diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 13 | ||||
| -rw-r--r-- | Documentation/arm64/cpu-feature-registers.txt | 240 | ||||
| -rw-r--r-- | Documentation/block/queue-sysfs.txt | 6 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/input/tps65218-pwrbutton.txt | 4 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/power/supply/tps65217_charger.txt | 7 | ||||
| -rw-r--r-- | Documentation/driver-api/infrastructure.rst | 15 | ||||
| -rw-r--r-- | Documentation/networking/mpls-sysctl.txt | 4 | ||||
| -rw-r--r-- | Documentation/vfio-mediated-device.txt | 27 |
8 files changed, 281 insertions, 35 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 21e2d8863705..be7c0d9506b1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -106,6 +106,16 @@ use by PCI Format: <irq>,<irq>... + acpi_mask_gpe= [HW,ACPI] + Due to the existence of _Lxx/_Exx, some GPEs triggered + by unsupported hardware/firmware features can result in + GPE floodings that cannot be automatically disabled by + the GPE dispatcher. + This facility can be used to prevent such uncontrolled + GPE floodings. + Format: <int> + Support masking of GPEs numbered from 0x00 to 0x7f. + acpi_no_auto_serialize [HW,ACPI] Disable auto-serialization of AML methods AML control methods that contain the opcodes to create @@ -3811,10 +3821,11 @@ it if 0 is given (See Documentation/cgroup-v1/memory.txt) swiotlb= [ARM,IA-64,PPC,MIPS,X86] - Format: { <int> | force } + Format: { <int> | force | noforce } <int> -- Number of I/O TLB slabs force -- force using of bounce buffers even if they wouldn't be automatically used by the kernel + noforce -- Never use bounce buffers (for debugging) switches= [HW,M68k] diff --git a/Documentation/arm64/cpu-feature-registers.txt b/Documentation/arm64/cpu-feature-registers.txt new file mode 100644 index 000000000000..61ca21ebef1a --- /dev/null +++ b/Documentation/arm64/cpu-feature-registers.txt @@ -0,0 +1,240 @@ + ARM64 CPU Feature Registers + =========================== + +Author: Suzuki K Poulose <suzuki.poulose@arm.com> + + +This file describes the ABI for exporting the AArch64 CPU ID/feature +registers to userspace. The availability of this ABI is advertised +via the HWCAP_CPUID in HWCAPs. + +1. Motivation +--------------- + +The ARM architecture defines a set of feature registers, which describe +the capabilities of the CPU/system. Access to these system registers is +restricted from EL0 and there is no reliable way for an application to +extract this information to make better decisions at runtime. There is +limited information available to the application via HWCAPs, however +there are some issues with their usage. + + a) Any change to the HWCAPs requires an update to userspace (e.g libc) + to detect the new changes, which can take a long time to appear in + distributions. Exposing the registers allows applications to get the + information without requiring updates to the toolchains. + + b) Access to HWCAPs is sometimes limited (e.g prior to libc, or + when ld is initialised at startup time). + + c) HWCAPs cannot represent non-boolean information effectively. The + architecture defines a canonical format for representing features + in the ID registers; this is well defined and is capable of + representing all valid architecture variations. + + +2. Requirements +----------------- + + a) Safety : + Applications should be able to use the information provided by the + infrastructure to run safely across the system. This has greater + implications on a system with heterogeneous CPUs. + The infrastructure exports a value that is safe across all the + available CPU on the system. + + e.g, If at least one CPU doesn't implement CRC32 instructions, while + others do, we should report that the CRC32 is not implemented. + Otherwise an application could crash when scheduled on the CPU + which doesn't support CRC32. + + b) Security : + Applications should only be able to receive information that is + relevant to the normal operation in userspace. Hence, some of the + fields are masked out(i.e, made invisible) and their values are set to + indicate the feature is 'not supported'. See Section 4 for the list + of visible features. Also, the kernel may manipulate the fields + based on what it supports. e.g, If FP is not supported by the + kernel, the values could indicate that the FP is not available + (even when the CPU provides it). + + c) Implementation Defined Features + The infrastructure doesn't expose any register which is + IMPLEMENTATION DEFINED as per ARMv8-A Architecture. + + d) CPU Identification : + MIDR_EL1 is exposed to help identify the processor. On a + heterogeneous system, this could be racy (just like getcpu()). The + process could be migrated to another CPU by the time it uses the + register value, unless the CPU affinity is set. Hence, there is no + guarantee that the value reflects the processor that it is + currently executing on. The REVIDR is not exposed due to this + constraint, as REVIDR makes sense only in conjunction with the + MIDR. Alternately, MIDR_EL1 and REVIDR_EL1 are exposed via sysfs + at: + + /sys/devices/system/cpu/cpu$ID/regs/identification/ + \- midr + \- revidr + +3. Implementation +-------------------- + +The infrastructure is built on the emulation of the 'MRS' instruction. +Accessing a restricted system register from an application generates an +exception and ends up in SIGILL being delivered to the process. +The infrastructure hooks into the exception handler and emulates the +operation if the source belongs to the supported system register space. + +The infrastructure emulates only the following system register space: + Op0=3, Op1=0, CRn=0, CRm=0,4,5,6,7 + +(See Table C5-6 'System instruction encodings for non-Debug System +register accesses' in ARMv8 ARM DDI 0487A.h, for the list of +registers). + +The following rules are applied to the value returned by the +infrastructure: + + a) The value of an 'IMPLEMENTATION DEFINED' field is set to 0. + b) The value of a reserved field is populated with the reserved + value as defined by the architecture. + c) The value of a 'visible' field holds the system wide safe value + for the particular feature (except for MIDR_EL1, see section 4). + d) All other fields (i.e, invisible fields) are set to indicate + the feature is missing (as defined by the architecture). + +4. List of registers with visible features +------------------------------------------- + + 1) ID_AA64ISAR0_EL1 - Instruction Set Attribute Register 0 + x--------------------------------------------------x + | Name | bits | visible | + |--------------------------------------------------| + | RES0 | [63-32] | n | + |--------------------------------------------------| + | RDM | [31-28] | y | + |--------------------------------------------------| + | ATOMICS | [23-20] | y | + |--------------------------------------------------| + | CRC32 | [19-16] | y | + |--------------------------------------------------| + | SHA2 | [15-12] | y | + |--------------------------------------------------| + | SHA1 | [11-8] | y | + |--------------------------------------------------| + | AES | [7-4] | y | + |--------------------------------------------------| + | RES0 | [3-0] | n | + x--------------------------------------------------x + + + 2) ID_AA64PFR0_EL1 - Processor Feature Register 0 + x--------------------------------------------------x + | Name | bits | visible | + |--------------------------------------------------| + | RES0 | [63-28] | n | + |--------------------------------------------------| + | GIC | [27-24] | n | + |--------------------------------------------------| + | AdvSIMD | [23-20] | y | + |--------------------------------------------------| + | FP | [19-16] | y | + |--------------------------------------------------| + | EL3 | [15-12] | n | + |--------------------------------------------------| + | EL2 | [11-8] | n | + |--------------------------------------------------| + | EL1 | [7-4] | n | + |--------------------------------------------------| + | EL0 | [3-0] | n | + x--------------------------------------------------x + + + 3) MIDR_EL1 - Main ID Register + x--------------------------------------------------x + | Name | bits | visible | + |--------------------------------------------------| + | Implementer | [31-24] | y | + |--------------------------------------------------| + | Variant | [23-20] | y | + |--------------------------------------------------| + | Architecture | [19-16] | y | + |--------------------------------------------------| + | PartNum | [15-4] | y | + |--------------------------------------------------| + | Revision | [3-0] | y | + x--------------------------------------------------x + + NOTE: The 'visible' fields of MIDR_EL1 will contain the value + as available on the CPU where it is fetched and is not a system + wide safe value. + +Appendix I: Example +--------------------------- + +/* + * Sample program to demonstrate the MRS emulation ABI. + * + * Copyright (C) 2015-2016, ARM Ltd + * + * Author: Suzuki K Poulose <suzuki.poulose@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <asm/hwcap.h> +#include <stdio.h> +#include <sys/auxv.h> + +#define get_cpu_ftr(id) ({ \ + unsigned long __val; \ + asm("mrs %0, "#id : "=r" (__val)); \ + printf("%-20s: 0x%016lx\n", #id, __val); \ + }) + +int main(void) +{ + + if (!(getauxval(AT_HWCAP) & HWCAP_CPUID)) { + fputs("CPUID registers unavailable\n", stderr); + return 1; + } + + get_cpu_ftr(ID_AA64ISAR0_EL1); + get_cpu_ftr(ID_AA64ISAR1_EL1); + get_cpu_ftr(ID_AA64MMFR0_EL1); + get_cpu_ftr(ID_AA64MMFR1_EL1); + get_cpu_ftr(ID_AA64PFR0_EL1); + get_cpu_ftr(ID_AA64PFR1_EL1); + get_cpu_ftr(ID_AA64DFR0_EL1); + get_cpu_ftr(ID_AA64DFR1_EL1); + + get_cpu_ftr(MIDR_EL1); + get_cpu_ftr(MPIDR_EL1); + get_cpu_ftr(REVIDR_EL1); + +#if 0 + /* Unexposed register access causes SIGILL */ + get_cpu_ftr(ID_MMFR0_EL1); +#endif + + return 0; +} + + + diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index 51642159aedb..c0a3bb5a6e4e 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -54,9 +54,9 @@ This is the hardware sector size of the device, in bytes. io_poll (RW) ------------ -When read, this file shows the total number of block IO polls and how -many returned success. Writing '0' to this file will disable polling -for this device. Writing any non-zero value will enable this feature. +When read, this file shows whether polling is enabled (1) or disabled +(0). Writing '0' to this file will disable polling for this device. +Writing any non-zero value will enable this feature. io_poll_delay (RW) ------------------ diff --git a/Documentation/devicetree/bindings/input/tps65218-pwrbutton.txt b/Documentation/devicetree/bindings/input/tps65218-pwrbutton.txt index 3e5b9793341f..8682ab6d4a50 100644 --- a/Documentation/devicetree/bindings/input/tps65218-pwrbutton.txt +++ b/Documentation/devicetree/bindings/input/tps65218-pwrbutton.txt @@ -8,8 +8,9 @@ This driver provides a simple power button event via an Interrupt. Required properties: - compatible: should be "ti,tps65217-pwrbutton" or "ti,tps65218-pwrbutton" -Required properties for TPS65218: +Required properties: - interrupts: should be one of the following + - <2>: For controllers compatible with tps65217 - <3 IRQ_TYPE_EDGE_BOTH>: For controllers compatible with tps65218 Examples: @@ -17,6 +18,7 @@ Examples: &tps { tps65217-pwrbutton { compatible = "ti,tps65217-pwrbutton"; + interrupts = <2>; }; }; diff --git a/Documentation/devicetree/bindings/power/supply/tps65217_charger.txt b/Documentation/devicetree/bindings/power/supply/tps65217_charger.txt index 98d131acee95..a11072c5a866 100644 --- a/Documentation/devicetree/bindings/power/supply/tps65217_charger.txt +++ b/Documentation/devicetree/bindings/power/supply/tps65217_charger.txt @@ -2,11 +2,16 @@ TPS65217 Charger Required Properties: -compatible: "ti,tps65217-charger" +-interrupts: TPS65217 interrupt numbers for the AC and USB charger input change. + Should be <0> for the USB charger and <1> for the AC adapter. +-interrupt-names: Should be "USB" and "AC" This node is a subnode of the tps65217 PMIC. Example: tps65217-charger { - compatible = "ti,tps65090-charger"; + compatible = "ti,tps65217-charger"; + interrupts = <0>, <1>; + interrupt-names = "USB", "AC"; }; diff --git a/Documentation/driver-api/infrastructure.rst b/Documentation/driver-api/infrastructure.rst index 0bb0b5fc9512..6d9ff316b608 100644 --- a/Documentation/driver-api/infrastructure.rst +++ b/Documentation/driver-api/infrastructure.rst @@ -55,21 +55,6 @@ Device Drivers DMA Management .. kernel-doc:: drivers/base/dma-mapping.c :export: -Device Drivers Power Management -------------------------------- - -.. kernel-doc:: drivers/base/power/main.c - :export: - -Device Drivers ACPI Support ---------------------------- - -.. kernel-doc:: drivers/acpi/scan.c - :export: - -.. kernel-doc:: drivers/acpi/scan.c - :internal: - Device drivers PnP support -------------------------- diff --git a/Documentation/networking/mpls-sysctl.txt b/Documentation/networking/mpls-sysctl.txt index 9ed15f86c17c..15d8d16934fd 100644 --- a/Documentation/networking/mpls-sysctl.txt +++ b/Documentation/networking/mpls-sysctl.txt @@ -5,8 +5,8 @@ platform_labels - INTEGER possible to configure forwarding for label values equal to or greater than the number of platform labels. - A dense utliziation of the entries in the platform label table - is possible and expected aas the platform labels are locally + A dense utilization of the entries in the platform label table + is possible and expected as the platform labels are locally allocated. If the number of platform label table entries is set to 0 no diff --git a/Documentation/vfio-mediated-device.txt b/Documentation/vfio-mediated-device.txt index b38afec35edc..d226c7a5ba8b 100644 --- a/Documentation/vfio-mediated-device.txt +++ b/Documentation/vfio-mediated-device.txt @@ -127,22 +127,22 @@ the VFIO when devices are unbound from the driver. Physical Device Driver Interface -------------------------------- -The physical device driver interface provides the parent_ops[3] structure to -define the APIs to manage work in the mediated core driver that is related to -the physical device. +The physical device driver interface provides the mdev_parent_ops[3] structure +to define the APIs to manage work in the mediated core driver that is related +to the physical device. -The structures in the parent_ops structure are as follows: +The structures in the mdev_parent_ops structure are as follows: * dev_attr_groups: attributes of the parent device * mdev_attr_groups: attributes of the mediated device * supported_config: attributes to define supported configurations -The functions in the parent_ops structure are as follows: +The functions in the mdev_parent_ops structure are as follows: * create: allocate basic resources in a driver for a mediated device * remove: free resources in a driver when a mediated device is destroyed -The callbacks in the parent_ops structure are as follows: +The callbacks in the mdev_parent_ops structure are as follows: * open: open callback of mediated device * close: close callback of mediated device @@ -151,14 +151,14 @@ The callbacks in the parent_ops structure are as follows: * write: write emulation callback * mmap: mmap emulation callback -A driver should use the parent_ops structure in the function call to register -itself with the mdev core driver: +A driver should use the mdev_parent_ops structure in the function call to +register itself with the mdev core driver: extern int mdev_register_device(struct device *dev, - const struct parent_ops *ops); + const struct mdev_parent_ops *ops); -However, the parent_ops structure is not required in the function call that a -driver should use to unregister itself with the mdev core driver: +However, the mdev_parent_ops structure is not required in the function call +that a driver should use to unregister itself with the mdev core driver: extern void mdev_unregister_device(struct device *dev); @@ -223,6 +223,9 @@ Directories and files under the sysfs for Each Physical Device sprintf(buf, "%s-%s", dev_driver_string(parent->dev), group->name); + (or using mdev_parent_dev(mdev) to arrive at the parent device outside + of the core mdev code) + * device_api This attribute should show which device API is being created, for example, @@ -394,5 +397,5 @@ References [1] See Documentation/vfio.txt for more information on VFIO. [2] struct mdev_driver in include/linux/mdev.h -[3] struct parent_ops in include/linux/mdev.h +[3] struct mdev_parent_ops in include/linux/mdev.h [4] struct vfio_iommu_driver_ops in include/linux/vfio.h |