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-rw-r--r--arch/x86/Kconfig14
-rw-r--r--arch/x86/include/asm/elf.h1
-rw-r--r--arch/x86/kernel/cpu/amd.c4
-rw-r--r--arch/x86/kernel/devicetree.c4
-rw-r--r--arch/x86/kernel/e820.c2
-rw-r--r--arch/x86/kernel/setup.c8
-rw-r--r--arch/x86/kernel/sys_x86_64.c30
-rw-r--r--arch/x86/mm/init.c68
-rw-r--r--arch/x86/mm/init_64.c14
-rw-r--r--arch/x86/mm/pageattr.c4
-rw-r--r--arch/x86/mm/pat.c6
-rw-r--r--arch/x86/mm/pgtable.c81
-rw-r--r--arch/x86/platform/efi/efi-bgrt.c4
-rw-r--r--include/linux/init.h38
14 files changed, 189 insertions, 89 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 867bc5bea8dc..faff6934c05a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1295,14 +1295,14 @@ config ARCH_DMA_ADDR_T_64BIT
def_bool y
depends on X86_64 || HIGHMEM64G
-config DIRECT_GBPAGES
- bool "Enable 1GB pages for kernel pagetables" if EXPERT
- default y
- depends on X86_64
+config X86_DIRECT_GBPAGES
+ def_bool y
+ depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
---help---
- Allow the kernel linear mapping to use 1GB pages on CPUs that
- support it. This can improve the kernel's performance a tiny bit by
- reducing TLB pressure. If in doubt, say "Y".
+ Certain kernel features effectively disable kernel
+ linear 1 GB mappings (even if the CPU otherwise
+ supports them), so don't confuse the user by printing
+ that we have them enabled.
# Common NUMA Features
config NUMA
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 3563107b5060..935588d95c82 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -366,6 +366,7 @@ enum align_flags {
struct va_alignment {
int flags;
unsigned long mask;
+ unsigned long bits;
} ____cacheline_aligned;
extern struct va_alignment va_align;
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index dd9e50500297..fd470ebf924e 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -5,6 +5,7 @@
#include <linux/io.h>
#include <linux/sched.h>
+#include <linux/random.h>
#include <asm/processor.h>
#include <asm/apic.h>
#include <asm/cpu.h>
@@ -488,6 +489,9 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
va_align.mask = (upperbit - 1) & PAGE_MASK;
va_align.flags = ALIGN_VA_32 | ALIGN_VA_64;
+
+ /* A random value per boot for bit slice [12:upper_bit) */
+ va_align.bits = get_random_int() & va_align.mask;
}
}
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 3d3503351242..6367a780cc8c 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -286,13 +286,13 @@ static void __init x86_flattree_get_config(void)
initial_boot_params = dt = early_memremap(initial_dtb, map_len);
size = of_get_flat_dt_size();
if (map_len < size) {
- early_iounmap(dt, map_len);
+ early_memunmap(dt, map_len);
initial_boot_params = dt = early_memremap(initial_dtb, size);
map_len = size;
}
unflatten_and_copy_device_tree();
- early_iounmap(dt, map_len);
+ early_memunmap(dt, map_len);
}
#else
static inline void x86_flattree_get_config(void) { }
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 46201deee923..7d46bb260334 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -661,7 +661,7 @@ void __init parse_e820_ext(u64 phys_addr, u32 data_len)
extmap = (struct e820entry *)(sdata->data);
__append_e820_map(extmap, entries);
sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
- early_iounmap(sdata, data_len);
+ early_memunmap(sdata, data_len);
printk(KERN_INFO "e820: extended physical RAM map:\n");
e820_print_map("extended");
}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 014466b152b5..d74ac33290ae 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -354,7 +354,7 @@ static void __init relocate_initrd(void)
mapaddr = ramdisk_image & PAGE_MASK;
