Commit 5a9e3e15 authored by Jisheng Zhang's avatar Jisheng Zhang Committed by Will Deacon
Browse files

arm64: apply __ro_after_init to some objects 

These objects are set during initialization, thereafter are read only.

Previously I only want to mark vdso_pages, vdso_spec, vectors_page and
cpu_ops as __read_mostly from performance point of view. Then inspired
by Kees's patch[1] to apply more __ro_after_init for arm, I think it's
better to mark them as __ro_after_init. What's more, I find some more
objects are also read only after init. So apply __ro_after_init to all
of them.

This patch also removes global vdso_pagelist and tries to clean up
vdso_spec[] assignment code.

[1] http://www.spinics.net/lists/arm-kernel/msg523188.html



Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarJisheng Zhang <jszhang@marvell.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent b6d081bd

arch/arm64/kernel/cpu_ops.c

+2 −1
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
 */



#include <linux/acpi.h>

#include <linux/cache.h>

#include <linux/errno.h>

#include <linux/of.h>

#include <linux/string.h>
@@ -28,7 +29,7 @@ extern const struct cpu_operations smp_spin_table_ops; 
extern const struct cpu_operations acpi_parking_protocol_ops;

extern const struct cpu_operations cpu_psci_ops;



const struct cpu_operations *cpu_ops[NR_CPUS];

const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;



static const struct cpu_operations *dt_supported_cpu_ops[] __initconst = {

	&smp_spin_table_ops,

arch/arm64/kernel/kaslr.c

+2 −1
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
 * published by the Free Software Foundation.

 */



#include <linux/cache.h>

#include <linux/crc32.h>

#include <linux/init.h>

#include <linux/libfdt.h>
@@ -20,7 +21,7 @@ 
#include <asm/pgtable.h>

#include <asm/sections.h>



u64 __read_mostly module_alloc_base;

u64 __ro_after_init module_alloc_base;

u16 __initdata memstart_offset_seed;



static __init u64 get_kaslr_seed(void *fdt)

arch/arm64/kernel/vdso.c

+15 −15
Original line number Diff line number Diff line
@@ -18,12 +18,13 @@ 
 * Author: Will Deacon <will.deacon@arm.com>

 */



#include <linux/kernel.h>

#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>
@@ -37,8 +38,7 @@ 
#include <asm/vdso_datapage.h>



extern char vdso_start, vdso_end;

static unsigned long vdso_pages;

static struct page **vdso_pagelist;

static unsigned long vdso_pages __ro_after_init;



/*

 * The vDSO data page.
@@ -53,7 +53,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data; 
/*

 * Create and map the vectors page for AArch32 tasks.

 */

static struct page *vectors_page[1];

static struct page *vectors_page[1] __ro_after_init;



static int __init alloc_vectors_page(void)

{
@@ -110,11 +110,19 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp) 
}

#endif /* CONFIG_COMPAT */



static struct vm_special_mapping vdso_spec[2];

static struct vm_special_mapping vdso_spec[2] __ro_after_init = {

	{

		.name	= "[vvar]",

	},

	{

		.name	= "[vdso]",

	},

};



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");
@@ -138,16 +146,8 @@ static int __init vdso_init(void) 
	for (i = 0; i < vdso_pages; i++)

		vdso_pagelist[i + 1] = pfn_to_page(PHYS_PFN(__pa(&vdso_start)) + i);



	/* Populate the special mapping structures */

	vdso_spec[0] = (struct vm_special_mapping) {

		.name	= "[vvar]",

		.pages	= vdso_pagelist,

	};



	vdso_spec[1] = (struct vm_special_mapping) {

		.name	= "[vdso]",

		.pages	= &vdso_pagelist[1],

	};

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

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



	return 0;

}

arch/arm64/mm/dma-mapping.c

+2 −1
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/gfp.h>

#include <linux/acpi.h>

#include <linux/bootmem.h>

#include <linux/cache.h>

#include <linux/export.h>

#include <linux/slab.h>

#include <linux/genalloc.h>
@@ -30,7 +31,7 @@ 


#include <asm/cacheflush.h>



static int swiotlb __read_mostly;

static int swiotlb __ro_after_init;



static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot,

				 bool coherent)

arch/arm64/mm/init.c

+3 −2
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/swap.h>

#include <linux/init.h>

#include <linux/bootmem.h>

#include <linux/cache.h>

#include <linux/mman.h>

#include <linux/nodemask.h>

#include <linux/initrd.h>
@@ -55,8 +56,8 @@ 
 * executes, which assigns it its actual value. So use a default value

 * that cannot be mistaken for a real physical address.

 */

s64 memstart_addr __read_mostly = -1;

phys_addr_t arm64_dma_phys_limit __read_mostly;

s64 memstart_addr __ro_after_init = -1;

phys_addr_t arm64_dma_phys_limit __ro_after_init;



#ifdef CONFIG_BLK_DEV_INITRD

static int __init early_initrd(char *p)

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