Merge tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull vdso data page handling updates from Thomas Gleixner:
 "First steps of consolidating the VDSO data page handling.

  The VDSO data page handling is architecture specific for historical
  reasons, but there is no real technical reason to do so.

  Aside of that VDSO data has become a dump ground for various
  mechanisms and fail to provide a clear separation of the
  functionalities.

  Clean this up by:

   - consolidating the VDSO page data by getting rid of architecture
     specific warts especially in x86 and PowerPC.

   - removing the last includes of header files which are pulling in
     other headers outside of the VDSO namespace.

   - seperating timekeeping and other VDSO data accordingly.

  Further consolidation of the VDSO page handling is done in subsequent
  changes scheduled for the next merge window.

  This also lays the ground for expanding the VDSO time getters for
  independent PTP clocks in a generic way without making every
  architecture add support seperately"

* tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
  x86/vdso: Add missing brackets in switch case
  vdso: Rename struct arch_vdso_data to arch_vdso_time_data
  powerpc: Split systemcfg struct definitions out from vdso
  powerpc: Split systemcfg data out of vdso data page
  powerpc: Add kconfig option for the systemcfg page
  powerpc/pseries/lparcfg: Use num_possible_cpus() for potential processors
  powerpc/pseries/lparcfg: Fix printing of system_active_processors
  powerpc/procfs: Propagate error of remap_pfn_range()
  powerpc/vdso: Remove offset comment from 32bit vdso_arch_data
  x86/vdso: Split virtual clock pages into dedicated mapping
  x86/vdso: Delete vvar.h
  x86/vdso: Access vdso data without vvar.h
  x86/vdso: Move the rng offset to vsyscall.h
  x86/vdso: Access rng vdso data without vvar.h
  x86/vdso: Access timens vdso data without vvar.h
  x86/vdso: Allocate vvar page from C code
  x86/vdso: Access rng data from kernel without vvar
  x86/vdso: Place vdso_data at beginning of vvar page
  x86/vdso: Use __arch_get_vdso_data() to access vdso data
  x86/mm/mmap: Remove arch_vma_name()
  ...

3 files changed, 20 insertions, 38 deletions

diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index cea0ca2bf2a2..711a31f27c3d 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -402,7 +402,7 @@ static int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs,
 static int __init init_hwprobe_vdso_data(void)
 {
 	struct vdso_data *vd = __arch_get_k_vdso_data();
-	struct arch_vdso_data *avd = &vd->arch_data;
+	struct arch_vdso_time_data *avd = &vd->arch_data;
 	u64 id_bitsmash = 0;
 	struct riscv_hwprobe pair;
 	int key;
diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
index 98315b98256d..3ca3ae4277e1 100644
--- a/arch/riscv/kernel/vdso.c
+++ b/arch/riscv/kernel/vdso.c
@@ -23,11 +23,6 @@ enum vvar_pages {
 	VVAR_NR_PAGES,
 };
 
-enum rv_vdso_map {
-	RV_VDSO_MAP_VVAR,
-	RV_VDSO_MAP_VDSO,
-};
-
 #define VVAR_SIZE  (VVAR_NR_PAGES << PAGE_SHIFT)
 
 static union vdso_data_store vdso_data_store __page_aligned_data;
@@ -38,8 +33,6 @@ struct __vdso_info {
 	const char *vdso_code_start;
 	const char *vdso_code_end;
 	unsigned long vdso_pages;
-	/* Data Mapping */
-	struct vm_special_mapping *dm;
 	/* Code Mapping */
 	struct vm_special_mapping *cm;
 };
@@ -92,6 +85,8 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page)
 	return (struct vdso_data *)(vvar_page);
 }
 
+static const struct vm_special_mapping rv_vvar_map;
+
 /*
  * The vvar mapping contains data for a specific time namespace, so when a task
  * changes namespace we must unmap its vvar data for the old namespace.
@@ -108,12 +103,8 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
 	mmap_read_lock(mm);
 
 	for_each_vma(vmi, vma) {
-		if (vma_is_special_mapping(vma, vdso_info.dm))
-			zap_vma_pages(vma);
-#ifdef CONFIG_COMPAT
-		if (vma_is_special_mapping(vma, compat_vdso_info.dm))
+		if (vma_is_special_mapping(vma, &rv_vvar_map))
 			zap_vma_pages(vma);
-#endif
 	}
 
 	mmap_read_unlock(mm);
@@ -155,43 +146,34 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 	return vmf_insert_pfn(vma, vmf->address, pfn);
 }
 