p = early_memremap(mapaddr, clen+slop);
memcpy(q, p+slop, clen);
- early_iounmap(p, clen+slop);
+ early_memunmap(p, clen+slop);
q += clen;
ramdisk_image += clen;
ramdisk_size -= clen;
@@ -438,7 +438,7 @@ static void __init parse_setup_data(void)
data_len = data->len + sizeof(struct setup_data);
data_type = data->type;
pa_next = data->next;
- early_iounmap(data, sizeof(*data));
+ early_memunmap(data, sizeof(*data));
switch (data_type) {
case SETUP_E820_EXT:
@@ -470,7 +470,7 @@ static void __init e820_reserve_setup_data(void)
E820_RAM, E820_RESERVED_KERN);
found = 1;
pa_data = data->next;
- early_iounmap(data, sizeof(*data));
+ early_memunmap(data, sizeof(*data));
}
if (!found)
return;
@@ -491,7 +491,7 @@ static void __init memblock_x86_reserve_range_setup_data(void)
data = early_memremap(pa_data, sizeof(*data));
memblock_reserve(pa_data, sizeof(*data) + data->len);
pa_data = data->next;
- early_iounmap(data, sizeof(*data));
+ early_memunmap(data, sizeof(*data));
}
}
diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index 30277e27431a..10e0272d789a 100644
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -34,10 +34,26 @@ static unsigned long get_align_mask(void)
return va_align.mask;
}
+/*
+ * To avoid aliasing in the I$ on AMD F15h, the bits defined by the
+ * va_align.bits, [12:upper_bit), are set to a random value instead of
+ * zeroing them. This random value is computed once per boot. This form
+ * of ASLR is known as "per-boot ASLR".
+ *
+ * To achieve this, the random value is added to the info.align_offset
+ * value before calling vm_unmapped_area() or ORed directly to the
+ * address.
+ */
+static unsigned long get_align_bits(void)
+{
+ return va_align.bits & get_align_mask();
+}
+
unsigned long align_vdso_addr(unsigned long addr)
{
unsigned long align_mask = get_align_mask();
- return (addr + align_mask) & ~align_mask;
+ addr = (addr + align_mask) & ~align_mask;
+ return addr | get_align_bits();
}
static int __init control_va_addr_alignment(char *str)
@@ -135,8 +151,12 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
info.length = len;
info.low_limit = begin;
info.high_limit = end;
- info.align_mask = filp ? get_align_mask() : 0;
+ info.align_mask = 0;
info.align_offset = pgoff << PAGE_SHIFT;
+ if (filp) {
+ info.align_mask = get_align_mask();
+ info.align_offset += get_align_bits();
+ }
return vm_unmapped_area(&info);
}
@@ -174,8 +194,12 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
info.length = len;
info.low_limit = PAGE_SIZE;
info.high_limit = mm->mmap_base;
- info.align_mask = filp ? get_align_mask() : 0;
+ info.align_mask = 0;
info.align_offset = pgoff << PAGE_SHIFT;
+ if (filp) {
+ info.align_mask = get_align_mask();
+ info.align_offset += get_align_bits();
+ }
addr = vm_unmapped_area(&info);
if (!(addr & ~PAGE_MASK))
return addr;
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 52417e771af9..1d553186c434 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -29,29 +29,33 @@
/*
* Tables translating between page_cache_type_t and pte encoding.
- * Minimal supported modes are defined statically, modified if more supported
- * cache modes are available.
- * Index into __cachemode2pte_tbl is the cachemode.
- * Index into __pte2cachemode_tbl are the caching attribute bits of the pte
- * (_PAGE_PWT, _PAGE_PCD, _PAGE_PAT) at index bit positions 0, 1, 2.
+ *
+ * Minimal supported modes are defined statically, they are modified
+ * during bootup if more supported cache modes are available.
+ *
+ * Index into __cachemode2pte_tbl[] is the cachemode.
+ *
+ * Index into __pte2cachemode_tbl[] are the caching attribute bits of the pte
+ * (_PAGE_PWT, _PAGE_PCD, _PAGE_PAT) at index bit positions 0, 1, 2.
