srmmu.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

	: "g5", "cc");
	FLUSH_END
}

static void cypress_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
	struct mm_struct *mm = vma->vm_mm;

	FLUSH_BEGIN(mm)
	__asm__ __volatile__(
	"lda	[%0] %3, %%g5\n\t"
	"sta	%1, [%0] %3\n\t"
	"sta	%%g0, [%2] %4\n\t"
	"sta	%%g5, [%0] %3\n"
	: /* no outputs */
	: "r" (SRMMU_CTX_REG), "r" (mm->context), "r" (page & PAGE_MASK),
	  "i" (ASI_M_MMUREGS), "i" (ASI_M_FLUSH_PROBE)
	: "g5");
	FLUSH_END
}

/* viking.S */
extern void viking_flush_cache_all(void);
extern void viking_flush_cache_mm(struct mm_struct *mm);
extern void viking_flush_cache_range(struct mm_struct *mm, unsigned long start,
				     unsigned long end);
extern void viking_flush_cache_page(struct vm_area_struct *vma,
				    unsigned long page);
extern void viking_flush_page_to_ram(unsigned long page);
extern void viking_flush_page_for_dma(unsigned long page);
extern void viking_flush_sig_insns(struct mm_struct *mm, unsigned long addr);
extern void viking_flush_page(unsigned long page);
extern void viking_mxcc_flush_page(unsigned long page);
extern void viking_flush_tlb_all(void);
extern void viking_flush_tlb_mm(struct mm_struct *mm);
extern void viking_flush_tlb_range(struct mm_struct *mm, unsigned long start,
				   unsigned long end);
extern void viking_flush_tlb_page(struct vm_area_struct *vma,
				  unsigned long page);
extern void sun4dsmp_flush_tlb_all(void);
extern void sun4dsmp_flush_tlb_mm(struct mm_struct *mm);
extern void sun4dsmp_flush_tlb_range(struct mm_struct *mm, unsigned long start,
				   unsigned long end);
extern void sun4dsmp_flush_tlb_page(struct vm_area_struct *vma,
				  unsigned long page);

/* hypersparc.S */
extern void hypersparc_flush_cache_all(void);
extern void hypersparc_flush_cache_mm(struct mm_struct *mm);
extern void hypersparc_flush_cache_range(struct mm_struct *mm, unsigned long start, unsigned long end);
extern void hypersparc_flush_cache_page(struct vm_area_struct *vma, unsigned long page);
extern void hypersparc_flush_page_to_ram(unsigned long page);
extern void hypersparc_flush_page_for_dma(unsigned long page);
extern void hypersparc_flush_sig_insns(struct mm_struct *mm, unsigned long insn_addr);
extern void hypersparc_flush_tlb_all(void);
extern void hypersparc_flush_tlb_mm(struct mm_struct *mm);
extern void hypersparc_flush_tlb_range(struct mm_struct *mm, unsigned long start, unsigned long end);
extern void hypersparc_flush_tlb_page(struct vm_area_struct *vma, unsigned long page);
extern void hypersparc_setup_blockops(void);

/*
 * NOTE: All of this startup code assumes the low 16mb (approx.) of
 *       kernel mappings are done with one single contiguous chunk of
 *       ram.  On small ram machines (classics mainly) we only get
 *       around 8mb mapped for us.
 */

void __init early_pgtable_allocfail(char *type)
{
	prom_printf("inherit_prom_mappings: Cannot alloc kernel %s.\n", type);
	prom_halt();
}

void __init srmmu_early_allocate_ptable_skeleton(unsigned long start, unsigned long end)
{
	pgd_t *pgdp;
	pmd_t *pmdp;
	pte_t *ptep;

	while(start < end) {
		pgdp = pgd_offset_k(start);
		if(srmmu_pgd_none(*(pgd_t *)__nocache_fix(pgdp))) {
			pmdp = (pmd_t *)__srmmu_get_nocache(SRMMU_PMD_TABLE_SIZE, SRMMU_PMD_TABLE_SIZE);
			if (pmdp == NULL)
				early_pgtable_allocfail("pmd");
			memset(__nocache_fix(pmdp), 0, SRMMU_PMD_TABLE_SIZE);
			srmmu_pgd_set(__nocache_fix(pgdp), pmdp);
		}
		pmdp = srmmu_pmd_offset(__nocache_fix(pgdp), start);
		if(srmmu_pmd_none(*(pmd_t *)__nocache_fix(pmdp))) {
			ptep = (pte_t *)__srmmu_get_nocache(SRMMU_PTE_TABLE_SIZE, SRMMU_PTE_TABLE_SIZE);
			if (ptep == NULL)
				early_pgtable_allocfail("pte");
			memset(__nocache_fix(ptep), 0, SRMMU_PTE_TABLE_SIZE);
			srmmu_pmd_set(__nocache_fix(pmdp), ptep);
		}
		start = (start + SRMMU_PMD_SIZE) & SRMMU_PMD_MASK;
	}
}

