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authorLinus Torvalds <torvalds@linux-foundation.org>2025-04-04 09:49:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-04-04 09:49:17 -0700
commit4a1d8ababde685a77fd4fd61e58f973cbdf29f8c (patch)
tree5ff581604cb5c3e74ea054785cedcba2fa2c393d
parent61f96e684edd28ca40555ec49ea1555df31ba619 (diff)
parent3eb64093f533a29d3291a463fd65126bf430ba60 (diff)
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Merge tag 'riscv-for-linus-6.15-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt: - The sub-architecture selection Kconfig system has been cleaned up, the documentation has been improved, and various detections have been fixed - The vector-related extensions dependencies are now validated when parsing from device tree and in the DT bindings - Misaligned access probing can be overridden via a kernel command-line parameter, along with various fixes to misalign access handling - Support for relocatable !MMU kernels builds - Support for hpge pfnmaps, which should improve TLB utilization - Support for runtime constants, which improves the d_hash() performance - Support for bfloat16, Zicbom, Zaamo, Zalrsc, Zicntr, Zihpm - Various fixes, including: - We were missing a secondary mmu notifier call when flushing the tlb which is required for IOMMU - Fix ftrace panics by saving the registers as expected by ftrace - Fix a couple of stimecmp usage related to cpu hotplug - purgatory_start is now aligned as per the STVEC requirements - A fix for hugetlb when calculating the size of non-present PTEs * tag 'riscv-for-linus-6.15-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (65 commits) riscv: Add norvc after .option arch in runtime const riscv: Make sure toolchain supports zba before using zba instructions riscv/purgatory: 4B align purgatory_start riscv/kexec_file: Handle R_RISCV_64 in purgatory relocator selftests: riscv: fix v_exec_initval_nolibc.c riscv: Fix hugetlb retrieval of number of ptes in case of !present pte riscv: print hartid on bringup riscv: Add norvc after .option arch in runtime const riscv: Remove CONFIG_PAGE_OFFSET riscv: Support CONFIG_RELOCATABLE on riscv32 asm-generic: Always define Elf_Rel and Elf_Rela riscv: Support CONFIG_RELOCATABLE on NOMMU riscv: Allow NOMMU kernels to access all of RAM riscv: Remove duplicate CONFIG_PAGE_OFFSET definition RISC-V: errata: Use medany for relocatable builds dt-bindings: riscv: document vector crypto requirements dt-bindings: riscv: add vector sub-extension dependencies dt-bindings: riscv: d requires f RISC-V: add f & d extension validation checks RISC-V: add vector crypto extension validation checks ...
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt16
-rw-r--r--Documentation/arch/riscv/hwprobe.rst32
-rw-r--r--Documentation/devicetree/bindings/riscv/extensions.yaml149
-rw-r--r--arch/riscv/Kbuild1
-rw-r--r--arch/riscv/Kconfig84
-rw-r--r--arch/riscv/Kconfig.socs2
-rw-r--r--arch/riscv/Makefile1
-rw-r--r--arch/riscv/boot/dts/Makefile2
-rw-r--r--arch/riscv/configs/defconfig2
-rw-r--r--arch/riscv/configs/nommu_k210_defconfig2
-rw-r--r--arch/riscv/configs/nommu_k210_sdcard_defconfig2
-rw-r--r--arch/riscv/errata/Makefile6
-rw-r--r--arch/riscv/include/asm/arch_hweight.h6
-rw-r--r--arch/riscv/include/asm/asm.h1
-rw-r--r--arch/riscv/include/asm/bitops.h4
-rw-r--r--arch/riscv/include/asm/checksum.h3
-rw-r--r--arch/riscv/include/asm/cmpxchg.h38
-rw-r--r--arch/riscv/include/asm/cpufeature.h7
-rw-r--r--arch/riscv/include/asm/ftrace.h7
-rw-r--r--arch/riscv/include/asm/hwcap.h5
-rw-r--r--arch/riscv/include/asm/hwprobe.h2
-rw-r--r--arch/riscv/include/asm/insn-def.h3
-rw-r--r--arch/riscv/include/asm/page.h27
-rw-r--r--arch/riscv/include/asm/pgtable.h55
-rw-r--r--arch/riscv/include/asm/ptrace.h18
