Merge branch 'stable/autoballoon.v5.2' into stable/for-linus-3.5

* stable/autoballoon.v5.2:
  xen/setup: update VA mapping when releasing memory during setup
  xen/setup: Combine the two hypercall functions - since they are quite similar.
  xen/setup: Populate freed MFNs from non-RAM E820 entries and gaps to E820 RAM
  xen/setup: Only print "Freeing XXX-YYY pfn range: Z pages freed" if Z > 0
  xen/p2m: An early bootup variant of set_phys_to_machine
  xen/p2m: Collapse early_alloc_p2m_middle redundant checks.
  xen/p2m: Allow alloc_p2m_middle to call reserve_brk depending on argument
  xen/p2m: Move code around to allow for better re-usage.

6 files changed, 207 insertions, 94 deletions

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index c34f96c2f7a0..93971e841dd5 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -44,6 +44,7 @@ extern unsigned long  machine_to_phys_nr;
 
 extern unsigned long get_phys_to_machine(unsigned long pfn);
 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
+extern bool __init early_set_phys_to_machine(unsigned long pfn, unsigned long mfn);
 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
 extern unsigned long set_phys_range_identity(unsigned long pfn_s,
                                              unsigned long pfn_e);
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index eca90e5be1e7..d1f9a0472d44 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1316,7 +1316,6 @@ asmlinkage void __init xen_start_kernel(void)
 
         xen_raw_console_write("mapping kernel into physical memory\n");
         pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
-        xen_ident_map_ISA();
 
         /* Allocate and initialize top and mid mfn levels for p2m structure */
         xen_build_mfn_list_list();
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index b8e279479a6b..b756d8cf4df5 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1929,29 +1929,6 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
 #endif
 }
 
-void __init xen_ident_map_ISA(void)
-{
-        unsigned long pa;
-
-        /*
-         * If we're dom0, then linear map the ISA machine addresses into
-         * the kernel's address space.
-         */
-        if (!xen_initial_domain())
-                return;
-
-        xen_raw_printk("Xen: setup ISA identity maps\n");
-
-        for (pa = ISA_START_ADDRESS; pa < ISA_END_ADDRESS; pa += PAGE_SIZE) {
-                pte_t pte = mfn_pte(PFN_DOWN(pa), PAGE_KERNEL_IO);
-
-                if (HYPERVISOR_update_va_mapping(PAGE_OFFSET + pa, pte, 0))
-                        BUG();
-        }
-
-        xen_flush_tlb();
-}
-
 static void __init xen_post_allocator_init(void)
 {
         pv_mmu_ops.set_pte = xen_set_pte;
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 1b267e75158d..ffd08c414e91 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -499,16 +499,18 @@ static bool alloc_p2m(unsigned long pfn)
         return true;
 }
 
-static bool __init __early_alloc_p2m(unsigned long pfn)
+static bool __init early_alloc_p2m_middle(unsigned long pfn, bool check_boundary)
 {
         unsigned topidx, mididx, idx;
+        unsigned long *p2m;
+        unsigned long *mid_mfn_p;
 
         topidx = p2m_top_index(pfn);
         mididx = p2m_mid_index(pfn);
         idx = p2m_index(pfn);
 
         /* Pfff.. No boundary cross-over, lets get out. */
-        if (!idx)
+        if (!idx && check_boundary)
                 return false;
 
         WARN(p2m_top[topidx][mididx] == p2m_identity,
@@ -522,24 +524,66 @@ static bool __init __early_alloc_p2m(unsigned long pfn)
                 return false;
 
         /* Boundary cross-over for the edges: */
-        if (idx) {
-                unsigned long *p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);
-                unsigned long *mid_mfn_p;
+        p2m = extend_brk(PAGE_SIZE, PAGE_SIZE);
 
-                p2m_init(p2m);
+        p2m_init(p2m);
 
-                p2m_top[topidx][mididx] = p2m;
+        p2m_top[topidx][mididx] = p2m;
 
