i386 memory init cleanup
This patch improves code readability in the i386 memory initialization code
by refactoring, removal of needless casts, fixing of line width exceedings,
macro->inline function replacement, some comments and indentation correction.
Signed-off-by: Johannes Weiner <[EMAIL PROTECTED]>
---
Note: Functionality was modified in set_kernel_exec(): It bails out if
lookup_address() fails to prevent a NULL pointer dereference.
arch/i386/mm/init.c | 211 +++++++++++++++++++++++++++------------------------
1 files changed, 113 insertions(+), 98 deletions(-)
diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c
index dc3c03f..15a109e 100644
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -64,13 +64,12 @@ static pmd_t * __init one_md_table_init(pgd_t *pgd)
#ifdef CONFIG_X86_PAE
if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
- pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+ pmd_table = alloc_bootmem_low_pages(PAGE_SIZE);
paravirt_alloc_pd(__pa(pmd_table) >> PAGE_SHIFT);
set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
pud = pud_offset(pgd, 0);
- if (pmd_table != pmd_offset(pud, 0))
- BUG();
+ BUG_ON(pmd_table != pmd_offset(pud, 0));
}
#endif
pud = pud_offset(pgd, 0);
@@ -85,7 +84,7 @@ static pmd_t * __init one_md_table_init(pgd_t *pgd)
static pte_t * __init one_page_table_init(pmd_t *pmd)
{
if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
- pte_t *page_table = (pte_t *)
alloc_bootmem_low_pages(PAGE_SIZE);
+ pte_t *page_table = alloc_bootmem_low_pages(PAGE_SIZE);
paravirt_alloc_pt(&init_mm, __pa(page_table) >> PAGE_SHIFT);
set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
@@ -106,27 +105,25 @@ static pte_t * __init one_page_table_init(pmd_t *pmd)
* so we can cache the place of the first one and move around without
* checking the pgd every time.
*/
-static void __init page_table_range_init (unsigned long start, unsigned long
end, pgd_t *pgd_base)
-{
- pgd_t *pgd;
- pmd_t *pmd;
- int pgd_idx, pmd_idx;
- unsigned long vaddr;
-
- vaddr = start;
- pgd_idx = pgd_index(vaddr);
- pmd_idx = pmd_index(vaddr);
- pgd = pgd_base + pgd_idx;
-
- for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
- pmd = one_md_table_init(pgd);
- pmd = pmd + pmd_index(vaddr);
- for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); pmd++,
pmd_idx++) {
- one_page_table_init(pmd);
+static void __init page_table_range_init(unsigned long start,
+ unsigned long end, pgd_t *pgd_base)
+{
+ unsigned long vaddr = start;
+ int pgd_idx = pgd_index(start);
+ int pmd_idx = pmd_index(start);
+ pgd_t *pgd = pgd_base + pgd_idx;
+ while (pgd_idx < PTRS_PER_PGD && vaddr != end) {
+ pmd_t *pmd = one_md_table_init(pgd) + pmd_index(vaddr);
+ while (pmd_idx < PTRS_PER_PMD && vaddr != end) {
+ one_page_table_init(pmd);
vaddr += PMD_SIZE;
+ pmd++;
+ pmd_idx++;
}
pmd_idx = 0;
+ pgd++;
+ pgd_idx++;
}
}
@@ -137,6 +134,43 @@ static inline int is_kernel_text(unsigned long addr)
return 0;
}
+static void __init kernel_pmd_init(pmd_t *pmd, unsigned long *pfnp)
+{
+ unsigned long pfn = *pfnp;
+ unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
+
+ /* Map with big pages if possible, otherwise create normal
+ * page tables. */
+ if (cpu_has_pse) {
+ unsigned int addr2 = (pfn + PTRS_PER_PTE - 1) * PAGE_SIZE +
+ PAGE_OFFSET + PAGE_SIZE - 1;
+
+ if (is_kernel_text(addr) || is_kernel_text(addr2))
+ set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC));
+ else
+ set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE));
+
+ pfn += PTRS_PER_PTE;
+ } else {
