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
  ...

1 files changed, 19 insertions, 0 deletions

diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
index 7594df37cc9f..94e33216b2d9 100644
--- a/arch/riscv/include/asm/switch_to.h
+++ b/arch/riscv/include/asm/switch_to.h
@@ -70,6 +70,24 @@ static __always_inline bool has_fpu(void) { return false; }
 #define __switch_to_fpu(__prev, __next) do { } while (0)
 #endif
 
+static inline void envcfg_update_bits(struct task_struct *task,
+				      unsigned long mask, unsigned long val)
+{
+	unsigned long envcfg;
+
+	envcfg = (task->thread.envcfg & ~mask) | val;
+	task->thread.envcfg = envcfg;
+	if (task == current)
+		csr_write(CSR_ENVCFG, envcfg);
+}
+
+static inline void __switch_to_envcfg(struct task_struct *next)
+{
+	asm volatile (ALTERNATIVE("nop", "csrw " __stringify(CSR_ENVCFG) ", %0",
+				  0, RISCV_ISA_EXT_XLINUXENVCFG, 1)
+			:: "r" (next->thread.envcfg) : "memory");
+}
+
 extern struct task_struct *__switch_to(struct task_struct *,
 				       struct task_struct *);
 
@@ -103,6 +121,7 @@ do {							\
 		__switch_to_vector(__prev, __next);	\
 	if (switch_to_should_flush_icache(__next))	\
 		local_flush_icache_all();		\
+	__switch_to_envcfg(__next);			\
 	((last) = __switch_to(__prev, __next));		\
 } while (0)