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authorLinus Torvalds <torvalds@linux-foundation.org>2024-11-27 11:19:09 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-11-27 11:19:09 -0800
commit91dbbe6c9ffe5eded9a3e75d773ff92da8d2bc57 (patch)
tree30c98b08c3906a35d34327eff7725618c9045588 /arch/riscv/Kconfig
parentc94696977527f69cbb41aa6a9af9d1991895d002 (diff)
parent8d4f1e05ff821a5d59116ab8c3a30fcae81d8597 (diff)
downloadlwn-91dbbe6c9ffe5eded9a3e75d773ff92da8d2bc57.tar.gz
lwn-91dbbe6c9ffe5eded9a3e75d773ff92da8d2bc57.zip
Merge tag 'riscv-for-linus-6.13-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-v updates from Palmer Dabbelt: - Support for pointer masking in userspace - Support for probing vector misaligned access performance - Support for qspinlock on systems with Zacas and Zabha * tag 'riscv-for-linus-6.13-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (38 commits) RISC-V: Remove unnecessary include from compat.h riscv: Fix default misaligned access trap riscv: Add qspinlock support dt-bindings: riscv: Add Ziccrse ISA extension description riscv: Add ISA extension parsing for Ziccrse asm-generic: ticket-lock: Add separate ticket-lock.h asm-generic: ticket-lock: Reuse arch_spinlock_t of qspinlock riscv: Implement xchg8/16() using Zabha riscv: Implement arch_cmpxchg128() using Zacas riscv: Improve zacas fully-ordered cmpxchg() riscv: Implement cmpxchg8/16() using Zabha dt-bindings: riscv: Add Zabha ISA extension description riscv: Implement cmpxchg32/64() using Zacas riscv: Do not fail to build on byte/halfword operations with Zawrs riscv: Move cpufeature.h macros into their own header KVM: riscv: selftests: Add Smnpm and Ssnpm to get-reg-list test RISC-V: KVM: Allow Smnpm and Ssnpm extensions for guests riscv: hwprobe: Export the Supm ISA extension riscv: selftests: Add a pointer masking test riscv: Allow ptrace control of the tagged address ABI ...
Diffstat (limited to 'arch/riscv/Kconfig')
-rw-r--r--arch/riscv/Kconfig138
1 files changed, 136 insertions, 2 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index ff1e353b0d6f..cc63aef41e94 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -83,6 +83,7 @@ config RISCV
select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
select ARCH_WANTS_NO_INSTR
select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS
select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU
select BUILDTIME_TABLE_SORT if MMU
select CLINT_TIMER if RISCV_M_MODE
@@ -116,6 +117,7 @@ config RISCV
select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO
select HARDIRQS_SW_RESEND
select HAS_IOPORT if MMU
+ select HAVE_ALIGNED_STRUCT_PAGE
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT
@@ -507,6 +509,39 @@ config NODES_SHIFT
Specify the maximum number of NUMA Nodes available on the target
system. Increases memory reserved to accommodate various tables.
+choice
+ prompt "RISC-V spinlock type"
+ default RISCV_COMBO_SPINLOCKS
+
+config RISCV_TICKET_SPINLOCKS
+ bool "Using ticket spinlock"
+
+config RISCV_QUEUED_SPINLOCKS
+ bool "Using queued spinlock"
+ depends on SMP && MMU && NONPORTABLE
+ select ARCH_USE_QUEUED_SPINLOCKS
+ help
+ The queued spinlock implementation requires the forward progress
+ guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or
+ LR/SC with Ziccrse provide such guarantee.
+
+ Select this if and only if Zabha or Ziccrse is available on your
+ platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms
+ without one of those extensions.
+
+ If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks
+ when supported and otherwise ticket spinlocks.
+
+config RISCV_COMBO_SPINLOCKS
+ bool "Using combo spinlock"
+ depends on SMP && MMU
+ select ARCH_USE_QUEUED_SPINLOCKS
+ help
+ Embed both queued spinlock and ticket lock so that the spinlock
+ implementation can be chosen at runtime.
+
+endchoice
+
config RISCV_ALTERNATIVE
bool
depends on !XIP_KERNEL
@@ -532,6 +567,17 @@ config RISCV_ISA_C
If you don't know what to do here, say Y.
+config RISCV_ISA_SUPM
+ bool "Supm extension for userspace pointer masking"
+ depends on 64BIT
+ default y
+ help
+ Add support for pointer masking in userspace (Supm) when the
+ underlying hardware extension (Smnpm or Ssnpm) is detected at boot.
+
+ If this option is disabled, userspace will be unable to use
+ the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API.
