mm-armv.c

linux-2.6.15.6

		.prot_l1   = PMD_TYPE_TABLE,
		.domain    = DOMAIN_USER,
	},
	[MT_HIGH_VECTORS] = {
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
				L_PTE_USER | L_PTE_EXEC,
		.prot_l1   = PMD_TYPE_TABLE,
		.domain    = DOMAIN_USER,
	},
	[MT_MEMORY] = {
		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_ROM] = {
		.prot_sect = PMD_TYPE_SECT,
		.domain    = DOMAIN_KERNEL,
	},
	[MT_IXP2000_DEVICE] = { /* IXP2400 requires XCB=101 for on-chip I/O */
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
				L_PTE_WRITE,
		.prot_l1   = PMD_TYPE_TABLE,
		.prot_sect = PMD_TYPE_SECT | PMD_SECT_UNCACHED |
				PMD_SECT_AP_WRITE | PMD_SECT_BUFFERABLE |
				PMD_SECT_TEX(1),
		.domain    = DOMAIN_IO,
	}
};

/*
 * Adjust the PMD section entries according to the CPU in use.
 */
void __init build_mem_type_table(void)
{
	struct cachepolicy *cp;
	unsigned int cr = get_cr();
	unsigned int user_pgprot, kern_pgprot;
	int cpu_arch = cpu_architecture();
	int i;

#if defined(CONFIG_CPU_DCACHE_DISABLE)
	if (cachepolicy > CPOLICY_BUFFERED)
		cachepolicy = CPOLICY_BUFFERED;
#elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
	if (cachepolicy > CPOLICY_WRITETHROUGH)
		cachepolicy = CPOLICY_WRITETHROUGH;
#endif
	if (cpu_arch < CPU_ARCH_ARMv5) {
		if (cachepolicy >= CPOLICY_WRITEALLOC)
			cachepolicy = CPOLICY_WRITEBACK;
		ecc_mask = 0;
	}

	if (cpu_arch <= CPU_ARCH_ARMv5TEJ) {
		for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
			if (mem_types[i].prot_l1)
				mem_types[i].prot_l1 |= PMD_BIT4;
			if (mem_types[i].prot_sect)
				mem_types[i].prot_sect |= PMD_BIT4;
		}
	}

	cp = &cache_policies[cachepolicy];
	kern_pgprot = user_pgprot = cp->pte;

	/*
	 * ARMv6 and above have extended page tables.
	 */
	if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
		/*
		 * bit 4 becomes XN which we must clear for the
		 * kernel memory mapping.
		 */
		mem_types[MT_MEMORY].prot_sect &= ~PMD_BIT4;
		mem_types[MT_ROM].prot_sect &= ~PMD_BIT4;

		/*
		 * Mark cache clean areas and XIP ROM read only
		 * from SVC mode and no access from userspace.
		 */
		mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
		mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;

		/*
		 * Mark the device area as "shared device"
		 */
		mem_types[MT_DEVICE].prot_pte |= L_PTE_BUFFERABLE;
		mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;

		/*
		 * User pages need to be mapped with the ASID
		 * (iow, non-global)
		 */
		user_pgprot |= L_PTE_ASID;

#ifdef CONFIG_SMP
		/*
		 * Mark memory with the "shared" attribute for SMP systems
		 */
		user_pgprot |= L_PTE_SHARED;
		kern_pgprot |= L_PTE_SHARED;
		mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
#endif
	}

	for (i = 0; i < 16; i++) {
		unsigned long v = pgprot_val(protection_map[i]);
		v = (v & ~(L_PTE_BUFFERABLE|L_PTE_CACHEABLE)) | user_pgprot;
		protection_map[i] = __pgprot(v);
	}

	mem_types[MT_LOW_VECTORS].prot_pte |= kern_pgprot;
	mem_types[MT_HIGH_VECTORS].prot_pte |= kern_pgprot;

	if (cpu_arch >= CPU_ARCH_ARMv5) {
#ifndef CONFIG_SMP
		/*
		 * Only use write-through for non-SMP systems
		 */
		mem_types[MT_LOW_VECTORS].prot_pte &= ~L_PTE_BUFFERABLE;
		mem_types[MT_HIGH_VECTORS].prot_pte &= ~L_PTE_BUFFERABLE;
#endif
	} else {
		mem_types[MT_MINICLEAN].prot_sect &= ~PMD_SECT_TEX(1);
	}

	pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
				 L_PTE_DIRTY | L_PTE_WRITE |
				 L_PTE_EXEC | kern_pgprot);

	mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
	mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
	mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd;
	mem_types[MT_ROM].prot_sect |= cp->pmd;

	switch (cp->pmd) {
	case PMD_SECT_WT:
		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT;
		break;
	case PMD_SECT_WB:
	case PMD_SECT_WBWA:
		mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB;
		break;
	}
	printk("Memory policy: ECC %sabled, Data cache %s\n",
		ecc_mask ? "en" : "dis", cp->policy);
}

#define vectors_base()	(vectors_high() ? 0xffff0000 : 0)

