summaryrefslogtreecommitdiff
path: root/arch/riscv
diff options
context:
space:
mode:
authorPalmer Dabbelt <palmer@sifive.com>2017-12-02 00:12:10 +0300
committerPalmer Dabbelt <palmer@sifive.com>2017-12-02 00:12:10 +0300
commit07f8ba7439f9c942d5bd7b63074e7a1528601713 (patch)
treea9ea3bf949955e5808617e4b21372c0ed85bc009 /arch/riscv
parentf8182f613c9887744eb469b1a3352636481cb395 (diff)
parent0e710ac6521f13c68a5c634471f40ae448c31e0a (diff)
downloadlinux-07f8ba7439f9c942d5bd7b63074e7a1528601713.tar.xz
RISC-V: User-Visible Changes
This merge contains the user-visible, ABI-breaking changes that we want to make sure we have in Linux before our first release. Highlights include: * VDSO entries for clock_get/gettimeofday/getcpu have been added. These are simple syscalls now, but we want to let glibc use them from the start so we can make them faster later. * A VDSO entry for instruction cache flushing has been added so userspace can flush the instruction cache. * The VDSO symbol versions for __vdso_cmpxchg{32,64} have been removed, as those VDSO entries don't actually exist. Conflicts: arch/riscv/include/asm/tlbflush.h
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/include/asm/cacheflush.h30
-rw-r--r--arch/riscv/include/asm/mmu.h4
-rw-r--r--arch/riscv/include/asm/mmu_context.h44
-rw-r--r--arch/riscv/include/asm/pgtable.h58
-rw-r--r--arch/riscv/include/asm/tlbflush.h2
-rw-r--r--arch/riscv/include/asm/vdso-syscalls.h28
-rw-r--r--arch/riscv/include/asm/vdso.h4
-rw-r--r--arch/riscv/kernel/smp.c48
-rw-r--r--arch/riscv/kernel/sys_riscv.c33
-rw-r--r--arch/riscv/kernel/syscall_table.c2
-rw-r--r--arch/riscv/kernel/vdso/Makefile7
-rw-r--r--arch/riscv/kernel/vdso/clock_getres.S26
-rw-r--r--arch/riscv/kernel/vdso/clock_gettime.S26
-rw-r--r--arch/riscv/kernel/vdso/flush_icache.S31
-rw-r--r--arch/riscv/kernel/vdso/getcpu.S26
-rw-r--r--arch/riscv/kernel/vdso/gettimeofday.S26
-rw-r--r--arch/riscv/kernel/vdso/vdso.lds.S7
-rw-r--r--arch/riscv/mm/Makefile1
-rw-r--r--arch/riscv/mm/cacheflush.c23
19 files changed, 392 insertions, 34 deletions
diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h
index 0595585013b0..efd89a88d2d0 100644
--- a/arch/riscv/include/asm/cacheflush.h
+++ b/arch/riscv/include/asm/cacheflush.h
@@ -18,22 +18,44 @@
#undef flush_icache_range
#undef flush_icache_user_range
+#undef flush_dcache_page
static inline void local_flush_icache_all(void)
{
asm volatile ("fence.i" ::: "memory");
}
+#define PG_dcache_clean PG_arch_1
+
+static inline void flush_dcache_page(struct page *page)
+{
+ if (test_bit(PG_dcache_clean, &page->flags))
+ clear_bit(PG_dcache_clean, &page->flags);
+}
+
+/*
+ * RISC-V doesn't have an instruction to flush parts of the instruction cache,
+ * so instead we just flush the whole thing.
+ */
+#define flush_icache_range(start, end) flush_icache_all()
+#define flush_icache_user_range(vma, pg, addr, len) flush_icache_all()
+
#ifndef CONFIG_SMP
-#define flush_icache_range(start, end) local_flush_icache_all()
-#define flush_icache_user_range(vma, pg, addr, len) local_flush_icache_all()
+#define flush_icache_all() local_flush_icache_all()
+#define flush_icache_mm(mm, local) flush_icache_all()
#else /* CONFIG_SMP */
-#define flush_icache_range(start, end) sbi_remote_fence_i(0)
-#define flush_icache_user_range(vma, pg, addr, len) sbi_remote_fence_i(0)
+#define flush_icache_all() sbi_remote_fence_i(0)
+void flush_icache_mm(struct mm_struct *mm, bool local);
#endif /* CONFIG_SMP */
+/*
+ * Bits in sys_riscv_flush_icache()'s flags argument.
