Merge tag 'riscv-for-linus-6.5-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull more RISC-V updates from Palmer Dabbelt:

 - A bunch of fixes/cleanups from the first part of the merge window,
   mostly related to ACPI and vector as those were large

 - Some documentation improvements, mostly related to the new code

 - The "riscv,isa" DT key is deprecated

 - Support for link-time dead code elimination

 - Support for minor fault registration in userfaultd

 - A handful of cleanups around CMO alternatives

* tag 'riscv-for-linus-6.5-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (23 commits)
  riscv: mm: mark noncoherent_supported as __ro_after_init
  riscv: mm: mark CBO relate initialization funcs as __init
  riscv: errata: thead: only set cbom size & noncoherent during boot
  riscv: Select HAVE_ARCH_USERFAULTFD_MINOR
  RISC-V: Document the ISA string parsing rules for ACPI
  risc-v: Fix order of IPI enablement vs RCU startup
  mm: riscv: fix an unsafe pte read in huge_pte_alloc()
  dt-bindings: riscv: deprecate riscv,isa
  RISC-V: drop error print from riscv_hartid_to_cpuid()
  riscv: Discard vector state on syscalls
  riscv: move memblock_allow_resize() after linear mapping is ready
  riscv: Enable ARCH_SUSPEND_POSSIBLE for s2idle
  riscv: vdso: include vdso/vsyscall.h for vdso_data
  selftests: Test RISC-V Vector's first-use handler
  riscv: vector: clear V-reg in the first-use trap
  riscv: vector: only enable interrupts in the first-use trap
  RISC-V: Fix up some vector state related build failures
  RISC-V: Document that V registers are clobbered on syscalls
  riscv: disable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for LLD
  riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION
  ...

Documentation/devicetree/bindings/riscv/cpus.yaml

@@ -25,6 +25,7 @@ description: |
 
 allOf:
   - $ref: /schemas/cpu.yaml#
+  - $ref: extensions.yaml
 
 properties:
   compatible:
@@ -82,25 +83,6 @@ properties:
     description:
       The blocksize in bytes for the Zicboz cache operations.
 
-  riscv,isa:
-    description:
-      Identifies the specific RISC-V instruction set architecture
-      supported by the hart.  These are documented in the RISC-V
-      User-Level ISA document, available from
-      https://riscv.org/specifications/
-
-      Due to revisions of the ISA specification, some deviations
-      have arisen over time.
-      Notably, riscv,isa was defined prior to the creation of the
-      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.
-    $ref: /schemas/types.yaml#/definitions/string
-    pattern: ^rv(?:64|32)imaf?d?q?c?b?k?j?p?v?h?(?:[hsxz](?:[a-z])+)?(?:_[hsxz](?:[a-z])+)*$
-
   # RISC-V has multiple properties for cache op block sizes as the sizes
   # differ between individual CBO extensions
   cache-op-block-size: false
@@ -139,8 +121,17 @@ properties:
       DMIPS/MHz, relative to highest capacity-dmips-mhz
       in the system.
 
-required:
+anyOf:
+  - required:
       - riscv,isa
+  - required:
+      - riscv,isa-base
+
+dependencies:
+  riscv,isa-base: [ "riscv,isa-extensions" ]
+  riscv,isa-extensions: [ "riscv,isa-base" ]
+
+required:
   - interrupt-controller
 
 unevaluatedProperties: false
@@ -160,7 +151,9 @@ examples:
                 i-cache-sets = <128>;
                 i-cache-size = <16384>;
                 reg = <0>;
-                riscv,isa = "rv64imac";
+                riscv,isa-base = "rv64i";
+                riscv,isa-extensions = "i", "m", "a", "c";
+
                 cpu_intc0: interrupt-controller {
                         #interrupt-cells = <1>;
                         compatible = "riscv,cpu-intc";
@@ -183,8 +176,10 @@ examples:
                 i-tlb-size = <32>;
                 mmu-type = "riscv,sv39";
                 reg = <1>;
-                riscv,isa = "rv64imafdc";
                 tlb-split;
+                riscv,isa-base = "rv64i";
+                riscv,isa-extensions = "i", "m", "a", "f", "d", "c";
+
                 cpu_intc1: interrupt-controller {
                         #interrupt-cells = <1>;
                         compatible = "riscv,cpu-intc";
@@ -202,8 +197,10 @@ examples:
                 device_type = "cpu";
                 reg = <0>;
                 compatible = "riscv";
-                riscv,isa = "rv64imafdc";
                 mmu-type = "riscv,sv48";
+                riscv,isa-base = "rv64i";
+                riscv,isa-extensions = "i", "m", "a", "f", "d", "c";
+
                 interrupt-controller {
                         #interrupt-cells = <1>;
                         interrupt-controller;