-                /* For save/restore we need to MFN of the P2M saved */
-                
-                mid_mfn_p = p2m_top_mfn_p[topidx];
-                WARN(mid_mfn_p[mididx] != virt_to_mfn(p2m_missing),
-                        "P2M_TOP_P[%d][%d] != MFN of p2m_missing!\n",
-                        topidx, mididx);
-                mid_mfn_p[mididx] = virt_to_mfn(p2m);
+        /* For save/restore we need to MFN of the P2M saved */
+
+        mid_mfn_p = p2m_top_mfn_p[topidx];
+        WARN(mid_mfn_p[mididx] != virt_to_mfn(p2m_missing),
+                "P2M_TOP_P[%d][%d] != MFN of p2m_missing!\n",
+                topidx, mididx);
+        mid_mfn_p[mididx] = virt_to_mfn(p2m);
+
+        return true;
+}
+
+static bool __init early_alloc_p2m(unsigned long pfn)
+{
+        unsigned topidx = p2m_top_index(pfn);
+        unsigned long *mid_mfn_p;
+        unsigned long **mid;
+
+        mid = p2m_top[topidx];
+        mid_mfn_p = p2m_top_mfn_p[topidx];
+        if (mid == p2m_mid_missing) {
+                mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
+
+                p2m_mid_init(mid);
+
+                p2m_top[topidx] = mid;
 
+                BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
         }
-        return idx != 0;
+        /* And the save/restore P2M tables.. */
+        if (mid_mfn_p == p2m_mid_missing_mfn) {
+                mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
+                p2m_mid_mfn_init(mid_mfn_p);
+
+                p2m_top_mfn_p[topidx] = mid_mfn_p;
+                p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
+                /* Note: we don't set mid_mfn_p[midix] here,
+                 * look in early_alloc_p2m_middle */
+        }
+        return true;
+}
+bool __init early_set_phys_to_machine(unsigned long pfn, unsigned long mfn)
+{
+        if (unlikely(!__set_phys_to_machine(pfn, mfn)))  {
+                if (!early_alloc_p2m(pfn))
+                        return false;
+
+                if (!early_alloc_p2m_middle(pfn, false /* boundary crossover OK!*/))
+                        return false;
+
+                if (!__set_phys_to_machine(pfn, mfn))
+                        return false;
+        }
+
+        return true;
 }
 unsigned long __init set_phys_range_identity(unsigned long pfn_s,
                                       unsigned long pfn_e)
@@ -559,35 +603,11 @@ unsigned long __init set_phys_range_identity(unsigned long pfn_s,
                 pfn < ALIGN(pfn_e, (P2M_MID_PER_PAGE * P2M_PER_PAGE));
                 pfn += P2M_MID_PER_PAGE * P2M_PER_PAGE)
         {
-                unsigned topidx = p2m_top_index(pfn);
-                unsigned long *mid_mfn_p;
-                unsigned long **mid;
-
-                mid = p2m_top[topidx];
-                mid_mfn_p = p2m_top_mfn_p[topidx];
-                if (mid == p2m_mid_missing) {
-                        mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
-
-                        p2m_mid_init(mid);
-
-                        p2m_top[topidx] = mid;
-
-                        BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
-                }
-                /* And the save/restore P2M tables.. */
-                if (mid_mfn_p == p2m_mid_missing_mfn) {
-                        mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
-                        p2m_mid_mfn_init(mid_mfn_p);
-
-                        p2m_top_mfn_p[topidx] = mid_mfn_p;
-                        p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
-                        /* Note: we don't set mid_mfn_p[midix] here,
-                         * look in __early_alloc_p2m */
-                }
+                WARN_ON(!early_alloc_p2m(pfn));
         }
 
-        __early_alloc_p2m(pfn_s);
-        __early_alloc_p2m(pfn_e);
+        early_alloc_p2m_middle(pfn_s, true);
+        early_alloc_p2m_middle(pfn_e, true);
 
         for (pfn = pfn_s; pfn < pfn_e; pfn++)
                 if (!__set_phys_to_machine(pfn, IDENTITY_FRAME(pfn)))
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 1ba8dff26753..3ebba0753d38 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -26,7 +26,6 @@
 #include <xen/interface/memory.h>
 #include <xen/interface/physdev.h>
 #include <xen/features.h>
-
 #include "xen-ops.h"
 #include "vdso.h"
 
