Merge branch 'x86/hyperv' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Topic branch for stable KVM clockource under Hyper-V.

Thanks to Christoffer Dall for resolving the ARM conflict.

12 files changed, 56 insertions, 64 deletions

diff --git a/arch/riscv/include/asm/barrier.h b/arch/riscv/include/asm/barrier.h
index 773c4e039cd7..c0319cbf1eec 100644
--- a/arch/riscv/include/asm/barrier.h
+++ b/arch/riscv/include/asm/barrier.h
@@ -38,6 +38,25 @@
 #define smp_rmb()	RISCV_FENCE(r,r)
 #define smp_wmb()	RISCV_FENCE(w,w)
 
+/*
+ * This is a very specific barrier: it's currently only used in two places in
+ * the kernel, both in the scheduler.  See include/linux/spinlock.h for the two
+ * orderings it guarantees, but the "critical section is RCsc" guarantee
+ * mandates a barrier on RISC-V.  The sequence looks like:
+ *
+ *    lr.aq lock
+ *    sc    lock <= LOCKED
+ *    smp_mb__after_spinlock()
+ *    // critical section
+ *    lr    lock
+ *    sc.rl lock <= UNLOCKED
+ *
+ * The AQ/RL pair provides a RCpc critical section, but there's not really any
+ * way we can take advantage of that here because the ordering is only enforced
+ * on that one lock.  Thus, we're just doing a full fence.
+ */
+#define smp_mb__after_spinlock()	RISCV_FENCE(rw,rw)
+
 #include <asm-generic/barrier.h>
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 0d64bc9f4f91..3c7a2c97e377 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -17,10 +17,10 @@
 #include <linux/const.h>
 
 /* Status register flags */
-#define SR_IE   _AC(0x00000002, UL) /* Interrupt Enable */
-#define SR_PIE  _AC(0x00000020, UL) /* Previous IE */
-#define SR_PS   _AC(0x00000100, UL) /* Previously Supervisor */
-#define SR_SUM  _AC(0x00040000, UL) /* Supervisor may access User Memory */
+#define SR_SIE	_AC(0x00000002, UL) /* Supervisor Interrupt Enable */
+#define SR_SPIE	_AC(0x00000020, UL) /* Previous Supervisor IE */
+#define SR_SPP	_AC(0x00000100, UL) /* Previously Supervisor */
+#define SR_SUM	_AC(0x00040000, UL) /* Supervisor may access User Memory */
 
 #define SR_FS           _AC(0x00006000, UL) /* Floating-point Status */
 #define SR_FS_OFF       _AC(0x00000000, UL)
diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h
index a82ce599b639..b269451e7e85 100644
--- a/arch/riscv/include/asm/io.h
+++ b/arch/riscv/include/asm/io.h
@@ -21,8 +21,6 @@
 
 #include <linux/types.h>
 
-#ifdef CONFIG_MMU
-
 extern void __iomem *ioremap(phys_addr_t offset, unsigned long size);
 
 /*
@@ -36,8 +34,6 @@ extern void __iomem *ioremap(phys_addr_t offset, unsigned long size);
 
 extern void iounmap(volatile void __iomem *addr);
 
-#endif /* CONFIG_MMU */
-
 /* Generic IO read/write.  These perform native-endian accesses. */
 #define __raw_writeb __raw_writeb
 static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
diff --git a/arch/riscv/include/asm/irqflags.h b/arch/riscv/include/asm/irqflags.h
index 6fdc860d7f84..07a3c6d5706f 100644
--- a/arch/riscv/include/asm/irqflags.h
+++ b/arch/riscv/include/asm/irqflags.h
@@ -27,25 +27,25 @@ static inline unsigned long arch_local_save_flags(void)
 /* unconditionally enable interrupts */
 static inline void arch_local_irq_enable(void)
 {
-	csr_set(sstatus, SR_IE);
+	csr_set(sstatus, SR_SIE);
 }
 
 /* unconditionally disable interrupts */
 static inline void arch_local_irq_disable(void)
 {
-	csr_clear(sstatus, SR_IE);
+	csr_clear(sstatus, SR_SIE);
 }
 
 /* get status and disable interrupts */
 static inline unsigned long arch_local_irq_save(void)
 {
-	return csr_read_clear(sstatus, SR_IE);
+	return csr_read_clear(sstatus, SR_SIE);
 }
 