-static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
-	[RV_VDSO_MAP_VVAR] = {
-		.name   = "[vvar]",
-		.fault = vvar_fault,
-	},
-	[RV_VDSO_MAP_VDSO] = {
-		.name   = "[vdso]",
-		.mremap = vdso_mremap,
-	},
+static const struct vm_special_mapping rv_vvar_map = {
+	.name   = "[vvar]",
+	.fault = vvar_fault,
+};
+
+static struct vm_special_mapping rv_vdso_map __ro_after_init = {
+	.name   = "[vdso]",
+	.mremap = vdso_mremap,
 };
 
 static struct __vdso_info vdso_info __ro_after_init = {
 	.name = "vdso",
 	.vdso_code_start = vdso_start,
 	.vdso_code_end = vdso_end,
-	.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
-	.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
+	.cm = &rv_vdso_map,
 };
 
 #ifdef CONFIG_COMPAT
-static struct vm_special_mapping rv_compat_vdso_maps[] __ro_after_init = {
-	[RV_VDSO_MAP_VVAR] = {
-		.name   = "[vvar]",
-		.fault = vvar_fault,
-	},
-	[RV_VDSO_MAP_VDSO] = {
-		.name   = "[vdso]",
-		.mremap = vdso_mremap,
-	},
+static struct vm_special_mapping rv_compat_vdso_map __ro_after_init = {
+	.name   = "[vdso]",
+	.mremap = vdso_mremap,
 };
 
 static struct __vdso_info compat_vdso_info __ro_after_init = {
 	.name = "compat_vdso",
 	.vdso_code_start = compat_vdso_start,
 	.vdso_code_end = compat_vdso_end,
-	.dm = &rv_compat_vdso_maps[RV_VDSO_MAP_VVAR],
-	.cm = &rv_compat_vdso_maps[RV_VDSO_MAP_VDSO],
+	.cm = &rv_compat_vdso_map,
 };
 #endif
 
@@ -227,7 +209,7 @@ static int __setup_additional_pages(struct mm_struct *mm,
 	}
 
 	ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE,
-		(VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info->dm);
+		(VM_READ | VM_MAYREAD | VM_PFNMAP), &rv_vvar_map);
 	if (IS_ERR(ret))
 		goto up_fail;
 
diff --git a/arch/riscv/kernel/vdso/hwprobe.c b/arch/riscv/kernel/vdso/hwprobe.c
index 1e926e4b5881..a158c029344f 100644
--- a/arch/riscv/kernel/vdso/hwprobe.c
+++ b/arch/riscv/kernel/vdso/hwprobe.c
@@ -17,7 +17,7 @@ static int riscv_vdso_get_values(struct riscv_hwprobe *pairs, size_t pair_count,
 				 unsigned int flags)
 {
 	const struct vdso_data *vd = __arch_get_vdso_data();
-	const struct arch_vdso_data *avd = &vd->arch_data;
+	const struct arch_vdso_time_data *avd = &vd->arch_data;
 	bool all_cpus = !cpusetsize && !cpus;
 	struct riscv_hwprobe *p = pairs;
 	struct riscv_hwprobe *end = pairs + pair_count;
@@ -52,7 +52,7 @@ static int riscv_vdso_get_cpus(struct riscv_hwprobe *pairs, size_t pair_count,
 			       unsigned int flags)
 {
 	const struct vdso_data *vd = __arch_get_vdso_data();
-	const struct arch_vdso_data *avd = &vd->arch_data;
+	const struct arch_vdso_time_data *avd = &vd->arch_data;
 	struct riscv_hwprobe *p = pairs;
 	struct riscv_hwprobe *end = pairs + pair_count;
 	unsigned char *c = (unsigned char *)cpus;