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Groups > linux.kernel > #1520404
| From | Matt Fleming <matt@codeblueprint.co.uk> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 9/9] thunderbolt: Use Device ROM retrieved from EFI |
| Date | 2016-11-12 22:40 +0100 |
| Message-ID | <sCObM-7JU-35@gated-at.bofh.it> (permalink) |
| References | <sCObL-7JU-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Lukas Wunner <lukas@wunner.de>
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.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Tested-by: Lukas Wunner <lukas@wunner.de> [MacBookPro9,1]
Tested-by: Pierre Moreau <pierre.morrow@free.fr> [MacBookPro11,3]
Acked-by: Andreas Noever <andreas.noever@gmail.com>
Cc: Pedro Vilaça <reverser@put.as>
Cc: Peter Jones <pjones@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
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 c121acc15bfe..0056df7f3c09 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 2b9602c2c355..6392990c984d 100644
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -5,6 +5,7 @@
*/
#include <linux/crc32.h>
+#include <linux/property.h>
#include <linux/slab.h>
#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 9840fdecb73b..c6f30b1695a9 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);
--
2.10.0
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[GIT PULL 0/9] EFI changes for v4.10 Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-12 22:40 +0100
[PATCH 3/9] efi: Add support for seeding the RNG from a UEFI config table Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-12 22:40 +0100
[tip:efi/core] efi: Add support for seeding the RNG from a UEFI config table tip-bot for Ard Biesheuvel <tipbot@zytor.com> - 2016-11-13 10:10 +0100
[PATCH 4/9] efi/libstub: Add random.c to ARM build Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-12 22:40 +0100
[tip:efi/core] efi/libstub: Add random.c to ARM build tip-bot for Ard Biesheuvel <tipbot@zytor.com> - 2016-11-13 10:10 +0100
[PATCH 2/9] MAINTAINERS: Add ARM and arm64 EFI specific files to EFI subsystem Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-12 22:40 +0100
[tip:efi/core] MAINTAINERS: Add ARM and arm64 EFI specific files to EFI subsystem tip-bot for Ard Biesheuvel <tipbot@zytor.com> - 2016-11-13 10:10 +0100
[PATCH 7/9] efi: Allow bitness-agnostic protocol calls Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-12 22:40 +0100
[tip:efi/core] efi: Allow bitness-agnostic protocol calls tip-bot for Lukas Wunner <tipbot@zytor.com> - 2016-11-13 10:10 +0100
[PATCH 8/9] x86/efi: Retrieve and assign Apple device properties Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-12 22:40 +0100
[tip:efi/core] x86/efi: Retrieve and assign Apple device properties tip-bot for Lukas Wunner <tipbot@zytor.com> - 2016-11-13 10:20 +0100
[PATCH 5/9] efi/arm*: libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-12 22:40 +0100
Re: [PATCH 5/9] efi/arm*: libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table Ingo Molnar <mingo@kernel.org> - 2016-11-13 08:20 +0100
Re: [PATCH 5/9] efi/arm*: libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-14 14:30 +0100
Re: [PATCH 5/9] efi/arm*: libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table Ingo Molnar <mingo@kernel.org> - 2016-11-14 15:00 +0100
Re: [PATCH 5/9] efi/arm*: libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-14 15:10 +0100
Re: [PATCH 5/9] efi/arm*: libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table Lukas Wunner <lukas@wunner.de> - 2016-11-14 16:10 +0100
[tip:efi/core] thunderbolt, efi: Fix Kconfig dependencies tip-bot for Lukas Wunner <tipbot@zytor.com> - 2016-11-15 12:00 +0100
[tip:efi/core] efi/arm*/libstub: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table tip-bot for Ard Biesheuvel <tipbot@zytor.com> - 2016-11-13 10:10 +0100
[PATCH 1/9] efi/libstub: Fix allocation size calculations Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-12 22:40 +0100
[tip:efi/core] efi/libstub: Fix allocation size calculations tip-bot for Roy Franz <tipbot@zytor.com> - 2016-11-13 10:10 +0100
[PATCH 9/9] thunderbolt: Use Device ROM retrieved from EFI Matt Fleming <matt@codeblueprint.co.uk> - 2016-11-12 22:40 +0100
[tip:efi/core] thunderbolt: Use Device ROM retrieved from EFI tip-bot for Lukas Wunner <tipbot@zytor.com> - 2016-11-13 10:20 +0100
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