void __init srmmu_allocate_ptable_skeleton(unsigned long start, unsigned long end)
{
	pgd_t *pgdp;
	pmd_t *pmdp;
	pte_t *ptep;

	while(start < end) {
		pgdp = pgd_offset_k(start);
		if(srmmu_pgd_none(*pgdp)) {
			pmdp = (pmd_t *)__srmmu_get_nocache(SRMMU_PMD_TABLE_SIZE, SRMMU_PMD_TABLE_SIZE);
			if (pmdp == NULL)
				early_pgtable_allocfail("pmd");
			memset(pmdp, 0, SRMMU_PMD_TABLE_SIZE);
			srmmu_pgd_set(pgdp, pmdp);
		}
		pmdp = srmmu_pmd_offset(pgdp, start);
		if(srmmu_pmd_none(*pmdp)) {
			ptep = (pte_t *)__srmmu_get_nocache(SRMMU_PTE_TABLE_SIZE, SRMMU_PTE_TABLE_SIZE);
			if (ptep == NULL)
				early_pgtable_allocfail("pte");
			memset(ptep, 0, SRMMU_PTE_TABLE_SIZE);
			srmmu_pmd_set(pmdp, ptep);
		}
		start = (start + SRMMU_PMD_SIZE) & SRMMU_PMD_MASK;
	}
}

/*
 * This is much cleaner than poking around physical address space
 * looking at the prom's page table directly which is what most
 * other OS's do.  Yuck... this is much better.
 */
void __init srmmu_inherit_prom_mappings(unsigned long start,unsigned long end)
{
	pgd_t *pgdp;
	pmd_t *pmdp;
	pte_t *ptep;
	int what = 0; /* 0 = normal-pte, 1 = pmd-level pte, 2 = pgd-level pte */
	unsigned long prompte;

	while(start <= end) {
		if (start == 0)
			break; /* probably wrap around */
		if(start == 0xfef00000)
			start = KADB_DEBUGGER_BEGVM;
		if(!(prompte = srmmu_hwprobe(start))) {
			start += PAGE_SIZE;
			continue;
		}
    
		/* A red snapper, see what it really is. */
		what = 0;
    
		if(!(start & ~(SRMMU_PMD_MASK))) {
			if(srmmu_hwprobe((start-PAGE_SIZE) + SRMMU_PMD_SIZE) == prompte)
				what = 1;
		}
    
		if(!(start & ~(SRMMU_PGDIR_MASK))) {
			if(srmmu_hwprobe((start-PAGE_SIZE) + SRMMU_PGDIR_SIZE) ==
			   prompte)
				what = 2;
		}
    
		pgdp = pgd_offset_k(start);
		if(what == 2) {
			*(pgd_t *)__nocache_fix(pgdp) = __pgd(prompte);
			start += SRMMU_PGDIR_SIZE;
			continue;
		}
		if(srmmu_pgd_none(*(pgd_t *)__nocache_fix(pgdp))) {
			pmdp = (pmd_t *)__srmmu_get_nocache(SRMMU_PMD_TABLE_SIZE, SRMMU_PMD_TABLE_SIZE);
			if (pmdp == NULL)
				early_pgtable_allocfail("pmd");
			memset(__nocache_fix(pmdp), 0, SRMMU_PMD_TABLE_SIZE);
			srmmu_pgd_set(__nocache_fix(pgdp), pmdp);
		}
		pmdp = srmmu_pmd_offset(__nocache_fix(pgdp), start);
		if(what == 1) {
			*(pmd_t *)__nocache_fix(pmdp) = __pmd(prompte);
			start += SRMMU_PMD_SIZE;
			continue;
		}
		if(srmmu_pmd_none(*(pmd_t *)__nocache_fix(pmdp))) {
			ptep = (pte_t *)__srmmu_get_nocache(SRMMU_PTE_TABLE_SIZE, SRMMU_PTE_TABLE_SIZE);
			if (ptep == NULL)
				early_pgtable_allocfail("pte");
			memset(__nocache_fix(ptep), 0, SRMMU_PTE_TABLE_SIZE);
			srmmu_pmd_set(__nocache_fix(pmdp), ptep);
		}
		ptep = srmmu_pte_offset(__nocache_fix(pmdp), start);
		*(pte_t *)__nocache_fix(ptep) = __pte(prompte);
		start += PAGE_SIZE;
	}
}

