nds32: VDSO support

/*

 * SPDX-License-Identifier: GPL-2.0

 * Copyright (C) 2005-2017 Andes Technology Corporation

 */

#ifndef __ASM_VDSO_H

#define __ASM_VDSO_H

#ifdef __KERNEL__

#ifndef __ASSEMBLY__

#include <generated/vdso-offsets.h>

#define VDSO_SYMBOL(base, name)						   \

({									   \

	(unsigned long)(vdso_offset_##name + (unsigned long)(base)); \

})

#endif /* !__ASSEMBLY__ */

#endif /* __KERNEL__ */

#endif /* __ASM_VDSO_H */

// SPDX-License-Identifier: GPL-2.0

// Copyright (C) 2012 ARM Limited

// Copyright (C) 2005-2017 Andes Technology Corporation

#ifndef __ASM_VDSO_DATAPAGE_H

#define __ASM_VDSO_DATAPAGE_H

#ifdef __KERNEL__

#ifndef __ASSEMBLY__

struct vdso_data {

	bool cycle_count_down;	/* timer cyclye counter is decrease with time */

	u32 cycle_count_offset;	/* offset of timer cycle counter register */

	u32 seq_count;		/* sequence count - odd during updates */

	u32 xtime_coarse_sec;	/* coarse time */

	u32 xtime_coarse_nsec;

	u32 wtm_clock_sec;	/* wall to monotonic offset */

	u32 wtm_clock_nsec;

	u32 xtime_clock_sec;	/* CLOCK_REALTIME - seconds */

	u32 cs_mult;		/* clocksource multiplier */

	u32 cs_shift;		/* Cycle to nanosecond divisor (power of two) */

	u64 cs_cycle_last;	/* last cycle value */

	u64 cs_mask;		/* clocksource mask */

	u64 xtime_clock_nsec;	/* CLOCK_REALTIME sub-ns base */

	u32 tz_minuteswest;	/* timezone info for gettimeofday(2) */

	u32 tz_dsttime;

};

#endif /* !__ASSEMBLY__ */

#endif /* __KERNEL__ */

#endif /* __ASM_VDSO_DATAPAGE_H */

// SPDX-License-Identifier: GPL-2.0

// Copyright (C) 2005-2017 Andes Technology Corporation

extern struct timer_info_t timer_info;

#define EMPTY_VALUE ~(0UL)

#define EMPTY_TIMER_MAPPING EMPTY_VALUE

#define EMPTY_REG_OFFSET EMPTY_VALUE

struct timer_info_t

{

	bool cycle_count_down;

	unsigned long mapping_base;

	unsigned long cycle_count_reg_offset;

};

// SPDX-License-Identifier: GPL-2.0

// Copyright (C) 2012 ARM Limited

// Copyright (C) 2005-2017 Andes Technology Corporation

#include <linux/cache.h>

#include <linux/clocksource.h>

#include <linux/elf.h>

#include <linux/err.h>

#include <linux/errno.h>

#include <linux/gfp.h>

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/sched.h>

#include <linux/signal.h>

#include <linux/slab.h>

#include <linux/timekeeper_internal.h>

#include <linux/vmalloc.h>

#include <linux/random.h>

#include <asm/cacheflush.h>

#include <asm/vdso.h>

#include <asm/vdso_datapage.h>

#include <asm/vdso_timer_info.h>

#include <asm/cache_info.h>

extern struct cache_info L1_cache_info[2];

extern char vdso_start, vdso_end;

static unsigned long vdso_pages __ro_after_init;

static unsigned long timer_mapping_base;

struct timer_info_t timer_info = {

	.cycle_count_down = true,

	.mapping_base = EMPTY_TIMER_MAPPING,

	.cycle_count_reg_offset = EMPTY_REG_OFFSET

};

/*

 * The vDSO data page.