Documentation/devicetree/bindings/riscv/extensions.yaml

@@ -0,0 +1,250 @@
+# SPDX-License-Identifier: (GPL-2.0 OR MIT)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/riscv/extensions.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V ISA extensions
+
+maintainers:
+  - Paul Walmsley <paul.walmsley@sifive.com>
+  - Palmer Dabbelt <palmer@sifive.com>
+  - Conor Dooley <conor@kernel.org>
+
+description: |
+  RISC-V has a large number of extensions, some of which are "standard"
+  extensions, meaning they are ratified by RISC-V International, and others
+  are "vendor" extensions.
+  This document defines properties that indicate whether a hart supports a
+  given extension.
+
+  Once a standard extension has been ratified, no changes in behaviour can be
+  made without the creation of a new extension.
+  The properties for standard extensions therefore map to their originally
+  ratified states, with the exception of the I, Zicntr & Zihpm extensions.
+  See the "i" property for more information.
+
+select:
+  properties:
+    compatible:
+      contains:
+        const: riscv
+
+properties:
+  riscv,isa:
+    description:
+      Identifies the specific RISC-V instruction set architecture
+      supported by the hart.  These are documented in the RISC-V
+      User-Level ISA document, available from
+      https://riscv.org/specifications/
+
+      Due to revisions of the ISA specification, some deviations
+      have arisen over time.
+      Notably, riscv,isa was defined prior to the creation of the
+      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.
+    $ref: /schemas/types.yaml#/definitions/string
+    pattern: ^rv(?:64|32)imaf?d?q?c?b?k?j?p?v?h?(?:[hsxz](?:[a-z])+)?(?:_[hsxz](?:[a-z])+)*$
+    deprecated: true
+
+  riscv,isa-base:
+    description:
+      The base ISA implemented by this hart, as described by the 20191213
+      version of the unprivileged ISA specification.
+    enum:
+      - rv32i
+      - rv64i
+
+  riscv,isa-extensions:
+    $ref: /schemas/types.yaml#/definitions/string-array
+    minItems: 1
+    description: Extensions supported by the hart.
+    items:
+      anyOf:
+        # single letter extensions, in canonical order
+        - const: i
+          description: |
+            The base integer instruction set, as ratified in the 20191213
+            version of the unprivileged ISA specification.
+
+            This does not include Chapter 10, "Counters", which was moved into
+            the Zicntr and Zihpm extensions after the ratification of the
+            20191213 version of the unprivileged specification.
+
+        - const: m
+          description:
+            The standard M extension for integer multiplication and division, as
+            ratified in the 20191213 version of the unprivileged ISA
+            specification.
+
+        - const: a
+          description:
+            The standard A extension for atomic instructions, as ratified in the
+            20191213 version of the unprivileged ISA specification.
+
+        - const: f
+          description:
+            The standard F extension for single-precision floating point, as
+            ratified in the 20191213 version of the unprivileged ISA
+            specification.
+
+        - const: d
+          description:
+            The standard D extension for double-precision floating-point, as
+            ratified in the 20191213 version of the unprivileged ISA
+            specification.
+
+        - const: q
+          description:
+            The standard Q extension for quad-precision floating-point, as
+            ratified in the 20191213 version of the unprivileged ISA
+            specification.
+
+        - const: c
+          description:
+            The standard C extension for compressed instructions, as ratified in
+            the 20191213 version of the unprivileged ISA specification.
+
+        - const: v
+          description:
+            The standard V extension for vector operations, as ratified
+            in-and-around commit 7a6c8ae ("Fix text that describes vfmv.v.f
+            encoding") of the riscv-v-spec.
+
+        - const: h
+          description:
+            The standard H extension for hypervisors as ratified in the 20191213
+            version of the privileged ISA specification.
+
+        # multi-letter extensions, sorted alphanumerically
+        - const: smaia
+          description: |
+            The standard Smaia supervisor-level extension for the advanced
+            interrupt architecture for machine-mode-visible csr and behavioural
+            changes to interrupts as frozen at commit ccbddab ("Merge pull
+            request #42 from riscv/jhauser-2023-RC4") of riscv-aia.
+
+        - const: ssaia
+          description: |
+            The standard Ssaia supervisor-level extension for the advanced
+            interrupt architecture for supervisor-mode-visible csr and
