sun4c.c

linux-2.6.15.6

					free_user_entry(new_ctx, entry);

					entry = next;
				} while (entry != head);
				sun4c_set_context(savectx);
			}
			local_irq_restore(flags);
		}
	}
}

static void sun4c_flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
	struct mm_struct *mm = vma->vm_mm;
	int new_ctx = mm->context;

	if (new_ctx != NO_CONTEXT) {
		struct sun4c_mmu_entry *head = &sun4c_context_ring[new_ctx].ringhd;
		struct sun4c_mmu_entry *entry;
		unsigned long flags;

		flush_user_windows();

		local_irq_save(flags);
		/* All user segmap chains are ordered on entry->vaddr. */
		for (entry = head->next;
		     (entry != head) && ((entry->vaddr+SUN4C_REAL_PGDIR_SIZE) < start);
		     entry = entry->next)
			;

		/* Tracing various job mixtures showed that this conditional
		 * only passes ~35% of the time for most worse case situations,
		 * therefore we avoid all of this gross overhead ~65% of the time.
		 */
		if ((entry != head) && (entry->vaddr < end)) {
			int octx = sun4c_get_context();
			sun4c_set_context(new_ctx);

			/* At this point, always, (start >= entry->vaddr) and
			 * (entry->vaddr < end), once the latter condition
			 * ceases to hold, or we hit the end of the list, we
			 * exit the loop.  The ordering of all user allocated
			 * segmaps makes this all work out so beautifully.
			 */
			do {
				struct sun4c_mmu_entry *next = entry->next;
				unsigned long realend;

				/* "realstart" is always >= entry->vaddr */
				realend = entry->vaddr + SUN4C_REAL_PGDIR_SIZE;
				if (end < realend)
					realend = end;
				if ((realend - entry->vaddr) <= (PAGE_SIZE << 3)) {
					unsigned long page = entry->vaddr;
					while (page < realend) {
						sun4c_flush_page(page);
						page += PAGE_SIZE;
					}
				} else {
					sun4c_flush_segment(entry->vaddr);
					sun4c_user_unmap(entry);
					free_user_entry(new_ctx, entry);
				}
				entry = next;
			} while ((entry != head) && (entry->vaddr < end));
			sun4c_set_context(octx);
		}
		local_irq_restore(flags);
	}
}

static void sun4c_flush_cache_page(struct vm_area_struct *vma, unsigned long page)
{
	struct mm_struct *mm = vma->vm_mm;
	int new_ctx = mm->context;

	/* Sun4c has no separate I/D caches so cannot optimize for non
	 * text page flushes.
	 */
	if (new_ctx != NO_CONTEXT) {
		int octx = sun4c_get_context();
		unsigned long flags;

		flush_user_windows();
		local_irq_save(flags);
		sun4c_set_context(new_ctx);
		sun4c_flush_page(page);
		sun4c_set_context(octx);
		local_irq_restore(flags);
	}
}

static void sun4c_flush_page_to_ram(unsigned long page)
{
	unsigned long flags;

	local_irq_save(flags);
	sun4c_flush_page(page);
	local_irq_restore(flags);
}

/* Sun4c cache is unified, both instructions and data live there, so
 * no need to flush the on-stack instructions for new signal handlers.
 */
static void sun4c_flush_sig_insns(struct mm_struct *mm, unsigned long insn_addr)
{
}

/* TLB flushing on the sun4c.  These routines count on the cache
 * flushing code to flush the user register windows so that we need
 * not do so when we get here.
 */

static void sun4c_flush_tlb_all(void)
{
	struct sun4c_mmu_entry *this_entry, *next_entry;
	unsigned long flags;
	int savectx, ctx;

	local_irq_save(flags);
	this_entry = sun4c_kernel_ring.ringhd.next;
	savectx = sun4c_get_context();
	flush_user_windows();
	while (sun4c_kernel_ring.num_entries) {
		next_entry = this_entry->next;
		sun4c_flush_segment(this_entry->vaddr);
		for (ctx = 0; ctx < num_contexts; ctx++) {
			sun4c_set_context(ctx);
			sun4c_put_segmap(this_entry->vaddr, invalid_segment);
		}
		free_kernel_entry(this_entry, &sun4c_kernel_ring);
		this_entry = next_entry;
	}
	sun4c_set_context(savectx);
	local_irq_restore(flags);
}

static void sun4c_flush_tlb_mm(struct mm_struct *mm)
{
	int new_ctx = mm->context;

	if (new_ctx != NO_CONTEXT) {
		struct sun4c_mmu_entry *head = &sun4c_context_ring[new_ctx].ringhd;
		unsigned long flags;

		local_irq_save(flags);
		if (head->next != head) {
			struct sun4c_mmu_entry *entry = head->next;
			int savectx = sun4c_get_context();

			sun4c_set_context(new_ctx);
			sun4c_flush_context();
			do {
				struct sun4c_mmu_entry *next = entry->next;

				sun4c_user_unmap(entry);
				free_user_entry(new_ctx, entry);

				entry = next;
			} while (entry != head);
			sun4c_set_context(savectx);
		}
		local_irq_restore(flags);
	}
}

