From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Lv Zheng <lv.zheng@intel.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Len Brown <len.brown@intel.com>, Lv Zheng <zetalog@gmail.com>,
linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org
Subject: Re: [PATCH v3 2/7] ACPICA: Linux: Add stub implementation of ACPICA 64-bit mathematics.
Date: Sun, 20 Jul 2014 01:46:25 +0200 [thread overview]
Message-ID: <3777197.HSR7Q9huIS@vostro.rjw.lan> (raw)
In-Reply-To: <01bab2394df93a3064f09d961f4011b62895eef2.1405500886.git.lv.zheng@intel.com>
On Wednesday, July 16, 2014 04:58:00 PM Lv Zheng wrote:
> This patch adds default 64-bit mathematics in aclinux.h using do_div(). As
> do_div() can be used for all Linux architectures, this can also be used as
> stub macros for ACPICA 64-bit mathematics.
>
> But this is not a performance friendly way, as ACPICA's architecture
> specific division OSL only requires a dividing 64-bit number with a 32-bit
> number implementation, while Linux __div64_32() is not available for all
> build environments. So currently, if an architecture really wants to
> support ACPICA, it must implement its own division OSL.
What does this mean for i386, in particular?
> This is required by the ACPICA header stub support. ACPICA header stubs are
> useful to protect CONFIG_ACPI=n Linux kernel builds where ACPICA headers
> are included. Lv Zheng.
>
> Signed-off-by: Lv Zheng <lv.zheng@intel.com>
> ---
> include/acpi/platform/aclinuxex.h | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/include/acpi/platform/aclinuxex.h b/include/acpi/platform/aclinuxex.h
> index 191e741..568d4b8 100644
> --- a/include/acpi/platform/aclinuxex.h
> +++ b/include/acpi/platform/aclinuxex.h
> @@ -46,6 +46,28 @@
>
> #ifdef __KERNEL__
>
> +#ifndef ACPI_USE_NATIVE_DIVIDE
> +
> +#ifndef ACPI_DIV_64_BY_32
> +#define ACPI_DIV_64_BY_32(n_hi, n_lo, d32, q32, r32) \
> + do { \
> + u64 (__n) = ((u64) n_hi) << 32 | (n_lo); \
> + (r32) = do_div ((__n), (d32)); \
> + (q32) = (u32) (__n); \
> + } while (0)
> +#endif
> +
> +#ifndef ACPI_SHIFT_RIGHT_64
> +#define ACPI_SHIFT_RIGHT_64(n_hi, n_lo) \
> + do { \
> + (n_lo) >>= 1; \
> + (n_lo) |= (((n_hi) & 1) << 31); \
> + (n_hi) >>= 1; \
> + } while (0)
> +#endif
> +
> +#endif
> +
> /*
> * Overrides for in-kernel ACPICA
> */
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
next prev parent reply other threads:[~2014-07-19 23:28 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-18 9:05 [RFC PATCH 00/15] ACPICA: Add CONFIG_ACPI=n build support for ACPICA header files Lv Zheng
2013-12-18 9:05 ` [RFC PATCH 01/15] ACPICA: OSL: Add configurability mechanism for global variables Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 02/15] ACPICA: Linux: Add configurability for external globals Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 03/15] ACPICA: Linux: Add configurability for OSL APIs Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 04/15] ACPICA: OSL: Cleanup external macros and add stubs for macros Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 05/15] ACPICA: OSL: Add configurability to error message functions Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 06/15] ACPICA: OSL: Add configurability to debug output functions Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 07/15] ACPICA: OSL: Add configurability mechanism for external APIs Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 08/15] ACPICA: OSL: Updates ACPI_EXTERNAL_RETURN_x usages " Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 09/15] ACPICA: Linux: Add stub support for Linux specific variables and functions Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 10/15] ACPICA: Linux: Add architecture specific ACPICA headers in Linux Lv Zheng
