Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

5 files changed, 665 insertions, 0 deletions

diff --git a/kernel/arch/cris/mm/Makefile b/kernel/arch/cris/mm/Makefile
new file mode 100644
index 000000000..d3ae08c90
--- /dev/null
+++ b/kernel/arch/cris/mm/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for the linux cris-specific parts of the memory manager.
+#
+
+obj-y	 := init.o fault.o tlb.o ioremap.o
+
diff --git a/kernel/arch/cris/mm/fault.c b/kernel/arch/cris/mm/fault.c
new file mode 100644
index 000000000..3066d40a6
--- /dev/null
+++ b/kernel/arch/cris/mm/fault.c
@@ -0,0 +1,388 @@
+/*
+ *  arch/cris/mm/fault.c
+ *
+ *  Copyright (C) 2000-2010  Axis Communications AB
+ */
+
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/wait.h>
+#include <linux/uaccess.h>
+#include <arch/system.h>
+
+extern int find_fixup_code(struct pt_regs *);
+extern void die_if_kernel(const char *, struct pt_regs *, long);
+extern void show_registers(struct pt_regs *regs);
+
+/* debug of low-level TLB reload */
+#undef DEBUG
+
+#ifdef DEBUG
+#define D(x) x
+#else
+#define D(x)
+#endif
+
+/* debug of higher-level faults */
+#define DPG(x)
+
+/* current active page directory */
+
+DEFINE_PER_CPU(pgd_t *, current_pgd);
+unsigned long cris_signal_return_page;
+
+/*
+ * This routine handles page faults.  It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ *
+ * Notice that the address we're given is aligned to the page the fault
+ * occurred in, since we only get the PFN in R_MMU_CAUSE not the complete
+ * address.
+ *
+ * error_code:
+ *      bit 0 == 0 means no page found, 1 means protection fault
+ *      bit 1 == 0 means read, 1 means write
+ *
+ * If this routine detects a bad access, it returns 1, otherwise it
+ * returns 0.
+ */
+
+asmlinkage void
+do_page_fault(unsigned long address, struct pt_regs *regs,
+	      int protection, int writeaccess)
+{
+	struct task_struct *tsk;
+	struct mm_struct *mm;
+	struct vm_area_struct * vma;
+	siginfo_t info;
+	int fault;
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+
+	D(printk(KERN_DEBUG
+		 "Page fault for %lX on %X at %lX, prot %d write %d\n",
+		 address, smp_processor_id(), instruction_pointer(regs),
+		 protection, writeaccess));
+
+	tsk = current;
+
+	/*
+	 * We fault-in kernel-space virtual memory on-demand. The
+	 * 'reference' page table is init_mm.pgd.
+	 *
+	 * NOTE! We MUST NOT take any locks for this case. We may
+	 * be in an interrupt or a critical region, and should
+	 * only copy the information from the master page table,
+	 * nothing more.
+	 *
+	 * NOTE2: This is done so that, when updating the vmalloc
+	 * mappings we don't have to walk all processes pgdirs and
+	 * add the high mappings all at once. Instead we do it as they
+	 * are used. However vmalloc'ed page entries have the PAGE_GLOBAL
+	 * bit set so sometimes the TLB can use a lingering entry.
+	 *
+	 * This verifies that the fault happens in kernel space
+	 * and that the fault was not a protection error (error_code & 1).
+	 */
+
+	if (address >= VMALLOC_START &&
+	    !protection &&
+	    !user_mode(regs))
+		goto vmalloc_fault;
+
+	/* When stack execution is not allowed we store the signal
+	 * trampolines in the reserved cris_signal_return_page.
+	 * Handle this in the exact same way as vmalloc (we know
+	 * that the mapping is there and is valid so no need to
+	 * call handle_mm_fault).
+	 */
+	if (cris_signal_return_page &&
+	    address == cris_signal_return_page &&
+	    !protection && user_mode(regs))
+		goto vmalloc_fault;
+
+	/* we can and should enable interrupts at this point */
+	local_irq_enable();
+
+	mm = tsk->mm;
+	info.si_code = SEGV_MAPERR;
+
+	/*
+	 * If we're in an interrupt, have pagefaults disabled or have no
+	 * user context, we must not take the fault.