+ */
+#define SYS_RISCV_FLUSH_ICACHE_LOCAL 1UL
+#define SYS_RISCV_FLUSH_ICACHE_ALL (SYS_RISCV_FLUSH_ICACHE_LOCAL)
+
#endif /* _ASM_RISCV_CACHEFLUSH_H */
diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h
index 66805cba9a27..5df2dccdba12 100644
--- a/arch/riscv/include/asm/mmu.h
+++ b/arch/riscv/include/asm/mmu.h
@@ -19,6 +19,10 @@
typedef struct {
void *vdso;
+#ifdef CONFIG_SMP
+ /* A local icache flush is needed before user execution can resume. */
+ cpumask_t icache_stale_mask;
+#endif
} mm_context_t;
#endif /* __ASSEMBLY__ */
diff --git a/arch/riscv/include/asm/mmu_context.h b/arch/riscv/include/asm/mmu_context.h
index de1fc1631fc4..b15b169e3d22 100644
--- a/arch/riscv/include/asm/mmu_context.h
+++ b/arch/riscv/include/asm/mmu_context.h
@@ -1,5 +1,6 @@
/*
* Copyright (C) 2012 Regents of the University of California
+ * 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
@@ -19,6 +20,7 @@
#include <linux/mm.h>
#include <linux/sched.h>
#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
static inline void enter_lazy_tlb(struct mm_struct *mm,
struct task_struct *task)
@@ -46,12 +48,54 @@ static inline void set_pgdir(pgd_t *pgd)
csr_write(sptbr, virt_to_pfn(pgd) | SPTBR_MODE);
}
+/*
+ * When necessary, performs a deferred icache flush for the given MM context,
+ * on the local CPU. RISC-V has no direct mechanism for instruction cache
+ * shoot downs, so instead we send an IPI that informs the remote harts they
+ * need to flush their local instruction caches. To avoid pathologically slow
+ * behavior in a common case (a bunch of single-hart processes on a many-hart
+ * machine, ie 'make -j') we avoid the IPIs for harts that are not currently
+ * executing a MM context and instead schedule a deferred local instruction
+ * cache flush to be performed before execution resumes on each hart. This
+ * actually performs that local instruction cache flush, which implicitly only
+ * refers to the current hart.
+ */
+static inline void flush_icache_deferred(struct mm_struct *mm)
+{
+#ifdef CONFIG_SMP
+ unsigned int cpu = smp_processor_id();
+ cpumask_t *mask = &mm->context.icache_stale_mask;
+
+ if (cpumask_test_cpu(cpu, mask)) {
+ cpumask_clear_cpu(cpu, mask);
+ /*
+ * Ensure the remote hart's writes are visible to this hart.
+ * This pairs with a barrier in flush_icache_mm.
+ */
+ smp_mb();
+ local_flush_icache_all();
+ }
+#endif
+}
+
static inline void switch_mm(struct mm_struct *prev,
struct mm_struct *next, struct task_struct *task)
{
if (likely(prev != next)) {
+ /*
+ * Mark the current MM context as inactive, and the next as
+ * active. This is at least used by the icache flushing
+ * routines in order to determine who should
+ */
+ unsigned int cpu = smp_processor_id();
+
+ cpumask_clear_cpu(cpu, mm_cpumask(prev));
+ cpumask_set_cpu(cpu, mm_cpumask(next));
+
set_pgdir(next->pgd);
local_flush_tlb_all();
+
+ flush_icache_deferred(next);
}
}
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 3399257780b2..2cbd92ed1629 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -178,28 +178,6 @@ static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long addr)
#define pte_offset_map(dir, addr) pte_offset_kernel((dir), (addr))
#define pte_unmap(pte) ((void)(pte))
-/*
- * Certain architectures need to do special things when PTEs within
- * a page table are directly modified. Thus, the following hook is
- * made available.