-rw-r--r--arch/riscv/include/asm/runtime-const.h268
-rw-r--r--arch/riscv/include/asm/suspend.h4
-rw-r--r--arch/riscv/include/uapi/asm/hwprobe.h9
-rw-r--r--arch/riscv/include/uapi/asm/kvm.h2
-rw-r--r--arch/riscv/kernel/asm-offsets.c1
-rw-r--r--arch/riscv/kernel/cpufeature.c197
-rw-r--r--arch/riscv/kernel/elf_kexec.c3
-rw-r--r--arch/riscv/kernel/ftrace.c6
-rw-r--r--arch/riscv/kernel/jump_label.c4
-rw-r--r--arch/riscv/kernel/mcount.S24
-rw-r--r--arch/riscv/kernel/setup.c5
-rw-r--r--arch/riscv/kernel/smp.c2
-rw-r--r--arch/riscv/kernel/smpboot.c4
-rw-r--r--arch/riscv/kernel/stacktrace.c2
-rw-r--r--arch/riscv/kernel/suspend.c14
-rw-r--r--arch/riscv/kernel/sys_hwprobe.c15
-rw-r--r--arch/riscv/kernel/traps_misaligned.c14
-rw-r--r--arch/riscv/kernel/unaligned_access_speed.c242
-rw-r--r--arch/riscv/kernel/vec-copy-unaligned.S2
-rw-r--r--arch/riscv/kernel/vendor_extensions.c2
-rw-r--r--arch/riscv/kernel/vmlinux.lds.S3
-rw-r--r--arch/riscv/kvm/vcpu_onereg.c4
-rw-r--r--arch/riscv/lib/csum.c21
-rw-r--r--arch/riscv/lib/strcmp.S5
-rw-r--r--arch/riscv/lib/strlen.S5
-rw-r--r--arch/riscv/lib/strncmp.S5
-rw-r--r--arch/riscv/mm/context.c2
-rw-r--r--arch/riscv/mm/hugetlbpage.c76
-rw-r--r--arch/riscv/mm/init.c97
-rw-r--r--arch/riscv/mm/physaddr.c2
-rw-r--r--arch/riscv/mm/tlbflush.c35
-rw-r--r--arch/riscv/purgatory/entry.S1
-rw-r--r--drivers/clocksource/timer-riscv.c6
-rw-r--r--include/asm-generic/module.h8
-rw-r--r--tools/testing/selftests/kvm/riscv/get-reg-list.c8
-rw-r--r--tools/testing/selftests/riscv/hwprobe/cbo.c66
-rw-r--r--tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c10
62 files changed, 1250 insertions, 399 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index f5af86b3c4a2..d53aee542460 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -7535,6 +7535,22 @@
Note that genuine overcurrent events won't be
reported either.
+ unaligned_scalar_speed=
+ [RISCV]
+ Format: {slow | fast | unsupported}
+ Allow skipping scalar unaligned access speed tests. This
+ is useful for testing alternative code paths and to skip
+ the tests in environments where they run too slowly. All
+ CPUs must have the same scalar unaligned access speed.
+
+ unaligned_vector_speed=
+ [RISCV]
+ Format: {slow | fast | unsupported}
+ Allow skipping vector unaligned access speed tests. This
+ is useful for testing alternative code paths and to skip
+ the tests in environments where they run too slowly. All
+ CPUs must have the same vector unaligned access speed.
+
unknown_nmi_panic
[X86] Cause panic on unknown NMI.
diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index f273ea15a8e8..53607d962653 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -183,6 +183,9 @@ The following keys are defined:
defined in the Atomic Compare-and-Swap (CAS) instructions manual starting
from commit 5059e0ca641c ("update to ratified").
+ * :c:macro:`RISCV_HWPROBE_EXT_ZICNTR`: The Zicntr extension version 2.0
+ is supported as defined in the RISC-V ISA manual.
+
* :c:macro:`RISCV_HWPROBE_EXT_ZICOND`: The Zicond extension is supported as
defined in the RISC-V Integer Conditional (Zicond) operations extension
manual starting from commit 95cf1f9 ("Add changes requested by Ved
@@ -192,6 +195,9 @@ The following keys are defined:
supported as defined in the RISC-V ISA manual starting from commit
d8ab5c78c207 ("Zihintpause is ratified").
+ * :c:macro:`RISCV_HWPROBE_EXT_ZIHPM`: The Zihpm extension version 2.0
+ is supported as defined in the RISC-V ISA manual.
+
* :c:macro:`RISCV_HWPROBE_EXT_ZVE32X`: The Vector sub-extension Zve32x is
supported, as defined by version 1.0 of the RISC-V Vector extension manual.
@@ -239,9 +245,32 @@ The following keys are defined:
ratified in commit 98918c844281 ("Merge pull request #1217 from
riscv/zawrs") of riscv-isa-manual.