+	 */
+
+	if (faulthandler_disabled() || !mm)
+		goto no_context;
+
+	if (user_mode(regs))
+		flags |= FAULT_FLAG_USER;
+retry:
+	down_read(&mm->mmap_sem);
+	vma = find_vma(mm, address);
+	if (!vma)
+		goto bad_area;
+	if (vma->vm_start <= address)
+		goto good_area;
+	if (!(vma->vm_flags & VM_GROWSDOWN))
+		goto bad_area;
+	if (user_mode(regs)) {
+		/*
+		 * accessing the stack below usp is always a bug.
+		 * we get page-aligned addresses so we can only check
+		 * if we're within a page from usp, but that might be
+		 * enough to catch brutal errors at least.
+		 */
+		if (address + PAGE_SIZE < rdusp())
+			goto bad_area;
+	}
+	if (expand_stack(vma, address))
+		goto bad_area;
+
+	/*
+	 * Ok, we have a good vm_area for this memory access, so
+	 * we can handle it..
+	 */
+
+ good_area:
+	info.si_code = SEGV_ACCERR;
+
+	/* first do some preliminary protection checks */
+
+	if (writeaccess == 2){
+		if (!(vma->vm_flags & VM_EXEC))
+			goto bad_area;
+	} else if (writeaccess == 1) {
+		if (!(vma->vm_flags & VM_WRITE))
+			goto bad_area;
+		flags |= FAULT_FLAG_WRITE;
+	} else {
+		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+			goto bad_area;
+	}
+
+	/*
+	 * If for any reason at all we couldn't handle the fault,
+	 * make sure we exit gracefully rather than endlessly redo
+	 * the fault.
+	 */
+
+	fault = handle_mm_fault(mm, vma, address, flags);
+
+	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+		return;
+
+	if (unlikely(fault & VM_FAULT_ERROR)) {
+		if (fault & VM_FAULT_OOM)
+			goto out_of_memory;
+		else if (fault & VM_FAULT_SIGSEGV)
+			goto bad_area;
+		else if (fault & VM_FAULT_SIGBUS)
+			goto do_sigbus;
+		BUG();
+	}
+
+	if (flags & FAULT_FLAG_ALLOW_RETRY) {
+		if (fault & VM_FAULT_MAJOR)
+			tsk->maj_flt++;
+		else
+			tsk->min_flt++;
+		if (fault & VM_FAULT_RETRY) {
+			flags &= ~FAULT_FLAG_ALLOW_RETRY;
+			flags |= FAULT_FLAG_TRIED;
+
+			/*
+			 * No need to up_read(&mm->mmap_sem) as we would
+			 * have already released it in __lock_page_or_retry
+			 * in mm/filemap.c.
+			 */
+
+			goto retry;
+		}
+	}
+
+	up_read(&mm->mmap_sem);
+	return;
+
+	/*
+	 * Something tried to access memory that isn't in our memory map..
+	 * Fix it, but check if it's kernel or user first..
+	 */
+
+ bad_area:
+	up_read(&mm->mmap_sem);
+
+ bad_area_nosemaphore:
+	DPG(show_registers(regs));
+
+	/* User mode accesses just cause a SIGSEGV */
+
+	if (user_mode(regs)) {
+#ifdef CONFIG_NO_SEGFAULT_TERMINATION
+		DECLARE_WAIT_QUEUE_HEAD(wq);
+#endif
+		printk(KERN_NOTICE "%s (pid %d) segfaults for page "
+			"address %08lx at pc %08lx\n",
+			tsk->comm, tsk->pid,
+			address, instruction_pointer(regs));
+
+		/* With DPG on, we've already dumped registers above.  */
+		DPG(if (0))
+			show_registers(regs);
+
+#ifdef CONFIG_NO_SEGFAULT_TERMINATION
+		wait_event_interruptible(wq, 0 == 1);
+#else
+		info.si_signo = SIGSEGV;
+		info.si_errno = 0;
+		/* info.si_code has been set above */
+		info.si_addr = (void *)address;
+		force_sig_info(SIGSEGV, &info, tsk);
+#endif
+		return;
+	}
+
+ no_context:
+
+	/* Are we prepared to handle this kernel fault?
+	 *
+	 * (The kernel has valid exception-points in the source
+	 *  when it accesses user-memory. When it fails in one
+	 *  of those points, we find it in a table and do a jump
+	 *  to some fixup code that loads an appropriate error
+	 *  code)
+	 */
+
+	if (find_fixup_code(regs))
+		return;
+
+	/*
+	 * Oops. The kernel tried to access some bad page. We'll have to
+	 * terminate things with extreme prejudice.
