Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933192AbcKMJK3 (ORCPT ); Sun, 13 Nov 2016 04:10:29 -0500 Received: from terminus.zytor.com ([198.137.202.10]:58572 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932961AbcKMJK1 (ORCPT ); Sun, 13 Nov 2016 04:10:27 -0500 Date: Sun, 13 Nov 2016 01:08:56 -0800 From: tip-bot for Lukas Wunner Message-ID: Cc: torvalds@linux-foundation.org, mingo@kernel.org, reverser@put.as, andreas.noever@gmail.com, peterz@infradead.org, ard.biesheuvel@linaro.org, hpa@zytor.com, matt@codeblueprint.co.uk, pjones@redhat.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, lukas@wunner.de Reply-To: pjones@redhat.com, lukas@wunner.de, linux-kernel@vger.kernel.org, tglx@linutronix.de, torvalds@linux-foundation.org, mingo@kernel.org, andreas.noever@gmail.com, reverser@put.as, ard.biesheuvel@linaro.org, peterz@infradead.org, hpa@zytor.com, matt@codeblueprint.co.uk In-Reply-To: <20161112213237.8804-10-matt@codeblueprint.co.uk> References: <20161112213237.8804-10-matt@codeblueprint.co.uk> To: linux-tip-commits@vger.kernel.org Subject: [tip:efi/core] thunderbolt: Use Device ROM retrieved from EFI Git-Commit-ID: c9cc3aaa0281fec487794a473c82544bb7ac1b68 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5777 Lines: 164 Commit-ID: c9cc3aaa0281fec487794a473c82544bb7ac1b68 Gitweb: http://git.kernel.org/tip/c9cc3aaa0281fec487794a473c82544bb7ac1b68 Author: Lukas Wunner AuthorDate: Sat, 12 Nov 2016 21:32:37 +0000 Committer: Ingo Molnar CommitDate: Sun, 13 Nov 2016 08:23:16 +0100 thunderbolt: Use Device ROM retrieved from EFI Macs with Thunderbolt 1 do not have a unit-specific DROM: The DROM is empty with uid 0x1000000000000. (Apple started factory-burning a unit- specific DROM with Thunderbolt 2.) Instead, the NHI EFI driver supplies a DROM in a device property. Use it if available. It's only available when booting with the efistub. If it's not available, silently fall back to our hardcoded DROM. The size of the DROM is always 256 bytes. The number is hardcoded into the NHI EFI driver. This commit can deal with an arbitrary size however, just in case they ever change that. Background information: The EFI firmware volume contains ROM files for the NHI, GMUX and several other chips as well as key material. This strategy allows Apple to deploy ROM or key updates by simply publishing an EFI firmware update on their website. Drivers do not access those files directly but rather through a file server via EFI protocol AC5E4829-A8FD-440B-AF33-9FFE013B12D8. Files are identified by GUID, the NHI DROM has 339370BD-CFC6-4454-8EF7-704653120818. The NHI EFI driver amends that file with a unit-specific uid. The uid has 64 bit but its entropy is much lower: 24 bit represent the model, 24 bit are taken from a serial number, 16 bit are fixed. The NHI EFI driver obtains the serial number via the DataHub protocol, copies it into the DROM, calculates the CRC and submits the result as a device property. A modification is needed in the resume code where we currently read the uid of all switches in the hierarchy to detect plug events that occurred during sleep. On Thunderbolt 1 root switches this will now lead to a mismatch between the uid of the empty DROM and the EFI DROM. Exempt the root switch from this check: It's built in, so the uid should never change. However we continue to *read* the uid of the root switch, this seems like a good way to test its reachability after resume. Tested-by: Lukas Wunner [MacBookPro9,1] Tested-by: Pierre Moreau [MacBookPro11,3] Signed-off-by: Lukas Wunner Signed-off-by: Matt Fleming Acked-by: Andreas Noever Cc: Ard Biesheuvel Cc: Linus Torvalds Cc: Pedro Vilaça Cc: Peter Jones Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20161112213237.8804-10-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar --- drivers/thunderbolt/Kconfig | 1 + drivers/thunderbolt/eeprom.c | 43 +++++++++++++++++++++++++++++++++++++++++++ drivers/thunderbolt/switch.c | 2 +- 3 files changed, 45 insertions(+), 1 deletion(-) diff --git a/drivers/thunderbolt/Kconfig b/drivers/thunderbolt/Kconfig index c121acc..0056df7 100644 --- a/drivers/thunderbolt/Kconfig +++ b/drivers/thunderbolt/Kconfig @@ -1,6 +1,7 @@ menuconfig THUNDERBOLT tristate "Thunderbolt support for Apple devices" depends on PCI + select APPLE_PROPERTIES select CRC32 help Cactus Ridge Thunderbolt Controller driver diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c index 2b9602c..6392990 100644 --- a/drivers/thunderbolt/eeprom.c +++ b/drivers/thunderbolt/eeprom.c @@ -5,6 +5,7 @@ */ #include +#include #include #include "tb.h" @@ -360,6 +361,40 @@ static int tb_drom_parse_entries(struct tb_switch *sw) } /** + * tb_drom_copy_efi - copy drom supplied by EFI to sw->drom if present + */ +static int tb_drom_copy_efi(struct tb_switch *sw, u16 *size) +{ + struct device *dev = &sw->tb->nhi->pdev->dev; + int len, res; + + len = device_property_read_u8_array(dev, "ThunderboltDROM", NULL, 0); + if (len < 0 || len < sizeof(struct tb_drom_header)) + return -EINVAL; + + sw->drom = kmalloc(len, GFP_KERNEL); + if (!sw->drom) + return -ENOMEM; + + res = device_property_read_u8_array(dev, "ThunderboltDROM", sw->drom, + len); + if (res) + goto err; + + *size = ((struct tb_drom_header *)sw->drom)->data_len + + TB_DROM_DATA_START; + if (*size > len) + goto err; + + return 0; + +err: + kfree(sw->drom); + sw->drom = NULL; + return -EINVAL; +} + +/** * tb_drom_read - copy drom to sw->drom and parse it */ int tb_drom_read(struct tb_switch *sw) @@ -374,6 +409,13 @@ int tb_drom_read(struct tb_switch *sw) if (tb_route(sw) == 0) { /* + * Apple's NHI EFI driver supplies a DROM for the root switch + * in a device property. Use it if available. + */ + if (tb_drom_copy_efi(sw, &size) == 0) + goto parse; + + /* * The root switch contains only a dummy drom (header only, * no entries). Hardcode the configuration here. */ @@ -418,6 +460,7 @@ int tb_drom_read(struct tb_switch *sw) if (res) goto err; +parse: header = (void *) sw->drom; if (header->data_len + TB_DROM_DATA_START != size) { diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index 9840fde..c6f30b1 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -460,7 +460,7 @@ int tb_switch_resume(struct tb_switch *sw) tb_sw_warn(sw, "uid read failed\n"); return err; } - if (sw->uid != uid) { + if (sw != sw->tb->root_switch && sw->uid != uid) { tb_sw_info(sw, "changed while suspended (uid %#llx -> %#llx)\n", sw->uid, uid);