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>

1 files changed, 864 insertions, 0 deletions

diff --git a/kernel/arch/x86/xen/setup.c b/kernel/arch/x86/xen/setup.c
new file mode 100644
index 000000000..55f388ef4
--- /dev/null
+++ b/kernel/arch/x86/xen/setup.c
@@ -0,0 +1,864 @@
+/*
+ * Machine specific setup for xen
+ *
+ * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/pm.h>
+#include <linux/memblock.h>
+#include <linux/cpuidle.h>
+#include <linux/cpufreq.h>
+
+#include <asm/elf.h>
+#include <asm/vdso.h>
+#include <asm/e820.h>
+#include <asm/setup.h>
+#include <asm/acpi.h>
+#include <asm/numa.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+#include <xen/xen.h>
+#include <xen/page.h>
+#include <xen/interface/callback.h>
+#include <xen/interface/memory.h>
+#include <xen/interface/physdev.h>
+#include <xen/features.h>
+#include "xen-ops.h"
+#include "vdso.h"
+#include "p2m.h"
+#include "mmu.h"
+
+/* Amount of extra memory space we add to the e820 ranges */
+struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
+
+/* Number of pages released from the initial allocation. */
+unsigned long xen_released_pages;
+
+/*
+ * Buffer used to remap identity mapped pages. We only need the virtual space.
+ * The physical page behind this address is remapped as needed to different
+ * buffer pages.
+ */
+#define REMAP_SIZE	(P2M_PER_PAGE - 3)
+static struct {
+	unsigned long	next_area_mfn;
+	unsigned long	target_pfn;
+	unsigned long	size;
+	unsigned long	mfns[REMAP_SIZE];
+} xen_remap_buf __initdata __aligned(PAGE_SIZE);
+static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
+
+/* 
+ * The maximum amount of extra memory compared to the base size.  The
+ * main scaling factor is the size of struct page.  At extreme ratios
+ * of base:extra, all the base memory can be filled with page
+ * structures for the extra memory, leaving no space for anything
+ * else.
+ * 
+ * 10x seems like a reasonable balance between scaling flexibility and
+ * leaving a practically usable system.
+ */
+#define EXTRA_MEM_RATIO		(10)
+
+static void __init xen_add_extra_mem(phys_addr_t start, phys_addr_t size)
+{
+	int i;
+
+	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+		/* Add new region. */
+		if (xen_extra_mem[i].size == 0) {
+			xen_extra_mem[i].start = start;
+			xen_extra_mem[i].size  = size;
+			break;
+		}
+		/* Append to existing region. */
+		if (xen_extra_mem[i].start + xen_extra_mem[i].size == start) {
+			xen_extra_mem[i].size += size;
+			break;
+		}
+	}
+	if (i == XEN_EXTRA_MEM_MAX_REGIONS)
+		printk(KERN_WARNING "Warning: not enough extra memory regions\n");
+
+	memblock_reserve(start, size);
+}
+
+static void __init xen_del_extra_mem(phys_addr_t start, phys_addr_t size)
+{
+	int i;
+	phys_addr_t start_r, size_r;
+
+	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+		start_r = xen_extra_mem[i].start;
+		size_r = xen_extra_mem[i].size;
+
+		/* Start of region. */
+		if (start_r == start) {
+			BUG_ON(size > size_r);
+			xen_extra_mem[i].start += size;
+			xen_extra_mem[i].size -= size;
+			break;
+		}
+		/* End of region. */
+		if (start_r + size_r == start + size) {
+			BUG_ON(size > size_r);
+			xen_extra_mem[i].size -= size;
+			break;
+		}
+		/* Mid of region. */
+		if (start > start_r && start < start_r + size_r) {
+			BUG_ON(start + size > start_r + size_r);
+			xen_extra_mem[i].size = start - start_r;
+			/* Calling memblock_reserve() again is okay. */
+			xen_add_extra_mem(start + size, start_r + size_r -
+					  (start + size));
+			break;
+		}
+	}
+	memblock_free(start, size);
+}
+
+/*
+ * Called during boot before the p2m list can take entries beyond the
+ * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
+ * invalid.