 */

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

static union {

	struct vdso_data data;

	u8 page[PAGE_SIZE];

} vdso_data_store __page_aligned_data;

struct vdso_data *vdso_data = &vdso_data_store.data;

static struct vm_special_mapping vdso_spec[2] __ro_after_init = {

	{

	 .name = "[vvar]",

	 .pages = no_pages,

	 },

	{

	 .name = "[vdso]",

	 },

};

static void get_timer_node_info(void)

{

	timer_mapping_base = timer_info.mapping_base;

	vdso_data->cycle_count_offset =

		timer_info.cycle_count_reg_offset;

	vdso_data->cycle_count_down =

		timer_info.cycle_count_down;

}

static int __init vdso_init(void)

{

	int i;

	struct page **vdso_pagelist;

	if (memcmp(&vdso_start, "\177ELF", 4)) {

		pr_err("vDSO is not a valid ELF object!\n");

		return -EINVAL;

	}

	/* Creat a timer io mapping to get clock cycles counter */

	get_timer_node_info();

	vdso_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT;

	pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n",

		vdso_pages + 1, vdso_pages, &vdso_start, 1L, vdso_data);

	/* Allocate the vDSO pagelist */

	vdso_pagelist = kcalloc(vdso_pages, sizeof(struct page *), GFP_KERNEL);

	if (vdso_pagelist == NULL)

		return -ENOMEM;

	for (i = 0; i < vdso_pages; i++)

		vdso_pagelist[i] = virt_to_page(&vdso_start + i * PAGE_SIZE);

	vdso_spec[1].pages = &vdso_pagelist[0];

	return 0;

}

arch_initcall(vdso_init);

unsigned long inline vdso_random_addr(unsigned long vdso_mapping_len)

{

	unsigned long start = current->mm->mmap_base, end, offset, addr;

	start = PAGE_ALIGN(start);

	/* Round the lowest possible end address up to a PMD boundary. */

	end = (start + vdso_mapping_len + PMD_SIZE - 1) & PMD_MASK;

	if (end >= TASK_SIZE)

		end = TASK_SIZE;

	end -= vdso_mapping_len;

	if (end > start) {

		offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1);

		addr = start + (offset << PAGE_SHIFT);

	} else {

		addr = start;

	}

	return addr;

}

int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)

{

	struct mm_struct *mm = current->mm;

	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;

	struct vm_area_struct *vma;

	unsigned long addr = 0;

	pgprot_t prot;

	int ret, vvar_page_num = 2;

	vdso_text_len = vdso_pages << PAGE_SHIFT;

	if(timer_mapping_base == EMPTY_VALUE)

		vvar_page_num = 1;

	/* Be sure to map the data page */

	vdso_mapping_len = vdso_text_len + vvar_page_num * PAGE_SIZE;

#ifdef CONFIG_CPU_CACHE_ALIASING

	vdso_mapping_len += L1_cache_info[DCACHE].aliasing_num - 1;

#endif

	if (down_write_killable(&mm->mmap_sem))

		return -EINTR;

	addr = vdso_random_addr(vdso_mapping_len);

	vdso_base = get_unmapped_area(NULL, addr, vdso_mapping_len, 0, 0);

	if (IS_ERR_VALUE(vdso_base)) {

		ret = vdso_base;

		goto up_fail;

	}

#ifdef CONFIG_CPU_CACHE_ALIASING

	{

		unsigned int aliasing_mask =

		    L1_cache_info[DCACHE].aliasing_mask;

		unsigned int page_colour_ofs;

		page_colour_ofs = ((unsigned int)vdso_data & aliasing_mask) -

		    (vdso_base & aliasing_mask);

		vdso_base += page_colour_ofs & aliasing_mask;

	}

#endif

	vma = _install_special_mapping(mm, vdso_base, vvar_page_num * PAGE_SIZE,

				       VM_READ | VM_MAYREAD, &vdso_spec[0]);

	if (IS_ERR(vma)) {

		ret = PTR_ERR(vma);

		goto up_fail;

	}

	/*Map vdata to user space */

	ret = io_remap_pfn_range(vma, vdso_base,

				 virt_to_phys(vdso_data) >> PAGE_SHIFT,

				 PAGE_SIZE, vma->vm_page_prot);

	if (ret)

		goto up_fail;

	/*Map timer to user space */

	vdso_base += PAGE_SIZE;

	prot = __pgprot(_PAGE_V | _PAGE_M_UR_KR | _PAGE_D |  _PAGE_C_DEV);

	ret = io_remap_pfn_range(vma, vdso_base, timer_mapping_base >> PAGE_SHIFT,

				 PAGE_SIZE, prot);

	if (ret)

		goto up_fail;

