powerpc/vdso: Switch to generic storage implementation

The generic storage implementation provides the same features as the
custom one. However it can be shared between architectures, making
maintenance easier.

Co-developed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-14-13a4669dfc8c@linutronix.de

6 files changed, 57 insertions, 78 deletions

diff --git a/arch/powerpc/include/asm/vdso.h b/arch/powerpc/include/asm/vdso.h
index 8d972bc98b55..1ca23fbfe087 100644
--- a/arch/powerpc/include/asm/vdso.h
+++ b/arch/powerpc/include/asm/vdso.h
@@ -3,6 +3,7 @@
 #define _ASM_POWERPC_VDSO_H
 
 #define VDSO_VERSION_STRING	LINUX_2.6.15
+#define __VDSO_PAGES		4
 
 #ifndef __ASSEMBLY__
 
diff --git a/arch/powerpc/include/asm/vdso/arch_data.h b/arch/powerpc/include/asm/vdso/arch_data.h
new file mode 100644
index 000000000000..c240a6b87518
--- /dev/null
+++ b/arch/powerpc/include/asm/vdso/arch_data.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2002 Peter Bergner <bergner@vnet.ibm.com>, IBM
+ * Copyright (C) 2005 Benjamin Herrenschmidy <benh@kernel.crashing.org>,
+ * 		      IBM Corp.
+ */
+#ifndef _ASM_POWERPC_VDSO_ARCH_DATA_H
+#define _ASM_POWERPC_VDSO_ARCH_DATA_H
+
+#include <linux/unistd.h>
+#include <linux/types.h>
+
+#define SYSCALL_MAP_SIZE      ((NR_syscalls + 31) / 32)
+
+#ifdef CONFIG_PPC64
+
+struct vdso_arch_data {
+	__u64 tb_ticks_per_sec;			/* Timebase tics / sec */
+	__u32 dcache_block_size;		/* L1 d-cache block size     */
+	__u32 icache_block_size;		/* L1 i-cache block size     */
+	__u32 dcache_log_block_size;		/* L1 d-cache log block size */
+	__u32 icache_log_block_size;		/* L1 i-cache log block size */
+	__u32 syscall_map[SYSCALL_MAP_SIZE];	/* Map of syscalls  */
+	__u32 compat_syscall_map[SYSCALL_MAP_SIZE];	/* Map of compat syscalls */
+};
+
+#else /* CONFIG_PPC64 */
+
+struct vdso_arch_data {
+	__u64 tb_ticks_per_sec;		/* Timebase tics / sec */
+	__u32 syscall_map[SYSCALL_MAP_SIZE]; /* Map of syscalls */
+	__u32 compat_syscall_map[0];	/* No compat syscalls on PPC32 */
+};
+
+#endif /* CONFIG_PPC64 */
+
+#endif /* _ASM_POWERPC_VDSO_ARCH_DATA_H */
diff --git a/arch/powerpc/include/asm/vdso/getrandom.h b/arch/powerpc/include/asm/vdso/getrandom.h
index 80ce0709725e..067a5396aac6 100644
--- a/arch/powerpc/include/asm/vdso/getrandom.h
+++ b/arch/powerpc/include/asm/vdso/getrandom.h
@@ -43,20 +43,21 @@ static __always_inline ssize_t getrandom_syscall(void *buffer, size_t len, unsig
 			    (unsigned long)len, (unsigned long)flags);
 }
 
-static __always_inline struct vdso_rng_data *__arch_get_vdso_rng_data(void)
+static __always_inline const struct vdso_rng_data *__arch_get_vdso_u_rng_data(void)
 {
-	struct vdso_arch_data *data;
+	struct vdso_rng_data *data;
 
 	asm (
 		"	bcl	20, 31, .+4 ;"
 		"0:	mflr	%0 ;"
-		"	addis	%0, %0, (_vdso_datapage - 0b)@ha ;"
-		"	addi	%0, %0, (_vdso_datapage - 0b)@l  ;"
+		"	addis	%0, %0, (vdso_u_rng_data - 0b)@ha ;"
+		"	addi	%0, %0, (vdso_u_rng_data - 0b)@l  ;"
 		: "=r" (data) : : "lr"
 	);
 
-	return &data->rng_data;
+	return data;
 }
+#define __arch_get_vdso_u_rng_data __arch_get_vdso_u_rng_data
 
 ssize_t __c_kernel_getrandom(void *buffer, size_t len, unsigned int flags, void *opaque_state,
 			     size_t opaque_len);
diff --git a/arch/powerpc/include/asm/vdso/gettimeofday.h b/arch/powerpc/include/asm/vdso/gettimeofday.h
index c6390890a60c..dc955f2e0cc5 100644
--- a/arch/powerpc/include/asm/vdso/gettimeofday.h
+++ b/arch/powerpc/include/asm/vdso/gettimeofday.h
@@ -94,22 +94,12 @@ int clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
 #endif
 
 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
-						 const struct vdso_data *vd)
+						 const struct vdso_time_data *vd)
 {
 	return get_tb();
 }
 