@@ -84,8 +83,8 @@ static void __init xen_add_extra_mem(u64 start, u64 size)
                 __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
 }
 
-static unsigned long __init xen_release_chunk(unsigned long start,
-                                              unsigned long end)
+static unsigned long __init xen_do_chunk(unsigned long start,
+                                         unsigned long end, bool release)
 {
         struct xen_memory_reservation reservation = {
                 .address_bits = 0,
@@ -96,30 +95,138 @@ static unsigned long __init xen_release_chunk(unsigned long start,
         unsigned long pfn;
         int ret;
 
-        for(pfn = start; pfn < end; pfn++) {
+        for (pfn = start; pfn < end; pfn++) {
+                unsigned long frame;
                 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;
-
-                set_xen_guest_handle(reservation.extent_start, &mfn);
+                if (release) {
+                        /* Make sure pfn exists to start with */
+                        if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
+                                continue;
+                        frame = mfn;
+                } else {
+                        if (mfn != INVALID_P2M_ENTRY)
+                                continue;
+                        frame = pfn;
+                }
+                set_xen_guest_handle(reservation.extent_start, &frame);
                 reservation.nr_extents = 1;
 
-                ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
+                ret = HYPERVISOR_memory_op(release ? XENMEM_decrease_reservation : XENMEM_populate_physmap,
                                            &reservation);
-                WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
+                WARN(ret != 1, "Failed to %s pfn %lx err=%d\n",
+                     release ? "release" : "populate", pfn, ret);
+
                 if (ret == 1) {
-                        __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+                        if (!early_set_phys_to_machine(pfn, release ? INVALID_P2M_ENTRY : frame)) {
+                                if (release)
+                                        break;
+                                set_xen_guest_handle(reservation.extent_start, &frame);
+                                reservation.nr_extents = 1;
+                                ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
+                                                           &reservation);
+                                break;
+                        }
                         len++;
-                }
+                } else
+                        break;
         }
-        printk(KERN_INFO "Freeing  %lx-%lx pfn range: %lu pages freed\n",
-               start, end, len);
+        if (len)
+                printk(KERN_INFO "%s %lx-%lx pfn range: %lu pages %s\n",
+                       release ? "Freeing" : "Populating",
+                       start, end, len,
+                       release ? "freed" : "added");
 
