Merge tag 'v5.4.64' into linux-5.4-at91

This is the 5.4.64 stable release

Documentation/ABI/testing/sysfs-bus-iio

@@ -1566,7 +1566,8 @@ What:		/sys/bus/iio/devices/iio:deviceX/in_concentrationX_voc_raw
 KernelVersion:	4.3
 Contact:	[email protected]
 Description:
-		Raw (unscaled no offset etc.) percentage reading of a substance.
+		Raw (unscaled no offset etc.) reading of a substance. Units
+		after application of scale and offset are percents.
 
 What:		/sys/bus/iio/devices/iio:deviceX/in_resistance_raw
 What:		/sys/bus/iio/devices/iio:deviceX/in_resistanceX_raw

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -486,6 +486,7 @@ What:		/sys/devices/system/cpu/vulnerabilities
 		/sys/devices/system/cpu/vulnerabilities/spec_store_bypass
 		/sys/devices/system/cpu/vulnerabilities/l1tf
 		/sys/devices/system/cpu/vulnerabilities/mds
+		/sys/devices/system/cpu/vulnerabilities/srbds
 		/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
 		/sys/devices/system/cpu/vulnerabilities/itlb_multihit
 Date:		January 2018

Documentation/admin-guide/hw-vuln/index.rst

@@ -14,3 +14,4 @@ are configurable at compile, boot or run time.
    mds
    tsx_async_abort
    multihit.rst
+   special-register-buffer-data-sampling.rst