+ */
+unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
+{
+	int i;
+	phys_addr_t addr = PFN_PHYS(pfn);
+
+	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+		if (addr >= xen_extra_mem[i].start &&
+		    addr < xen_extra_mem[i].start + xen_extra_mem[i].size)
+			return INVALID_P2M_ENTRY;
+	}
+
+	return IDENTITY_FRAME(pfn);
+}
+
+/*
+ * Mark all pfns of extra mem as invalid in p2m list.
+ */
+void __init xen_inv_extra_mem(void)
+{
+	unsigned long pfn, pfn_s, pfn_e;
+	int i;
+
+	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+		if (!xen_extra_mem[i].size)
+			continue;
+		pfn_s = PFN_DOWN(xen_extra_mem[i].start);
+		pfn_e = PFN_UP(xen_extra_mem[i].start + xen_extra_mem[i].size);
+		for (pfn = pfn_s; pfn < pfn_e; pfn++)
+			set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+	}
+}
+
+/*
+ * Finds the next RAM pfn available in the E820 map after min_pfn.
+ * This function updates min_pfn with the pfn found and returns
+ * the size of that range or zero if not found.
+ */
+static unsigned long __init xen_find_pfn_range(
+	const struct e820entry *list, size_t map_size,
+	unsigned long *min_pfn)
+{
+	const struct e820entry *entry;
+	unsigned int i;
+	unsigned long done = 0;
+
+	for (i = 0, entry = list; i < map_size; i++, entry++) {
+		unsigned long s_pfn;
+		unsigned long e_pfn;
+
+		if (entry->type != E820_RAM)
+			continue;
+
+		e_pfn = PFN_DOWN(entry->addr + entry->size);
+
+		/* We only care about E820 after this */
+		if (e_pfn < *min_pfn)
+			continue;
+
+		s_pfn = PFN_UP(entry->addr);
+
+		/* If min_pfn falls within the E820 entry, we want to start
+		 * at the min_pfn PFN.
+		 */
+		if (s_pfn <= *min_pfn) {
+			done = e_pfn - *min_pfn;
+		} else {
+			done = e_pfn - s_pfn;
+			*min_pfn = s_pfn;
+		}
+		break;
+	}
+
+	return done;
+}
+
+static int __init xen_free_mfn(unsigned long mfn)
+{
+	struct xen_memory_reservation reservation = {
+		.address_bits = 0,
+		.extent_order = 0,
+		.domid        = DOMID_SELF
+	};
+
+	set_xen_guest_handle(reservation.extent_start, &mfn);
+	reservation.nr_extents = 1;
+
+	return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
+}
+
+/*
+ * This releases a chunk of memory and then does the identity map. It's used
+ * as a fallback if the remapping fails.
+ */
+static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
+	unsigned long end_pfn, unsigned long nr_pages, unsigned long *released)
+{
+	unsigned long pfn, end;
+	int ret;
+
+	WARN_ON(start_pfn > end_pfn);
+
+	/* Release pages first. */
+	end = min(end_pfn, nr_pages);
+	for (pfn = start_pfn; pfn < end; pfn++) {
+		unsigned long mfn = pfn_to_mfn(pfn);
+
+		/* Make sure pfn exists to start with */
+		if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
+			continue;
+
+		ret = xen_free_mfn(mfn);
+		WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
+
+		if (ret == 1) {
+			(*released)++;
+			if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
+				break;
+		} else
+			break;
+	}
+
+	set_phys_range_identity(start_pfn, end_pfn);
+}
+
+/*
+ * Helper function to update the p2m and m2p tables and kernel mapping.