#define KERNEL_PTE(page_shifted) ((page_shifted)|SRMMU_CACHE|SRMMU_PRIV|SRMMU_VALID)

/* Create a third-level SRMMU 16MB page mapping. */
static void __init do_large_mapping(unsigned long vaddr, unsigned long phys_base)
{
	pgd_t *pgdp = pgd_offset_k(vaddr);
	unsigned long big_pte;

	big_pte = KERNEL_PTE(phys_base >> 4);
	*(pgd_t *)__nocache_fix(pgdp) = __pgd(big_pte);
}

/* Map sp_bank entry SP_ENTRY, starting at virtual address VBASE. */
static unsigned long __init map_spbank(unsigned long vbase, int sp_entry)
{
	unsigned long pstart = (sp_banks[sp_entry].base_addr & SRMMU_PGDIR_MASK);
	unsigned long vstart = (vbase & SRMMU_PGDIR_MASK);
	unsigned long vend = SRMMU_PGDIR_ALIGN(vbase + sp_banks[sp_entry].num_bytes);
	/* Map "low" memory only */
	const unsigned long min_vaddr = PAGE_OFFSET;
	const unsigned long max_vaddr = PAGE_OFFSET + SRMMU_MAXMEM;

	if (vstart < min_vaddr || vstart >= max_vaddr)
		return vstart;
	
	if (vend > max_vaddr || vend < min_vaddr)
		vend = max_vaddr;

	while(vstart < vend) {
		do_large_mapping(vstart, pstart);
		vstart += SRMMU_PGDIR_SIZE; pstart += SRMMU_PGDIR_SIZE;
	}
	return vstart;
}

static inline void memprobe_error(char *msg)
{
	prom_printf(msg);
	prom_printf("Halting now...\n");
	prom_halt();
}

static inline void map_kernel(void)
{
	int i;

	if (phys_base > 0) {
		do_large_mapping(PAGE_OFFSET, phys_base);
	}

	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
		map_spbank((unsigned long)__va(sp_banks[i].base_addr), i);
	}

	BTFIXUPSET_SIMM13(user_ptrs_per_pgd, PAGE_OFFSET / SRMMU_PGDIR_SIZE);
}

/* Paging initialization on the Sparc Reference MMU. */
extern void sparc_context_init(int);

extern int linux_num_cpus;
extern unsigned long totalhigh_pages;

void (*poke_srmmu)(void) __initdata = NULL;

extern unsigned long bootmem_init(unsigned long *pages_avail);
extern void sun_serial_setup(void);

void __init srmmu_paging_init(void)
{
	int i, cpunode;
	char node_str[128];
	pgd_t *pgd;
	pmd_t *pmd;
	pte_t *pte;
	unsigned long pages_avail;

	sparc_iomap.start = SUN4M_IOBASE_VADDR;	/* 16MB of IOSPACE on all sun4m's. */

	if (sparc_cpu_model == sun4d)
		num_contexts = 65536; /* We know it is Viking */
	else {
		/* Find the number of contexts on the srmmu. */
		cpunode = prom_getchild(prom_root_node);
		num_contexts = 0;
		while(cpunode != 0) {
			prom_getstring(cpunode, "device_type", node_str, sizeof(node_str));
			if(!strcmp(node_str, "cpu")) {
				num_contexts = prom_getintdefault(cpunode, "mmu-nctx", 0x8);
				break;
			}
			cpunode = prom_getsibling(cpunode);
		}
	}

	if(!num_contexts) {
		prom_printf("Something wrong, can't find cpu node in paging_init.\n");
		prom_halt();
	}

	pages_avail = 0;
	last_valid_pfn = bootmem_init(&pages_avail);

	srmmu_nocache_init();
        srmmu_inherit_prom_mappings(0xfe400000,(LINUX_OPPROM_ENDVM-PAGE_SIZE));
	map_kernel();