 /* test flags */
 static inline int arch_irqs_disabled_flags(unsigned long flags)
 {
-	return !(flags & SR_IE);
+	return !(flags & SR_SIE);
 }
 
 /* test hardware interrupt enable bit */
@@ -57,7 +57,7 @@ static inline int arch_irqs_disabled(void)
 /* set interrupt enabled status */
 static inline void arch_local_irq_restore(unsigned long flags)
 {
-	csr_set(sstatus, flags & SR_IE);
+	csr_set(sstatus, flags & SR_SIE);
 }
 
 #endif /* _ASM_RISCV_IRQFLAGS_H */
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 2cbd92ed1629..16301966d65b 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -20,8 +20,6 @@
 
 #ifndef __ASSEMBLY__
 
-#ifdef CONFIG_MMU
-
 /* Page Upper Directory not used in RISC-V */
 #include <asm-generic/pgtable-nopud.h>
 #include <asm/page.h>
@@ -413,8 +411,6 @@ static inline void pgtable_cache_init(void)
 	/* No page table caches to initialize */
 }
 
-#endif /* CONFIG_MMU */
-
 #define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
 #define VMALLOC_END      (PAGE_OFFSET - 1)
 #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h
index 93b8956e25e4..2c5df945d43c 100644
--- a/arch/riscv/include/asm/ptrace.h
+++ b/arch/riscv/include/asm/ptrace.h
@@ -66,7 +66,7 @@ struct pt_regs {
 #define REG_FMT "%08lx"
 #endif
 
-#define user_mode(regs) (((regs)->sstatus & SR_PS) == 0)
+#define user_mode(regs) (((regs)->sstatus & SR_SPP) == 0)
 
 
 /* Helpers for working with the instruction pointer */
diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
index 22c3536ed281..f8fa1cd2dad9 100644
--- a/arch/riscv/include/asm/thread_info.h
+++ b/arch/riscv/include/asm/thread_info.h
@@ -64,8 +64,6 @@ struct thread_info {
 	.addr_limit	= KERNEL_DS,		\
 }
 
-#define init_stack		(init_thread_union.stack)
-
 #endif /* !__ASSEMBLY__ */
 
 /*
diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index 715b0f10af58..7b9c24ebdf52 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -15,8 +15,6 @@
 #ifndef _ASM_RISCV_TLBFLUSH_H
 #define _ASM_RISCV_TLBFLUSH_H
 
-#ifdef CONFIG_MMU
-
 #include <linux/mm_types.h>
 
 /*
@@ -64,6 +62,4 @@ static inline void flush_tlb_kernel_range(unsigned long start,
 	flush_tlb_all();
 }
 
-#endif /* CONFIG_MMU */
-
 #endif /* _ASM_RISCV_TLBFLUSH_H */
diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
index 27b90d64814b..14b0b22fb578 100644
--- a/arch/riscv/include/asm/uaccess.h
+++ b/arch/riscv/include/asm/uaccess.h
@@ -127,7 +127,6 @@ extern int fixup_exception(struct pt_regs *state);
  * call.
  */
 
-#ifdef CONFIG_MMU
 #define __get_user_asm(insn, x, ptr, err)			\
 do {								\
 	uintptr_t __tmp;					\
@@ -153,13 +152,11 @@ do {								\
 	__disable_user_access();				\
 	(x) = __x;						\
 } while (0)
-#endif /* CONFIG_MMU */
 
 #ifdef CONFIG_64BIT
 #define __get_user_8(x, ptr, err) \
 	__get_user_asm("ld", x, ptr, err)
 #else /* !CONFIG_64BIT */
-#ifdef CONFIG_MMU
 #define __get_user_8(x, ptr, err)				\
 do {								\
 	u32 __user *__ptr = (u32 __user *)(ptr);		\
@@ -193,7 +190,6 @@ do {								\
 	(x) = (__typeof__(x))((__typeof__((x)-(x)))(		\
 		(((u64)__hi << 32) | __lo)));			\
 } while (0)
-#endif /* CONFIG_MMU */
 #endif /* CONFIG_64BIT */
 
 
@@ -267,8 +263,6 @@ do {								\
 		((x) = 0, -EFAULT);				\
 })
 