+            behavioural changes to interrupts as frozen at commit ccbddab
+            ("Merge pull request #42 from riscv/jhauser-2023-RC4") of riscv-aia.
+
+        - const: sscofpmf
+          description: |
+            The standard Sscofpmf supervisor-level extension for count overflow
+            and mode-based filtering as ratified at commit 01d1df0 ("Add ability
+            to manually trigger workflow. (#2)") of riscv-count-overflow.
+
+        - const: sstc
+          description: |
+            The standard Sstc supervisor-level extension for time compare as
+            ratified at commit 3f9ed34 ("Add ability to manually trigger
+            workflow. (#2)") of riscv-time-compare.
+
+        - const: svinval
+          description:
+            The standard Svinval supervisor-level extension for fine-grained
+            address-translation cache invalidation as ratified in the 20191213
+            version of the privileged ISA specification.
+
+        - const: svnapot
+          description:
+            The standard Svnapot supervisor-level extensions for napot
+            translation contiguity as ratified in the 20191213 version of the
+            privileged ISA specification.
+
+        - const: svpbmt
+          description:
+            The standard Svpbmt supervisor-level extensions for page-based
+            memory types as ratified in the 20191213 version of the privileged
+            ISA specification.
+
+        - const: zba
+          description: |
+            The standard Zba bit-manipulation extension for address generation
+            acceleration instructions as ratified at commit 6d33919 ("Merge pull
+            request #158 from hirooih/clmul-fix-loop-end-condition") of
+            riscv-bitmanip.
+
+        - const: zbb
+          description: |
+            The standard Zbb bit-manipulation extension for basic bit-manipulation
+            as ratified at commit 6d33919 ("Merge pull request #158 from
+            hirooih/clmul-fix-loop-end-condition") of riscv-bitmanip.
+
+        - const: zbc
+          description: |
+            The standard Zbc bit-manipulation extension for carry-less
+            multiplication as ratified at commit 6d33919 ("Merge pull request
+            #158 from hirooih/clmul-fix-loop-end-condition") of riscv-bitmanip.
+
+        - const: zbs
+          description: |
+            The standard Zbs bit-manipulation extension for single-bit
+            instructions as ratified at commit 6d33919 ("Merge pull request #158
+            from hirooih/clmul-fix-loop-end-condition") of riscv-bitmanip.
+
+        - const: zicbom
+          description:
+            The standard Zicbom extension for base cache management operations as
+            ratified in commit 3dd606f ("Create cmobase-v1.0.pdf") of riscv-CMOs.
+
+        - const: zicbop
+          description:
+            The standard Zicbop extension for cache-block prefetch instructions
+            as ratified in commit 3dd606f ("Create cmobase-v1.0.pdf") of
+            riscv-CMOs.
+
+        - const: zicboz
+          description:
+            The standard Zicboz extension for cache-block zeroing as ratified
+            in commit 3dd606f ("Create cmobase-v1.0.pdf") of riscv-CMOs.
+
+        - const: zicntr
+          description:
+            The standard Zicntr extension for base counters and timers, as
+            ratified in the 20191213 version of the unprivileged ISA
+            specification.
+
+        - const: zicsr
+          description: |
+            The standard Zicsr extension for control and status register
+            instructions, as ratified in the 20191213 version of the
+            unprivileged ISA specification.
+
+            This does not include Chapter 10, "Counters", which documents
+            special case read-only CSRs, that were moved into the Zicntr and
+            Zihpm extensions after the ratification of the 20191213 version of
+            the unprivileged specification.
+
+        - const: zifencei
+          description:
+            The standard Zifencei extension for instruction-fetch fence, as
+            ratified in the 20191213 version of the unprivileged ISA
+            specification.
+
+        - const: zihintpause
+          description:
+            The standard Zihintpause extension for pause hints, as ratified in
+            commit d8ab5c7 ("Zihintpause is ratified") of the riscv-isa-manual.
+
+        - const: zihpm
+          description:
+            The standard Zihpm extension for hardware performance counters, as
+            ratified in the 20191213 version of the unprivileged ISA
+            specification.
+
+        - const: ztso
+          description:
+            The standard Ztso extension for total store ordering, as ratified
+            in commit 2e5236 ("Ztso is now ratified.") of the
+            riscv-isa-manual.
+
+additionalProperties: true
+...

