From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx2.suse.de ([195.135.220.15]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1cHUE0-0006ac-1I for kexec@lists.infradead.org; Thu, 15 Dec 2016 11:29:25 +0000 Date: Thu, 15 Dec 2016 12:28:56 +0100 From: Jean Delvare Subject: Re: [PATCH v1 2/2] firmware: dmi_scan: Pass dmi_entry_point to kexec'ed kernel Message-ID: <20161215122856.7d24b7a8@endymion> In-Reply-To: <20161202195416.58953-3-andriy.shevchenko@linux.intel.com> References: <20161202195416.58953-1-andriy.shevchenko@linux.intel.com> <20161202195416.58953-3-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Andy Shevchenko Cc: kexec@lists.infradead.org, Mika Westerberg , Eric Biederman , linux-kernel@vger.kernel.org Hi Andy, On Fri, 2 Dec 2016 21:54:16 +0200, Andy Shevchenko wrote: > Until now kexec'ed kernel has no clue where to look for DMI entry point. > > Pass it via kernel command line parameter in the same way as it's done for ACPI > RSDP. I am no kexec expert but this confuses me. Shouldn't the second kernel have access to the EFI systab as the first kernel does? It includes many more pointers than just ACPI and DMI tables, and it would seem inconvenient to have to pass all these addresses individually explicitly. Adding Eric to Cc for his opinion. > > Signed-off-by: Andy Shevchenko > --- > Documentation/admin-guide/kernel-parameters.txt | 5 +++++ > drivers/firmware/dmi_scan.c | 14 ++++++++++++++ > 2 files changed, 19 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index be2d6d0..94f219f 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -843,6 +843,11 @@ > The filter can be disabled or changed to another > driver later using sysfs. > > + dmi_entry_point= [DMI,EFI,KEXEC] > + Pass the DMI entry point to the kernel, mostly used > + on machines running EFI runtime service to boot the > + second kernel for kdump. > + > drm_kms_helper.edid_firmware=[:][,[:]] > Broken monitors, graphic adapters, KVMs and EDIDless > panels may send no or incorrect EDID data sets. > diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c > index b88def6..215843f 100644 > --- a/drivers/firmware/dmi_scan.c > +++ b/drivers/firmware/dmi_scan.c > @@ -595,8 +595,22 @@ static int __init dmi_smbios3_present(const u8 *buf) > return 1; > } > > +#ifdef CONFIG_KEXEC > +static unsigned long dmi_entry_point; > +static int __init setup_dmi_entry_point(char *arg) > +{ > + return kstrtoul(arg, 16, &dmi_entry_point); > +} > +early_param("dmi_entry_point", setup_dmi_entry_point); > +#endif > + > static resource_size_t __init dmi_get_entry_point(void) > { > +#ifdef CONFIG_KEXEC > + if (dmi_entry_point) > + return dmi_entry_point; > +#endif > + > if (efi_enabled(EFI_CONFIG_TABLES)) { > /* > * According to the DMTF SMBIOS reference spec v3.0.0, it is -- Jean Delvare SUSE L3 Support _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec