From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [RFC PATCH 2/4] firmware: dmi: Add function to look up a handle and return DIMM size Date: Mon, 4 Dec 2017 22:38:14 +0100 Message-ID: <20171204213813.rm32qqeqchx37c5x@pd.tnic> References: <2fae02861e5c446c0cdd30ba3e00fad55db97807.1512070562.git.tony.luck@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Received: from mail.skyhub.de ([5.9.137.197]:35104 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751628AbdLDViU (ORCPT ); Mon, 4 Dec 2017 16:38:20 -0500 Content-Disposition: inline In-Reply-To: <2fae02861e5c446c0cdd30ba3e00fad55db97807.1512070562.git.tony.luck@intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Tony Luck Cc: linux-edac@vger.kernel.org, Dan Williams , Jean Delvare , Len Brown , linux-acpi@vger.kernel.org, linux-nvdimm@lists.01.org, Lv Zheng , Mauro Carvalho Chehab , "Rafael J. Wysocki" , Qiuxu Zhuo , Aristeu Rozanski On Thu, Nov 30, 2017 at 12:40:40PM -0800, Tony Luck wrote: > When we first scan the SMBIOS table, save the size of the DIMM. > > Provide a function for other code (EDAC driver) to look up the size > of a DIMM from its SMBIOS handle. > > Signed-off-by: Tony Luck > --- > drivers/firmware/dmi_scan.c | 29 +++++++++++++++++++++++++++++ > include/linux/dmi.h | 2 ++ > 2 files changed, 31 insertions(+) > > diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c > index 783041964439..946e86fb1ec6 100644 > --- a/drivers/firmware/dmi_scan.c > +++ b/drivers/firmware/dmi_scan.c > @@ -37,6 +37,7 @@ static char dmi_ids_string[128] __initdata; > static struct dmi_memdev_info { > const char *device; > const char *bank; > + u64 size; > u16 handle; > } *dmi_memdev; > static int dmi_memdev_nr; > @@ -395,6 +396,8 @@ static void __init save_mem_devices(const struct dmi_header *dm, void *v) > { > const char *d = (const char *)dm; > static int nr; > + u64 bytes; > + u16 size; > > if (dm->type != DMI_ENTRY_MEM_DEVICE || dm->length < 0x12) > return; > @@ -405,6 +408,18 @@ static void __init save_mem_devices(const struct dmi_header *dm, void *v) > dmi_memdev[nr].handle = get_unaligned(&dm->handle); > dmi_memdev[nr].device = dmi_string(dm, d[0x10]); > dmi_memdev[nr].bank = dmi_string(dm, d[0x11]); <---- newline here. > + size = get_unaligned((u16 *)&d[0xC]); > + if (size == 0) > + bytes = 0; > + else if (size == 0xffff) > + bytes = ~0ul; > + else if (size & 0x8000) > + bytes = (u64)(size & 0x7fff) << 10; > + else if (size != 0x7fff) > + bytes = (u64)size << 20; > + else > + bytes = (u64)get_unaligned((u32 *)&d[0x1C]) << 20; <---- newline here. > + dmi_memdev[nr].size = bytes; > nr++; > } > > @@ -1073,3 +1088,17 @@ void dmi_memdev_name(u16 handle, const char **bank, const char **device) > } > } > EXPORT_SYMBOL_GPL(dmi_memdev_name); > + > +u64 dmi_memdev_size(u16 handle) > +{ > + int n; > + > + if (dmi_memdev) { > + for (n = 0; n < dmi_memdev_nr; n++) { > + if (handle == dmi_memdev[n].handle) > + return dmi_memdev[n].size; > + } > + } > + return ~0ul; > +} So dmi_memdev_name() also loops over dmi_memdev and returns bank and device. This new function returns size. If code is going to be calling those one after the other, you could do a dmi_memdev_desc(u16 handle, struct memdev_desc *desc) which fills up a descriptor with all fields a caller would need in one go so that you don't have to iterate multiple times. Looking at struct dmi_memdev_info, there are no more fields so maybe this is probably silly though or you can simply return struct dmi_memdev_info directly... Meh. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.