-const struct vdso_data *__arch_get_vdso_data(void);
-
-#ifdef CONFIG_TIME_NS
-static __always_inline
-const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
-{
-	return (void *)vd + (1U << CONFIG_PAGE_SHIFT);
-}
-#endif
-
-static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
+static inline bool vdso_clocksource_ok(const struct vdso_time_data *vd)
 {
 	return true;
 }
@@ -135,21 +125,22 @@ static __always_inline u64 vdso_shift_ns(u64 ns, unsigned long shift)
 
 #ifdef __powerpc64__
 int __c_kernel_clock_gettime(clockid_t clock, struct __kernel_timespec *ts,
-			     const struct vdso_data *vd);
+			     const struct vdso_time_data *vd);
 int __c_kernel_clock_getres(clockid_t clock_id, struct __kernel_timespec *res,
-			    const struct vdso_data *vd);
+			    const struct vdso_time_data *vd);
 #else
 int __c_kernel_clock_gettime(clockid_t clock, struct old_timespec32 *ts,
-			     const struct vdso_data *vd);
+			     const struct vdso_time_data *vd);
 int __c_kernel_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts,
-			       const struct vdso_data *vd);
+			       const struct vdso_time_data *vd);
 int __c_kernel_clock_getres(clockid_t clock_id, struct old_timespec32 *res,
-			    const struct vdso_data *vd);
+			    const struct vdso_time_data *vd);
 #endif
 int __c_kernel_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz,
-			    const struct vdso_data *vd);
+			    const struct vdso_time_data *vd);
 __kernel_old_time_t __c_kernel_time(__kernel_old_time_t *time,
-				    const struct vdso_data *vd);
+				    const struct vdso_time_data *vd);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_VDSO_GETTIMEOFDAY_H */
diff --git a/arch/powerpc/include/asm/vdso/vsyscall.h b/arch/powerpc/include/asm/vdso/vsyscall.h
index 48560a119559..c2c9ae1b22e7 100644
--- a/arch/powerpc/include/asm/vdso/vsyscall.h
+++ b/arch/powerpc/include/asm/vdso/vsyscall.h
@@ -6,19 +6,6 @@
 
 #include <asm/vdso_datapage.h>
 
-static __always_inline
-struct vdso_data *__arch_get_k_vdso_data(void)
-{
-	return vdso_data->data;
-}
-#define __arch_get_k_vdso_data __arch_get_k_vdso_data
-
-static __always_inline
-struct vdso_rng_data *__arch_get_k_vdso_rng_data(void)
-{
-	return &vdso_data->rng_data;
-}
-
 /* The asm-generic header needs to be included after the definitions above */
 #include <asm-generic/vdso/vsyscall.h>
 
diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
index a202f5b63479..95d45a50355d 100644
--- a/arch/powerpc/include/asm/vdso_datapage.h
+++ b/arch/powerpc/include/asm/vdso_datapage.h
@@ -11,56 +11,18 @@
 
 #ifndef __ASSEMBLY__
 
-#include <linux/unistd.h>
-#include <linux/time.h>
 #include <vdso/datapage.h>
 
-#define SYSCALL_MAP_SIZE      ((NR_syscalls + 31) / 32)
-
-#ifdef CONFIG_PPC64
-
-struct vdso_arch_data {
-	__u64 tb_ticks_per_sec;			/* Timebase tics / sec */
-	__u32 dcache_block_size;		/* L1 d-cache block size     */
-	__u32 icache_block_size;		/* L1 i-cache block size     */
-	__u32 dcache_log_block_size;		/* L1 d-cache log block size */
-	__u32 icache_log_block_size;		/* L1 i-cache log block size */
-	__u32 syscall_map[SYSCALL_MAP_SIZE];	/* Map of syscalls  */
-	__u32 compat_syscall_map[SYSCALL_MAP_SIZE];	/* Map of compat syscalls */
-
-	struct vdso_rng_data rng_data;
-
-	struct vdso_data data[CS_BASES] __aligned(1 << CONFIG_PAGE_SHIFT);
-};
-
-#else /* CONFIG_PPC64 */
-
-struct vdso_arch_data {
-	__u64 tb_ticks_per_sec;		/* Timebase tics / sec */
-	__u32 syscall_map[SYSCALL_MAP_SIZE]; /* Map of syscalls */
-	__u32 compat_syscall_map[0];	/* No compat syscalls on PPC32 */
-	struct vdso_rng_data rng_data;
-
-	struct vdso_data data[CS_BASES] __aligned(1 << CONFIG_PAGE_SHIFT);
-};
-
-#endif /* CONFIG_PPC64 */
-
-extern struct vdso_arch_data *vdso_data;
-
 #else /* __ASSEMBLY__ */
 
-.macro get_datapage ptr offset=0
+.macro get_datapage ptr symbol
 	bcl	20, 31, .+4
 999:
 	mflr	\ptr
-	addis	\ptr, \ptr, (_vdso_datapage - 999b + \offset)@ha
-	addi	\ptr, \ptr, (_vdso_datapage - 999b + \offset)@l
+	addis	\ptr, \ptr, (\symbol - 999b)@ha
+	addi	\ptr, \ptr, (\symbol - 999b)@l
 .endm
 
-#include <asm/asm-offsets.h>
-#include <asm/page.h>
-
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */