Merge tag 'riscv-for-linus-6.5-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for ACPI

 - Various cleanups to the ISA string parsing, including making them
   case-insensitive

 - Support for the vector extension

 - Support for independent irq/softirq stacks

 - Our CPU DT binding now has "unevaluatedProperties: false"

* tag 'riscv-for-linus-6.5-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (78 commits)
  riscv: hibernate: remove WARN_ON in save_processor_state
  dt-bindings: riscv: cpus: switch to unevaluatedProperties: false
  dt-bindings: riscv: cpus: add a ref the common cpu schema
  riscv: stack: Add config of thread stack size
  riscv: stack: Support HAVE_SOFTIRQ_ON_OWN_STACK
  riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK
  RISC-V: always report presence of extensions formerly part of the base ISA
  dt-bindings: riscv: explicitly mention assumption of Zicntr & Zihpm support
  RISC-V: remove decrement/increment dance in ISA string parser
  RISC-V: rework comments in ISA string parser
  RISC-V: validate riscv,isa at boot, not during ISA string parsing
  RISC-V: split early & late of_node to hartid mapping
  RISC-V: simplify register width check in ISA string parsing
  perf: RISC-V: Limit the number of counters returned from SBI
  riscv: replace deprecated scall with ecall
  riscv: uprobes: Restore thread.bad_cause
  riscv: mm: try VMA lock-based page fault handling first
  riscv: mm: Pre-allocate PGD entries for vmalloc/modules area
  RISC-V: hwprobe: Expose Zba, Zbb, and Zbs
  RISC-V: Track ISA extensions per hart
  ...

Author: torvalds

Documentation/admin-guide/kernel-parameters.txt

@@ -1,17 +1,17 @@
-	acpi=		[HW,ACPI,X86,ARM64]
+	acpi=		[HW,ACPI,X86,ARM64,RISCV64]
 			Advanced Configuration and Power Interface
 			Format: { force | on | off | strict | noirq | rsdt |
 				  copy_dsdt }
 			force -- enable ACPI if default was off
-			on -- enable ACPI but allow fallback to DT [arm64]
+			on -- enable ACPI but allow fallback to DT [arm64,riscv64]
 			off -- disable ACPI if default was on
 			noirq -- do not use ACPI for IRQ routing
 			strict -- Be less tolerant of platforms that are not
 				strictly ACPI specification compliant.
 			rsdt -- prefer RSDT over (default) XSDT
 			copy_dsdt -- copy DSDT to memory
-			For ARM64, ONLY "acpi=off", "acpi=on" or "acpi=force"
-			are available
+			For ARM64 and RISCV64, ONLY "acpi=off", "acpi=on" or
+			"acpi=force" are available
 
 			See also Documentation/power/runtime_pm.rst, pci=noacpi
 

Documentation/devicetree/bindings/riscv/cpus.yaml

@@ -23,6 +23,9 @@ description: |
   two cores, each of which has two hyperthreads, could be described as
   having four harts.
 
+allOf:
+  - $ref: /schemas/cpu.yaml#
+
 properties:
   compatible:
     oneOf:
@@ -61,7 +64,7 @@ properties:
       hart.  These values originate from the RISC-V Privileged
       Specification document, available from
       https://riscv.org/specifications/
-    $ref: "/schemas/types.yaml#/definitions/string"
+    $ref: /schemas/types.yaml#/definitions/string
     enum:
       - riscv,sv32
       - riscv,sv39
@@ -89,15 +92,18 @@ properties:
       Due to revisions of the ISA specification, some deviations
       have arisen over time.
       Notably, riscv,isa was defined prior to the creation of the
-      Zicsr and Zifencei extensions and thus "i" implies
-      "zicsr_zifencei".
+      Zicntr, Zicsr, Zifencei and Zihpm extensions and thus "i"
+      implies "zicntr_zicsr_zifencei_zihpm".
 
       While the isa strings in ISA specification are case
       insensitive, letters in the riscv,isa string must be all
-      lowercase to simplify parsing.
-    $ref: "/schemas/types.yaml#/definitions/string"
+      lowercase.
+    $ref: /schemas/types.yaml#/definitions/string
     pattern: ^rv(?:64|32)imaf?d?q?c?b?k?j?p?v?h?(?:[hsxz](?:[a-z])+)?(?:_[hsxz](?:[a-z])+)*$
 
+  # RISC-V has multiple properties for cache op block sizes as the sizes
+  # differ between individual CBO extensions
+  cache-op-block-size: false
   # RISC-V requires 'timebase-frequency' in /cpus, so disallow it here
   timebase-frequency: false
 
@@ -120,7 +126,7 @@ properties:
       - interrupt-controller
 
   cpu-idle-states:
-    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    $ref: /schemas/types.yaml#/definitions/phandle-array
     items:
       maxItems: 1
     description: |
@@ -137,7 +143,7 @@ required:
   - riscv,isa
   - interrupt-controller
 
-additionalProperties: true
+unevaluatedProperties: false
 
 examples:
   - |

Documentation/riscv/hwprobe.rst

@@ -64,6 +64,19 @@ The following keys are defined:
   * :c:macro:`RISCV_HWPROBE_IMA_C`: The C extension is supported, as defined
     by version 2.2 of the RISC-V ISA manual.
 
+  * :c:macro:`RISCV_HWPROBE_IMA_V`: The V extension is supported, as defined by
+    version 1.0 of the RISC-V Vector extension manual.
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZBA`: The Zba address generation extension is
+       supported, as defined in version 1.0 of the Bit-Manipulation ISA
+       extensions.
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZBB`: The Zbb extension is supported, as defined
+       in version 1.0 of the Bit-Manipulation ISA extensions.
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZBS`: The Zbs extension is supported, as defined
+       in version 1.0 of the Bit-Manipulation ISA extensions.
+
 * :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A bitmask that contains performance
   information about the selected set of processors.
 

Documentation/riscv/index.rst

@@ -10,6 +10,7 @@ RISC-V architecture
     hwprobe
     patch-acceptance
     uabi
+    vector
 
     features
 

Documentation/riscv/vector.rst

@@ -0,0 +1,132 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=========================================
+Vector Extension Support for RISC-V Linux
+=========================================
+
+This document briefly outlines the interface provided to userspace by Linux in
+order to support the use of the RISC-V Vector Extension.
+
+1.  prctl() Interface
+---------------------
+
+Two new prctl() calls are added to allow programs to manage the enablement
+status for the use of Vector in userspace. The intended usage guideline for
+these interfaces is to give init systems a way to modify the availability of V
+for processes running under its domain. Calling thess interfaces is not
+recommended in libraries routines because libraries should not override policies
+configured from the parant process. Also, users must noted that these interfaces
+are not portable to non-Linux, nor non-RISC-V environments, so it is discourage
+to use in a portable code. To get the availability of V in an ELF program,
+please read :c:macro:`COMPAT_HWCAP_ISA_V` bit of :c:macro:`ELF_HWCAP` in the
+auxiliary vector.
+
+* prctl(PR_RISCV_V_SET_CONTROL, unsigned long arg)
+
+    Sets the Vector enablement status of the calling thread, where the control
+    argument consists of two 2-bit enablement statuses and a bit for inheritance
+    mode. Other threads of the calling process are unaffected.
+
+    Enablement status is a tri-state value each occupying 2-bit of space in
+    the control argument:
+
+    * :c:macro:`PR_RISCV_V_VSTATE_CTRL_DEFAULT`: Use the system-wide default
+      enablement status on execve(). The system-wide default setting can be
+      controlled via sysctl interface (see sysctl section below).
+
+    * :c:macro:`PR_RISCV_V_VSTATE_CTRL_ON`: Allow Vector to be run for the
+      thread.
+
+    * :c:macro:`PR_RISCV_V_VSTATE_CTRL_OFF`: Disallow Vector. Executing Vector
+      instructions under such condition will trap and casuse the termination of the thread.
+
+    arg: The control argument is a 5-bit value consisting of 3 parts, and
+    accessed by 3 masks respectively.
+
+    The 3 masks, PR_RISCV_V_VSTATE_CTRL_CUR_MASK,
+    PR_RISCV_V_VSTATE_CTRL_NEXT_MASK, and PR_RISCV_V_VSTATE_CTRL_INHERIT
+    represents bit[1:0], bit[3:2], and bit[4]. bit[1:0] accounts for the
+    enablement status of current thread, and the setting at bit[3:2] takes place
+    at next execve(). bit[4] defines the inheritance mode of the setting in
+    bit[3:2].
+
+        * :c:macro:`PR_RISCV_V_VSTATE_CTRL_CUR_MASK`: bit[1:0]: Account for the
+          Vector enablement status for the calling thread. The calling thread is
+          not able to turn off Vector once it has been enabled. The prctl() call
+          fails with EPERM if the value in this mask is PR_RISCV_V_VSTATE_CTRL_OFF
+          but the current enablement status is not off. Setting
+          PR_RISCV_V_VSTATE_CTRL_DEFAULT here takes no effect but to set back
+          the original enablement status.
+
+        * :c:macro:`PR_RISCV_V_VSTATE_CTRL_NEXT_MASK`: bit[3:2]: Account for the
+          Vector enablement setting for the calling thread at the next execve()
+          system call. If PR_RISCV_V_VSTATE_CTRL_DEFAULT is used in this mask,
+          then the enablement status will be decided by the system-wide
+          enablement status when execve() happen.
+
+        * :c:macro:`PR_RISCV_V_VSTATE_CTRL_INHERIT`: bit[4]: the inheritance