+	 */
+
+	if (!oops_in_progress) {
+		oops_in_progress = 1;
+		if ((unsigned long) (address) < PAGE_SIZE)
+			printk(KERN_ALERT "Unable to handle kernel NULL "
+				"pointer dereference");
+		else
+			printk(KERN_ALERT "Unable to handle kernel access"
+				" at virtual address %08lx\n", address);
+
+		die_if_kernel("Oops", regs, (writeaccess << 1) | protection);
+		oops_in_progress = 0;
+	}
+
+	do_exit(SIGKILL);
+
+	/*
+	 * We ran out of memory, or some other thing happened to us that made
+	 * us unable to handle the page fault gracefully.
+	 */
+
+ out_of_memory:
+	up_read(&mm->mmap_sem);
+	if (!user_mode(regs))
+		goto no_context;
+	pagefault_out_of_memory();
+	return;
+
+ do_sigbus:
+	up_read(&mm->mmap_sem);
+
+	/*
+	 * Send a sigbus, regardless of whether we were in kernel
+	 * or user mode.
+	 */
+	info.si_signo = SIGBUS;
+	info.si_errno = 0;
+	info.si_code = BUS_ADRERR;
+	info.si_addr = (void *)address;
+	force_sig_info(SIGBUS, &info, tsk);
+
+	/* Kernel mode? Handle exceptions or die */
+	if (!user_mode(regs))
+		goto no_context;
+	return;
+
+vmalloc_fault:
+	{
+		/*
+		 * Synchronize this task's top level page-table
+		 * with the 'reference' page table.
+		 *
+		 * Use current_pgd instead of tsk->active_mm->pgd
+		 * since the latter might be unavailable if this
+		 * code is executed in a misfortunately run irq
+		 * (like inside schedule() between switch_mm and
+		 *  switch_to...).
+		 */
+
+		int offset = pgd_index(address);
+		pgd_t *pgd, *pgd_k;
+		pud_t *pud, *pud_k;
+		pmd_t *pmd, *pmd_k;
+		pte_t *pte_k;
+
+		pgd = (pgd_t *)per_cpu(current_pgd, smp_processor_id()) + offset;
+		pgd_k = init_mm.pgd + offset;
+
+		/* Since we're two-level, we don't need to do both
+		 * set_pgd and set_pmd (they do the same thing). If
+		 * we go three-level at some point, do the right thing
+		 * with pgd_present and set_pgd here.
+		 *
+		 * Also, since the vmalloc area is global, we don't
+		 * need to copy individual PTE's, it is enough to
+		 * copy the pgd pointer into the pte page of the
+		 * root task. If that is there, we'll find our pte if
+		 * it exists.
+		 */
+
+		pud = pud_offset(pgd, address);
+		pud_k = pud_offset(pgd_k, address);
+		if (!pud_present(*pud_k))
+			goto no_context;
+
+		pmd = pmd_offset(pud, address);
+		pmd_k = pmd_offset(pud_k, address);
+
+		if (!pmd_present(*pmd_k))
+			goto bad_area_nosemaphore;
+
+		set_pmd(pmd, *pmd_k);
+
+		/* Make sure the actual PTE exists as well to
+		 * catch kernel vmalloc-area accesses to non-mapped
+		 * addresses. If we don't do this, this will just
+		 * silently loop forever.