2013-12-18 9:06 ` [RFC PATCH 11/15] ACPICA: Linux: Add stub implementation of ACPICA 64-bit mathematics Lv Zheng
2013-12-18 9:07 ` [RFC PATCH 12/15] ACPICA: Linux: Add configuration item to indicate the architecture specific support Lv Zheng
2013-12-18 9:07 ` [RFC PATCH 13/15] ACPICA: Linux: Remove <asm/acpi.h> inclusion from ACPICA headers Lv Zheng
2013-12-18 9:07 ` [RFC PATCH 14/15] ACPI/SFI: Fix wrong <acpi/acpi.h> inclusion in SFI/ACPI wrapper - table definitions Lv Zheng
2013-12-18 9:07 ` [RFC DBG PATCH] ACPICA: Add CONFIG_ACPI=n build test support Lv Zheng
2013-12-18 11:41 ` [RFC PATCH 15/15] ACPI/thinkpad: Fix wrong <acpi/acpi.h> inclusion in Thinkpad ACPI users Henrique de Moraes Holschuh
2013-12-18 13:06 ` [alsa-devel] " Takashi Iwai
2013-12-20 0:28 ` Zheng, Lv
2013-12-20 6:52 ` Takashi Iwai
2013-12-20 8:30 ` [UPDATE RFC " Lv Zheng
2013-12-20 9:15 ` Takashi Iwai
2014-07-07 4:16 ` [PATCH v2 0/7] ACPICA: Enable ACPICA prototypes for CONFIG_ACPI=n builds Lv Zheng
2014-07-07 4:17 ` [PATCH v2 1/7] ACPICA: Linux: Add stub support for Linux specific variables and functions Lv Zheng
2014-07-07 4:17 ` [PATCH v2 2/7] ACPICA: Linux: Add stub implementation of ACPICA 64-bit mathematics Lv Zheng
2014-07-07 4:17 ` [PATCH v2 3/7] ACPICA: Linux: Add configuration item to indicate the architecture specific support Lv Zheng
2014-07-07 4:17 ` [PATCH v2 4/7] ACPICA: Linux: Allow ACPICA inclusion for CONFIG_ACPI=n builds Lv Zheng
2014-07-07 4:17 ` [PATCH v2 5/7] ACPI/SFI: Fix wrong <acpi/acpi.h> inclusion in SFI/ACPI wrapper - table definitions Lv Zheng
2014-07-07 21:25 ` Rafael J. Wysocki
2014-07-08 0:08 ` Zheng, Lv
2014-07-07 4:17 ` [PATCH v2 6/7] ACPI: Cleanup useless ACPI inclusion Lv Zheng
2014-07-07 21:24 ` Rafael J. Wysocki
2014-07-08 0:05 ` Zheng, Lv
2014-07-07 4:17 ` [PATCH v2 7/7] ACPI: Add support to force header inclusion rules for <acpi/acpi.h> Lv Zheng
2014-07-16 8:57 ` [PATCH v3 0/7] ACPICA: Enable ACPICA prototypes for CONFIG_ACPI=n builds Lv Zheng
2014-07-16 8:57 ` [PATCH v3 1/7] ACPICA: Linux: Add stub support for Linux specific variables and functions Lv Zheng
2014-07-16 8:58 ` [PATCH v3 2/7] ACPICA: Linux: Add stub implementation of ACPICA 64-bit mathematics Lv Zheng
2014-07-19 23:46 ` Rafael J. Wysocki [this message]
2014-07-21 1:26 ` Zheng, Lv
2014-07-22 23:42 ` Rafael J. Wysocki
2014-07-16 8:58 ` [PATCH v3 3/7] ACPICA: Linux: Add support to exclude <asm/acenv.h> inclusion Lv Zheng
2014-07-16 8:58 ` [PATCH v3 4/7] ACPICA: Linux: Allow ACPICA inclusion for CONFIG_ACPI=n builds Lv Zheng
2014-07-16 8:58 ` [PATCH v3 5/7] ACPI/SFI: Fix wrong <acpi/acpi.h> inclusion in SFI/ACPI wrapper - table definitions Lv Zheng
2014-07-16 8:58 ` [PATCH v3 6/7] ACPI: Add support to force header inclusion rules for <acpi/acpi.h> Lv Zheng
2014-07-23 3:53 ` Hanjun Guo
2014-07-16 8:59 ` [PATCH v3 7/7] ACPI: Cleanup useless ACPI inclusion Lv Zheng
2014-07-16 12:07 ` Mark Brown
2014-07-16 21:46 ` Rafael J. Wysocki
2014-07-16 21:34 ` Mark Brown
2014-07-17 1:29 ` Zheng, Lv
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