Documentation/riscv/acpi.rst

@@ -0,0 +1,10 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============
+ACPI on RISC-V
+==============
+
+The ISA string parsing rules for ACPI are defined by `Version ASCIIDOC
+Conversion, 12/2022 of the RISC-V specifications, as defined by tag
+"riscv-isa-release-1239329-2023-05-23" (commit 1239329
+) <https://github.com/riscv/riscv-isa-manual/releases/tag/riscv-isa-release-1239329-2023-05-23>`_

Documentation/riscv/index.rst

@@ -5,6 +5,7 @@ RISC-V architecture
 .. toctree::
     :maxdepth: 1
 
+    acpi
     boot-image-header
     vm-layout
     hwprobe

Documentation/riscv/vector.rst

@@ -130,3 +130,11 @@ processes in form of sysctl knob:
 
     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.
+
+3.  Vector Register State Across System Calls
+---------------------------------------------
+
+As indicated by version 1.0 of the V extension [1], vector registers are
+clobbered by system calls.
+
+1: https://github.com/riscv/riscv-v-spec/blob/master/calling-convention.adoc

arch/riscv/Kconfig

@@ -100,11 +100,18 @@ config RISCV
 	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
+	select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD
 	select HAVE_ARCH_VMAP_STACK if MMU && 64BIT
 	select HAVE_ASM_MODVERSIONS
 	select HAVE_CONTEXT_TRACKING_USER
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DMA_CONTIGUOUS if MMU
+	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
+	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
+	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
+	select HAVE_FUNCTION_GRAPH_TRACER
+	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
+	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
 	select HAVE_EBPF_JIT if MMU
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select HAVE_FUNCTION_ERROR_INJECTION
@@ -114,7 +121,8 @@ config RISCV
 	select HAVE_KPROBES if !XIP_KERNEL
 	select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
 	select HAVE_KRETPROBES if !XIP_KERNEL
-	select HAVE_RETHOOK if !XIP_KERNEL
+	# https://github.com/ClangBuiltLinux/linux/issues/1881
+	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
 	select HAVE_MOVE_PMD
 	select HAVE_MOVE_PUD
 	select HAVE_PCI
@@ -123,6 +131,7 @@ config RISCV
 	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
 	select HAVE_REGS_AND_STACK_ACCESS_API
+	select HAVE_RETHOOK if !XIP_KERNEL
 	select HAVE_RSEQ
 	select HAVE_STACKPROTECTOR
 	select HAVE_SYSCALL_TRACEPOINTS
@@ -148,12 +157,6 @@ config RISCV
 	select TRACE_IRQFLAGS_SUPPORT
 	select UACCESS_MEMCPY if !MMU
 	select ZONE_DMA32 if 64BIT
-	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
-	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
-	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
-	select HAVE_FUNCTION_GRAPH_TRACER
-	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
-	select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
 
 config CLANG_SUPPORTS_DYNAMIC_FTRACE
 	def_bool CC_IS_CLANG
@@ -872,6 +875,9 @@ config ARCH_HIBERNATION_POSSIBLE
 config ARCH_HIBERNATION_HEADER
 	def_bool HIBERNATION
 
+config ARCH_SUSPEND_POSSIBLE
+	def_bool y
+
 endmenu # "Power management options"
 
 menu "CPU Power Management"

arch/riscv/errata/thead/errata.c

@@ -45,8 +45,11 @@ static bool errata_probe_cmo(unsigned int stage,
 	if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
 		return false;
 