+ int pte_ofs = 0;
+ pte_t *pte = one_page_table_init(pmd);
+
+ while (pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn) {
+ if (is_kernel_text(addr))
+ set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC));
+ else
+ set_pte(pte, pfn_pte(pfn, PAGE_KERNEL));
+
+ pte++;
+ pte_ofs++;
+ pfn++;
+ addr += PAGE_SIZE;
+ }
+ }
+
+ *pfnp = pfn;
+}
+
/*
* This maps the physical memory to kernel virtual address space, a total
* of max_low_pfn pages, by creating page tables starting from address
@@ -144,45 +178,25 @@ static inline int is_kernel_text(unsigned long addr)
*/
static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
{
- unsigned long pfn;
- pgd_t *pgd;
- pmd_t *pmd;
- pte_t *pte;
- int pgd_idx, pmd_idx, pte_ofs;
+ unsigned long pfn = 0;
+ int pgd_idx = pgd_index(PAGE_OFFSET);
+ pgd_t *pgd = pgd_base + pgd_idx;
- pgd_idx = pgd_index(PAGE_OFFSET);
- pgd = pgd_base + pgd_idx;
- pfn = 0;
+ while (pgd_idx < PTRS_PER_PGD) {
+ int pmd_idx = 0;
+ pmd_t *pmd = one_md_table_init(pgd);
- for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
- pmd = one_md_table_init(pgd);
if (pfn >= max_low_pfn)
continue;
- for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn;
pmd++, pmd_idx++) {
- unsigned int address = pfn * PAGE_SIZE + PAGE_OFFSET;
-
- /* Map with big pages if possible, otherwise create
normal page tables. */
- if (cpu_has_pse) {
- unsigned int address2 = (pfn + PTRS_PER_PTE -
1) * PAGE_SIZE + PAGE_OFFSET + PAGE_SIZE-1;
- if (is_kernel_text(address) ||
is_kernel_text(address2))
- set_pmd(pmd, pfn_pmd(pfn,
PAGE_KERNEL_LARGE_EXEC));
- else
- set_pmd(pmd, pfn_pmd(pfn,
PAGE_KERNEL_LARGE));
-
- pfn += PTRS_PER_PTE;
- } else {
- pte = one_page_table_init(pmd);
-
- for (pte_ofs = 0;
- pte_ofs < PTRS_PER_PTE && pfn <
max_low_pfn;
- pte++, pfn++, pte_ofs++, address +=
PAGE_SIZE) {
- if (is_kernel_text(address))
- set_pte(pte, pfn_pte(pfn,
PAGE_KERNEL_EXEC));
- else
- set_pte(pte, pfn_pte(pfn,
PAGE_KERNEL));
- }
- }
+
+ while (pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn) {
+ kernel_pmd_init(pmd, &pfn);
+ pmd++;
+ pmd_idx++;
}
+
+ pgd++;
+ pgd_idx++;
}
}
@@ -236,36 +250,30 @@ int page_is_ram(unsigned long pagenr)
pte_t *kmap_pte;
pgprot_t kmap_prot;
-#define kmap_get_fixmap_pte(vaddr) \
- pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), vaddr),
(vaddr)), (vaddr))
+static inline pte_t kmap_get_pte(pgd_t *pgd, unsigned long addr)
+{
+ pud_t *pud = pud_offset(pgd, addr);
+ pmd_t *pmd = pmd_offset(pud, addr);
+
+ return pte_offset_kernel(pmd, addr);
+}
static void __init kmap_init(void)
{
- unsigned long kmap_vstart;
+ unsigned long kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
/* cache the first kmap pte */
- kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
- kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
-
+ kmap_pte = kmap_get_fixmap_pte(pgd_offset_k(kmap_vstart), kmap_vstart);
kmap_prot = PAGE_KERNEL;
}
static void __init permanent_kmaps_init(pgd_t *pgd_base)
{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
- unsigned long vaddr;
-
- vaddr = PKMAP_BASE;
- page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
-
- pgd = swapper_pg_dir + pgd_index(vaddr);
- pud = pud_offset(pgd, vaddr);
- pmd = pmd_offset(pud, vaddr);
- pte = pte_offset_kernel(pmd, vaddr);
- pkmap_page_table = pte;
+ page_table_range_init(PKMAP_BASE,
+ PKMAP_BASE + PAGE_SIZE * LAST_PKMAP,
+ pgd_base);
+ pkmap_page_table = kmap_get_pte(swapper_pg_dir + pgd_index(PKMAP_BASE),
+ PKMAP_BASE);
}
static void __meminit free_new_highpage(struct page *page)
