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Commit Graph

15 Commits

Author SHA1 Message Date
Marc Zyngier
0ba5b4ba61 firmware/smccc: Call arch-specific hook on discovering KVM services
arm64 will soon require its own callback to initialise services
that are only available on this architecture. Introduce a hook
that can be overloaded by the architecture.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240830130150.8568-2-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2024-08-30 16:30:41 +01:00
Martin Botka
9cf3415ade firmware: smccc: Export revision soc_id function
The "SoC ID revision" as provided via the SMCCC SOCID interface can be
valuable information for drivers, when certain functionality depends
on a die revision, for instance.
One example is the sun50i-cpufreq-nvmem driver, which needs this
information to determine the speed bin of the SoC.

Export the arm_smccc_get_soc_id_revision() function so that it can be
called by any driver.

Signed-off-by: Martin Botka <martin.botka@somainline.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2024-04-19 12:34:27 +05:30
Punit Agrawal
d05799d7b4 firmware: smccc: Fix use of uninitialised results structure
Commit 35727af2b1 ("irqchip/gicv3: Workaround for NVIDIA erratum
T241-FABRIC-4") moved the initialisation of the SoC version to
arm_smccc_version_init() but forgot to update the results structure
and it's usage.

Fix the use of the uninitialised results structure and update the
error strings.

Fixes: 35727af2b1 ("irqchip/gicv3: Workaround for NVIDIA erratum T241-FABRIC-4")
Signed-off-by: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Vikram Sethi <vsethi@nvidia.com>
Cc: Shanker Donthineni <sdonthineni@nvidia.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230717171702.424253-1-punit.agrawal@bytedance.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-07-18 10:08:05 +01:00
Shanker Donthineni
35727af2b1 irqchip/gicv3: Workaround for NVIDIA erratum T241-FABRIC-4
The T241 platform suffers from the T241-FABRIC-4 erratum which causes
unexpected behavior in the GIC when multiple transactions are received
simultaneously from different sources. This hardware issue impacts
NVIDIA server platforms that use more than two T241 chips
interconnected. Each chip has support for 320 {E}SPIs.

This issue occurs when multiple packets from different GICs are
incorrectly interleaved at the target chip. The erratum text below
specifies exactly what can cause multiple transfer packets susceptible
to interleaving and GIC state corruption. GIC state corruption can
lead to a range of problems, including kernel panics, and unexpected
behavior.

>From the erratum text:
  "In some cases, inter-socket AXI4 Stream packets with multiple
  transfers, may be interleaved by the fabric when presented to ARM
  Generic Interrupt Controller. GIC expects all transfers of a packet
  to be delivered without any interleaving.

  The following GICv3 commands may result in multiple transfer packets
  over inter-socket AXI4 Stream interface:
   - Register reads from GICD_I* and GICD_N*
   - Register writes to 64-bit GICD registers other than GICD_IROUTERn*
   - ITS command MOVALL

  Multiple commands in GICv4+ utilize multiple transfer packets,
  including VMOVP, VMOVI, VMAPP, and 64-bit register accesses."

  This issue impacts system configurations with more than 2 sockets,
  that require multi-transfer packets to be sent over inter-socket
  AXI4 Stream interface between GIC instances on different sockets.
  GICv4 cannot be supported. GICv3 SW model can only be supported
  with the workaround. Single and Dual socket configurations are not
  impacted by this issue and support GICv3 and GICv4."

Link: https://developer.nvidia.com/docs/t241-fabric-4/nvidia-t241-fabric-4-errata.pdf

Writing to the chip alias region of the GICD_In{E} registers except
GICD_ICENABLERn has an equivalent effect as writing to the global
distributor. The SPI interrupt deactivate path is not impacted by
the erratum.

To fix this problem, implement a workaround that ensures read accesses
to the GICD_In{E} registers are directed to the chip that owns the
SPI, and disable GICv4.x features. To simplify code changes, the
gic_configure_irq() function uses the same alias region for both read
and write operations to GICD_ICFGR.