static void sun4c_flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
	struct mm_struct *mm = vma->vm_mm;
	int new_ctx = mm->context;

	if (new_ctx != NO_CONTEXT) {
		struct sun4c_mmu_entry *head = &sun4c_context_ring[new_ctx].ringhd;
		struct sun4c_mmu_entry *entry;
		unsigned long flags;

		local_irq_save(flags);
		/* See commentary in sun4c_flush_cache_range(). */
		for (entry = head->next;
		     (entry != head) && ((entry->vaddr+SUN4C_REAL_PGDIR_SIZE) < start);
		     entry = entry->next)
			;

		if ((entry != head) && (entry->vaddr < end)) {
			int octx = sun4c_get_context();

			sun4c_set_context(new_ctx);
			do {
				struct sun4c_mmu_entry *next = entry->next;

				sun4c_flush_segment(entry->vaddr);
				sun4c_user_unmap(entry);
				free_user_entry(new_ctx, entry);

				entry = next;
			} while ((entry != head) && (entry->vaddr < end));
			sun4c_set_context(octx);
		}
		local_irq_restore(flags);
	}
}

static void sun4c_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
	struct mm_struct *mm = vma->vm_mm;
	int new_ctx = mm->context;

	if (new_ctx != NO_CONTEXT) {
		int savectx = sun4c_get_context();
		unsigned long flags;

		local_irq_save(flags);
		sun4c_set_context(new_ctx);
		page &= PAGE_MASK;
		sun4c_flush_page(page);
		sun4c_put_pte(page, 0);
		sun4c_set_context(savectx);
		local_irq_restore(flags);
	}
}

static inline void sun4c_mapioaddr(unsigned long physaddr, unsigned long virt_addr)
{
	unsigned long page_entry;

	page_entry = ((physaddr >> PAGE_SHIFT) & SUN4C_PFN_MASK);
	page_entry |= ((pg_iobits | _SUN4C_PAGE_PRIV) & ~(_SUN4C_PAGE_PRESENT));
	sun4c_put_pte(virt_addr, page_entry);
}

static void sun4c_mapiorange(unsigned int bus, unsigned long xpa,
    unsigned long xva, unsigned int len)
{
	while (len != 0) {
		len -= PAGE_SIZE;
		sun4c_mapioaddr(xpa, xva);
		xva += PAGE_SIZE;
		xpa += PAGE_SIZE;
	}
}

static void sun4c_unmapiorange(unsigned long virt_addr, unsigned int len)
{
	while (len != 0) {
		len -= PAGE_SIZE;
		sun4c_put_pte(virt_addr, 0);
		virt_addr += PAGE_SIZE;
	}
}

static void sun4c_alloc_context(struct mm_struct *old_mm, struct mm_struct *mm)
{
	struct ctx_list *ctxp;

	ctxp = ctx_free.next;
	if (ctxp != &ctx_free) {
		remove_from_ctx_list(ctxp);
		add_to_used_ctxlist(ctxp);
		mm->context = ctxp->ctx_number;
		ctxp->ctx_mm = mm;
		return;
	}
	ctxp = ctx_used.next;
	if (ctxp->ctx_mm == old_mm)
		ctxp = ctxp->next;
	remove_from_ctx_list(ctxp);
	add_to_used_ctxlist(ctxp);
	ctxp->ctx_mm->context = NO_CONTEXT;
	ctxp->ctx_mm = mm;
	mm->context = ctxp->ctx_number;
	sun4c_demap_context(&sun4c_context_ring[ctxp->ctx_number],
			       ctxp->ctx_number);
}

/* Switch the current MM context. */
static void sun4c_switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk, int cpu)
{
	struct ctx_list *ctx;
	int dirty = 0;

	if (mm->context == NO_CONTEXT) {
		dirty = 1;
		sun4c_alloc_context(old_mm, mm);
	} else {
		/* Update the LRU ring of contexts. */
		ctx = ctx_list_pool + mm->context;
		remove_from_ctx_list(ctx);
		add_to_used_ctxlist(ctx);
	}
	if (dirty || old_mm != mm)
		sun4c_set_context(mm->context);
}

static void sun4c_destroy_context(struct mm_struct *mm)
{
	struct ctx_list *ctx_old;

	if (mm->context != NO_CONTEXT) {
		sun4c_demap_context(&sun4c_context_ring[mm->context], mm->context);
		ctx_old = ctx_list_pool + mm->context;
		remove_from_ctx_list(ctx_old);
		add_to_free_ctxlist(ctx_old);
		mm->context = NO_CONTEXT;
	}
}

static void sun4c_mmu_info(struct seq_file *m)
{
	int used_user_entries, i;

	used_user_entries = 0;
	for (i = 0; i < num_contexts; i++)
		used_user_entries += sun4c_context_ring[i].num_entries;

	seq_printf(m, 
		   "vacsize\t\t: %d bytes\n"
		   "vachwflush\t: %s\n"
		   "vaclinesize\t: %d bytes\n"
		   "mmuctxs\t\t: %d\n"
		   "mmupsegs\t: %d\n"
		   "kernelpsegs\t: %d\n"
		   "kfreepsegs\t: %d\n"
		   "usedpsegs\t: %d\n"
		   "ufreepsegs\t: %d\n"
		   "user_taken\t: %d\n"
		   "max_taken\t: %d\n",
		   sun4c_vacinfo.num_bytes,
		   (sun4c_vacinfo.do_hwflushes ? "yes" : "no"),
		   sun4c_vacinfo.linesize,
		   num_contexts,
		   (invalid_segment + 1),
		   sun4c_kernel_ring.num_entries,
		   sun4c_kfree_ring.num_entries,
		   used_user_entries,
		   sun4c_ufree_ring.num_entries,
		   sun4c_user_taken_entries,
		   max_user_taken_entries);
}