*/
uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = {
- [_PAGE_CACHE_MODE_WB] = 0,
- [_PAGE_CACHE_MODE_WC] = _PAGE_PWT,
- [_PAGE_CACHE_MODE_UC_MINUS] = _PAGE_PCD,
- [_PAGE_CACHE_MODE_UC] = _PAGE_PCD | _PAGE_PWT,
- [_PAGE_CACHE_MODE_WT] = _PAGE_PCD,
- [_PAGE_CACHE_MODE_WP] = _PAGE_PCD,
+ [_PAGE_CACHE_MODE_WB ] = 0 | 0 ,
+ [_PAGE_CACHE_MODE_WC ] = _PAGE_PWT | 0 ,
+ [_PAGE_CACHE_MODE_UC_MINUS] = 0 | _PAGE_PCD,
+ [_PAGE_CACHE_MODE_UC ] = _PAGE_PWT | _PAGE_PCD,
+ [_PAGE_CACHE_MODE_WT ] = 0 | _PAGE_PCD,
+ [_PAGE_CACHE_MODE_WP ] = 0 | _PAGE_PCD,
};
EXPORT_SYMBOL(__cachemode2pte_tbl);
+
uint8_t __pte2cachemode_tbl[8] = {
- [__pte2cm_idx(0)] = _PAGE_CACHE_MODE_WB,
- [__pte2cm_idx(_PAGE_PWT)] = _PAGE_CACHE_MODE_WC,
- [__pte2cm_idx(_PAGE_PCD)] = _PAGE_CACHE_MODE_UC_MINUS,
- [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD)] = _PAGE_CACHE_MODE_UC,
- [__pte2cm_idx(_PAGE_PAT)] = _PAGE_CACHE_MODE_WB,
- [__pte2cm_idx(_PAGE_PWT | _PAGE_PAT)] = _PAGE_CACHE_MODE_WC,
- [__pte2cm_idx(_PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS,
+ [__pte2cm_idx( 0 | 0 | 0 )] = _PAGE_CACHE_MODE_WB,
+ [__pte2cm_idx(_PAGE_PWT | 0 | 0 )] = _PAGE_CACHE_MODE_WC,
+ [__pte2cm_idx( 0 | _PAGE_PCD | 0 )] = _PAGE_CACHE_MODE_UC_MINUS,
+ [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | 0 )] = _PAGE_CACHE_MODE_UC,
+ [__pte2cm_idx( 0 | 0 | _PAGE_PAT)] = _PAGE_CACHE_MODE_WB,
+ [__pte2cm_idx(_PAGE_PWT | 0 | _PAGE_PAT)] = _PAGE_CACHE_MODE_WC,
+ [__pte2cm_idx(0 | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS,
[__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC,
};
EXPORT_SYMBOL(__pte2cachemode_tbl);
@@ -131,21 +135,7 @@ void __init early_alloc_pgt_buf(void)
int after_bootmem;
-int direct_gbpages
-#ifdef CONFIG_DIRECT_GBPAGES
- = 1
-#endif
-;
-
-static void __init init_gbpages(void)
-{
-#ifdef CONFIG_X86_64
- if (direct_gbpages && cpu_has_gbpages)
- printk(KERN_INFO "Using GB pages for direct mapping\n");
- else
- direct_gbpages = 0;
-#endif
-}
+early_param_on_off("gbpages", "nogbpages", direct_gbpages, CONFIG_X86_DIRECT_GBPAGES);
struct map_range {
unsigned long start;
@@ -157,16 +147,12 @@ static int page_size_mask;
static void __init probe_page_size_mask(void)
{
- init_gbpages();
-
#if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK)
/*
* For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
* This will simplify cpa(), which otherwise needs to support splitting
* large pages into small in interrupt context, etc.
