[PATCH v3 18/26] arm64: Introduce asm/vdso/processor.h

Vincenzo Frascino
2020-03-13T15:45:04Z

The vDSO library should only include the necessary headers required for
a userspace library (UAPI and a minimal set of kernel headers). To make
this possible it is necessary to isolate from the kernel headers the
common parts that are strictly necessary to build the library.

Introduce asm/vdso/processor.h to contain all the arm64 specific
functions that are suitable for vDSO inclusion.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
arch/arm64/include/asm/processor.h | 16 ++-----------
arch/arm64/include/asm/vdso/processor.h | 31 +++++++++++++++++++++++++
2 files changed, 33 insertions(+), 14 deletions(-)
create mode 100644 arch/arm64/include/asm/vdso/processor.h

diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index 5ba63204d078..89ba2c5be504 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -28,6 +28,8 @@
#include <linux/string.h>
#include <linux/thread_info.h>

+#include <vdso/processor.h>
+
#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/hw_breakpoint.h>
@@ -47,15 +49,6 @@
#define TASK_SIZE_64 (UL(1) << vabits_actual)

#ifdef CONFIG_COMPAT
-#if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
-/*
- * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
- * by the compat vectors page.
- */
-#define TASK_SIZE_32 UL(0x100000000)
-#else
-#define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE)
-#endif /* CONFIG_ARM64_64K_PAGES */
#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
TASK_SIZE_32 : TASK_SIZE_64)
#define TASK_SIZE_OF(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
@@ -256,11 +249,6 @@ extern void release_thread(struct task_struct *);

unsigned long get_wchan(struct task_struct *p);

-static inline void cpu_relax(void)
-{
- asm volatile("yield" ::: "memory");
-}
-
/* Thread switching */
extern struct task_struct *cpu_switch_to(struct task_struct *prev,
struct task_struct *next);
diff --git a/arch/arm64/include/asm/vdso/processor.h b/arch/arm64/include/asm/vdso/processor.h
new file mode 100644
index 000000000000..fb4883212a2d
--- /dev/null
+++ b/arch/arm64/include/asm/vdso/processor.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 ARM Ltd.
+ */
+#ifndef __ASM_VDSO_PROCESSOR_H
+#define __ASM_VDSO_PROCESSOR_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/page-def.h>
+
+#ifdef CONFIG_COMPAT
+#if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
+/*
+ * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
+ * by the compat vectors page.
+ */
+#define TASK_SIZE_32 UL(0x100000000)
+#else
+#define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE)
+#endif /* CONFIG_ARM64_64K_PAGES */
+#endif /* CONFIG_COMPAT */
+
+static inline void cpu_relax(void)
+{
+ asm volatile("yield" ::: "memory");
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_PROCESSOR_H */
--
2.25.1