+ * :c:macro:`RISCV_HWPROBE_EXT_ZAAMO`: The Zaamo extension is supported as
+ defined in the in the RISC-V ISA manual starting from commit e87412e621f1
+ ("integrate Zaamo and Zalrsc text (#1304)").
+
+ * :c:macro:`RISCV_HWPROBE_EXT_ZALRSC`: The Zalrsc extension is supported as
+ defined in the in the RISC-V ISA manual starting from commit e87412e621f1
+ ("integrate Zaamo and Zalrsc text (#1304)").
+
* :c:macro:`RISCV_HWPROBE_EXT_SUPM`: The Supm extension is supported as
defined in version 1.0 of the RISC-V Pointer Masking extensions.
+ * :c:macro:`RISCV_HWPROBE_EXT_ZFBFMIN`: The Zfbfmin extension is supported as
+ defined in the RISC-V ISA manual starting from commit 4dc23d6229de
+ ("Added Chapter title to BF16").
+
+ * :c:macro:`RISCV_HWPROBE_EXT_ZVFBFMIN`: The Zvfbfmin extension is supported as
+ defined in the RISC-V ISA manual starting from commit 4dc23d6229de
+ ("Added Chapter title to BF16").
+
+ * :c:macro:`RISCV_HWPROBE_EXT_ZVFBFWMA`: The Zvfbfwma extension is supported as
+ defined in the RISC-V ISA manual starting from commit 4dc23d6229de
+ ("Added Chapter title to BF16").
+
+ * :c:macro:`RISCV_HWPROBE_EXT_ZICBOM`: The Zicbom extension is supported, as
+ ratified in commit 3dd606f ("Create cmobase-v1.0.pdf") of riscv-CMOs.
+
* :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: Deprecated. Returns similar values to
:c:macro:`RISCV_HWPROBE_KEY_MISALIGNED_SCALAR_PERF`, but the key was
mistakenly classified as a bitmask rather than a value.
@@ -303,3 +332,6 @@ The following keys are defined:
* :c:macro:`RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR`: The xtheadvector vendor
extension is supported in the T-Head ISA extensions spec starting from
commit a18c801634 ("Add T-Head VECTOR vendor extension. ").
+
+* :c:macro:`RISCV_HWPROBE_KEY_ZICBOM_BLOCK_SIZE`: An unsigned int which
+ represents the size of the Zicbom block in bytes.
diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index a63b994e0763..bcab59e0cc2e 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -224,6 +224,12 @@ properties:
as ratified at commit 4a69197e5617 ("Update to ratified state") of
riscv-svvptc.
+ - const: zaamo
+ description: |
+ The standard Zaamo extension for atomic memory operations as
+ ratified at commit e87412e621f1 ("integrate Zaamo and Zalrsc text
+ (#1304)") of the unprivileged ISA specification.
+
- const: zabha
description: |
The Zabha extension for Byte and Halfword Atomic Memory Operations
@@ -236,6 +242,12 @@ properties:
is supported as ratified at commit 5059e0ca641c ("update to
ratified") of the riscv-zacas.
+ - const: zalrsc
+ description: |
+ The standard Zalrsc extension for load-reserved/store-conditional as
+ ratified at commit e87412e621f1 ("integrate Zaamo and Zalrsc text
+ (#1304)") of the unprivileged ISA specification.
+
- const: zawrs
description: |
The Zawrs extension for entering a low-power state or for trapping
@@ -329,6 +341,12 @@ properties:
instructions, as ratified in commit 056b6ff ("Zfa is ratified") of
riscv-isa-manual.
+ - const: zfbfmin
+ description:
+ The standard Zfbfmin extension which provides minimal support for
+ 16-bit half-precision brain floating-point instructions, as ratified
+ in commit 4dc23d62 ("Added Chapter title to BF16") of riscv-isa-manual.
+
- const: zfh
description:
The standard Zfh extension for 16-bit half-precision binary
@@ -525,6 +543,18 @@ properties:
in commit 6f702a2 ("Vector extensions are now ratified") of
riscv-v-spec.
+ - const: zvfbfmin
+ description:
+ The standard Zvfbfmin extension for minimal support for vectored
+ 16-bit half-precision brain floating-point instructions, as ratified
+ in commit 4dc23d62 ("Added Chapter title to BF16") of riscv-isa-manual.
+
+ - const: zvfbfwma
+ description:
+ The standard Zvfbfwma extension for vectored half-precision brain
+ floating-point widening multiply-accumulate instructions, as ratified
+ in commit 4dc23d62 ("Added Chapter title to BF16") of riscv-isa-manual.