-
-#ifdef CONFIG_MMU
 #define __put_user_asm(insn, x, ptr, err)			\
 do {								\
 	uintptr_t __tmp;					\
@@ -292,14 +286,11 @@ do {								\
 		: "rJ" (__x), "i" (-EFAULT));			\
 	__disable_user_access();				\
 } while (0)
-#endif /* CONFIG_MMU */
-
 
 #ifdef CONFIG_64BIT
 #define __put_user_8(x, ptr, err) \
 	__put_user_asm("sd", x, ptr, err)
 #else /* !CONFIG_64BIT */
-#ifdef CONFIG_MMU
 #define __put_user_8(x, ptr, err)				\
 do {								\
 	u32 __user *__ptr = (u32 __user *)(ptr);		\
@@ -329,7 +320,6 @@ do {								\
 		: "rJ" (__x), "rJ" (__x >> 32), "i" (-EFAULT));	\
 	__disable_user_access();				\
 } while (0)
-#endif /* CONFIG_MMU */
 #endif /* CONFIG_64BIT */
 
 
@@ -438,7 +428,6 @@ unsigned long __must_check clear_user(void __user *to, unsigned long n)
  * will set "err" to -EFAULT, while successful accesses return the previous
  * value.
  */
-#ifdef CONFIG_MMU
 #define __cmpxchg_user(ptr, old, new, err, size, lrb, scb)	\
 ({								\
 	__typeof__(ptr) __ptr = (ptr);				\
@@ -508,6 +497,5 @@ unsigned long __must_check clear_user(void __user *to, unsigned long n)
 	(err) = __err;						\
 	__ret;							\
 })
-#endif /* CONFIG_MMU */
 
 #endif /* _ASM_RISCV_UACCESS_H */
diff --git a/arch/riscv/include/asm/unistd.h b/arch/riscv/include/asm/unistd.h
index 9f250ed007cd..2f704a5c4196 100644
--- a/arch/riscv/include/asm/unistd.h
+++ b/arch/riscv/include/asm/unistd.h
@@ -14,3 +14,4 @@
 #define __ARCH_HAVE_MMU
 #define __ARCH_WANT_SYS_CLONE
 #include <uapi/asm/unistd.h>
+#include <uapi/asm/syscalls.h>
diff --git a/arch/riscv/include/asm/vdso-syscalls.h b/arch/riscv/include/asm/vdso-syscalls.h
deleted file mode 100644
index a2ccf1894929..000000000000
--- a/arch/riscv/include/asm/vdso-syscalls.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * Copyright (C) 2017 SiFive
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef _ASM_RISCV_VDSO_SYSCALLS_H
-#define _ASM_RISCV_VDSO_SYSCALLS_H
-
-#ifdef CONFIG_SMP
-
-/* These syscalls are only used by the vDSO and are not in the uapi. */
-#define __NR_riscv_flush_icache (__NR_arch_specific_syscall + 15)
-__SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache)
-
-#endif
-
-#endif /* _ASM_RISCV_VDSO_H */
diff --git a/arch/riscv/include/uapi/asm/syscalls.h b/arch/riscv/include/uapi/asm/syscalls.h
new file mode 100644
index 000000000000..818655b0d535
--- /dev/null
+++ b/arch/riscv/include/uapi/asm/syscalls.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2017 SiFive
+ */
+
+#ifndef _ASM__UAPI__SYSCALLS_H
+#define _ASM__UAPI__SYSCALLS_H
+
+/*
+ * Allows the instruction cache to be flushed from userspace.  Despite RISC-V
+ * having a direct 'fence.i' instruction available to userspace (which we
+ * can't trap!), that's not actually viable when running on Linux because the
+ * kernel might schedule a process on another hart.  There is no way for
+ * userspace to handle this without invoking the kernel (as it doesn't know the
+ * thread->hart mappings), so we've defined a RISC-V specific system call to
+ * flush the instruction cache.
+ *
+ * __NR_riscv_flush_icache is defined to flush the instruction cache over an
+ * address range, with the flush applying to either all threads or just the
+ * caller.  We don't currently do anything with the address range, that's just
+ * in there for forwards compatibility.
+ */
+#define __NR_riscv_flush_icache (__NR_arch_specific_syscall + 15)
+__SYSCALL(__NR_riscv_flush_icache, sys_riscv_flush_icache)
+
+#endif