+		 */
+
+		pte_k = pte_offset_kernel(pmd_k, address);
+		if (!pte_present(*pte_k))
+			goto no_context;
+
+		return;
+	}
+}
+
+/* Find fixup code. */
+int
+find_fixup_code(struct pt_regs *regs)
+{
+	const struct exception_table_entry *fixup;
+	/* in case of delay slot fault (v32) */
+	unsigned long ip = (instruction_pointer(regs) & ~0x1);
+
+	fixup = search_exception_tables(ip);
+	if (fixup != 0) {
+		/* Adjust the instruction pointer in the stackframe. */
+		instruction_pointer(regs) = fixup->fixup;
+		arch_fixup(regs);
+		return 1;
+	}
+
+	return 0;
+}
diff --git a/kernel/arch/cris/mm/init.c b/kernel/arch/cris/mm/init.c
new file mode 100644
index 000000000..1e7fd45b6
--- /dev/null
+++ b/kernel/arch/cris/mm/init.c
@@ -0,0 +1,68 @@
+/*
+ *  linux/arch/cris/mm/init.c
+ *
+ *  Copyright (C) 1995  Linus Torvalds
+ *  Copyright (C) 2000,2001  Axis Communications AB
+ *
+ *  Authors:  Bjorn Wesen (bjornw@axis.com)
+ *
+ */
+
+#include <linux/gfp.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/proc_fs.h>
+#include <linux/kcore.h>
+#include <asm/tlb.h>
+#include <asm/sections.h>
+
+unsigned long empty_zero_page;
+EXPORT_SYMBOL(empty_zero_page);
+
+void __init mem_init(void)
+{
+	BUG_ON(!mem_map);
+
+	/* max/min_low_pfn was set by setup.c
+	 * now we just copy it to some other necessary places...
+	 *
+	 * high_memory was also set in setup.c
+	 */
+	max_mapnr = max_low_pfn - min_low_pfn;
+        free_all_bootmem();
+	mem_init_print_info(NULL);
+}
+
+/* Free a range of init pages. Virtual addresses. */
+
+void free_init_pages(const char *what, unsigned long begin, unsigned long end)
+{
+	unsigned long addr;
+
+	for (addr = begin; addr < end; addr += PAGE_SIZE) {
+		ClearPageReserved(virt_to_page(addr));
+		init_page_count(virt_to_page(addr));
+		free_page(addr);
+		totalram_pages++;
+	}
+
+	printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
+}
+
+/* Free the pages occupied by initialization code. */
+
+void free_initmem(void)
+{
+	free_initmem_default(-1);
+}
+
+/* Free the pages occupied by initrd code. */
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_init_pages("initrd memory",
+	                start,
+	                end);
+}
+#endif
diff --git a/kernel/arch/cris/mm/ioremap.c b/kernel/arch/cris/mm/ioremap.c
new file mode 100644
index 000000000..80fdb995a
--- /dev/null
+++ b/kernel/arch/cris/mm/ioremap.c
@@ -0,0 +1,89 @@
+/*
+ * arch/cris/mm/ioremap.c
+ *
+ * Re-map IO memory to kernel address space so that we can access it.
+ * Needed for memory-mapped I/O devices mapped outside our normal DRAM
+ * window (that is, all memory-mapped I/O devices).
+ *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ * CRIS-port by Axis Communications AB
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/io.h>
+#include <asm/pgalloc.h>
+#include <arch/memmap.h>
+
+/*
+ * Generic mapping function (not visible outside):
+ */
+
+/*
+ * Remap an arbitrary physical address space into the kernel virtual
+ * address space. Needed when the kernel wants to access high addresses
+ * directly.
+ *
+ * NOTE! We need to allow non-page-aligned mappings too: we will obviously
+ * have to convert them into an offset in a page-aligned mapping, but the
+ * caller shouldn't need to know that small detail.
+ */
+void __iomem * __ioremap_prot(unsigned long phys_addr, unsigned long size, pgprot_t prot)
+{
+	void __iomem * addr;
+	struct vm_struct * area;
+	unsigned long offset, last_addr;
+
+	/* Don't allow wraparound or zero size */
+	last_addr = phys_addr + size - 1;
+	if (!size || last_addr < phys_addr)
+		return NULL;
+
+	/*
+	 * Mappings have to be page-aligned
+	 */
+	offset = phys_addr & ~PAGE_MASK;
+	phys_addr &= PAGE_MASK;
+	size = PAGE_ALIGN(last_addr+1) - phys_addr;
+
+	/*
+	 * Ok, go for it..
+	 */
+	area = get_vm_area(size, VM_IOREMAP);
+	if (!area)
+		return NULL;
+	addr = (void __iomem *)area->addr;
+	if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
+			       phys_addr, prot)) {
+		vfree((void __force *)addr);
+		return NULL;
+	}
+	return (void __iomem *) (offset + (char __iomem *)addr);
+}
+
+void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
+{
+	return __ioremap_prot(phys_addr, size,
+		              __pgprot(_PAGE_PRESENT | __READABLE |
+				       __WRITEABLE | _PAGE_GLOBAL |
+				       _PAGE_KERNEL | flags));
+}
+
+/**
+ * ioremap_nocache     -   map bus memory into CPU space
+ * @offset:    bus address of the memory
+ * @size:      size of the resource to map
+ *
+ * Must be freed with iounmap.
