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
  ...

2 files changed, 38 insertions, 0 deletions

diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
index 04c0b07bf6cd..3d78930cab51 100644
--- a/arch/riscv/include/asm/vector.h
+++ b/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)
diff --git a/arch/riscv/include/uapi/asm/sigcontext.h b/arch/riscv/include/uapi/asm/sigcontext.h
index 8b8a8541673a..8c8712aa9551 100644
--- a/arch/riscv/include/uapi/asm/sigcontext.h
+++ b/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 */