- */
-static inline void set_pte(pte_t *ptep, pte_t pteval)
-{
- *ptep = pteval;
-}
-
-static inline void set_pte_at(struct mm_struct *mm,
- unsigned long addr, pte_t *ptep, pte_t pteval)
-{
- set_pte(ptep, pteval);
-}
-
-static inline void pte_clear(struct mm_struct *mm,
- unsigned long addr, pte_t *ptep)
-{
- set_pte_at(mm, addr, ptep, __pte(0));
-}
-
static inline int pte_present(pte_t pte)
{
return (pte_val(pte) & _PAGE_PRESENT);
@@ -210,21 +188,22 @@ static inline int pte_none(pte_t pte)
return (pte_val(pte) == 0);
}
-/* static inline int pte_read(pte_t pte) */
-
static inline int pte_write(pte_t pte)
{
return pte_val(pte) & _PAGE_WRITE;
}
+static inline int pte_exec(pte_t pte)
+{
+ return pte_val(pte) & _PAGE_EXEC;
+}
+
static inline int pte_huge(pte_t pte)
{
return pte_present(pte)
&& (pte_val(pte) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
}
-/* static inline int pte_exec(pte_t pte) */
-
static inline int pte_dirty(pte_t pte)
{
return pte_val(pte) & _PAGE_DIRTY;
@@ -311,6 +290,33 @@ static inline int pte_same(pte_t pte_a, pte_t pte_b)
return pte_val(pte_a) == pte_val(pte_b);
}
+/*
+ * Certain architectures need to do special things when PTEs within
+ * a page table are directly modified. Thus, the following hook is
+ * made available.
+ */
+static inline void set_pte(pte_t *ptep, pte_t pteval)
+{
+ *ptep = pteval;
+}
+
+void flush_icache_pte(pte_t pte);
+
+static inline void set_pte_at(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep, pte_t pteval)
+{
+ if (pte_present(pteval) && pte_exec(pteval))
+ flush_icache_pte(pteval);
+
+ set_pte(ptep, pteval);
+}
+
+static inline void pte_clear(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ set_pte_at(mm, addr, ptep, __pte(0));
+}
+
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
static inline int ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,
diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index c79fab3d377d..715b0f10af58 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -17,6 +17,8 @@
#ifdef CONFIG_MMU
+#include <linux/mm_types.h>
+
/*
* Flush entire local TLB. 'sfence.vma' implicitly fences with the instruction
* cache as well, so a 'fence.i' is not necessary.
diff --git a/arch/riscv/include/asm/vdso-syscalls.h b/arch/riscv/include/asm/vdso-syscalls.h
new file mode 100644
index 000000000000..a2ccf1894929
--- /dev/null
+++ b/arch/riscv/include/asm/vdso-syscalls.h
@@ -0,0 +1,28 @@
+/*
+ * 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/asm/vdso.h b/arch/riscv/include/asm/vdso.h
index 602f61257553..541544d64c33 100644
--- a/arch/riscv/include/asm/vdso.h
+++ b/arch/riscv/include/asm/vdso.h
@@ -38,4 +38,8 @@ struct vdso_data {
(void __user *)((unsigned long)(base) + __vdso_##name); \
})
+#ifdef CONFIG_SMP
+asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
+#endif
+
#endif /* _ASM_RISCV_VDSO_H */
diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c
index b4a71ec5906f..1b27ade437b4 100644
--- a/arch/riscv/kernel/smp.c
+++ b/arch/riscv/kernel/smp.c
@@ -108,3 +108,51 @@ void smp_send_reschedule(int cpu)
{
send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
}
+
+/*
+ * Performs an icache flush for the given MM context. RISC-V has no direct
+ * mechanism for instruction cache shoot downs, so instead we send an IPI that
+ * informs the remote harts they need to flush their local instruction caches.
+ * To avoid pathologically slow behavior in a common case (a bunch of
+ * single-hart processes on a many-hart machine, ie 'make -j') we avoid the
+ * IPIs for harts that are not currently executing a MM context and instead
+ * schedule a deferred local instruction cache flush to be performed before
+ * execution resumes on each hart.
+ */
+void flush_icache_mm(struct mm_struct *mm, bool local)
+{
+ unsigned int cpu;
+ cpumask_t others, *mask;
+
+ preempt_disable();
+
+ /* Mark every hart's icache as needing a flush for this MM. */
+ mask = &mm->context.icache_stale_mask;
+ cpumask_setall(mask);
+ /* Flush this hart's I$ now, and mark it as flushed. */
+ cpu = smp_processor_id();
+ cpumask_clear_cpu(cpu, mask);
+ local_flush_icache_all();
+
+ /*
+ * Flush the I$ of other harts concurrently executing, and mark them as
+ * flushed.