+          mode for the setting at PR_RISCV_V_VSTATE_CTRL_NEXT_MASK. If the bit
+          is set then the following execve() will not clear the setting in both
+          PR_RISCV_V_VSTATE_CTRL_NEXT_MASK and PR_RISCV_V_VSTATE_CTRL_INHERIT.
+          This setting persists across changes in the system-wide default value.
+
+    Return value:
+        * 0 on success;
+        * EINVAL: Vector not supported, invalid enablement status for current or
+          next mask;
+        * EPERM: Turning off Vector in PR_RISCV_V_VSTATE_CTRL_CUR_MASK if Vector
+          was enabled for the calling thread.
+
+    On success:
+        * A valid setting for PR_RISCV_V_VSTATE_CTRL_CUR_MASK takes place
+          immediately. The enablement status specified in
+          PR_RISCV_V_VSTATE_CTRL_NEXT_MASK happens at the next execve() call, or
+          all following execve() calls if PR_RISCV_V_VSTATE_CTRL_INHERIT bit is
+          set.
+        * Every successful call overwrites a previous setting for the calling
+          thread.
+
+* prctl(PR_RISCV_V_GET_CONTROL)
+
+    Gets the same Vector enablement status for the calling thread. Setting for
+    next execve() call and the inheritance bit are all OR-ed together.
+
+    Note that ELF programs are able to get the availability of V for itself by
+    reading :c:macro:`COMPAT_HWCAP_ISA_V` bit of :c:macro:`ELF_HWCAP` in the
+    auxiliary vector.
+
+    Return value:
+        * a nonnegative value on success;
+        * EINVAL: Vector not supported.
+
+2.  System runtime configuration (sysctl)
+-----------------------------------------
+
+To mitigate the ABI impact of expansion of the signal stack, a
+policy mechanism is provided to the administrators, distro maintainers, and
+developers to control the default Vector enablement status for userspace
+processes in form of sysctl knob:
+
+* /proc/sys/abi/riscv_v_default_allow
+
+    Writing the text representation of 0 or 1 to this file sets the default
+    system enablement status for new starting userspace programs. Valid values
+    are:
+
+    * 0: Do not allow Vector code to be executed as the default for new processes.
+    * 1: Allow Vector code to be executed as the default for new processes.
+
+    Reading this file returns the current system default enablement status.
+
+    At every execve() call, a new enablement status of the new process is set to
+    the system default, unless:
+
+      * PR_RISCV_V_VSTATE_CTRL_INHERIT is set for the calling process, and the
+        setting in PR_RISCV_V_VSTATE_CTRL_NEXT_MASK is not
+        PR_RISCV_V_VSTATE_CTRL_DEFAULT. Or,
+
+      * The setting in PR_RISCV_V_VSTATE_CTRL_NEXT_MASK is not
+        PR_RISCV_V_VSTATE_CTRL_DEFAULT.
+
+    Modifying the system default enablement status does not affect the enablement
+    status of any existing process of thread that do not make an execve() call.

MAINTAINERS

@@ -406,6 +406,13 @@ L:	[email protected] (moderated for non-subscribers)
 S:	Maintained
 F:	drivers/acpi/arm64
 
+ACPI FOR RISC-V (ACPI/riscv)
+M:	Sunil V L <[email protected]>
+L:	[email protected]
+L:	[email protected]
+S:	Maintained
+F:	drivers/acpi/riscv/
+
 ACPI PCC(Platform Communication Channel) MAILBOX DRIVER
 M:	Sudeep Holla <[email protected]>
 L:	[email protected]

arch/riscv/Kconfig

@@ -12,6 +12,8 @@ config 32BIT
 
 config RISCV
 	def_bool y
+	select ACPI_GENERIC_GSI if ACPI
+	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
 	select ARCH_DMA_DEFAULT_COHERENT
 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
@@ -43,6 +45,7 @@ config RISCV
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
 	select ARCH_SUPPORTS_HUGETLBFS if MMU
 	select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
+	select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
 	select ARCH_USE_MEMTEST
 	select ARCH_USE_QUEUED_RWLOCKS
 	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
@@ -265,6 +268,12 @@ config RISCV_DMA_NONCOHERENT
 config AS_HAS_INSN
 	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
 
+config AS_HAS_OPTION_ARCH
+	# https://reviews.llvm.org/D123515
+	def_bool y
+	depends on $(as-instr, .option arch$(comma) +m)
+	depends on !$(as-instr, .option arch$(comma) -i)
+
 source "arch/riscv/Kconfig.socs"
 source "arch/riscv/Kconfig.errata"
 
@@ -463,13 +472,44 @@ config RISCV_ISA_SVPBMT
 
 	   If you don't know what to do here, say Y.
 