/*
 * Create the page directory entries and any necessary
 * page tables for the mapping specified by `md'.  We
 * are able to cope here with varying sizes and address
 * offsets, and we take full advantage of sections and
 * supersections.
 */
void __init create_mapping(struct map_desc *md)
{
	unsigned long virt, length;
	int prot_sect, prot_l1, domain;
	pgprot_t prot_pte;
	unsigned long off = (u32)__pfn_to_phys(md->pfn);

	if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
		printk(KERN_WARNING "BUG: not creating mapping for "
		       "0x%08llx at 0x%08lx in user region\n",
		       __pfn_to_phys((u64)md->pfn), md->virtual);
		return;
	}

	if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
	    md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) {
		printk(KERN_WARNING "BUG: mapping for 0x%08llx at 0x%08lx "
		       "overlaps vmalloc space\n",
		       __pfn_to_phys((u64)md->pfn), md->virtual);
	}

	domain	  = mem_types[md->type].domain;
	prot_pte  = __pgprot(mem_types[md->type].prot_pte);
	prot_l1   = mem_types[md->type].prot_l1 | PMD_DOMAIN(domain);
	prot_sect = mem_types[md->type].prot_sect | PMD_DOMAIN(domain);

	/*
	 * Catch 36-bit addresses
	 */
	if(md->pfn >= 0x100000) {
		if(domain) {
			printk(KERN_ERR "MM: invalid domain in supersection "
				"mapping for 0x%08llx at 0x%08lx\n",
				__pfn_to_phys((u64)md->pfn), md->virtual);
			return;
		}
		if((md->virtual | md->length | __pfn_to_phys(md->pfn))
			& ~SUPERSECTION_MASK) {
			printk(KERN_ERR "MM: cannot create mapping for "
				"0x%08llx at 0x%08lx invalid alignment\n",
				__pfn_to_phys((u64)md->pfn), md->virtual);
			return;
		}

		/*
		 * Shift bits [35:32] of address into bits [23:20] of PMD
		 * (See ARMv6 spec).
		 */
		off |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20);
	}

	virt   = md->virtual;
	off   -= virt;
	length = md->length;

	if (mem_types[md->type].prot_l1 == 0 &&
	    (virt & 0xfffff || (virt + off) & 0xfffff || (virt + length) & 0xfffff)) {
		printk(KERN_WARNING "BUG: map for 0x%08lx at 0x%08lx can not "
		       "be mapped using pages, ignoring.\n",
		       __pfn_to_phys(md->pfn), md->virtual);
		return;
	}

	while ((virt & 0xfffff || (virt + off) & 0xfffff) && length >= PAGE_SIZE) {
		alloc_init_page(virt, virt + off, prot_l1, prot_pte);

		virt   += PAGE_SIZE;
		length -= PAGE_SIZE;
	}

	/* N.B.	ARMv6 supersections are only defined to work with domain 0.
	 *	Since domain assignments can in fact be arbitrary, the
	 *	'domain == 0' check below is required to insure that ARMv6
	 *	supersections are only allocated for domain 0 regardless
	 *	of the actual domain assignments in use.
	 */
	if (cpu_architecture() >= CPU_ARCH_ARMv6 && domain == 0) {
		/*
		 * Align to supersection boundary if !high pages.
		 * High pages have already been checked for proper
		 * alignment above and they will fail the SUPSERSECTION_MASK
		 * check because of the way the address is encoded into
		 * offset.
		 */
		if (md->pfn <= 0x100000) {
			while ((virt & ~SUPERSECTION_MASK ||
			        (virt + off) & ~SUPERSECTION_MASK) &&
				length >= (PGDIR_SIZE / 2)) {
				alloc_init_section(virt, virt + off, prot_sect);

				virt   += (PGDIR_SIZE / 2);
				length -= (PGDIR_SIZE / 2);
			}
		}

		while (length >= SUPERSECTION_SIZE) {
			alloc_init_supersection(virt, virt + off, prot_sect);

			virt   += SUPERSECTION_SIZE;
			length -= SUPERSECTION_SIZE;
		}
	}

	/*
	 * A section mapping covers half a "pgdir" entry.
	 */
	while (length >= (PGDIR_SIZE / 2)) {
		alloc_init_section(virt, virt + off, prot_sect);

		virt   += (PGDIR_SIZE / 2);
		length -= (PGDIR_SIZE / 2);
	}

	while (length >= PAGE_SIZE) {
		alloc_init_page(virt, virt + off, prot_l1, prot_pte);

		virt   += PAGE_SIZE;
		length -= PAGE_SIZE;
	}
}

/*
 * In order to soft-boot, we need to insert a 1:1 mapping in place of
 * the user-mode pages.  This will then ensure that we have predictable
 * results when turning the mmu off
 */
void setup_mm_for_reboot(char mode)
{
	unsigned long base_pmdval;
	pgd_t *pgd;
	int i;

	if (current->mm && current->mm->pgd)
		pgd = current->mm->pgd;
	else
		pgd = init_mm.pgd;

	base_pmdval = PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | PMD_TYPE_SECT;
	if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ)
		base_pmdval |= PMD_BIT4;

	for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++, pgd++) {
		unsigned long pmdval = (i << PGDIR_SHIFT) | base_pmdval;
		pmd_t *pmd;

		pmd = pmd_off(pgd, i << PGDIR_SHIFT);
		pmd[0] = __pmd(pmdval);
		pmd[1] = __pmd(pmdval + (1 << (PGDIR_SHIFT - 1)));
		flush_pmd_entry(pmd);
	}
}

/*
 * Create the architecture specific mappings
 */
void __init iotable_init(struct map_desc *io_desc, int nr)
{
	int i;

	for (i = 0; i < nr; i++)
		create_mapping(io_desc + i);
}