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Commit 4e29684c authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

x86: introduce init_memory_mapping for 32bit #1 



... so can we use mem below max_low_pfn earlier.

this allows us to move several functions more early instead of waiting
to after paging_init.

That includes moving relocate_initrd() earlier in the bootup, and kva
related early setup done in initmem_init. (in followup patches)

Signed-off-by: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent c3c2fee3

arch/x86/kernel/setup_32.c

+6 −4
Original line number Diff line number Diff line
@@ -226,9 +226,7 @@ static void __init reserve_initrd(void) 
	}



	/* We need to move the initrd down into lowmem */

	ramdisk_target = max_pfn_mapped<<PAGE_SHIFT;

	ramdisk_here = find_e820_area(min(ramdisk_target, end_of_lowmem>>1),

				 end_of_lowmem, ramdisk_size,

	ramdisk_here = find_e820_area(0, end_of_lowmem, ramdisk_size,

					 PAGE_SIZE);



	if (ramdisk_here == -1ULL)
@@ -433,8 +431,12 @@ void __init setup_arch(char **cmdline_p) 
		max_pfn = e820_end_of_ram();

	}



	/* max_low_pfn get updated here */

	find_low_pfn_range();



	/* max_pfn_mapped is updated here */

	init_memory_mapping(0, (max_low_pfn << PAGE_SHIFT));



	reserve_initrd();



	dmi_scan_machine();

arch/x86/mm/init_32.c

+112 −29
Original line number Diff line number Diff line
@@ -57,6 +57,27 @@ unsigned long highstart_pfn, highend_pfn; 


static noinline int do_test_wp_bit(void);





static unsigned long __initdata table_start;

static unsigned long __meminitdata table_end;

static unsigned long __meminitdata table_top;



static int __initdata after_init_bootmem;



static __init void *alloc_low_page(unsigned long *phys)

{

	unsigned long pfn = table_end++;

	void *adr;



	if (pfn >= table_top)

		panic("alloc_low_page: ran out of memory");



	adr = __va(pfn * PAGE_SIZE);

	memset(adr, 0, PAGE_SIZE);

	*phys  = pfn * PAGE_SIZE;

	return adr;

}



/*

 * Creates a middle page table and puts a pointer to it in the

 * given global directory entry. This only returns the gd entry
@@ -68,9 +89,12 @@ static pmd_t * __init one_md_table_init(pgd_t *pgd) 
	pmd_t *pmd_table;



#ifdef CONFIG_X86_PAE

	unsigned long phys;

	if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {

		if (after_init_bootmem)

			pmd_table = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);



		else

			pmd_table = (pmd_t *)alloc_low_page(&phys);

		paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);

		set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));

		pud = pud_offset(pgd, 0);
@@ -92,12 +116,16 @@ static pte_t * __init one_page_table_init(pmd_t *pmd) 
	if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {

		pte_t *page_table = NULL;



		if (after_init_bootmem) {

#ifdef CONFIG_DEBUG_PAGEALLOC

			page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);

#endif

		if (!page_table) {

			if (!page_table)

				page_table =

				(pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);

		} else {

			unsigned long phys;

			page_table = (pte_t *)alloc_low_page(&phys);

		}



		paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
@@ -155,7 +183,9 @@ static inline int is_kernel_text(unsigned long addr) 
 * of max_low_pfn pages, by creating page tables starting from address

 * PAGE_OFFSET:

 */

static void __init kernel_physical_mapping_init(pgd_t *pgd_base)

static void __init kernel_physical_mapping_init(pgd_t *pgd_base,

						unsigned long start,

						unsigned long end)

{

	int pgd_idx, pmd_idx, pte_ofs;

	unsigned long pfn;
@@ -163,18 +193,19 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base) 
	pmd_t *pmd;

	pte_t *pte;

	unsigned pages_2m = 0, pages_4k = 0;

	unsigned limit_pfn = end >> PAGE_SHIFT;



	pgd_idx = pgd_index(PAGE_OFFSET);

	pgd = pgd_base + pgd_idx;

	pfn = 0;

	pfn = start >> PAGE_SHIFT;



	for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {

		pmd = one_md_table_init(pgd);

		if (pfn >= max_low_pfn)

		if (pfn >= limit_pfn)

			continue;



		for (pmd_idx = 0;

		     pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn;

		     pmd_idx < PTRS_PER_PMD && pfn < limit_pfn;

		     pmd++, pmd_idx++) {

			unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
@@ -418,20 +449,7 @@ static void __init pagetable_init(void) 


	paravirt_pagetable_setup_start(pgd_base);