+ */
+static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
+{
+	struct mmu_update update = {
+		.ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
+		.val = pfn
+	};
+
+	/* Update p2m */
+	if (!set_phys_to_machine(pfn, mfn)) {
+		WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
+		     pfn, mfn);
+		BUG();
+	}
+
+	/* Update m2p */
+	if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
+		WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
+		     mfn, pfn);
+		BUG();
+	}
+
+	/* Update kernel mapping, but not for highmem. */
+	if (pfn >= PFN_UP(__pa(high_memory - 1)))
+		return;
+
+	if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
+					 mfn_pte(mfn, PAGE_KERNEL), 0)) {
+		WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
+		      mfn, pfn);
+		BUG();
+	}
+}
+
+/*
+ * This function updates the p2m and m2p tables with an identity map from
+ * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
+ * original allocation at remap_pfn. The information needed for remapping is
+ * saved in the memory itself to avoid the need for allocating buffers. The
+ * complete remap information is contained in a list of MFNs each containing
+ * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
+ * This enables us to preserve the original mfn sequence while doing the
+ * remapping at a time when the memory management is capable of allocating
+ * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
+ * its callers.
+ */
+static void __init xen_do_set_identity_and_remap_chunk(
+        unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
+{
+	unsigned long buf = (unsigned long)&xen_remap_buf;
+	unsigned long mfn_save, mfn;
+	unsigned long ident_pfn_iter, remap_pfn_iter;
+	unsigned long ident_end_pfn = start_pfn + size;
+	unsigned long left = size;
+	unsigned int i, chunk;
+
+	WARN_ON(size == 0);
+
+	BUG_ON(xen_feature(XENFEAT_auto_translated_physmap));
+
+	mfn_save = virt_to_mfn(buf);
+
+	for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
+	     ident_pfn_iter < ident_end_pfn;
+	     ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
+		chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
+
+		/* Map first pfn to xen_remap_buf */
+		mfn = pfn_to_mfn(ident_pfn_iter);
+		set_pte_mfn(buf, mfn, PAGE_KERNEL);
+
+		/* Save mapping information in page */
+		xen_remap_buf.next_area_mfn = xen_remap_mfn;
+		xen_remap_buf.target_pfn = remap_pfn_iter;
+		xen_remap_buf.size = chunk;
+		for (i = 0; i < chunk; i++)
+			xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
+
+		/* Put remap buf into list. */
+		xen_remap_mfn = mfn;
+
+		/* Set identity map */
+		set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
+
+		left -= chunk;
+	}
+
+	/* Restore old xen_remap_buf mapping */
+	set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
+}
+
+/*
+ * This function takes a contiguous pfn range that needs to be identity mapped
+ * and:
+ *
+ *  1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
+ *  2) Calls the do_ function to actually do the mapping/remapping work.
+ *
+ * The goal is to not allocate additional memory but to remap the existing
+ * pages. In the case of an error the underlying memory is simply released back
+ * to Xen and not remapped.
+ */
+static unsigned long __init xen_set_identity_and_remap_chunk(
+        const struct e820entry *list, size_t map_size, unsigned long start_pfn,
+	unsigned long end_pfn, unsigned long nr_pages, unsigned long remap_pfn,
+	unsigned long *released, unsigned long *remapped)
+{
+	unsigned long pfn;
+	unsigned long i = 0;
+	unsigned long n = end_pfn - start_pfn;
+
+	while (i < n) {
+		unsigned long cur_pfn = start_pfn + i;
+		unsigned long left = n - i;
+		unsigned long size = left;
+		unsigned long remap_range_size;
+
+		/* Do not remap pages beyond the current allocation */
+		if (cur_pfn >= nr_pages) {
+			/* Identity map remaining pages */
+			set_phys_range_identity(cur_pfn, cur_pfn + size);
+			break;
+		}
+		if (cur_pfn + size > nr_pages)
+			size = nr_pages - cur_pfn;
+
+		remap_range_size = xen_find_pfn_range(list, map_size,
+						      &remap_pfn);
+		if (!remap_range_size) {
+			pr_warning("Unable to find available pfn range, not remapping identity pages\n");
+			xen_set_identity_and_release_chunk(cur_pfn,
+				cur_pfn + left, nr_pages, released);
+			break;
+		}
+		/* Adjust size to fit in current e820 RAM region */
+		if (size > remap_range_size)
+			size = remap_range_size;
+
+		xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
+
+		/* Update variables to reflect new mappings. */
+		i += size;
+		remap_pfn += size;
+		*remapped += size;
+	}
+
+	/*
+	 * If the PFNs are currently mapped, the VA mapping also needs
+	 * to be updated to be 1:1.