@@ -284,7 +292,8 @@ void __init add_one_highpage_init(struct page *page, int
pfn, int bad_ppro)
SetPageReserved(page);
}
-static int __meminit add_one_highpage_hotplug(struct page *page, unsigned long
pfn)
+static int __meminit add_one_highpage_hotplug(struct page *page,
+ unsigned long pfn)
{
free_new_highpage(page);
totalram_pages++;
@@ -527,16 +536,18 @@ static void __init set_nx(void)
int __init set_kernel_exec(unsigned long vaddr, int enable)
{
pte_t *pte;
- int ret = 1;
+ int prev;
if (!nx_enabled)
- goto out;
+ return 1;
pte = lookup_address(vaddr);
- BUG_ON(!pte);
+ if (!pte) {
+ BUG();
+ return 1;
+ }
- if (!pte_exec_kernel(*pte))
- ret = 0;
+ prev = pte_exec_kernel(*pte);
if (enable)
pte->pte_high &= ~(1 << (_PAGE_BIT_NX - 32));
@@ -544,11 +555,11 @@ int __init set_kernel_exec(unsigned long vaddr, int
enable)
pte->pte_high |= 1 << (_PAGE_BIT_NX - 32);
pte_update_defer(&init_mm, vaddr, pte);
__flush_tlb_all();
-out:
- return ret;
+
+ return prev;
}
-#endif
+#endif /* CONFIG_X86_PAE */
/*
* paging_init() sets up the page tables - note that the first 8MB are
@@ -591,7 +602,8 @@ void __init paging_init(void)
static void __init test_wp_bit(void)
{
- printk("Checking if this processor honours the WP bit even in
supervisor mode... ");
+ printk("Checking if this processor honours the WP bit "
+ "even in supervisor mode... ");
/* Any page-aligned address will do, the test is non-destructive */
__set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY);
@@ -601,7 +613,8 @@ static void __init test_wp_bit(void)
if (!boot_cpu_data.wp_works_ok) {
printk("No.\n");
#ifdef CONFIG_X86_WP_WORKS_OK
- panic("This kernel doesn't support CPU's with broken WP.
Recompile it for a 386!");
+ panic("This kernel doesn't support CPU's with broken WP. "
+ "Recompile it for a 386!");
#endif
} else {
printk("Ok.\n");
@@ -626,9 +639,11 @@ void __init mem_init(void)
#ifdef CONFIG_HIGHMEM
/* check that fixmap and pkmap do not overlap */
if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
- printk(KERN_ERR "fixmap and kmap areas overlap - this will
crash\n");
+ printk(KERN_ERR "fixmap and kmap areas overlap "
+ "- this will crash\n");
printk(KERN_ERR "pkstart: %lxh pkend: %lxh fixstart %lxh\n",
- PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
FIXADDR_START);
+ PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
+ FIXADDR_START);
BUG();
}
#endif
@@ -654,15 +669,15 @@ void __init mem_init(void)
kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
VMALLOC_END-VMALLOC_START);
- printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk
reserved, %dk data, %dk init, %ldk highmem)\n",
- (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
- num_physpages << (PAGE_SHIFT-10),
- codesize >> 10,
- reservedpages << (PAGE_SHIFT-10),
- datasize >> 10,
- initsize >> 10,
- (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10))
- );
+ printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
+ "%dk reserved, %dk data, %dk init, %ldk highmem)\n",
+ (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
+ num_physpages << (PAGE_SHIFT-10),
+ codesize >> 10,
+ reservedpages << (PAGE_SHIFT-10),
+ datasize >> 10,
+ initsize >> 10,
+ (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
#if 1 /* double-sanity-check paranoia */
printk("virtual kernel memory layout:\n"
@@ -826,7 +841,7 @@ void mark_rodata_ro(void)
*/
global_flush_tlb();
}
-#endif
+#endif /* CONFIG_DEBUG_RODATA */
void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
-
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