+	if (stage == RISCV_ALTERNATIVES_BOOT) {
 		riscv_cbom_block_size = L1_CACHE_BYTES;
 		riscv_noncoherent_supported();
+	}
+
 	return true;
 }
 

arch/riscv/include/asm/vector.h

@@ -33,6 +33,11 @@ static inline void __riscv_v_vstate_clean(struct pt_regs *regs)
 	regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN;
 }
 
+static inline void __riscv_v_vstate_dirty(struct pt_regs *regs)
+{
+	regs->status = (regs->status & ~SR_VS) | SR_VS_DIRTY;
+}
+
 static inline void riscv_v_vstate_off(struct pt_regs *regs)
 {
 	regs->status = (regs->status & ~SR_VS) | SR_VS_OFF;
@@ -128,6 +133,34 @@ static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_
 	riscv_v_disable();
 }
 
+static inline void __riscv_v_vstate_discard(void)
+{
+	unsigned long vl, vtype_inval = 1UL << (BITS_PER_LONG - 1);
+
+	riscv_v_enable();
+	asm volatile (
+		".option push\n\t"
+		".option arch, +v\n\t"
+		"vsetvli	%0, x0, e8, m8, ta, ma\n\t"
+		"vmv.v.i	v0, -1\n\t"
+		"vmv.v.i	v8, -1\n\t"
+		"vmv.v.i	v16, -1\n\t"
+		"vmv.v.i	v24, -1\n\t"
+		"vsetvl		%0, x0, %1\n\t"
+		".option pop\n\t"
+		: "=&r" (vl) : "r" (vtype_inval) : "memory");
+	riscv_v_disable();
+}
+
+static inline void riscv_v_vstate_discard(struct pt_regs *regs)
+{
+	if ((regs->status & SR_VS) == SR_VS_OFF)
+		return;
+
+	__riscv_v_vstate_discard();
+	__riscv_v_vstate_dirty(regs);
+}
+
 static inline void riscv_v_vstate_save(struct task_struct *task,
 				       struct pt_regs *regs)
 {
@@ -173,6 +206,7 @@ static inline bool riscv_v_first_use_handler(struct pt_regs *regs) { return fals
 static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; }
 static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; }
 #define riscv_v_vsize (0)
+#define riscv_v_vstate_discard(regs)		do {} while (0)
 #define riscv_v_vstate_save(task, regs)		do {} while (0)
 #define riscv_v_vstate_restore(task, regs)	do {} while (0)
 #define __switch_to_vector(__prev, __next)	do {} while (0)

arch/riscv/include/uapi/asm/sigcontext.h

@@ -15,6 +15,8 @@
 /* The size of END signal context header. */
 #define END_HDR_SIZE	0x0
 
+#ifndef __ASSEMBLY__
+
 struct __sc_riscv_v_state {
 	struct __riscv_v_ext_state v_state;
 } __attribute__((aligned(16)));
@@ -33,4 +35,6 @@ struct sigcontext {
 	};
 };
 
+#endif /*!__ASSEMBLY__*/
+
 #endif /* _UAPI_ASM_RISCV_SIGCONTEXT_H */

arch/riscv/kernel/smp.c

@@ -58,7 +58,6 @@ int riscv_hartid_to_cpuid(unsigned long hartid)
 		if (cpuid_to_hartid_map(i) == hartid)
 			return i;
 
-	pr_err("Couldn't find cpu id for hartid [%lu]\n", hartid);
 	return -ENOENT;
 }
 

arch/riscv/kernel/smpboot.c

@@ -238,10 +238,11 @@ asmlinkage __visible void smp_callin(void)
 	mmgrab(mm);
 	current->active_mm = mm;
 
-	riscv_ipi_enable();
-
 	store_cpu_topology(curr_cpuid);
 	notify_cpu_starting(curr_cpuid);
+
+	riscv_ipi_enable();
+
 	numa_add_cpu(curr_cpuid);
 	set_cpu_online(curr_cpuid, 1);
 	probe_vendor_features(curr_cpuid);

arch/riscv/kernel/traps.c

@@ -150,12 +150,18 @@ DO_ERROR_INFO(do_trap_insn_fault,
 
 asmlinkage __visible __trap_section void do_trap_insn_illegal(struct pt_regs *regs)
 {
+	bool handled;
+
 	if (user_mode(regs)) {
 		irqentry_enter_from_user_mode(regs);
 
 		local_irq_enable();
 
