sun4c.c

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

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

static void sun4c_flush_cache_range_hw(struct mm_struct *mm, unsigned long start, unsigned long end)
{
	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();

		save_and_cli(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_hw(page);
						page += PAGE_SIZE;
					}
				} else {
					sun4c_flush_segment_hw(entry->vaddr);
					sun4c_user_unmap(entry);
					free_user_entry(new_ctx, entry);
				}
				entry = next;
			} while ((entry != head) && (entry->vaddr < end));
			sun4c_set_context(octx);
		}
		restore_flags(flags);
	}
}

static void sun4c_flush_cache_page_hw(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();
		save_and_cli(flags);
		sun4c_set_context(new_ctx);
		sun4c_flush_page_hw(page);
		sun4c_set_context(octx);
		restore_flags(flags);
	}
}

static void sun4c_flush_page_to_ram_hw(unsigned long page)
{
	unsigned long flags;

	save_and_cli(flags);
	sun4c_flush_page_hw(page);
	restore_flags(flags);
}

static void sun4c_flush_cache_mm_sw(struct mm_struct *mm)
{
	int new_ctx = mm->context;

	if (new_ctx != NO_CONTEXT) {
		flush_user_windows();

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

			save_and_cli(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_sw();
				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);
			}
			restore_flags(flags);
		}
	}
}

static void sun4c_flush_cache_range_sw(struct mm_struct *mm, unsigned long start, unsigned long end)
{
	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();

		save_and_cli(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_sw(page);
						page += PAGE_SIZE;
					}
				} else {
					sun4c_flush_segment_sw(entry->vaddr);
					sun4c_user_unmap(entry);
					free_user_entry(new_ctx, entry);
				}
				entry = next;
			} while ((entry != head) && (entry->vaddr < end));
			sun4c_set_context(octx);
		}
		restore_flags(flags);
	}
}

static void sun4c_flush_cache_page_sw(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();
		save_and_cli(flags);
		sun4c_set_context(new_ctx);
		sun4c_flush_page_sw(page);
		sun4c_set_context(octx);
		restore_flags(flags);
	}
}

static void sun4c_flush_page_to_ram_sw(unsigned long page)
{
	unsigned long flags;

	save_and_cli(flags);
	sun4c_flush_page_sw(page);
	restore_flags(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;

	save_and_cli(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;
		if (sun4c_vacinfo.do_hwflushes)
			sun4c_flush_segment_hw(this_entry->vaddr);
		else
			sun4c_flush_segment_sw(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);
	restore_flags(flags);
}

static void sun4c_flush_tlb_mm_hw(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;

		save_and_cli(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_hw();
			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);
		}
		restore_flags(flags);
	}
}

static void sun4c_flush_tlb_range_hw(struct mm_struct *mm, unsigned long start, unsigned long end)
{
	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;

		save_and_cli(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_hw(entry->vaddr);
				sun4c_user_unmap(entry);
				free_user_entry(new_ctx, entry);

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

static void sun4c_flush_tlb_page_hw(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;

		save_and_cli(flags);
		sun4c_set_context(new_ctx);
		page &= PAGE_MASK;
		sun4c_flush_page_hw(page);
		sun4c_put_pte(page, 0);
		sun4c_set_context(savectx);
		restore_flags(flags);
	}
}

static void sun4c_flush_tlb_mm_sw(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;

		save_and_cli(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_sw();
			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);
		}
		restore_flags(flags);
	}
}

static void sun4c_flush_tlb_range_sw(struct mm_struct *mm, unsigned long start, unsigned long end)
{
	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;

		save_and_cli(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_sw(entry->vaddr);
				sun4c_user_unmap(entry);
				free_user_entry(new_ctx, entry);

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

static void sun4c_flush_tlb_page_sw(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;

		save_and_cli(flags);
		sun4c_set_context(new_ctx);
		page &= PAGE_MASK;
		sun4c_flush_page_sw(page);
		sun4c_put_pte(page, 0);
		sun4c_set_context(savectx);
		restore_flags(flags);
	}
}

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)
{
}

void sun4c_mapioaddr(unsigned long physaddr, unsigned long virt_addr,
		     int bus_type, int rdonly)
{
	unsigned long page_entry;

	page_entry = ((physaddr >> PAGE_SHIFT) & SUN4C_PFN_MASK);
	page_entry |= ((pg_iobits | _SUN4C_PAGE_PRIV) & ~(_SUN4C_PAGE_PRESENT));
	if (rdonly)
		page_entry &= ~_SUN4C_WRITEABLE;
	sun4c_put_pte(virt_addr, page_entry);
}

void sun4c_unmapioaddr(unsigned long virt_addr)
{
	sun4c_put_pte(virt_addr, 0);
}

static void sun4c_alloc_context_hw(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_hw(&sun4c_context_ring[ctxp->ctx_number],
			       ctxp->ctx_number);
}

/* Switch the current MM context. */
static void sun4c_switch_mm_hw(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_hw(old_mm, mm);
	} else {