*/
- if (direct_gbpages)
- page_size_mask |= 1 << PG_LEVEL_1G;
if (cpu_has_pse)
page_size_mask |= 1 << PG_LEVEL_2M;
#endif
@@ -181,6 +167,14 @@ static void __init probe_page_size_mask(void)
__supported_pte_mask |= _PAGE_GLOBAL;
} else
__supported_pte_mask &= ~_PAGE_GLOBAL;
+
+ /* Enable 1 GB linear kernel mappings if available: */
+ if (direct_gbpages && cpu_has_gbpages) {
+ printk(KERN_INFO "Using GB pages for direct mapping\n");
+ page_size_mask |= 1 << PG_LEVEL_1G;
+ } else {
+ direct_gbpages = 0;
+ }
}
#ifdef CONFIG_X86_32
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 30eb05ae7061..3fba623e3ba5 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -130,20 +130,6 @@ int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
return 0;
}
-static int __init parse_direct_gbpages_off(char *arg)
-{
- direct_gbpages = 0;
- return 0;
-}
-early_param("nogbpages", parse_direct_gbpages_off);
-
-static int __init parse_direct_gbpages_on(char *arg)
-{
- direct_gbpages = 1;
- return 0;
-}
-early_param("gbpages", parse_direct_gbpages_on);
-
/*
* NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
* physical space so we can cache the place of the first one and move
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 536ea2fb6e33..89af288ec674 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -81,11 +81,9 @@ void arch_report_meminfo(struct seq_file *m)
seq_printf(m, "DirectMap4M: %8lu kB\n",
direct_pages_count[PG_LEVEL_2M] << 12);
#endif
-#ifdef CONFIG_X86_64
if (direct_gbpages)
seq_printf(m, "DirectMap1G: %8lu kB\n",
direct_pages_count[PG_LEVEL_1G] << 20);
-#endif
}
#else
static inline void split_page_count(int level) { }
@@ -1654,13 +1652,11 @@ int set_memory_ro(unsigned long addr, int numpages)
{
return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW), 0);
}
-EXPORT_SYMBOL_GPL(set_memory_ro);
int set_memory_rw(unsigned long addr, int numpages)
{
return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0);
}
-EXPORT_SYMBOL_GPL(set_memory_rw);
int set_memory_np(unsigned long addr, int numpages)
{
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 7ac68698406c..35af6771a95a 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -610,7 +610,7 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
}
#ifdef CONFIG_STRICT_DEVMEM
-/* This check is done in drivers/char/mem.c in case of STRICT_DEVMEM*/
+/* This check is done in drivers/char/mem.c in case of STRICT_DEVMEM */
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
return 1;
@@ -628,8 +628,8 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
while (cursor < to) {
if (!devmem_is_allowed(pfn)) {
- printk(KERN_INFO "Program %s tried to access /dev/mem between [mem %#010Lx-%#010Lx]\n",
- current->comm, from, to - 1);
+ printk(KERN_INFO "Program %s tried to access /dev/mem between [mem %#010Lx-%#010Lx], PAT prevents it\n",
+ current->comm, from, to - 1);
return 0;
}
cursor += PAGE_SIZE;
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 7b22adaad4f1..5a7e5252c878 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -275,12 +275,87 @@ static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[])
}
}
+/*
+ * Xen paravirt assumes pgd table should be in one page. 64 bit kernel also
+ * assumes that pgd should be in one page.
+ *
+ * But kernel with PAE paging that is not running as a Xen domain
+ * only needs to allocate 32 bytes for pgd instead of one page.
+ */
+#ifdef CONFIG_X86_PAE
+
+#include <linux/slab.h>
+
+#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
+#define PGD_ALIGN 32
+
+static struct kmem_cache *pgd_cache;
+
+static int __init pgd_cache_init(void)
+{
+ /*
+ * When PAE kernel is running as a Xen domain, it does not use
+ * shared kernel pmd. And this requires a whole page for pgd.
+ */
+ if (!SHARED_KERNEL_PMD)
+ return 0;
+
+ /*
+ * when PAE kernel is not running as a Xen domain, it uses
+ * shared kernel pmd. Shared kernel pmd does not require a whole
+ * page for pgd. We are able to just allocate a 32-byte for pgd.
+ * During boot time, we create a 32-byte slab for pgd table allocation.
+ */
+ pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_ALIGN,
+ SLAB_PANIC, NULL);
+ if (!pgd_cache)
+ return -ENOMEM;
+
+ return 0;
+}
+core_initcall(pgd_cache_init);
+
+static inline pgd_t *_pgd_alloc(void)
+{
+ /*
+ * If no SHARED_KERNEL_PMD, PAE kernel is running as a Xen domain.
+ * We allocate one page for pgd.
+ */
+ if (!SHARED_KERNEL_PMD)
+ return (pgd_t *)__get_free_page(PGALLOC_GFP);
+
+ /*
+ * Now PAE kernel is not running as a Xen domain. We can allocate
+ * a 32-byte slab for pgd to save memory space.