         return len;
 }
 
+static unsigned long __init xen_release_chunk(unsigned long start,
+                                              unsigned long end)
+{
+        return xen_do_chunk(start, end, true);
+}
+
+static unsigned long __init xen_populate_chunk(
+        const struct e820entry *list, size_t map_size,
+        unsigned long max_pfn, unsigned long *last_pfn,
+        unsigned long credits_left)
+{
+        const struct e820entry *entry;
+        unsigned int i;
+        unsigned long done = 0;
+        unsigned long dest_pfn;
+
+        for (i = 0, entry = list; i < map_size; i++, entry++) {
+                unsigned long credits = credits_left;
+                unsigned long s_pfn;
+                unsigned long e_pfn;
+                unsigned long pfns;
+                long capacity;
+
+                if (credits <= 0)
+                        break;
+
+                if (entry->type != E820_RAM)
+                        continue;
+
+                e_pfn = PFN_UP(entry->addr + entry->size);
+
+                /* We only care about E820 after the xen_start_info->nr_pages */
+                if (e_pfn <= max_pfn)
+                        continue;
+
+                s_pfn = PFN_DOWN(entry->addr);
+                /* If the E820 falls within the nr_pages, we want to start
+                 * at the nr_pages PFN.
+                 * If that would mean going past the E820 entry, skip it
+                 */
+                if (s_pfn <= max_pfn) {
+                        capacity = e_pfn - max_pfn;
+                        dest_pfn = max_pfn;
+                } else {
+                        /* last_pfn MUST be within E820_RAM regions */
+                        if (*last_pfn && e_pfn >= *last_pfn)
+                                s_pfn = *last_pfn;
+                        capacity = e_pfn - s_pfn;
+                        dest_pfn = s_pfn;
+                }
+                /* If we had filled this E820_RAM entry, go to the next one. */
+                if (capacity <= 0)
+                        continue;
+
+                if (credits > capacity)
+                        credits = capacity;
+
+                pfns = xen_do_chunk(dest_pfn, dest_pfn + credits, false);
+                done += pfns;
+                credits_left -= pfns;
+                *last_pfn = (dest_pfn + pfns);
+        }
+        return done;
+}
+
+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 *identity)
+{
+        unsigned long pfn;
+
+        /*
+         * 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);
+
+        if (start_pfn < nr_pages)
+                *released += xen_release_chunk(
+                        start_pfn, min(end_pfn, nr_pages));
+
+        *identity += set_phys_range_identity(start_pfn, end_pfn);
+}
+
 static unsigned long __init xen_set_identity_and_release(
         const struct e820entry *list, size_t map_size, unsigned long nr_pages)
 {
@@ -142,7 +249,6 @@ static unsigned long __init xen_set_identity_and_release(
          */
         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);
@@ -150,20 +256,19 @@ static unsigned long __init xen_set_identity_and_release(
                         if (entry->type == E820_RAM)
                                 end_pfn = PFN_UP(entry->addr);
 
-                        if (start_pfn < end_pfn) {
-                                if (start_pfn < nr_pages)
-                                        released += xen_release_chunk(
-                                                start_pfn, min(end_pfn, nr_pages));
+                        if (start_pfn < end_pfn)
+                                xen_set_identity_and_release_chunk(
+                                        start_pfn, end_pfn, nr_pages,
+                                        &released, &identity);
 
-                                identity += set_phys_range_identity(
-                                        start_pfn, end_pfn);
-                        }
                         start = end;
                 }
         }
 
-        printk(KERN_INFO "Released %lu pages of unused memory\n", released);
-        printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
+        if (released)
+                printk(KERN_INFO "Released %lu pages of unused memory\n", released);
+        if (identity)
+                printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
 
         return released;
 }
@@ -217,7 +322,9 @@ char * __init xen_memory_setup(void)
         int rc;
         struct xen_memory_map memmap;
         unsigned long max_pages;
+        unsigned long last_pfn = 0;
         unsigned long extra_pages = 0;
+        unsigned long populated;
         int i;
         int op;
 
@@ -257,9 +364,20 @@ char * __init xen_memory_setup(void)
          */
         xen_released_pages = xen_set_identity_and_release(
                 map, memmap.nr_entries, max_pfn);
-        extra_pages += xen_released_pages;
 
         /*
+         * Populate back the non-RAM pages and E820 gaps that had been
+         * released. */
+        populated = xen_populate_chunk(map, memmap.nr_entries,
+                        max_pfn, &last_pfn, xen_released_pages);
+
+        extra_pages += (xen_released_pages - populated);
+
+        if (last_pfn > max_pfn) {
+                max_pfn = min(MAX_DOMAIN_PAGES, last_pfn);
+                mem_end = PFN_PHYS(max_pfn);
+        }
+        /*
          * 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
@@ -272,7 +390,6 @@ char * __init xen_memory_setup(void)
          */
         extra_pages = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
                           extra_pages);
-
         i = 0;
         while (i < memmap.nr_entries) {
                 u64 addr = map[i].addr;
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index b095739ccd4c..506fa08d934a 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -28,7 +28,6 @@ void xen_setup_shared_info(void);
 void xen_build_mfn_list_list(void);
 void xen_setup_machphys_mapping(void);
 pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn);
-void xen_ident_map_ISA(void);
 void xen_reserve_top(void);
 extern unsigned long xen_max_p2m_pfn;