+
- const: zvfh
description:
The standard Zvfh extension for vectored half-precision
@@ -639,6 +669,12 @@ properties:
https://github.com/T-head-Semi/thead-extension-spec/blob/95358cb2cca9489361c61d335e03d3134b14133f/xtheadvector.adoc.
allOf:
+ - if:
+ contains:
+ const: d
+ then:
+ contains:
+ const: f
# Zcb depends on Zca
- if:
contains:
@@ -673,6 +709,119 @@ properties:
then:
contains:
const: zca
+ # Zfbfmin depends on F
+ - if:
+ contains:
+ const: zfbfmin
+ then:
+ contains:
+ const: f
+ # Zvfbfmin depends on V or Zve32f
+ - if:
+ contains:
+ const: zvfbfmin
+ then:
+ oneOf:
+ - contains:
+ const: v
+ - contains:
+ const: zve32f
+ # Zvfbfwma depends on Zfbfmin and Zvfbfmin
+ - if:
+ contains:
+ const: zvfbfwma
+ then:
+ allOf:
+ - contains:
+ const: zfbfmin
+ - contains:
+ const: zvfbfmin
+ # Zacas depends on Zaamo
+ - if:
+ contains:
+ const: zacas
+ then:
+ contains:
+ const: zaamo
+
+ - if:
+ contains:
+ const: zve32x
+ then:
+ contains:
+ const: zicsr
+
+ - if:
+ contains:
+ const: zve32f
+ then:
+ allOf:
+ - contains:
+ const: f
+ - contains:
+ const: zve32x
+
+ - if:
+ contains:
+ const: zve64x
+ then:
+ contains:
+ const: zve32x
+
+ - if:
+ contains:
+ const: zve64f
+ then:
+ allOf:
+ - contains:
+ const: f
+ - contains:
+ const: zve32f
+ - contains:
+ const: zve64x
+
+ - if:
+ contains:
+ const: zve64d
+ then:
+ allOf:
+ - contains:
+ const: d
+ - contains:
+ const: zve64f
+
+ - if:
+ contains:
+ anyOf:
+ - const: zvbc
+ - const: zvkn
+ - const: zvknc
+ - const: zvkng
+ - const: zvknhb
+ - const: zvksc
+ then:
+ contains:
+ anyOf:
+ - const: v
+ - const: zve64x
+
+ - if:
+ contains:
+ anyOf:
+ - const: zvbb
+ - const: zvkb
+ - const: zvkg
+ - const: zvkned
+ - const: zvknha
+ - const: zvksed
+ - const: zvksh
+ - const: zvks
+ - const: zvkt
+ then:
+ contains:
+ anyOf:
+ - const: v
+ - const: zve32x
allOf:
# Zcf extension does not exist on rv64
diff --git a/arch/riscv/Kbuild b/arch/riscv/Kbuild
index 2c585f7a0b6e..126fb738fc44 100644
--- a/arch/riscv/Kbuild
+++ b/arch/riscv/Kbuild
@@ -1,7 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-y += kernel/ mm/ net/
-obj-$(CONFIG_BUILTIN_DTB) += boot/dts/
obj-$(CONFIG_CRYPTO) += crypto/
obj-y += errata/
obj-$(CONFIG_KVM) += kvm/
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index e776fb35667e..1fd197afd2f7 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -65,6 +65,7 @@ config RISCV
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_CFI_CLANG
select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
+ select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
select ARCH_SUPPORTS_HUGETLBFS if MMU
# LLD >= 14: https://github.com/llvm/llvm-project/issues/50505
select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000
@@ -153,7 +154,7 @@ config RISCV
select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_GRAPH_FUNC
select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
- select HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS
select HAVE_FUNCTION_GRAPH_FREGS
select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
select HAVE_EBPF_JIT if MMU
@@ -205,6 +206,7 @@ config RISCV
select PCI_DOMAINS_GENERIC if PCI
select PCI_ECAM if (ACPI && PCI)
select PCI_MSI if PCI
+ select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED
select RISCV_ALTERNATIVE if !XIP_KERNEL
select RISCV_APLIC
select RISCV_IMSIC
@@ -292,13 +294,6 @@ config MMU
Select if you want MMU-based virtualised addressing space
support by paged memory management. If unsure, say 'Y'.
-config PAGE_OFFSET
- hex
- default 0x80000000 if !MMU && RISCV_M_MODE
- default 0x80200000 if !MMU
- default 0xc0000000 if 32BIT
- default 0xff60000000000000 if 64BIT
-
config KASAN_SHADOW_OFFSET
hex
depends on KASAN_GENERIC
@@ -570,7 +565,8 @@ config RISCV_ISA_C
help
Adds "C" to the ISA subsets that the toolchain is allowed to emit
when building Linux, which results in compressed instructions in the
- Linux binary.