Co-developed-by: Vikram Sethi <vsethi@nvidia.com>
Signed-off-by: Vikram Sethi <vsethi@nvidia.com>
Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com> (for SMCCC/SOC ID bits)
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230319024314.3540573-2-sdonthineni@nvidia.com
2023-04-08 10:51:23 +01:00
Peter Collingbourne
534aa1dc97 printk: stop including cache.h from printk.h
An inclusion of cache.h in printk.h was added in 2014 in commit
c28aa1f0a8 ("printk/cache: mark printk_once test variable
__read_mostly") in order to bring in the definition of __read_mostly.  The
usage of __read_mostly was later removed in commit 3ec25826ae ("printk:
Tie printk_once / printk_deferred_once into .data.once for reset") which
made the inclusion of cache.h unnecessary, so remove it.

We have a small amount of code that depended on the inclusion of cache.h
from printk.h; fix that code to include the appropriate header.

This fixes a circular inclusion on arm64 (linux/printk.h -> linux/cache.h
-> asm/cache.h -> linux/kasan-enabled.h -> linux/static_key.h ->
linux/jump_label.h -> linux/bug.h -> asm/bug.h -> linux/printk.h) that
would otherwise be introduced by the next patch.

Build tested using {allyesconfig,defconfig} x {arm64,x86_64}.

Link: https://linux-review.googlesource.com/id/I8fd51f72c9ef1f2d6afd3b2cbc875aa4792c1fba
Link: https://lkml.kernel.org/r/20220427195820.1716975-1-pcc@google.com
Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13 07:20:07 -07:00
Michael Kelley
e95d8eaee2 firmware: smccc: Fix check for ARCH_SOC_ID not implemented
The ARCH_FEATURES function ID is a 32-bit SMC call, which returns
a 32-bit result per the SMCCC spec.  Current code is doing a 64-bit
comparison against -1 (SMCCC_RET_NOT_SUPPORTED) to detect that the
feature is unimplemented.  That check doesn't work in a Hyper-V VM,
where the upper 32-bits are zero as allowed by the spec.

Cast the result as an 'int' so the comparison works. The change also
makes the code consistent with other similar checks in this file.

Fixes: 821b67fa46 ("firmware: smccc: Add ARCH_SOC_ID support")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-11-22 11:42:59 +01:00
Andre Przywara
b83c2d92be firmware: smccc: Register smccc_trng platform device
At the moment we probe for the Random Number Generator SMCCC service,
and use that in the core code (arch_get_random). However the hardware
entropy can also be useful to access from userland, and be it to assess
its quality.

Register a platform device when the SMCCC TRNG service is detected, to
allow a hw_random driver to hook onto this.

The function registering the device is deliberately made in a way which
allows expansion, so other services that could be exposed via a platform
device (or some other interface), can be added here easily.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2021-08-06 19:45:25 +08:00
Mark Brown
cfa7ff959a arm64: smccc: Support SMCCC v1.3 SVE register saving hint
SMCCC v1.2 requires that all SVE state be preserved over SMC calls which
introduces substantial overhead in the common case where there is no SVE
state in the registers. To avoid this SMCCC v1.3 introduces a flag which
allows the caller to say that there is no state that needs to be preserved
in the registers. Make use of this flag, setting it if the SMCCC version
indicates support for it and the TIF_ flags indicate that there is no live
SVE state in the registers, this avoids placing any constraints on when
SMCCC calls can be done or triggering extra saving and reloading of SVE
register state in the kernel.

This would be straightforward enough except for the rather entertaining
inline assembly we use to do SMCCC v1.1 calls to allow us to take advantage
of the limited number of registers it clobbers. Deal with this by having a
function which we call immediately before issuing the SMCCC call to make
our checks and set the flag. Using alternatives the overhead if SVE is
supported but not detected at runtime can be reduced to a single NOP.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210603184118.15090-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-06-08 14:00:12 +01:00
Will Deacon
6e085e0ac9 arm/arm64: Probe for the presence of KVM hypervisor
Although the SMCCC specification provides some limited functionality for
describing the presence of hypervisor and firmware services, this is
generally applicable only to functions designated as "Arm Architecture
Service Functions" and no portable discovery mechanism is provided for
standard hypervisor services, despite having a designated range of
function identifiers reserved by the specification.