+ */
+ cpumask_andnot(&others, mm_cpumask(mm), cpumask_of(cpu));
+ local |= cpumask_empty(&others);
+ if (mm != current->active_mm || !local)
+ sbi_remote_fence_i(others.bits);
+ else {
+ /*
+ * It's assumed that at least one strongly ordered operation is
+ * performed on this hart between setting a hart's cpumask bit
+ * and scheduling this MM context on that hart. Sending an SBI
+ * remote message will do this, but in the case where no
+ * messages are sent we still need to order this hart's writes
+ * with flush_icache_deferred().
+ */
+ smp_mb();
+ }
+
+ preempt_enable();
+}
diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
index 4351be7d0533..a2ae936a093e 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -14,8 +14,8 @@
*/
#include <linux/syscalls.h>
-#include <asm/cmpxchg.h>
#include <asm/unistd.h>
+#include <asm/cacheflush.h>
static long riscv_sys_mmap(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
@@ -47,3 +47,34 @@ SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 12);
}
#endif /* !CONFIG_64BIT */
+
+#ifdef CONFIG_SMP
+/*
+ * 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.
+ *
+ * sys_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.
+ */
+SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end,
+ uintptr_t, flags)
+{
+ struct mm_struct *mm = current->mm;
+ bool local = (flags & SYS_RISCV_FLUSH_ICACHE_LOCAL) != 0;
+
+ /* Check the reserved flags. */
+ if (unlikely(flags & !SYS_RISCV_FLUSH_ICACHE_ALL))
+ return -EINVAL;
+
+ flush_icache_mm(mm, local);
+
+ return 0;
+}
+#endif
diff --git a/arch/riscv/kernel/syscall_table.c b/arch/riscv/kernel/syscall_table.c
index 4e30dc5fb593..a5bd6401f95e 100644
--- a/arch/riscv/kernel/syscall_table.c
+++ b/arch/riscv/kernel/syscall_table.c
@@ -15,6 +15,7 @@
#include <linux/linkage.h>
#include <linux/syscalls.h>
#include <asm-generic/syscalls.h>
+#include <asm/vdso.h>
#undef __SYSCALL
#define __SYSCALL(nr, call) [nr] = (call),
@@ -22,4 +23,5 @@
void *sys_call_table[__NR_syscalls] = {
[0 ... __NR_syscalls - 1] = sys_ni_syscall,
#include <asm/unistd.h>
+#include <asm/vdso-syscalls.h>
};
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 523d0a8ac8db..324568d33921 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -1,7 +1,12 @@
# Copied from arch/tile/kernel/vdso/Makefile
# Symbols present in the vdso
-vdso-syms = rt_sigreturn
+vdso-syms = rt_sigreturn
+vdso-syms += gettimeofday
+vdso-syms += clock_gettime
+vdso-syms += clock_getres
+vdso-syms += getcpu
+vdso-syms += flush_icache
# Files to link into the vdso
obj-vdso = $(patsubst %, %.o, $(vdso-syms))
diff --git a/arch/riscv/kernel/vdso/clock_getres.S b/arch/riscv/kernel/vdso/clock_getres.S
new file mode 100644
index 000000000000..edf7e2339648
--- /dev/null
+++ b/arch/riscv/kernel/vdso/clock_getres.S
@@ -0,0 +1,26 @@
+/*
+ * 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
+ * as published by the Free Software Foundation, version 2.
+ *
+ * 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.
+ */
+
+#include <linux/linkage.h>
+#include <asm/unistd.h>
+
+ .text
+/* int __vdso_clock_getres(clockid_t clock_id, struct timespec *res); */
+ENTRY(__vdso_clock_getres)
+ .cfi_startproc
+ /* For now, just do the syscall. */
+ li a7, __NR_clock_getres
+ ecall
+ ret
+ .cfi_endproc
+ENDPROC(__vdso_clock_getres)
diff --git a/arch/riscv/kernel/vdso/clock_gettime.S b/arch/riscv/kernel/vdso/clock_gettime.S
new file mode 100644
index 000000000000..aac65676c6d5
--- /dev/null
+++ b/arch/riscv/kernel/vdso/clock_gettime.S
@@ -0,0 +1,26 @@
+/*
+ * 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
+ * as published by the Free Software Foundation, version 2.
+ *
+ * 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.