+	 */
+	for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
+		(void)HYPERVISOR_update_va_mapping(
+			(unsigned long)__va(pfn << PAGE_SHIFT),
+			mfn_pte(pfn, PAGE_KERNEL_IO), 0);
+
+	return remap_pfn;
+}
+
+static void __init xen_set_identity_and_remap(
+	const struct e820entry *list, size_t map_size, unsigned long nr_pages,
+	unsigned long *released, unsigned long *remapped)
+{
+	phys_addr_t start = 0;
+	unsigned long last_pfn = nr_pages;
+	const struct e820entry *entry;
+	unsigned long num_released = 0;
+	unsigned long num_remapped = 0;
+	int i;
+
+	/*
+	 * Combine non-RAM regions and gaps until a RAM region (or the
+	 * end of the map) is reached, then set the 1:1 map and
+	 * remap the memory in those non-RAM regions.
+	 *
+	 * The combined non-RAM regions are rounded to a whole number
+	 * of pages so any partial pages are accessible via the 1:1
+	 * mapping.  This is needed for some BIOSes that put (for
+	 * example) the DMI tables in a reserved region that begins on
+	 * a non-page boundary.
+	 */
+	for (i = 0, entry = list; i < map_size; i++, entry++) {
+		phys_addr_t end = entry->addr + entry->size;
+		if (entry->type == E820_RAM || i == map_size - 1) {
+			unsigned long start_pfn = PFN_DOWN(start);
+			unsigned long end_pfn = PFN_UP(end);
+
+			if (entry->type == E820_RAM)
+				end_pfn = PFN_UP(entry->addr);
+
+			if (start_pfn < end_pfn)
+				last_pfn = xen_set_identity_and_remap_chunk(
+						list, map_size, start_pfn,
+						end_pfn, nr_pages, last_pfn,
+						&num_released, &num_remapped);
+			start = end;
+		}
+	}
+
+	*released = num_released;
+	*remapped = num_remapped;
+
+	pr_info("Released %ld page(s)\n", num_released);
+}
+
+/*
+ * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
+ * The remap information (which mfn remap to which pfn) is contained in the
+ * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
+ * This scheme allows to remap the different chunks in arbitrary order while
+ * the resulting mapping will be independant from the order.
+ */
+void __init xen_remap_memory(void)
+{
+	unsigned long buf = (unsigned long)&xen_remap_buf;
+	unsigned long mfn_save, mfn, pfn;
+	unsigned long remapped = 0;
+	unsigned int i;
+	unsigned long pfn_s = ~0UL;
+	unsigned long len = 0;
+
+	mfn_save = virt_to_mfn(buf);
+
+	while (xen_remap_mfn != INVALID_P2M_ENTRY) {
+		/* Map the remap information */
+		set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
+
+		BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
+
+		pfn = xen_remap_buf.target_pfn;
+		for (i = 0; i < xen_remap_buf.size; i++) {
+			mfn = xen_remap_buf.mfns[i];
+			xen_update_mem_tables(pfn, mfn);
+			remapped++;
+			pfn++;
+		}
+		if (pfn_s == ~0UL || pfn == pfn_s) {
+			pfn_s = xen_remap_buf.target_pfn;
+			len += xen_remap_buf.size;
+		} else if (pfn_s + len == xen_remap_buf.target_pfn) {
+			len += xen_remap_buf.size;
+		} else {
+			xen_del_extra_mem(PFN_PHYS(pfn_s), PFN_PHYS(len));
+			pfn_s = xen_remap_buf.target_pfn;
+			len = xen_remap_buf.size;
+		}
+
+		mfn = xen_remap_mfn;
+		xen_remap_mfn = xen_remap_buf.next_area_mfn;
+	}
+
+	if (pfn_s != ~0UL && len)
+		xen_del_extra_mem(PFN_PHYS(pfn_s), PFN_PHYS(len));
+
+	set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
+
+	pr_info("Remapped %ld page(s)\n", remapped);
+}
+
+static unsigned long __init xen_get_max_pages(void)
+{
+	unsigned long max_pages = MAX_DOMAIN_PAGES;
+	domid_t domid = DOMID_SELF;
+	int ret;
+
+	/*
+	 * For the initial domain we use the maximum reservation as
+	 * the maximum page.