-		if (!riscv_v_first_use_handler(regs))
+		handled = riscv_v_first_use_handler(regs);
+
+		local_irq_disable();
+
+		if (!handled)
 			do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->epc,
 				      "Oops - illegal instruction");
 
@@ -296,6 +302,8 @@ asmlinkage __visible __trap_section void do_trap_ecall_u(struct pt_regs *regs)
 		regs->epc += 4;
 		regs->orig_a0 = regs->a0;
 
+		riscv_v_vstate_discard(regs);
+
 		syscall = syscall_enter_from_user_mode(regs, syscall);
 
 		if (syscall < NR_syscalls)

arch/riscv/kernel/vdso.c

@@ -15,6 +15,7 @@
 #include <asm/vdso.h>
 #include <linux/time_namespace.h>
 #include <vdso/datapage.h>
+#include <vdso/vsyscall.h>
 
 enum vvar_pages {
 	VVAR_DATA_PAGE_OFFSET,

arch/riscv/kernel/vector.c

@@ -167,6 +167,7 @@ bool riscv_v_first_use_handler(struct pt_regs *regs)
 		return true;
 	}
 	riscv_v_vstate_on(regs);
+	riscv_v_vstate_restore(current, regs);
 	return true;
 }
 

arch/riscv/kernel/vmlinux-xip.lds.S

@@ -98,12 +98,6 @@ SECTIONS
 		__soc_builtin_dtb_table_end = .;
 	}
 
-	. = ALIGN(8);
-	.alternative : {
-		__alt_start = .;
-		*(.alternative)
-		__alt_end = .;
-	}
 	__init_end = .;
 
 	. = ALIGN(16);

arch/riscv/kernel/vmlinux.lds.S

@@ -85,11 +85,11 @@ SECTIONS
 	INIT_DATA_SECTION(16)
 
 	.init.pi : {
-		*(.init.pi*)
+		KEEP(*(.init.pi*))
 	}
 
 	.init.bss : {
-		*(.init.bss)	/* from the EFI stub */
+		KEEP(*(.init.bss*))	/* from the EFI stub */
 	}
 	.exit.data :
 	{
@@ -112,7 +112,7 @@ SECTIONS
 	. = ALIGN(8);
 	.alternative : {
 		__alt_start = .;
-		*(.alternative)
+		KEEP(*(.alternative))
 		__alt_end = .;
 	}
 	__init_end = .;

arch/riscv/mm/cacheflush.c

@@ -104,7 +104,7 @@ EXPORT_SYMBOL_GPL(riscv_cbom_block_size);
 unsigned int riscv_cboz_block_size;
 EXPORT_SYMBOL_GPL(riscv_cboz_block_size);
 
-static void cbo_get_block_size(struct device_node *node,
+static void __init cbo_get_block_size(struct device_node *node,
 				      const char *name, u32 *block_size,
 				      unsigned long *first_hartid)
 {
@@ -126,7 +126,7 @@ static void cbo_get_block_size(struct device_node *node,
 	}
 }
 
-void riscv_init_cbo_blocksizes(void)
+void __init riscv_init_cbo_blocksizes(void)
 {
 	unsigned long cbom_hartid, cboz_hartid;
 	u32 cbom_block_size = 0, cboz_block_size = 0;

arch/riscv/mm/dma-noncoherent.c

@@ -10,7 +10,7 @@
 #include <linux/mm.h>
 #include <asm/cacheflush.h>
 
-static bool noncoherent_supported;
+static bool noncoherent_supported __ro_after_init;
 
 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
 			      enum dma_data_direction dir)

arch/riscv/mm/hugetlbpage.c

@@ -73,7 +73,11 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
 	}
 
 out:
-	WARN_ON_ONCE(pte && pte_present(*pte) && !pte_huge(*pte));
+	if (pte) {
+		pte_t pteval = ptep_get_lockless(pte);
+
+		WARN_ON_ONCE(pte_present(pteval) && !pte_huge(pteval));
+	}
 	return pte;
 }
 

arch/riscv/mm/init.c

@@ -267,7 +267,6 @@ static void __init setup_bootmem(void)
 	dma_contiguous_reserve(dma32_phys_limit);
 	if (IS_ENABLED(CONFIG_64BIT))
 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
-	memblock_allow_resize();
 }
 