+ */
+ return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
+}
+
+static inline void _pgd_free(pgd_t *pgd)
+{
+ if (!SHARED_KERNEL_PMD)
+ free_page((unsigned long)pgd);
+ else
+ kmem_cache_free(pgd_cache, pgd);
+}
+#else
+static inline pgd_t *_pgd_alloc(void)
+{
+ return (pgd_t *)__get_free_page(PGALLOC_GFP);
+}
+
+static inline void _pgd_free(pgd_t *pgd)
+{
+ free_page((unsigned long)pgd);
+}
+#endif /* CONFIG_X86_PAE */
+
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *pgd;
pmd_t *pmds[PREALLOCATED_PMDS];
- pgd = (pgd_t *)__get_free_page(PGALLOC_GFP);
+ pgd = _pgd_alloc();
if (pgd == NULL)
goto out;
@@ -310,7 +385,7 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
out_free_pmds:
free_pmds(mm, pmds);
out_free_pgd:
- free_page((unsigned long)pgd);
+ _pgd_free(pgd);
out:
return NULL;
}
@@ -320,7 +395,7 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
pgd_mop_up_pmds(mm, pgd);
pgd_dtor(pgd);
paravirt_pgd_free(mm, pgd);
- free_page((unsigned long)pgd);
+ _pgd_free(pgd);
}
/*
diff --git a/arch/x86/platform/efi/efi-bgrt.c b/arch/x86/platform/efi/efi-bgrt.c
index d143d216d52b..d7f997f7c26d 100644
--- a/arch/x86/platform/efi/efi-bgrt.c
+++ b/arch/x86/platform/efi/efi-bgrt.c
@@ -67,7 +67,7 @@ void __init efi_bgrt_init(void)
image = efi_lookup_mapped_addr(bgrt_tab->image_address);
if (!image) {
- image = early_memremap(bgrt_tab->image_address,
+ image = early_ioremap(bgrt_tab->image_address,
sizeof(bmp_header));
ioremapped = true;
if (!image) {
@@ -89,7 +89,7 @@ void __init efi_bgrt_init(void)
}
if (ioremapped) {
- image = early_memremap(bgrt_tab->image_address,
+ image = early_ioremap(bgrt_tab->image_address,
bmp_header.size);
if (!image) {
pr_err("Ignoring BGRT: failed to map image memory\n");
diff --git a/include/linux/init.h b/include/linux/init.h
index 2df8e8dd10a4..21b6d768edd7 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -253,21 +253,41 @@ struct obs_kernel_param {
* obs_kernel_param "array" too far apart in .init.setup.
*/
#define __setup_param(str, unique_id, fn, early) \
- static const char __setup_str_##unique_id[] __initconst \
- __aligned(1) = str; \
- static struct obs_kernel_param __setup_##unique_id \
- __used __section(.init.setup) \
- __attribute__((aligned((sizeof(long))))) \
+ static const char __setup_str_##unique_id[] __initconst \
+ __aligned(1) = str; \
+ static struct obs_kernel_param __setup_##unique_id \
+ __used __section(.init.setup) \
+ __attribute__((aligned((sizeof(long))))) \
= { __setup_str_##unique_id, fn, early }
-#define __setup(str, fn) \
+#define __setup(str, fn) \
__setup_param(str, fn, fn, 0)
-/* NOTE: fn is as per module_param, not __setup! Emits warning if fn
- * returns non-zero. */
-#define early_param(str, fn) \
+/*
+ * NOTE: fn is as per module_param, not __setup!
+ * Emits warning if fn returns non-zero.
+ */
+#define early_param(str, fn) \
__setup_param(str, fn, fn, 1)
+#define early_param_on_off(str_on, str_off, var, config) \
+ \
+ int var = IS_ENABLED(config); \
+ \
+ static int __init parse_##var##_on(char *arg) \
+ { \
+ var = 1; \
+ return 0; \
+ } \
+ __setup_param(str_on, parse_##var##_on, parse_##var##_on, 1); \
+ \
+ static int __init parse_##var##_off(char *arg) \
+ { \
+ var = 0; \
+ return 0; \
+ } \
+ __setup_param(str_off, parse_##var##_off, parse_##var##_off, 1)
+
/* Relies on boot_command_line being set */
void __init parse_early_param(void);
void __init parse_early_options(char *cmdline);