+	 *
+	 * For guest domains the current maximum reservation reflects
+	 * the current maximum rather than the static maximum. In this
+	 * case the e820 map provided to us will cover the static
+	 * maximum region.
+	 */
+	if (xen_initial_domain()) {
+		ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
+		if (ret > 0)
+			max_pages = ret;
+	}
+
+	return min(max_pages, MAX_DOMAIN_PAGES);
+}
+
+static void __init xen_align_and_add_e820_region(phys_addr_t start,
+						 phys_addr_t size, int type)
+{
+	phys_addr_t end = start + size;
+
+	/* Align RAM regions to page boundaries. */
+	if (type == E820_RAM) {
+		start = PAGE_ALIGN(start);
+		end &= ~((phys_addr_t)PAGE_SIZE - 1);
+	}
+
+	e820_add_region(start, end - start, type);
+}
+
+static void __init xen_ignore_unusable(struct e820entry *list, size_t map_size)
+{
+	struct e820entry *entry;
+	unsigned int i;
+
+	for (i = 0, entry = list; i < map_size; i++, entry++) {
+		if (entry->type == E820_UNUSABLE)
+			entry->type = E820_RAM;
+	}
+}
+
+/**
+ * machine_specific_memory_setup - Hook for machine specific memory setup.
+ **/
+char * __init xen_memory_setup(void)
+{
+	static struct e820entry map[E820MAX] __initdata;
+
+	unsigned long max_pfn = xen_start_info->nr_pages;
+	phys_addr_t mem_end;
+	int rc;
+	struct xen_memory_map memmap;
+	unsigned long max_pages;
+	unsigned long extra_pages = 0;
+	unsigned long remapped_pages;
+	int i;
+	int op;
+
+	max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
+	mem_end = PFN_PHYS(max_pfn);
+
+	memmap.nr_entries = E820MAX;
+	set_xen_guest_handle(memmap.buffer, map);
+
+	op = xen_initial_domain() ?
+		XENMEM_machine_memory_map :
+		XENMEM_memory_map;
+	rc = HYPERVISOR_memory_op(op, &memmap);
+	if (rc == -ENOSYS) {
+		BUG_ON(xen_initial_domain());
+		memmap.nr_entries = 1;
+		map[0].addr = 0ULL;
+		map[0].size = mem_end;
+		/* 8MB slack (to balance backend allocations). */
+		map[0].size += 8ULL << 20;
+		map[0].type = E820_RAM;
+		rc = 0;
+	}
+	BUG_ON(rc);
+	BUG_ON(memmap.nr_entries == 0);
+
+	/*
+	 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
+	 * regions, so if we're using the machine memory map leave the
+	 * region as RAM as it is in the pseudo-physical map.
+	 *
+	 * UNUSABLE regions in domUs are not handled and will need
+	 * a patch in the future.
+	 */
+	if (xen_initial_domain())
+		xen_ignore_unusable(map, memmap.nr_entries);
+
+	/* Make sure the Xen-supplied memory map is well-ordered. */
+	sanitize_e820_map(map, memmap.nr_entries, &memmap.nr_entries);
+
+	max_pages = xen_get_max_pages();
+	if (max_pages > max_pfn)
+		extra_pages += max_pages - max_pfn;
+
+	/*
+	 * Set identity map on non-RAM pages and prepare remapping the
+	 * underlying RAM.