+
config RISCV_ISA_SVNAPOT
bool "Svnapot extension support for supervisor mode NAPOT pages"
depends on 64BIT && MMU
@@ -633,6 +679,40 @@ config RISCV_ISA_ZAWRS
use of these instructions in the kernel when the Zawrs extension is
detected at boot.
+config TOOLCHAIN_HAS_ZABHA
+ bool
+ default y
+ depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha)
+ depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha)
+ depends on AS_HAS_OPTION_ARCH
+
+config RISCV_ISA_ZABHA
+ bool "Zabha extension support for atomic byte/halfword operations"
+ depends on TOOLCHAIN_HAS_ZABHA
+ depends on RISCV_ALTERNATIVE
+ default y
+ help
+ Enable the use of the Zabha ISA-extension to implement kernel
+ byte/halfword atomic memory operations when it is detected at boot.
+
+ If you don't know what to do here, say Y.
+
+config TOOLCHAIN_HAS_ZACAS
+ bool
+ default y
+ depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas)
+ depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas)
+ depends on AS_HAS_OPTION_ARCH
+
+config RISCV_ISA_ZACAS
+ bool "Zacas extension support for atomic CAS"
+ depends on TOOLCHAIN_HAS_ZACAS
+ depends on RISCV_ALTERNATIVE
+ default y
+ help
+ Enable the use of the Zacas ISA-extension to implement kernel atomic
+ cmpxchg operations when it is detected at boot.
+
If you don't know what to do here, say Y.
config TOOLCHAIN_HAS_ZBB
@@ -786,10 +866,24 @@ config THREAD_SIZE_ORDER
config RISCV_MISALIGNED
bool
+ help
+ Embed support for detecting and emulating misaligned
+ scalar or vector loads and stores.
+
+config RISCV_SCALAR_MISALIGNED
+ bool
+ select RISCV_MISALIGNED
select SYSCTL_ARCH_UNALIGN_ALLOW
help
Embed support for emulating misaligned loads and stores.
+config RISCV_VECTOR_MISALIGNED
+ bool
+ select RISCV_MISALIGNED
+ depends on RISCV_ISA_V
+ help
+ Enable detecting support for vector misaligned loads and stores.
+
choice
prompt "Unaligned Accesses Support"
default RISCV_PROBE_UNALIGNED_ACCESS
@@ -801,7 +895,7 @@ choice
config RISCV_PROBE_UNALIGNED_ACCESS
bool "Probe for hardware unaligned access support"
- select RISCV_MISALIGNED
+ select RISCV_SCALAR_MISALIGNED
help
During boot, the kernel will run a series of tests to determine the
speed of unaligned accesses. This probing will dynamically determine
@@ -812,7 +906,7 @@ config RISCV_PROBE_UNALIGNED_ACCESS
config RISCV_EMULATED_UNALIGNED_ACCESS
bool "Emulate unaligned access where system support is missing"
- select RISCV_MISALIGNED
+ select RISCV_SCALAR_MISALIGNED
help
If unaligned memory accesses trap into the kernel as they are not
supported by the system, the kernel will emulate the unaligned
@@ -841,6 +935,46 @@ config RISCV_EFFICIENT_UNALIGNED_ACCESS
endchoice
+choice
+ prompt "Vector unaligned Accesses Support"
+ depends on RISCV_ISA_V
+ default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
+ help
+ This determines the level of support for vector unaligned accesses. This
+ information is used by the kernel to perform optimizations. It is also
+ exposed to user space via the hwprobe syscall. The hardware will be
+ probed at boot by default.
+
+config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
+ bool "Probe speed of vector unaligned accesses"
+ select RISCV_VECTOR_MISALIGNED
+ depends on RISCV_ISA_V
+ help
+ During boot, the kernel will run a series of tests to determine the
+ speed of vector unaligned accesses if they are supported. This probing
+ will dynamically determine the speed of vector unaligned accesses on
+ the underlying system if they are supported.
+
+config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS
+ bool "Assume the system supports slow vector unaligned memory accesses"
+ depends on NONPORTABLE
+ help
+ Assume that the system supports slow vector unaligned memory accesses. The
+ kernel and userspace programs may not be able to run at all on systems
+ that do not support unaligned memory accesses.
+
+config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS
+ bool "Assume the system supports fast vector unaligned memory accesses"
+ depends on NONPORTABLE
+ help
+ Assume that the system supports fast vector unaligned memory accesses. When
+ enabled, this option improves the performance of the kernel on such
+ systems. However, the kernel and userspace programs will run much more
+ slowly, or will not be able to run at all, on systems that do not
+ support efficient unaligned memory accesses.
+
+endchoice
+
source "arch/riscv/Kconfig.vendor"
endmenu # "Platform type"