }
>
> And I got compile errors for this patch [1], seems "#include <linux/acpi.h>" in
> arch/arm64/include/asm/arch_timer.h triggers the problem of head
> file inclusions (too early to include <linux/sched.h>?), I'm looking into it,
> if you can help to take a look too, that will be great :)

This is really much more complicated (and uglier) than what I had in
mind, and I don't want to add more cruft to the erratum description
structure. So instead of trying to explain what I wanted to see, here's
the patches I whipped together.

Please let me know if they work for you (as I have no way of testing
them).

Thanks,

	M.

From 50eb735436f9f6482285939b39b52d858d848537 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <marc.zyngier@arm.com>
Date: Tue, 21 Feb 2017 14:37:30 +0000
Subject: [PATCH 1/2] arm64: arch_timer: Allow erratum matching with ACPI OEM
 information

Just as we're able to identify a broken platform using some DT
information, let's enable a way to spot the offenders with ACPI.

The difference is that we can only match on some OEM info instead
of implementation-specific properties. So in order to avoid the
insane multiplication of errata structures, we allow an array
of OEM descriptions to be attached to an erratum structure.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm64/include/asm/arch_timer.h  |  1 +
 drivers/clocksource/arm_arch_timer.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

[2/2] arch_timer: acpi: add hisi timer erratum data

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