+ */
+
+void __iomem *ioremap_nocache(unsigned long phys_addr, unsigned long size)
+{
+        return __ioremap(phys_addr | MEM_NON_CACHEABLE, size, 0);
+}
+EXPORT_SYMBOL(ioremap_nocache);
+
+void iounmap(volatile void __iomem *addr)
+{
+	if (addr > high_memory)
+		return vfree((void *) (PAGE_MASK & (unsigned long) addr));
+}
diff --git a/kernel/arch/cris/mm/tlb.c b/kernel/arch/cris/mm/tlb.c
new file mode 100644
index 000000000..b7f8de576
--- /dev/null
+++ b/kernel/arch/cris/mm/tlb.c
@@ -0,0 +1,114 @@
+/*
+ *  linux/arch/cris/mm/tlb.c
+ *
+ *  Copyright (C) 2000, 2001  Axis Communications AB
+ *  
+ *  Authors:   Bjorn Wesen (bjornw@axis.com)
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <asm/tlb.h>
+
+#define D(x)
+
+/* The TLB can host up to 64 different mm contexts at the same time.
+ * The running context is R_MMU_CONTEXT, and each TLB entry contains a
+ * page_id that has to match to give a hit. In page_id_map, we keep track
+ * of which mm we have assigned to which page_id, so that we know when
+ * to invalidate TLB entries.
+ *
+ * The last page_id is never running - it is used as an invalid page_id
+ * so we can make TLB entries that will never match.
+ *
+ * Notice that we need to make the flushes atomic, otherwise an interrupt
+ * handler that uses vmalloced memory might cause a TLB load in the middle
+ * of a flush causing.
+ */
+
+struct mm_struct *page_id_map[NUM_PAGEID];
+static int map_replace_ptr = 1;  /* which page_id_map entry to replace next */
+
+/* the following functions are similar to those used in the PPC port */
+
+static inline void
+alloc_context(struct mm_struct *mm)
+{
+	struct mm_struct *old_mm;
+
+	D(printk("tlb: alloc context %d (%p)\n", map_replace_ptr, mm));
+
+	/* did we replace an mm ? */
+
+	old_mm = page_id_map[map_replace_ptr];
+
+	if(old_mm) {
+		/* throw out any TLB entries belonging to the mm we replace
+		 * in the map
+		 */
+		flush_tlb_mm(old_mm);
+
+		old_mm->context.page_id = NO_CONTEXT;
+	}
+
+	/* insert it into the page_id_map */
+
+	mm->context.page_id = map_replace_ptr;
+	page_id_map[map_replace_ptr] = mm;
+
+	map_replace_ptr++;
+
+	if(map_replace_ptr == INVALID_PAGEID)
+		map_replace_ptr = 0;         /* wrap around */	
+}
+
+/* 
+ * if needed, get a new MMU context for the mm. otherwise nothing is done.
+ */
+
+void
+get_mmu_context(struct mm_struct *mm)
+{
+	if(mm->context.page_id == NO_CONTEXT)
+		alloc_context(mm);
+}
+
+/* called by __exit_mm to destroy the used MMU context if any before
+ * destroying the mm itself. this is only called when the last user of the mm
+ * drops it.
+ *
+ * the only thing we really need to do here is mark the used PID slot
+ * as empty.
+ */
+
+void
+destroy_context(struct mm_struct *mm)
+{
+	if(mm->context.page_id != NO_CONTEXT) {
+		D(printk("destroy_context %d (%p)\n", mm->context.page_id, mm));
+		flush_tlb_mm(mm);  /* TODO this might be redundant ? */
+		page_id_map[mm->context.page_id] = NULL;
+	}
+}
+
+/* called once during VM initialization, from init.c */
+
+void __init
+tlb_init(void)
+{
+	int i;
+
+	/* clear the page_id map */
+
+	for (i = 1; i < ARRAY_SIZE(page_id_map); i++)
+		page_id_map[i] = NULL;
+	
+	/* invalidate the entire TLB */
+
+	flush_tlb_all();
+
+	/* the init_mm has context 0 from the boot */
+
+	page_id_map[0] = &init_mm;
+}