+ */
+
+#include <linux/linkage.h>
+#include <asm/unistd.h>
+
+ .text
+/* int __vdso_clock_gettime(clockid_t clock_id, struct timespec *tp); */
+ENTRY(__vdso_clock_gettime)
+ .cfi_startproc
+ /* For now, just do the syscall. */
+ li a7, __NR_clock_gettime
+ ecall
+ ret
+ .cfi_endproc
+ENDPROC(__vdso_clock_gettime)
diff --git a/arch/riscv/kernel/vdso/flush_icache.S b/arch/riscv/kernel/vdso/flush_icache.S
new file mode 100644
index 000000000000..b0fbad74e873
--- /dev/null
+++ b/arch/riscv/kernel/vdso/flush_icache.S
@@ -0,0 +1,31 @@
+/*
+ * 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
+ * as published by the Free Software Foundation, version 2.
+ *
+ * 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.
+ */
+
+#include <linux/linkage.h>
+#include <asm/unistd.h>
+#include <asm/vdso-syscalls.h>
+
+ .text
+/* int __vdso_flush_icache(void *start, void *end, unsigned long flags); */
+ENTRY(__vdso_flush_icache)
+ .cfi_startproc
+#ifdef CONFIG_SMP
+ li a7, __NR_riscv_flush_icache
+ ecall
+#else
+ fence.i
+ li a0, 0
+#endif
+ ret
+ .cfi_endproc
+ENDPROC(__vdso_flush_icache)
diff --git a/arch/riscv/kernel/vdso/getcpu.S b/arch/riscv/kernel/vdso/getcpu.S
new file mode 100644
index 000000000000..cc7e98924484
--- /dev/null
+++ b/arch/riscv/kernel/vdso/getcpu.S
@@ -0,0 +1,26 @@
+/*
+ * 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
+ * as published by the Free Software Foundation, version 2.
+ *
+ * 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.
+ */
+
+#include <linux/linkage.h>
+#include <asm/unistd.h>
+
+ .text
+/* int __vdso_getcpu(unsigned *cpu, unsigned *node, void *unused); */
+ENTRY(__vdso_getcpu)
+ .cfi_startproc
+ /* For now, just do the syscall. */
+ li a7, __NR_getcpu
+ ecall
+ ret
+ .cfi_endproc
+ENDPROC(__vdso_getcpu)
diff --git a/arch/riscv/kernel/vdso/gettimeofday.S b/arch/riscv/kernel/vdso/gettimeofday.S
new file mode 100644
index 000000000000..da85d33e8990
--- /dev/null
+++ b/arch/riscv/kernel/vdso/gettimeofday.S
@@ -0,0 +1,26 @@
+/*
+ * 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
+ * as published by the Free Software Foundation, version 2.
+ *
+ * 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.
+ */
+
+#include <linux/linkage.h>
+#include <asm/unistd.h>
+
+ .text
+/* int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz); */
+ENTRY(__vdso_gettimeofday)
+ .cfi_startproc
+ /* For now, just do the syscall. */
+ li a7, __NR_gettimeofday
+ ecall
+ ret
+ .cfi_endproc
+ENDPROC(__vdso_gettimeofday)
diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vdso.lds.S
index 8c9dce95c11d..cd1d47e0724b 100644
--- a/arch/riscv/kernel/vdso/vdso.lds.S
+++ b/arch/riscv/kernel/vdso/vdso.lds.S
@@ -70,8 +70,11 @@ VERSION
LINUX_4.15 {
global:
__vdso_rt_sigreturn;
- __vdso_cmpxchg32;
- __vdso_cmpxchg64;
+ __vdso_gettimeofday;
+ __vdso_clock_gettime;
+ __vdso_clock_getres;
+ __vdso_getcpu;
+ __vdso_flush_icache;
local: *;
};
}
diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index 81f7d9ce6d88..eb22ab49b3e0 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -2,3 +2,4 @@ obj-y += init.o
obj-y += fault.o
obj-y += extable.o
obj-y += ioremap.o
+obj-y += cacheflush.o
diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c
new file mode 100644
index 000000000000..498c0a0814fe
--- /dev/null
+++ b/arch/riscv/mm/cacheflush.c
@@ -0,0 +1,23 @@
+/*
+ * 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
+ * as published by the Free Software Foundation, version 2.
+ *
+ * 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.
+ */
+
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+
+void flush_icache_pte(pte_t pte)
+{
+ struct page *page = pte_page(pte);
+
+ if (!test_and_set_bit(PG_dcache_clean, &page->flags))
+ flush_icache_all();
+}