/* Nothing below here should touch the mmu hardware nor the mmu_entry
 * data structures.
 */

/* First the functions which the mid-level code uses to directly
 * manipulate the software page tables.  Some defines since we are
 * emulating the i386 page directory layout.
 */
#define PGD_PRESENT  0x001
#define PGD_RW       0x002
#define PGD_USER     0x004
#define PGD_ACCESSED 0x020
#define PGD_DIRTY    0x040
#define PGD_TABLE    (PGD_PRESENT | PGD_RW | PGD_USER | PGD_ACCESSED | PGD_DIRTY)

static void sun4c_set_pte(pte_t *ptep, pte_t pte)
{
	*ptep = pte;
}

static void sun4c_pgd_set(pgd_t * pgdp, pmd_t * pmdp)
{
}

static void sun4c_pmd_set(pmd_t * pmdp, pte_t * ptep)
{
	pmdp->pmdv[0] = PGD_TABLE | (unsigned long) ptep;
}

static void sun4c_pmd_populate(pmd_t * pmdp, struct page * ptep)
{
	if (page_address(ptep) == NULL) BUG();	/* No highmem on sun4c */
	pmdp->pmdv[0] = PGD_TABLE | (unsigned long) page_address(ptep);
}

static int sun4c_pte_present(pte_t pte)
{
	return ((pte_val(pte) & (_SUN4C_PAGE_PRESENT | _SUN4C_PAGE_PRIV)) != 0);
}
static void sun4c_pte_clear(pte_t *ptep)	{ *ptep = __pte(0); }

static int sun4c_pte_read(pte_t pte)
{
	return (pte_val(pte) & _SUN4C_PAGE_READ);
}

static int sun4c_pmd_bad(pmd_t pmd)
{
	return (((pmd_val(pmd) & ~PAGE_MASK) != PGD_TABLE) ||
		(!virt_addr_valid(pmd_val(pmd))));
}

static int sun4c_pmd_present(pmd_t pmd)
{
	return ((pmd_val(pmd) & PGD_PRESENT) != 0);
}

#if 0 /* if PMD takes one word */
static void sun4c_pmd_clear(pmd_t *pmdp)	{ *pmdp = __pmd(0); }
#else /* if pmd_t is a longish aggregate */
static void sun4c_pmd_clear(pmd_t *pmdp) {
	memset((void *)pmdp, 0, sizeof(pmd_t));
}
#endif

static int sun4c_pgd_none(pgd_t pgd)		{ return 0; }
static int sun4c_pgd_bad(pgd_t pgd)		{ return 0; }
static int sun4c_pgd_present(pgd_t pgd)	        { return 1; }
static void sun4c_pgd_clear(pgd_t * pgdp)	{ }

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
static pte_t sun4c_pte_mkwrite(pte_t pte)
{
	pte = __pte(pte_val(pte) | _SUN4C_PAGE_WRITE);
	if (pte_val(pte) & _SUN4C_PAGE_MODIFIED)
		pte = __pte(pte_val(pte) | _SUN4C_PAGE_SILENT_WRITE);
	return pte;
}

static pte_t sun4c_pte_mkdirty(pte_t pte)
{
	pte = __pte(pte_val(pte) | _SUN4C_PAGE_MODIFIED);
	if (pte_val(pte) & _SUN4C_PAGE_WRITE)
		pte = __pte(pte_val(pte) | _SUN4C_PAGE_SILENT_WRITE);
	return pte;
}

static pte_t sun4c_pte_mkyoung(pte_t pte)
{
	pte = __pte(pte_val(pte) | _SUN4C_PAGE_ACCESSED);
	if (pte_val(pte) & _SUN4C_PAGE_READ)
		pte = __pte(pte_val(pte) | _SUN4C_PAGE_SILENT_READ);
	return pte;
}

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */
static pte_t sun4c_mk_pte(struct page *page, pgprot_t pgprot)
{
	return __pte(page_to_pfn(page) | pgprot_val(pgprot));
}

static pte_t sun4c_mk_pte_phys(unsigned long phys_page, pgprot_t pgprot)
{
	return __pte((phys_page >> PAGE_SHIFT) | pgprot_val(pgprot));
}

static pte_t sun4c_mk_pte_io(unsigned long page, pgprot_t pgprot, int space)
{
	return __pte(((page - PAGE_OFFSET) >> PAGE_SHIFT) | pgprot_val(pgprot));
}