In an attempt to avoid the need for additional firmware changes every
time a new function is added, introduce a UID to identify the service
provider as being compatible with KVM. Once this has been established,
additional services can be discovered via a feature bitmap.

Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
[maz: move code to its own file, plug it into PSCI]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201209060932.212364-2-jianyong.wu@arm.com
2021-03-31 09:16:55 +01:00
Andre Przywara
a37e31fc97 firmware: smccc: Introduce SMCCC TRNG framework
The ARM DEN0098 document describe an SMCCC based firmware service to
deliver hardware generated random numbers. Its existence is advertised
according to the SMCCC v1.1 specification.

Add a (dummy) call to probe functions implemented in each architecture
(ARM and arm64), to determine the existence of this interface.
For now this return false, but this will be overwritten by each
architecture's support patch.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2021-01-21 17:42:46 +00:00
Sudeep Holla
6825f17c95 firmware: smccc: Export both smccc functions
We need to export both arm_smccc_1_1_get_conduit and arm_smccc_get_version
to allow several modules make use of them. Arm FFA, Arm SCMI and PTP
drivers are few drivers that are planning to use these functions.

Let us export them in preparation to add support for SCMI as module.

Link: https://lore.kernel.org/r/20200907195046.56615-2-sudeep.holla@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-09-14 07:30:36 +01:00
Sudeep Holla
821b67fa46 firmware: smccc: Add ARCH_SOC_ID support
SMCCC v1.2 adds a new optional function SMCCC_ARCH_SOC_ID to obtain a
SiP defined SoC identification value. Add support for the same.

Also using the SoC bus infrastructure, let us expose the platform
specific SoC atrributes under sysfs.

There are various ways in which it can be represented in shortened form
for efficiency and ease of parsing for userspace. The chosen form is
described in the ABI document.

Link: https://lore.kernel.org/r/20200625095939.50861-1-sudeep.holla@arm.com
Cc: Etienne Carriere <etienne.carriere@st.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-06 09:48:06 +01:00
Sudeep Holla
a4fb174651 firmware: smccc: Add function to fetch SMCCC version
For backward compatibility reasons, PSCI maintains SMCCC version as
SMCCC didn't provide ARM_SMCCC_VERSION_FUNC_ID until v1.1.

PSCI initialises both the SMCCC version and conduit. Similar to the
conduit, let us provide accessors to fetch the SMCCC version also so
that other SMCCC v1.1+ features can use it.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Etienne Carriere <etienne.carriere@st.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Etienne Carriere <etienne.carriere@st.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200518091222.27467-7-sudeep.holla@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-20 19:10:37 +01:00
Sudeep Holla
f2ae97062a firmware: smccc: Refactor SMCCC specific bits into separate file
In order to add newer SMCCC v1.1+ functionality and to avoid cluttering
PSCI firmware driver with SMCCC bits, let us move the SMCCC specific
details under drivers/firmware/smccc/smccc.c

We can also drop conduit and smccc_version from psci_operations structure
as SMCCC was the sole user and now it maintains those.

No functionality change in this patch though.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Etienne Carriere <etienne.carriere@st.com>
Reviewed-by: Etienne Carriere <etienne.carriere@st.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200518091222.27467-6-sudeep.holla@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-20 19:10:37 +01:00
Sudeep Holla
e5bfb21d98 firmware: smccc: Add HAVE_ARM_SMCCC_DISCOVERY to identify SMCCC v1.1 and above
SMCCC v1.0 lacked discoverability of version and features. To accelerate
adoption of few mitigations and protect systems more rapidly from various
vulnerability, PSCI v1.0 was updated to add SMCCC discovery mechanism
though the PSCI firmware implementation of PSCI_FEATURES(SMCCC_VERSION)
which returns success on firmware compliant to SMCCC v1.1 and above.

This inturn makes SMCCC v1.1 and above dependent on ARM_PSCI_FW for
backward compatibility. Let us introduce a new hidden config for the
same to build more features on top of SMCCC v1.1 and above.

While at it, also sort alphabetically the psci entry.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Etienne Carriere <etienne.carriere@st.com>
Reviewed-by: Etienne Carriere <etienne.carriere@st.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200518091222.27467-2-sudeep.holla@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-20 19:10:37 +01:00