	/* Enable PSE if available */

	if (cpu_has_pse)

		set_in_cr4(X86_CR4_PSE);



	/* Enable PGE if available */

	if (cpu_has_pge) {

		set_in_cr4(X86_CR4_PGE);

		__PAGE_KERNEL |= _PAGE_GLOBAL;

		__PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;

	}



	kernel_physical_mapping_init(pgd_base);

	remap_numa_kva();



	/*

	 * Fixed mappings, only the page table structure has to be

	 * created - mappings will be set by set_fixmap():
@@ -703,6 +721,7 @@ void __init setup_bootmem_allocator(void) 
		free_bootmem_with_active_regions(i, max_low_pfn);

	early_res_to_bootmem(0, max_low_pfn<<PAGE_SHIFT);



	after_init_bootmem = 1;

}



/*
@@ -723,26 +742,90 @@ static void __init remapped_pgdat_init(void) 
	}

}



static void __init find_early_table_space(unsigned long end)

{

	unsigned long puds, pmds, tables, start;



	puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;

	tables = PAGE_ALIGN(puds * sizeof(pud_t));



	pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;

	tables += PAGE_ALIGN(pmds * sizeof(pmd_t));



	/*

 * paging_init() sets up the page tables - note that the first 8MB are

 * already mapped by head.S.

 *

 * This routines also unmaps the page at virtual kernel address 0, so

 * that we can trap those pesky NULL-reference errors in the kernel.

	 * RED-PEN putting page tables only on node 0 could

	 * cause a hotspot and fill up ZONE_DMA. The page tables

	 * need roughly 0.5KB per GB.

	 */

void __init paging_init(void)

	start = 0x7000;

	table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,

					tables, PAGE_SIZE);

	if (table_start == -1UL)

		panic("Cannot find space for the kernel page tables");



	table_start >>= PAGE_SHIFT;

	table_end = table_start;

	table_top = table_start + (tables>>PAGE_SHIFT);



	printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",

		end, table_start << PAGE_SHIFT,

		(table_start << PAGE_SHIFT) + tables);

}



unsigned long __init_refok init_memory_mapping(unsigned long start,

						unsigned long end)

{

	pgd_t *pgd_base = swapper_pg_dir;



	/*

	 * Find space for the kernel direct mapping tables.

	 */

	if (!after_init_bootmem)

		find_early_table_space(end);



#ifdef CONFIG_X86_PAE

	set_nx();

	if (nx_enabled)

		printk(KERN_INFO "NX (Execute Disable) protection: active\n");

#endif

	pagetable_init();



	/* Enable PSE if available */

	if (cpu_has_pse)

		set_in_cr4(X86_CR4_PSE);



	/* Enable PGE if available */

	if (cpu_has_pge) {

		set_in_cr4(X86_CR4_PGE);

		__PAGE_KERNEL |= _PAGE_GLOBAL;

		__PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;

	}



	kernel_physical_mapping_init(pgd_base, start, end);



	load_cr3(swapper_pg_dir);



	__flush_tlb_all();



	if (!after_init_bootmem)

		reserve_early(table_start << PAGE_SHIFT,

				 table_end << PAGE_SHIFT, "PGTABLE");



	return end >> PAGE_SHIFT;

}



/*

 * paging_init() sets up the page tables - note that the first 8MB are

 * already mapped by head.S.

 *

 * This routines also unmaps the page at virtual kernel address 0, so

 * that we can trap those pesky NULL-reference errors in the kernel.

 */

void __init paging_init(void)

{

	pagetable_init();



	__flush_tlb_all();



	kmap_init();



	/*

include/asm-x86/page_32.h

+2 −0
Original line number Diff line number Diff line
@@ -93,6 +93,8 @@ extern int sysctl_legacy_va_layout; 
#define MAXMEM			(-__PAGE_OFFSET - __VMALLOC_RESERVE)



extern void find_low_pfn_range(void);

extern unsigned long init_memory_mapping(unsigned long start,

					 unsigned long end);

extern void initmem_init(unsigned long, unsigned long);

extern void zone_sizes_init(void);

extern void setup_bootmem_allocator(void);