Commit 69896119 authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Thomas Gleixner
Browse files

MIPS: 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: default avatarNam Cao <namcao@linutronix.de>
Signed-off-by: default avatarNam Cao <namcao@linutronix.de>
Signed-off-by: default avatarThomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-13-13a4669dfc8c@linutronix.de
parent 9bf39a65

arch/mips/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ config MIPS 
	select GENERIC_SMP_IDLE_THREAD

	select GENERIC_IDLE_POLL_SETUP

	select GENERIC_TIME_VSYSCALL

	select GENERIC_VDSO_DATA_STORE

	select GUP_GET_PXX_LOW_HIGH if CPU_MIPS32 && PHYS_ADDR_T_64BIT

	select HAS_IOPORT if !NO_IOPORT_MAP || ISA

	select HAVE_ARCH_COMPILER_H

arch/mips/include/asm/vdso/gettimeofday.h

+5 −4
Original line number Diff line number Diff line
@@ -167,7 +167,7 @@ static __always_inline u64 read_r4k_count(void) 


#ifdef CONFIG_CLKSRC_MIPS_GIC



static __always_inline u64 read_gic_count(const struct vdso_data *data)

static __always_inline u64 read_gic_count(const struct vdso_time_data *data)

{

	void __iomem *gic = get_gic(data);

	u32 hi, hi2, lo;
@@ -184,7 +184,7 @@ static __always_inline u64 read_gic_count(const struct vdso_data *data) 
#endif



static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,

						 const struct vdso_data *vd)

						 const struct vdso_time_data *vd)

{

#ifdef CONFIG_CSRC_R4K

	if (clock_mode == VDSO_CLOCKMODE_R4K)
@@ -209,10 +209,11 @@ static inline bool mips_vdso_hres_capable(void) 
}

#define __arch_vdso_hres_capable mips_vdso_hres_capable



static __always_inline const struct vdso_data *__arch_get_vdso_data(void)

static __always_inline const struct vdso_time_data *__arch_get_vdso_u_time_data(void)

{

	return get_vdso_data();

	return get_vdso_time_data();

}

#define __arch_get_vdso_u_time_data __arch_get_vdso_u_time_data



#endif /* !__ASSEMBLY__ */

arch/mips/include/asm/vdso/vdso.h

+8 −11
Original line number Diff line number Diff line
@@ -5,16 +5,18 @@ 
 */



#include <asm/sgidefs.h>

#include <vdso/page.h>



#define __VDSO_PAGES 4



#ifndef __ASSEMBLY__



#include <asm/asm.h>

#include <asm/page.h>

#include <asm/vdso.h>



static inline unsigned long get_vdso_base(void)

static inline const struct vdso_time_data *get_vdso_time_data(void)

{

	unsigned long addr;

	const struct vdso_time_data *addr;



	/*

	 * We can't use cpu_has_mips_r6 since it needs the cpu_data[]
@@ -27,7 +29,7 @@ static inline unsigned long get_vdso_base(void) 
	 * We can't use addiupc because there is no label-label

	 * support for the addiupc reloc

	 */

	__asm__("lapc	%0, _start			\n"

	__asm__("lapc	%0, vdso_u_time_data		\n"

		: "=r" (addr) : :);

#else

	/*
@@ -46,7 +48,7 @@ static inline unsigned long get_vdso_base(void) 
	"	.set noreorder				\n"

	"	bal	1f				\n"

	"	 nop					\n"

	"	.word	_start - .			\n"

	"	.word	vdso_u_time_data - .		\n"

	"1:	lw	%0, 0($31)			\n"

	"	" STR(PTR_ADDU) " %0, $31, %0		\n"

	"	.set pop				\n"
@@ -58,14 +60,9 @@ static inline unsigned long get_vdso_base(void) 
	return addr;

}



static inline const struct vdso_data *get_vdso_data(void)

{

	return (const struct vdso_data *)(get_vdso_base() - PAGE_SIZE);

}



#ifdef CONFIG_CLKSRC_MIPS_GIC



static inline void __iomem *get_gic(const struct vdso_data *data)

static inline void __iomem *get_gic(const struct vdso_time_data *data)

{

	return (void __iomem *)((unsigned long)data & PAGE_MASK) - PAGE_SIZE;

}

arch/mips/include/asm/vdso/vsyscall.h

+2 −12
Original line number Diff line number Diff line
@@ -2,22 +2,12 @@ 
#ifndef __ASM_VDSO_VSYSCALL_H

#define __ASM_VDSO_VSYSCALL_H



#include <asm/page.h>



#ifndef __ASSEMBLY__



#include <vdso/datapage.h>



extern struct vdso_data *vdso_data;



/*

 * Update the vDSO data page to keep in sync with kernel timekeeping.