Documentation/admin-guide/hw-vuln/special-register-buffer-data-sampling.rst

@@ -0,0 +1,149 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+SRBDS - Special Register Buffer Data Sampling
+=============================================
+
+SRBDS is a hardware vulnerability that allows MDS :doc:`mds` techniques to
+infer values returned from special register accesses.  Special register
+accesses are accesses to off core registers.  According to Intel's evaluation,
+the special register reads that have a security expectation of privacy are
+RDRAND, RDSEED and SGX EGETKEY.
+
+When RDRAND, RDSEED and EGETKEY instructions are used, the data is moved
+to the core through the special register mechanism that is susceptible
+to MDS attacks.
+
+Affected processors
+--------------------
+Core models (desktop, mobile, Xeon-E3) that implement RDRAND and/or RDSEED may
+be affected.
+
+A processor is affected by SRBDS if its Family_Model and stepping is
+in the following list, with the exception of the listed processors
+exporting MDS_NO while Intel TSX is available yet not enabled. The
+latter class of processors are only affected when Intel TSX is enabled
+by software using TSX_CTRL_MSR otherwise they are not affected.
+
+  =============  ============  ========
+  common name    Family_Model  Stepping
+  =============  ============  ========
+  IvyBridge      06_3AH        All
+
+  Haswell        06_3CH        All
+  Haswell_L      06_45H        All
+  Haswell_G      06_46H        All
+
+  Broadwell_G    06_47H        All
+  Broadwell      06_3DH        All
+
+  Skylake_L      06_4EH        All
+  Skylake        06_5EH        All
+
+  Kabylake_L     06_8EH        <= 0xC
+  Kabylake       06_9EH        <= 0xD
+  =============  ============  ========
+
+Related CVEs
+------------
+
+The following CVE entry is related to this SRBDS issue:
+
+    ==============  =====  =====================================
+    CVE-2020-0543   SRBDS  Special Register Buffer Data Sampling
+    ==============  =====  =====================================
+
+Attack scenarios
+----------------
+An unprivileged user can extract values returned from RDRAND and RDSEED
+executed on another core or sibling thread using MDS techniques.
+
+
+Mitigation mechanism
+-------------------
+Intel will release microcode updates that modify the RDRAND, RDSEED, and
+EGETKEY instructions to overwrite secret special register data in the shared
+staging buffer before the secret data can be accessed by another logical
+processor.
+
+During execution of the RDRAND, RDSEED, or EGETKEY instructions, off-core
+accesses from other logical processors will be delayed until the special
+register read is complete and the secret data in the shared staging buffer is
+overwritten.
+
+This has three effects on performance:
+
+#. RDRAND, RDSEED, or EGETKEY instructions have higher latency.
+
+#. Executing RDRAND at the same time on multiple logical processors will be
+   serialized, resulting in an overall reduction in the maximum RDRAND
+   bandwidth.
+
+#. Executing RDRAND, RDSEED or EGETKEY will delay memory accesses from other
+   logical processors that miss their core caches, with an impact similar to
+   legacy locked cache-line-split accesses.
+
+The microcode updates provide an opt-out mechanism (RNGDS_MITG_DIS) to disable
+the mitigation for RDRAND and RDSEED instructions executed outside of Intel
+Software Guard Extensions (Intel SGX) enclaves. On logical processors that
+disable the mitigation using this opt-out mechanism, RDRAND and RDSEED do not
+take longer to execute and do not impact performance of sibling logical
+processors memory accesses. The opt-out mechanism does not affect Intel SGX
+enclaves (including execution of RDRAND or RDSEED inside an enclave, as well
+as EGETKEY execution).
+
+IA32_MCU_OPT_CTRL MSR Definition
+--------------------------------
+Along with the mitigation for this issue, Intel added a new thread-scope
+IA32_MCU_OPT_CTRL MSR, (address 0x123). The presence of this MSR and
+RNGDS_MITG_DIS (bit 0) is enumerated by CPUID.(EAX=07H,ECX=0).EDX[SRBDS_CTRL =
+9]==1. This MSR is introduced through the microcode update.
+
+Setting IA32_MCU_OPT_CTRL[0] (RNGDS_MITG_DIS) to 1 for a logical processor
+disables the mitigation for RDRAND and RDSEED executed outside of an Intel SGX
+enclave on that logical processor. Opting out of the mitigation for a
+particular logical processor does not affect the RDRAND and RDSEED mitigations
+for other logical processors.
+
+Note that inside of an Intel SGX enclave, the mitigation is applied regardless
+of the value of RNGDS_MITG_DS.
+
+Mitigation control on the kernel command line
+---------------------------------------------
+The kernel command line allows control over the SRBDS mitigation at boot time
+with the option "srbds=".  The option for this is:
+
+  ============= =============================================================
+  off           This option disables SRBDS mitigation for RDRAND and RDSEED on
+                affected platforms.
+  ============= =============================================================
+
+SRBDS System Information
+-----------------------
+The Linux kernel provides vulnerability status information through sysfs.  For
+SRBDS this can be accessed by the following sysfs file:
+/sys/devices/system/cpu/vulnerabilities/srbds
+
+The possible values contained in this file are:
+
+ ============================== =============================================
+ Not affected                   Processor not vulnerable
+ Vulnerable                     Processor vulnerable and mitigation disabled
+ Vulnerable: No microcode       Processor vulnerable and microcode is missing
+                                mitigation
+ Mitigation: Microcode          Processor is vulnerable and mitigation is in
+                                effect.
+ Mitigation: TSX disabled       Processor is only vulnerable when TSX is
+                                enabled while this system was booted with TSX
+                                disabled.
+ Unknown: Dependent on
+ hypervisor status              Running on virtual guest processor that is
+                                affected but with no way to know if host
+                                processor is mitigated or vulnerable.
+ ============================== =============================================
+
+SRBDS Default mitigation
+------------------------
+This new microcode serializes processor access during execution of RDRAND,
+RDSEED ensures that the shared buffer is overwritten before it is released for
+reuse.  Use the "srbds=off" kernel command line to disable the mitigation for
+RDRAND and RDSEED.

Documentation/admin-guide/kernel-parameters.txt

@@ -4579,6 +4579,26 @@
 	spia_pedr=
 	spia_peddr=
 
+	srbds=		[X86,INTEL]
+			Control the Special Register Buffer Data Sampling
+			(SRBDS) mitigation.
+
+			Certain CPUs are vulnerable to an MDS-like
+			exploit which can leak bits from the random
+			number generator.
+
+			By default, this issue is mitigated by
+			microcode.  However, the microcode fix can cause
+			the RDRAND and RDSEED instructions to become
+			much slower.  Among other effects, this will
+			result in reduced throughput from /dev/urandom.
+
+			The microcode mitigation can be disabled with
+			the following option:
+
+			off:    Disable mitigation and remove
+				performance impact to RDRAND and RDSEED
+
 	srcutree.counter_wrap_check [KNL]
 			Specifies how frequently to check for
 			grace-period sequence counter wrap for the

Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.txt

@@ -16,6 +16,9 @@ Required properties:
   Documentation/devicetree/bindings/graph.txt. This port should be connected
   to the input port of an attached HDMI or LVDS encoder chip.
 
+Optional properties:
+- pinctrl-names: Contain "default" and "sleep".
+
 Example:
 
 dpi0: dpi@1401d000 {
@@ -26,6 +29,9 @@ dpi0: dpi@1401d000 {
 		 <&mmsys CLK_MM_DPI_ENGINE>,
 		 <&apmixedsys CLK_APMIXED_TVDPLL>;
 	clock-names = "pixel", "engine", "pll";
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&dpi_pin_func>;
+	pinctrl-1 = <&dpi_pin_idle>;
 
 	port {
 		dpi0_out: endpoint {

Documentation/devicetree/bindings/iio/multiplexer/io-channel-mux.txt

@@ -21,7 +21,7 @@ controller state. The mux controller state is described in
 
 Example:
 	mux: mux-controller {
-		compatible = "mux-gpio";
+		compatible = "gpio-mux";
 		#mux-control-cells = <0>;
 
 		mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,

Documentation/devicetree/bindings/mailbox/xlnx,zynqmp-ipi-mailbox.txt

@@ -87,7 +87,7 @@ Example:
 		ranges;
 
 		/* APU<->RPU0 IPI mailbox controller */
-		ipi_mailbox_rpu0: mailbox@ff90400 {
+		ipi_mailbox_rpu0: mailbox@ff990400 {
 			reg = <0xff990400 0x20>,
 			      <0xff990420 0x20>,
 			      <0xff990080 0x20>,

Documentation/devicetree/bindings/mmc/mtk-sd.txt

@@ -49,6 +49,8 @@ Optional properties:
 		     error caused by stop clock(fifo full)
 		     Valid range = [0:0x7]. if not present, default value is 0.
 		     applied to compatible "mediatek,mt2701-mmc".
+- resets: Phandle and reset specifier pair to softreset line of MSDC IP.
+- reset-names: Should be "hrst".
 
 Examples:
 mmc0: mmc@11230000 {

Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt

@@ -15,8 +15,15 @@ Required properties:
   - "nvidia,tegra210-sdhci": for Tegra210
   - "nvidia,tegra186-sdhci": for Tegra186
   - "nvidia,tegra194-sdhci": for Tegra194
-- clocks : Must contain one entry, for the module clock.
-  See ../clocks/clock-bindings.txt for details.
+- clocks: For Tegra210, Tegra186 and Tegra194 must contain two entries.
+	  One for the module clock and one for the timeout clock.
+	  For all other Tegra devices, must contain a single entry for
+	  the module clock. See ../clocks/clock-bindings.txt for details.
+- clock-names: For Tegra210, Tegra186 and Tegra194 must contain the
+	       strings 'sdhci' and 'tmclk' to represent the module and
+	       the timeout clocks, respectively.
+	       For all other Tegra devices must contain the string 'sdhci'
+	       to represent the module clock.
 - resets : Must contain an entry for each entry in reset-names.
   See ../reset/reset.txt for details.
 - reset-names : Must include the following entries:
@@ -99,7 +106,7 @@ Optional properties for Tegra210, Tegra186 and Tegra194:
 