	/* ctx table has to be physically aligned to its size */
	srmmu_context_table = (ctxd_t *)__srmmu_get_nocache(num_contexts*sizeof(ctxd_t), num_contexts*sizeof(ctxd_t));
	srmmu_ctx_table_phys = (ctxd_t *)__nocache_pa((unsigned long)srmmu_context_table);

	for(i = 0; i < num_contexts; i++)
		srmmu_ctxd_set((ctxd_t *)__nocache_fix(&srmmu_context_table[i]), srmmu_swapper_pg_dir);

	flush_cache_all();
	srmmu_set_ctable_ptr((unsigned long)srmmu_ctx_table_phys);
	flush_tlb_all();
	poke_srmmu();

#if CONFIG_SUN_IO
	srmmu_allocate_ptable_skeleton(sparc_iomap.start, IOBASE_END);
	srmmu_allocate_ptable_skeleton(DVMA_VADDR, DVMA_END);
#endif

	srmmu_allocate_ptable_skeleton(FIX_KMAP_BEGIN, FIX_KMAP_END);
	srmmu_allocate_ptable_skeleton(PKMAP_BASE, PKMAP_BASE_END);

	pgd = pgd_offset_k(PKMAP_BASE);
	pmd = pmd_offset(pgd, PKMAP_BASE);
	pte = pte_offset(pmd, PKMAP_BASE);
	pkmap_page_table = pte;

	flush_cache_all();
	flush_tlb_all();

	/*
	 * This does not logically belong here, but we need to
	 * call it at the moment we are able to use the bootmem
	 * allocator.
	 */
	sun_serial_setup();

	sparc_context_init(num_contexts);

	kmap_init();

	{
		unsigned long zones_size[MAX_NR_ZONES];
		unsigned long zholes_size[MAX_NR_ZONES];
		unsigned long npages;
		int znum;

		for (znum = 0; znum < MAX_NR_ZONES; znum++)
			zones_size[znum] = zholes_size[znum] = 0;

		npages = max_low_pfn - (phys_base >> PAGE_SHIFT);

		zones_size[ZONE_DMA] = npages;
		zholes_size[ZONE_DMA] = npages - pages_avail;

		npages = highend_pfn - max_low_pfn;
		zones_size[ZONE_HIGHMEM] = npages;
		zholes_size[ZONE_HIGHMEM] = npages - calc_highpages();

		free_area_init_node(0, NULL, NULL, zones_size,
				    phys_base, zholes_size);
	}
}

static void srmmu_mmu_info(struct seq_file *m)
{
	seq_printf(m, 
		   "MMU type\t: %s\n"
		   "contexts\t: %d\n"
		   "nocache total\t: %ld\n"
		   "nocache used\t: %d\n",
		   srmmu_name,
		   num_contexts,
		   SRMMU_NOCACHE_SIZE,
		   (srmmu_nocache_used << SRMMU_NOCACHE_BITMAP_SHIFT));
}

static void srmmu_update_mmu_cache(struct vm_area_struct * vma, unsigned long address, pte_t pte)
{
}

static void srmmu_destroy_context(struct mm_struct *mm)
{

	if(mm->context != NO_CONTEXT) {
		flush_cache_mm(mm);
		srmmu_ctxd_set(&srmmu_context_table[mm->context], srmmu_swapper_pg_dir);
		flush_tlb_mm(mm);
		spin_lock(&srmmu_context_spinlock);
		free_context(mm->context);
		spin_unlock(&srmmu_context_spinlock);
		mm->context = NO_CONTEXT;
	}
}

/* Init various srmmu chip types. */
static void __init srmmu_is_bad(void)
{
	prom_printf("Could not determine SRMMU chip type.\n");
	prom_halt();
}

static void __init init_vac_layout(void)
{
	int nd, cache_lines;
	char node_str[128];
#ifdef CONFIG_SMP
	int cpu = 0;
	unsigned long max_size = 0;
	unsigned long min_line_size = 0x10000000;
#endif

	nd = prom_getchild(prom_root_node);
	while((nd = prom_getsibling(nd)) != 0) {
		prom_getstring(nd, "device_type", node_str, sizeof(node_str));
		if(!strcmp(node_str, "cpu")) {
			vac_line_size = prom_getint(nd, "cache-line-size");
			if (vac_line_size == -1) {
				prom_printf("can't determine cache-line-size, "
					    "halting.\n");
				prom_halt();
			}
			cache_lines = prom_getint(nd, "cache-nlines");