+	 */
+	xen_set_identity_and_remap(map, memmap.nr_entries, max_pfn,
+				   &xen_released_pages, &remapped_pages);
+
+	extra_pages += xen_released_pages;
+	extra_pages += remapped_pages;
+
+	/*
+	 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
+	 * factor the base size.  On non-highmem systems, the base
+	 * size is the full initial memory allocation; on highmem it
+	 * is limited to the max size of lowmem, so that it doesn't
+	 * get completely filled.
+	 *
+	 * In principle there could be a problem in lowmem systems if
+	 * the initial memory is also very large with respect to
+	 * lowmem, but we won't try to deal with that here.
+	 */
+	extra_pages = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
+			  extra_pages);
+	i = 0;
+	while (i < memmap.nr_entries) {
+		phys_addr_t addr = map[i].addr;
+		phys_addr_t size = map[i].size;
+		u32 type = map[i].type;
+
+		if (type == E820_RAM) {
+			if (addr < mem_end) {
+				size = min(size, mem_end - addr);
+			} else if (extra_pages) {
+				size = min(size, PFN_PHYS(extra_pages));
+				extra_pages -= PFN_DOWN(size);
+				xen_add_extra_mem(addr, size);
+				xen_max_p2m_pfn = PFN_DOWN(addr + size);
+			} else
+				type = E820_UNUSABLE;
+		}
+
+		xen_align_and_add_e820_region(addr, size, type);
+
+		map[i].addr += size;
+		map[i].size -= size;
+		if (map[i].size == 0)
+			i++;
+	}
+
+	/*
+	 * Set the rest as identity mapped, in case PCI BARs are
+	 * located here.
+	 *
+	 * PFNs above MAX_P2M_PFN are considered identity mapped as
+	 * well.
+	 */
+	set_phys_range_identity(map[i-1].addr / PAGE_SIZE, ~0ul);
+
+	/*
+	 * In domU, the ISA region is normal, usable memory, but we
+	 * reserve ISA memory anyway because too many things poke
+	 * about in there.
+	 */
+	e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
+			E820_RESERVED);
+
+	/*
+	 * Reserve Xen bits:
+	 *  - mfn_list
+	 *  - xen_start_info
+	 * See comment above "struct start_info" in <xen/interface/xen.h>
+	 * We tried to make the the memblock_reserve more selective so
+	 * that it would be clear what region is reserved. Sadly we ran
+	 * in the problem wherein on a 64-bit hypervisor with a 32-bit
+	 * initial domain, the pt_base has the cr3 value which is not
+	 * neccessarily where the pagetable starts! As Jan put it: "
+	 * Actually, the adjustment turns out to be correct: The page
+	 * tables for a 32-on-64 dom0 get allocated in the order "first L1",
+	 * "first L2", "first L3", so the offset to the page table base is
+	 * indeed 2. When reading xen/include/public/xen.h's comment
+	 * very strictly, this is not a violation (since there nothing is said
+	 * that the first thing in the page table space is pointed to by
+	 * pt_base; I admit that this seems to be implied though, namely
+	 * do I think that it is implied that the page table space is the
+	 * range [pt_base, pt_base + nt_pt_frames), whereas that
+	 * range here indeed is [pt_base - 2, pt_base - 2 + nt_pt_frames),
+	 * which - without a priori knowledge - the kernel would have
+	 * difficulty to figure out)." - so lets just fall back to the
+	 * easy way and reserve the whole region.
+	 */
+	memblock_reserve(__pa(xen_start_info->mfn_list),
+			 xen_start_info->pt_base - xen_start_info->mfn_list);
+
+	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+
+	return "Xen";
+}
+
+/*
+ * Machine specific memory setup for auto-translated guests.