 #ifdef CONFIG_MMU
@@ -1370,6 +1369,9 @@ void __init paging_init(void)
 {
 	setup_bootmem();
 	setup_vm_final();
+
+	/* Depend on that Linear Mapping is ready */
+	memblock_allow_resize();
 }
 
 void __init misc_mem_init(void)

include/asm-generic/vmlinux.lds.h

@@ -688,7 +688,7 @@
 /* init and exit section handling */
 #define INIT_DATA							\
 	KEEP(*(SORT(___kentry+*)))					\
-	*(.init.data init.data.*)					\
+	*(.init.data .init.data.*)					\
 	MEM_DISCARD(init.data*)						\
 	KERNEL_CTORS()							\
 	MCOUNT_REC()							\

tools/testing/selftests/riscv/vector/.gitignore

@@ -1,2 +1,3 @@
 vstate_exec_nolibc
 vstate_prctl
+v_initval_nolibc

tools/testing/selftests/riscv/vector/Makefile

@@ -2,7 +2,7 @@
 # Copyright (C) 2021 ARM Limited
 # Originally tools/testing/arm64/abi/Makefile
 
-TEST_GEN_PROGS := vstate_prctl
+TEST_GEN_PROGS := vstate_prctl v_initval_nolibc
 TEST_GEN_PROGS_EXTENDED := vstate_exec_nolibc
 
 include ../../lib.mk
@@ -13,3 +13,7 @@ $(OUTPUT)/vstate_prctl: vstate_prctl.c ../hwprobe/sys_hwprobe.S
 $(OUTPUT)/vstate_exec_nolibc: vstate_exec_nolibc.c
 	$(CC) -nostdlib -static -include ../../../../include/nolibc/nolibc.h \
 		-Wall $(CFLAGS) $(LDFLAGS) $^ -o $@ -lgcc
+
+$(OUTPUT)/v_initval_nolibc: v_initval_nolibc.c
+	$(CC) -nostdlib -static -include ../../../../include/nolibc/nolibc.h \
+		-Wall $(CFLAGS) $(LDFLAGS) $^ -o $@ -lgcc

tools/testing/selftests/riscv/vector/v_initval_nolibc.c

@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "../../kselftest.h"
+#define MAX_VSIZE	(8192 * 32)
+
+void dump(char *ptr, int size)
+{
+	int i = 0;
+
+	for (i = 0; i < size; i++) {
+		if (i != 0) {
+			if (i % 16 == 0)
+				printf("\n");
+			else if (i % 8 == 0)
+				printf("  ");
+		}
+		printf("%02x ", ptr[i]);
+	}
+	printf("\n");
+}
+
+int main(void)
+{
+	int i;
+	unsigned long vl;
+	char *datap, *tmp;
+
+	datap = malloc(MAX_VSIZE);
+	if (!datap) {
+		ksft_test_result_fail("fail to allocate memory for size = %lu\n", MAX_VSIZE);
+		exit(-1);
+	}
+
+	tmp = datap;
+	asm volatile (
+		".option push\n\t"
+		".option arch, +v\n\t"
+		"vsetvli	%0, x0, e8, m8, ta, ma\n\t"
+		"vse8.v		v0, (%2)\n\t"
+		"add		%1, %2, %0\n\t"
+		"vse8.v		v8, (%1)\n\t"
+		"add		%1, %1, %0\n\t"
+		"vse8.v		v16, (%1)\n\t"
+		"add		%1, %1, %0\n\t"
+		"vse8.v		v24, (%1)\n\t"
+		".option pop\n\t"
+		: "=&r" (vl), "=r" (tmp) : "r" (datap) : "memory");
+
+	ksft_print_msg("vl = %lu\n", vl);
+
+	if (datap[0] != 0x00 && datap[0] != 0xff) {
+		ksft_test_result_fail("v-regesters are not properly initialized\n");
+		dump(datap, vl * 4);
+		exit(-1);
+	}
+
+	for (i = 1; i < vl * 4; i++) {
+		if (datap[i] != datap[0]) {
+			ksft_test_result_fail("detect stale values on v-regesters\n");
+			dump(datap, vl * 4);
+			exit(-2);
+		}
+	}
+
+	free(datap);
+	ksft_exit_pass();
+	return 0;
+}