 Example:
 sdhci@700b0000 {
-	compatible = "nvidia,tegra210-sdhci", "nvidia,tegra124-sdhci";
+	compatible = "nvidia,tegra124-sdhci";
 	reg = <0x0 0x700b0000 0x0 0x200>;
 	interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
 	clocks = <&tegra_car TEGRA210_CLK_SDMMC1>;
@@ -115,3 +122,22 @@ sdhci@700b0000 {
 	nvidia,pad-autocal-pull-down-offset-1v8 = <0x7b>;
 	status = "disabled";
 };
+
+sdhci@700b0000 {
+	compatible = "nvidia,tegra210-sdhci";
+	reg = <0x0 0x700b0000 0x0 0x200>;
+	interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&tegra_car TEGRA210_CLK_SDMMC1>,
+		 <&tegra_car TEGRA210_CLK_SDMMC_LEGACY>;
+	clock-names = "sdhci", "tmclk";
+	resets = <&tegra_car 14>;
+	reset-names = "sdhci";
+	pinctrl-names = "sdmmc-3v3", "sdmmc-1v8";
+	pinctrl-0 = <&sdmmc1_3v3>;
+	pinctrl-1 = <&sdmmc1_1v8>;
+	nvidia,pad-autocal-pull-up-offset-3v3 = <0x00>;
+	nvidia,pad-autocal-pull-down-offset-3v3 = <0x7d>;
+	nvidia,pad-autocal-pull-up-offset-1v8 = <0x7b>;
+	nvidia,pad-autocal-pull-down-offset-1v8 = <0x7b>;
+	status = "disabled";
+};

Documentation/devicetree/bindings/usb/dwc3.txt

@@ -75,6 +75,8 @@ Optional properties:
 			from P0 to P1/P2/P3 without delay.
  - snps,dis-tx-ipgap-linecheck-quirk: when set, disable u2mac linestate check
 			during HS transmit.
+ - snps,parkmode-disable-ss-quirk: when set, all SuperSpeed bus instances in
+			park mode are disabled.
  - snps,dis_metastability_quirk: when set, disable metastability workaround.
 			CAUTION: use only if you are absolutely sure of it.
  - snps,is-utmi-l1-suspend: true when DWC3 asserts output signal

Documentation/filesystems/affs.txt

@@ -93,13 +93,15 @@ The Amiga protection flags RWEDRWEDHSPARWED are handled as follows:
 
   - R maps to r for user, group and others. On directories, R implies x.
 
-  - If both W and D are allowed, w will be set.
+  - W maps to w.
 
   - E maps to x.
 
-  - H and P are always retained and ignored under Linux.
+  - D is ignored.
 
-  - A is always reset when a file is written to.
+  - H, S and P are always retained and ignored under Linux.
+
+  - A is cleared when a file is written to.
 
 User id and group id will be used unless set[gu]id are given as mount
 options. Since most of the Amiga file systems are single user systems
@@ -111,11 +113,13 @@ Linux -> Amiga:
 
 The Linux rwxrwxrwx file mode is handled as follows:
 
-  - r permission will set R for user, group and others.
+  - r permission will allow R for user, group and others.
+
+  - w permission will allow W for user, group and others.
 
-  - w permission will set W and D for user, group and others.
+  - x permission of the user will allow E for plain files.
 
-  - x permission of the user will set E for plain files.
+  - D will be allowed for user, group and others.
 
   - All other flags (suid, sgid, ...) are ignored and will
     not be retained.

Documentation/kbuild/index.rst

@@ -19,6 +19,7 @@ Kernel Build System
 
     issues
     reproducible-builds
+    llvm
 
 .. only::  subproject and html
 

Documentation/kbuild/kbuild.rst

@@ -262,3 +262,8 @@ KBUILD_BUILD_USER, KBUILD_BUILD_HOST
 These two variables allow to override the user@host string displayed during
 boot and in /proc/version. The default value is the output of the commands
 whoami and host, respectively.
+
+LLVM
+----
+If this variable is set to 1, Kbuild will use Clang and LLVM utilities instead
+of GCC and GNU binutils to build the kernel.