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Date: Thu, 23 Sep 2010 16:48:44 -0700
From: Andres Salomon <dilinger@...ued.net>
To: Daniel Drake <dsd@...top.org>
Cc: tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
x86@...nel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] OLPC: Rework BIOS signature check
Definitely an improvement, thanks. I have some minor style nits to
address, but I can do that w/ a followup patch.
Acked-by: Andres Salomon <dilinger@...ued.net>
On Thu, 23 Sep 2010
17:28:46 +0100 (BST) Daniel Drake <dsd@...top.org> wrote:
> The XO-1.5 laptop is not currently detected as an OLPC machine because
> it fails this XO-1-centric check.
>
> Now that we have OLPC OFW support in the kernel, a more sensible
> check is to see if we found OFW during boot and check the architecture
> property.
>
> Also remove a now-meaningless codepath, as we're always going to have
> OFW support with OLPC.
>
> Signed-off-by: Daniel Drake <dsd@...top.org>
> ---
>
> Replaces earlier patch: [PATCH 3/3] OLPC: Extend BIOS signature check
> Now checks OFW's architecture property to be really sure that we're
> running on an OLPC laptop.
>
> arch/x86/Kconfig | 3 +-
> arch/x86/include/asm/olpc_ofw.h | 4 +++
> arch/x86/kernel/olpc.c | 58
> +++++++++++++++++----------------------
> arch/x86/kernel/olpc_ofw.c | 6 ++++ 4 files changed, 37
> insertions(+), 34 deletions(-)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 0ed4c9b..c255255 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -2061,6 +2061,7 @@ config SCx200HR_TIMER
> config OLPC
> bool "One Laptop Per Child support"
> select GPIOLIB
> + select OLPC_OPENFIRMWARE
> ---help---
> Add support for detecting the unique features of the OLPC
> XO hardware.
> @@ -2068,7 +2069,7 @@ config OLPC
> config OLPC_OPENFIRMWARE
> bool "Support for OLPC's Open Firmware"
> depends on !X86_64 && !X86_PAE
> - default y if OLPC
> + default n
> help
> This option adds support for the implementation of Open
> Firmware that is used on the OLPC XO-1 Children's Machine.
> diff --git a/arch/x86/include/asm/olpc_ofw.h
> b/arch/x86/include/asm/olpc_ofw.h index 08fde47..2a84781 100644
> --- a/arch/x86/include/asm/olpc_ofw.h
> +++ b/arch/x86/include/asm/olpc_ofw.h
> @@ -21,10 +21,14 @@ extern void olpc_ofw_detect(void);
> /* install OFW's pde permanently into the kernel's pgtable */
> extern void setup_olpc_ofw_pgd(void);
>
> +/* check if OFW was detected during boot */
> +extern bool olpc_ofw_present(void);
> +
> #else /* !CONFIG_OLPC_OPENFIRMWARE */
>
> static inline void olpc_ofw_detect(void) { }
> static inline void setup_olpc_ofw_pgd(void) { }
> +static inline bool olpc_ofw_present(void) { return false; }
>
> #endif /* !CONFIG_OLPC_OPENFIRMWARE */
>
> diff --git a/arch/x86/kernel/olpc.c b/arch/x86/kernel/olpc.c
> index 635888c..37c49934 100644
> --- a/arch/x86/kernel/olpc.c
> +++ b/arch/x86/kernel/olpc.c
> @@ -183,8 +183,21 @@ err:
> }
> EXPORT_SYMBOL_GPL(olpc_ec_cmd);
>
> -#ifdef CONFIG_OLPC_OPENFIRMWARE
> -static void __init platform_detect(void)
> +static bool __init check_ofw_architecture(void)
> +{
> + size_t propsize;
> + char olpc_arch[5];
> + const void *args[] = { NULL, "architecture", olpc_arch,
> (void *)5 };
> + void *res[] = { &propsize };
> +
> + if (olpc_ofw("getprop", args, res)) {
> + printk(KERN_ERR "ofw: getprop call failed!\n");
> + return false;
> + }
> + return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;
> +}
> +
> +static u32 __init get_board_revision(void)
> {
> size_t propsize;
> __be32 rev;
> @@ -193,46 +206,27 @@ static void __init platform_detect(void)
>
> if (olpc_ofw("getprop", args, res) || propsize != 4) {
> printk(KERN_ERR "ofw: getprop call failed!\n");
> - rev = cpu_to_be32(0);
> + return cpu_to_be32(0);
> }
> - olpc_platform_info.boardrev = be32_to_cpu(rev);
> + return be32_to_cpu(rev);
> }
> -#else
> -static void __init platform_detect(void)
> +
> +static bool __init platform_detect(void)
> {
> - /* stopgap until OFW support is added to the kernel */
> - olpc_platform_info.boardrev = olpc_board(0xc2);
> + if (!check_ofw_architecture())
> + return false;
> + olpc_platform_info.flags |= OLPC_F_PRESENT;
> + olpc_platform_info.boardrev = get_board_revision();
> + return true;
> }
> -#endif
>
> static int __init olpc_init(void)
> {
> - unsigned char *romsig;
> -
> - /* The ioremap check is dangerous; limit what we run it on */
> - if (!is_geode() || cs5535_has_vsa2())
> + if (!olpc_ofw_present() || !platform_detect())
> return 0;
>
> spin_lock_init(&ec_lock);
>
> - romsig = ioremap(0xffffffc0, 16);
> - if (!romsig)
> - return 0;
> -
> - if (strncmp(romsig, "CL1 Q", 7))
> - goto unmap;
> - if (strncmp(romsig+6, romsig+13, 3)) {
> - printk(KERN_INFO "OLPC BIOS signature looks
> invalid. "
> - "Assuming not OLPC\n");
> - goto unmap;
> - }
> -
> - printk(KERN_INFO "OLPC board with OpenFirmware %.16s\n",
> romsig);
> - olpc_platform_info.flags |= OLPC_F_PRESENT;
> -
> - /* get the platform revision */
> - platform_detect();
> -
> /* assume B1 and above models always have a DCON */
> if (olpc_board_at_least(olpc_board(0xb1)))
> olpc_platform_info.flags |= OLPC_F_DCON;
> @@ -254,8 +248,6 @@ static int __init olpc_init(void)
> olpc_platform_info.boardrev >> 4,
> olpc_platform_info.ecver);
>
> -unmap:
> - iounmap(romsig);
> return 0;
> }
>
> diff --git a/arch/x86/kernel/olpc_ofw.c b/arch/x86/kernel/olpc_ofw.c
> index 3218aa7..7873204 100644
> --- a/arch/x86/kernel/olpc_ofw.c
> +++ b/arch/x86/kernel/olpc_ofw.c
> @@ -74,6 +74,12 @@ int __olpc_ofw(const char *name, int nr_args,
> const void **args, int nr_res, }
> EXPORT_SYMBOL_GPL(__olpc_ofw);
>
> +bool olpc_ofw_present(void)
> +{
> + return olpc_ofw_cif != NULL;
> +}
> +EXPORT_SYMBOL_GPL(olpc_ofw_present);
> +
> /* OFW cif _should_ be above this address */
> #define OFW_MIN 0xff000000
>
--
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