+ Linux binary. This option produces a kernel that will not run on
+ systems that do not support compressed instructions.
If you don't know what to do here, say Y.
@@ -591,8 +587,8 @@ config RISCV_ISA_SVNAPOT
depends on RISCV_ALTERNATIVE
default y
help
- Allow kernel to detect the Svnapot ISA-extension dynamically at boot
- time and enable its usage.
+ Enable support for the Svnapot ISA-extension when it is detected
+ at boot.
The Svnapot extension is used to mark contiguous PTEs as a range
of contiguous virtual-to-physical translations for a naturally
@@ -610,9 +606,8 @@ config RISCV_ISA_SVPBMT
depends on RISCV_ALTERNATIVE
default y
help
- Adds support to dynamically detect the presence of the Svpbmt
- ISA-extension (Supervisor-mode: page-based memory types) and
- enable its usage.
+ Add support for the Svpbmt ISA-extension (Supervisor-mode:
+ page-based memory types) in the kernel when it is detected at boot.
The memory type for a page contains a combination of attributes
that indicate the cacheability, idempotency, and ordering
@@ -631,14 +626,15 @@ config TOOLCHAIN_HAS_V
depends on AS_HAS_OPTION_ARCH
config RISCV_ISA_V
- bool "VECTOR extension support"
+ 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.
+ Add support for the Vector extension when it is detected at boot.
+ When this option is disabled, neither the kernel nor userspace may
+ use vector procedures.
If you don't know what to do here, say Y.
@@ -737,6 +733,14 @@ config TOOLCHAIN_HAS_VECTOR_CRYPTO
def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
depends on AS_HAS_OPTION_ARCH
+config TOOLCHAIN_HAS_ZBA
+ bool
+ default y
+ depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba)
+ depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba)
+ depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
+ depends on AS_HAS_OPTION_ARCH
+
config RISCV_ISA_ZBA
bool "Zba extension support for bit manipulation instructions"
default y
@@ -751,12 +755,12 @@ config RISCV_ISA_ZBA
config RISCV_ISA_ZBB
bool "Zbb extension support for bit manipulation instructions"
- depends on TOOLCHAIN_HAS_ZBB
depends on RISCV_ALTERNATIVE
default y
help
- Adds support to dynamically detect the presence of the ZBB
- extension (basic bit manipulation) and enable its usage.
+ Add support for enabling optimisations in the kernel when the
+ Zbb extension is detected at boot. Some optimisations may
+ additionally depend on toolchain support for Zbb.
The Zbb extension provides instructions to accelerate a number
of bit-specific operations (count bit population, sign extending,
@@ -787,6 +791,28 @@ config RISCV_ISA_ZBC
If you don't know what to do here, say Y.
+config TOOLCHAIN_HAS_ZBKB
+ bool
+ default y
+ depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb)
+ depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb)
+ depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
+ depends on AS_HAS_OPTION_ARCH
+
+config RISCV_ISA_ZBKB
+ bool "Zbkb extension support for bit manipulation instructions"
+ depends on TOOLCHAIN_HAS_ZBKB
+ depends on RISCV_ALTERNATIVE
+ default y
+ help
+ Adds support to dynamically detect the presence of the ZBKB
+ extension (bit manipulation for cryptography) and enable its usage.
+
+ The Zbkb extension provides instructions to accelerate a number
+ of common cryptography operations (pack, zip, etc).
+
+ If you don't know what to do here, say Y.
+
config RISCV_ISA_ZICBOM
bool "Zicbom extension support for non-coherent DMA operation"
depends on MMU
@@ -795,9 +821,9 @@ config RISCV_ISA_ZICBOM
select RISCV_DMA_NONCOHERENT
select DMA_DIRECT_REMAP
help
- Adds support to dynamically detect the presence of the ZICBOM
- extension (Cache Block Management Operations) and enable its
- usage.
+ Add support for the Zicbom extension (Cache Block Management
+ Operations) and enable its use in the kernel when it is detected
+ at boot.
The Zicbom extension can be used to handle for example
non-coherent DMA support on devices that need it.
@@ -810,7 +836,7 @@ config RISCV_ISA_ZICBOZ
default y
help
Enable the use of the Zicboz extension (cbo.zero instruction)
- when available.
+ in the kernel when it is detected at boot.