+ */
+char * __init xen_auto_xlated_memory_setup(void)
+{
+	static struct e820entry map[E820MAX] __initdata;
+
+	struct xen_memory_map memmap;
+	int i;
+	int rc;
+
+	memmap.nr_entries = E820MAX;
+	set_xen_guest_handle(memmap.buffer, map);
+
+	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
+	if (rc < 0)
+		panic("No memory map (%d)\n", rc);
+
+	sanitize_e820_map(map, ARRAY_SIZE(map), &memmap.nr_entries);
+
+	for (i = 0; i < memmap.nr_entries; i++)
+		e820_add_region(map[i].addr, map[i].size, map[i].type);
+
+	memblock_reserve(__pa(xen_start_info->mfn_list),
+			 xen_start_info->pt_base - xen_start_info->mfn_list);
+
+	return "Xen";
+}
+
+/*
+ * Set the bit indicating "nosegneg" library variants should be used.
+ * We only need to bother in pure 32-bit mode; compat 32-bit processes
+ * can have un-truncated segments, so wrapping around is allowed.
+ */
+static void __init fiddle_vdso(void)
+{
+#ifdef CONFIG_X86_32
+	/*
+	 * This could be called before selected_vdso32 is initialized, so
+	 * just fiddle with both possible images.  vdso_image_32_syscall
+	 * can't be selected, since it only exists on 64-bit systems.
+	 */
+	u32 *mask;
+	mask = vdso_image_32_int80.data +
+		vdso_image_32_int80.sym_VDSO32_NOTE_MASK;
+	*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
+	mask = vdso_image_32_sysenter.data +
+		vdso_image_32_sysenter.sym_VDSO32_NOTE_MASK;
+	*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
+#endif
+}
+
+static int register_callback(unsigned type, const void *func)
+{
+	struct callback_register callback = {
+		.type = type,
+		.address = XEN_CALLBACK(__KERNEL_CS, func),
+		.flags = CALLBACKF_mask_events,
+	};
+
+	return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
+}
+
+void xen_enable_sysenter(void)
+{
+	int ret;
+	unsigned sysenter_feature;
+
+#ifdef CONFIG_X86_32
+	sysenter_feature = X86_FEATURE_SEP;
+#else
+	sysenter_feature = X86_FEATURE_SYSENTER32;
+#endif
+
+	if (!boot_cpu_has(sysenter_feature))
+		return;
+
+	ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
+	if(ret != 0)
+		setup_clear_cpu_cap(sysenter_feature);
+}
+
+void xen_enable_syscall(void)
+{
+#ifdef CONFIG_X86_64
+	int ret;
+
+	ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
+	if (ret != 0) {
+		printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
+		/* Pretty fatal; 64-bit userspace has no other
+		   mechanism for syscalls. */
+	}
+
+	if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
+		ret = register_callback(CALLBACKTYPE_syscall32,
+					xen_syscall32_target);
+		if (ret != 0)
+			setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
+	}
+#endif /* CONFIG_X86_64 */
+}
+
+void __init xen_pvmmu_arch_setup(void)
+{
+	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
+	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
+
+	HYPERVISOR_vm_assist(VMASST_CMD_enable,
+			     VMASST_TYPE_pae_extended_cr3);
+
+	if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
+	    register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
+		BUG();
+
+	xen_enable_sysenter();
+	xen_enable_syscall();
+}
+
+/* This function is not called for HVM domains */
+void __init xen_arch_setup(void)
+{
+	xen_panic_handler_init();
+	if (!xen_feature(XENFEAT_auto_translated_physmap))
+		xen_pvmmu_arch_setup();
+
+#ifdef CONFIG_ACPI
+	if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
+		printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
+		disable_acpi();
+	}
+#endif
+
+	memcpy(boot_command_line, xen_start_info->cmd_line,
+	       MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
+	       COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
+
+	/* Set up idle, making sure it calls safe_halt() pvop */
+	disable_cpuidle();
+	disable_cpufreq();
+	WARN_ON(xen_set_default_idle());
+	fiddle_vdso();
+#ifdef CONFIG_NUMA
+	numa_off = 1;
+#endif
+}