+config TOOLCHAIN_HAS_V
+	bool
+	default y
+	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv)
+	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv)
+	depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
+	depends on AS_HAS_OPTION_ARCH
+
+config RISCV_ISA_V
+	bool "VECTOR extension support"
+	depends on TOOLCHAIN_HAS_V
+	depends on FPU
+	select DYNAMIC_SIGFRAME
+	default y
+	help
+	  Say N here if you want to disable all vector related procedure
+	  in the kernel.
+
+	  If you don't know what to do here, say Y.
+
+config RISCV_ISA_V_DEFAULT_ENABLE
+	bool "Enable userspace Vector by default"
+	depends on RISCV_ISA_V
+	default y
+	help
+	  Say Y here if you want to enable Vector in userspace by default.
+	  Otherwise, userspace has to make explicit prctl() call to enable
+	  Vector, or enable it via the sysctl interface.
+
+	  If you don't know what to do here, say Y.
+
 config TOOLCHAIN_HAS_ZBB
 	bool
 	default y
 	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
 	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
 	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
-	depends on AS_IS_GNU
+	depends on AS_HAS_OPTION_ARCH
 
 config RISCV_ISA_ZBB
 	bool "Zbb extension support for bit manipulation instructions"
@@ -554,6 +594,25 @@ config FPU
 
 	  If you don't know what to do here, say Y.
 
+config IRQ_STACKS
+	bool "Independent irq & softirq stacks" if EXPERT
+	default y
+	select HAVE_IRQ_EXIT_ON_IRQ_STACK
+	select HAVE_SOFTIRQ_ON_OWN_STACK
+	help
+	  Add independent irq & softirq stacks for percpu to prevent kernel stack
+	  overflows. We may save some memory footprint by disabling IRQ_STACKS.
+
+config THREAD_SIZE_ORDER
+	int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT
+	range 0 4
+	default 1 if 32BIT && !KASAN
+	default 3 if 64BIT && KASAN
+	default 2
+	help
+	  Specify the Pages of thread stack size (from 4KB to 64KB), which also
+	  affects irq stack size, which is equal to thread stack size.
+
 endmenu # "Platform type"
 
 menu "Kernel features"
@@ -710,6 +769,7 @@ config EFI
 	depends on OF && !XIP_KERNEL
 	depends on MMU
 	default y
+	select ARCH_SUPPORTS_ACPI if 64BIT
 	select EFI_GENERIC_STUB
 	select EFI_PARAMS_FROM_FDT
 	select EFI_RUNTIME_WRAPPERS
@@ -822,3 +882,5 @@ source "drivers/cpufreq/Kconfig"
 endmenu # "CPU Power Management"
 
 source "arch/riscv/kvm/Kconfig"
+
+source "drivers/acpi/Kconfig"

arch/riscv/Makefile

@@ -60,6 +60,7 @@ riscv-march-$(CONFIG_ARCH_RV32I)	:= rv32ima
 riscv-march-$(CONFIG_ARCH_RV64I)	:= rv64ima
 riscv-march-$(CONFIG_FPU)		:= $(riscv-march-y)fd
 riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
+riscv-march-$(CONFIG_RISCV_ISA_V)	:= $(riscv-march-y)v
 
 ifdef CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC
 KBUILD_CFLAGS += -Wa,-misa-spec=2.2
@@ -71,7 +72,10 @@ endif
 # Check if the toolchain supports Zihintpause extension
 riscv-march-$(CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE) := $(riscv-march-y)_zihintpause
 
-KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
+# Remove F,D,V from isa string for all. Keep extensions between "fd" and "v" by
+# matching non-v and non-multi-letter extensions out with the filter ([^v_]*)
+KBUILD_CFLAGS += -march=$(shell echo $(riscv-march-y) | sed -E 's/(rv32ima|rv64ima)fd([^v_]*)v?/\1\2/')
+
 KBUILD_AFLAGS += -march=$(riscv-march-y)
 
 KBUILD_CFLAGS += -mno-save-restore