 */

static __always_inline

struct vdso_data *__mips_get_k_vdso_data(void)

{

	return vdso_data;

}

#define __arch_get_k_vdso_data __mips_get_k_vdso_data



/* The asm-generic header needs to be included after the definitions above */

#include <asm-generic/vdso/vsyscall.h>

arch/mips/kernel/vdso.c

+18 −29
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/random.h>

#include <linux/sched.h>

#include <linux/slab.h>

#include <linux/vdso_datastore.h>



#include <asm/abi.h>

#include <asm/mips-cps.h>
@@ -23,20 +24,7 @@ 
#include <vdso/helpers.h>

#include <vdso/vsyscall.h>



/* Kernel-provided data used by the VDSO. */

static union vdso_data_store mips_vdso_data __page_aligned_data;

struct vdso_data *vdso_data = mips_vdso_data.data;



/*

 * Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as

 * what we map and where within the area they are mapped is determined at

 * runtime.

 */

static struct page *no_pages[] = { NULL };

static struct vm_special_mapping vdso_vvar_mapping = {

	.name = "[vvar]",

	.pages = no_pages,

};

static_assert(VDSO_NR_PAGES == __VDSO_PAGES);



static void __init init_vdso_image(struct mips_vdso_image *image)

{
@@ -90,7 +78,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 
{

	struct mips_vdso_image *image = current->thread.abi->vdso;

	struct mm_struct *mm = current->mm;

	unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr, gic_pfn, gic_base;

	unsigned long gic_size, size, base, data_addr, vdso_addr, gic_pfn, gic_base;

	struct vm_area_struct *vma;

	int ret;
@@ -119,8 +107,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 
	 * the counter registers at the start.

	 */

	gic_size = mips_gic_present() ? PAGE_SIZE : 0;

	vvar_size = gic_size + PAGE_SIZE;

	size = vvar_size + image->size;

	size = gic_size + VDSO_NR_PAGES * PAGE_SIZE + image->size;



	/*

	 * Find a region that's large enough for us to perform the
@@ -143,15 +130,13 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 
	 */

	if (cpu_has_dc_aliases) {

		base = __ALIGN_MASK(base, shm_align_mask);

		base += ((unsigned long)vdso_data - gic_size) & shm_align_mask;

		base += ((unsigned long)vdso_k_time_data - gic_size) & shm_align_mask;

	}



	data_addr = base + gic_size;

	vdso_addr = data_addr + PAGE_SIZE;

	vdso_addr = data_addr + VDSO_NR_PAGES * PAGE_SIZE;



	vma = _install_special_mapping(mm, base, vvar_size,

				       VM_READ | VM_MAYREAD,

				       &vdso_vvar_mapping);

	vma = vdso_install_vvar_mapping(mm, data_addr);

	if (IS_ERR(vma)) {

		ret = PTR_ERR(vma);

		goto out;
@@ -161,19 +146,23 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 
	if (gic_size) {

		gic_base = (unsigned long)mips_gic_base + MIPS_GIC_USER_OFS;

		gic_pfn = PFN_DOWN(__pa(gic_base));

		static const struct vm_special_mapping gic_mapping = {

			.name	= "[gic]",

			.pages	= (struct page **) { NULL },

		};



		ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size,

					 pgprot_noncached(vma->vm_page_prot));

		if (ret)

		vma = _install_special_mapping(mm, base, gic_size, VM_READ | VM_MAYREAD,

					       &gic_mapping);

		if (IS_ERR(vma)) {

			ret = PTR_ERR(vma);

			goto out;

		}



	/* Map data page. */

	ret = remap_pfn_range(vma, data_addr,

			      virt_to_phys(vdso_data) >> PAGE_SHIFT,

			      PAGE_SIZE, vma->vm_page_prot);

		ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size,

					 pgprot_noncached(vma->vm_page_prot));

		if (ret)

			goto out;

	}



	/* Map VDSO image. */

	vma = _install_special_mapping(mm, vdso_addr, image->size,