	/*Map vdso to user space */

	vdso_base += PAGE_SIZE;

	mm->context.vdso = (void *)vdso_base;

	vma = _install_special_mapping(mm, vdso_base, vdso_text_len,

				       VM_READ | VM_EXEC |

				       VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,

				       &vdso_spec[1]);

	if (IS_ERR(vma)) {

		ret = PTR_ERR(vma);

		goto up_fail;

	}

	up_write(&mm->mmap_sem);

	return 0;

up_fail:

	mm->context.vdso = NULL;

	up_write(&mm->mmap_sem);

	return ret;

}

static void vdso_write_begin(struct vdso_data *vdata)

{

	++vdso_data->seq_count;

	smp_wmb();		/* Pairs with smp_rmb in vdso_read_retry */

}

static void vdso_write_end(struct vdso_data *vdata)

{

	smp_wmb();		/* Pairs with smp_rmb in vdso_read_begin */

	++vdso_data->seq_count;

}

void update_vsyscall(struct timekeeper *tk)

{

	vdso_write_begin(vdso_data);

	vdso_data->cs_mask = tk->tkr_mono.mask;

	vdso_data->cs_mult = tk->tkr_mono.mult;

	vdso_data->cs_shift = tk->tkr_mono.shift;

	vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last;

	vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec;

	vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec;

	vdso_data->xtime_clock_sec = tk->xtime_sec;

	vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;

	vdso_data->xtime_coarse_sec = tk->xtime_sec;

	vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>

	    tk->tkr_mono.shift;

	vdso_write_end(vdso_data);

}

void update_vsyscall_tz(void)

{

	vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;

	vdso_data->tz_dsttime = sys_tz.tz_dsttime;

}

#

# Building a vDSO image for AArch64.

#

# Author: Will Deacon <will.deacon@arm.com>

# Heavily based on the vDSO Makefiles for other archs.

#

obj-vdso := note.o datapage.o sigreturn.o gettimeofday.o

# Build rules

targets := $(obj-vdso) vdso.so vdso.so.dbg

obj-vdso := $(addprefix $(obj)/, $(obj-vdso))

ccflags-y := -shared -fno-common -fno-builtin

ccflags-y += -nostdlib -Wl,-soname=linux-vdso.so.1 \

		$(call cc-ldoption, -Wl$(comma)--hash-style=sysv)

ccflags-y += -fPIC -Wl,-shared -g

# Disable gcov profiling for VDSO code

GCOV_PROFILE := n

obj-y += vdso.o

extra-y += vdso.lds

CPPFLAGS_vdso.lds += -P -C -U$(ARCH)

# Force dependency

$(obj)/vdso.o : $(obj)/vdso.so

# Link rule for the .so file, .lds has to be first

$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso)

	$(call if_changed,vdsold)

# Strip rule for the .so file

$(obj)/%.so: OBJCOPYFLAGS := -S

$(obj)/%.so: $(obj)/%.so.dbg FORCE

	$(call if_changed,objcopy)

# Generate VDSO offsets using helper script

gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh

quiet_cmd_vdsosym = VDSOSYM $@

define cmd_vdsosym

	$(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@

endef

include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE

	$(call if_changed,vdsosym)

# Assembly rules for the .S files

sigreturn.o : sigreturn.S

	$(call if_changed_dep,vdsoas)

note.o : note.S

	$(call if_changed_dep,vdsoas)

datapage.o : datapage.S

	$(call if_changed_dep,vdsoas)

gettimeofday.o : gettimeofday.c FORCE

	$(call if_changed_dep,vdsocc)

# Actual build commands

quiet_cmd_vdsold = VDSOL   $@

      cmd_vdsold = $(CC) $(c_flags) -Wl,-n -Wl,-T $^ -o $@

quiet_cmd_vdsoas = VDSOA   $@

      cmd_vdsoas = $(CC) $(a_flags) -c -o $@ $<

quiet_cmd_vdsocc = VDSOA   $@

      cmd_vdsocc = $(CC) $(c_flags) -c -o $@ $<

# Install commands for the unstripped file

quiet_cmd_vdso_install = INSTALL $@

      cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@

vdso.so: $(obj)/vdso.so.dbg

	@mkdir -p $(MODLIB)/vdso

	$(call cmd,vdso_install)

vdso_install: vdso.so