4 files changed, 252 insertions, 9 deletions

diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
index 359a7b50b158..d1b5dd566472 100644
--- a/arch/arm/include/asm/xen/page.h
+++ b/arch/arm/include/asm/xen/page.h
@@ -7,11 +7,10 @@
 #include <linux/pfn.h>
 #include <linux/types.h>
 
+#include <xen/xen.h>
 #include <xen/interface/grant_table.h>
 
-#define pfn_to_mfn(pfn)                 (pfn)
 #define phys_to_machine_mapping_valid(pfn) (1)
-#define mfn_to_pfn(mfn)                 (mfn)
 #define mfn_to_virt(m)                  (__va(mfn_to_pfn(m) << PAGE_SHIFT))
 
 #define pte_mfn     pte_pfn
@@ -32,6 +31,44 @@ typedef struct xpaddr {
 
 #define INVALID_P2M_ENTRY      (~0UL)
 
+unsigned long __pfn_to_mfn(unsigned long pfn);
+unsigned long __mfn_to_pfn(unsigned long mfn);
+extern struct rb_root phys_to_mach;
+
+static inline unsigned long pfn_to_mfn(unsigned long pfn)
+{
+        unsigned long mfn;
+        
+        if (phys_to_mach.rb_node != NULL) {
+                mfn = __pfn_to_mfn(pfn);
+                if (mfn != INVALID_P2M_ENTRY)
+                        return mfn;
+        }
+
+        if (xen_initial_domain())
+                return pfn;
+        else
+                return INVALID_P2M_ENTRY;
+}
+
+static inline unsigned long mfn_to_pfn(unsigned long mfn)
+{
+        unsigned long pfn;
+
+        if (phys_to_mach.rb_node != NULL) {
+                pfn = __mfn_to_pfn(mfn);
+                if (pfn != INVALID_P2M_ENTRY)
+                        return pfn;
+        }
+
+        if (xen_initial_domain())
+                return mfn;
+        else
+                return INVALID_P2M_ENTRY;
+}
+
+#define mfn_to_local_pfn(mfn) mfn_to_pfn(mfn)
+
 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
 {
         unsigned offset = phys.paddr & ~PAGE_MASK;
@@ -76,11 +113,9 @@ static inline int m2p_remove_override(struct page *page, bool clear_pte)
         return 0;
 }
 
-static inline bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
-{
-        BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
-        return true;
-}
+bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
+bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn,
+                unsigned long nr_pages);
 
 static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 {
diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
index 43841033afd3..21e6ff503178 100644
--- a/arch/arm/xen/Makefile
+++ b/arch/arm/xen/Makefile
@@ -1 +1 @@
-obj-y           := enlighten.o hypercall.o grant-table.o
+obj-y           := enlighten.o hypercall.o grant-table.o p2m.o
diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
new file mode 100644
index 000000000000..5df4a9afb8c6
--- /dev/null
+++ b/arch/arm/xen/p2m.c
@@ -0,0 +1,208 @@
+#include <linux/bootmem.h>
+#include <linux/gfp.h>
+#include <linux/export.h>
+#include <linux/rwlock.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/dma-mapping.h>
+#include <linux/vmalloc.h>
+#include <linux/swiotlb.h>
+
+#include <xen/xen.h>
+#include <xen/interface/memory.h>
+#include <xen/swiotlb-xen.h>
+
+#include <asm/cacheflush.h>
+#include <asm/xen/page.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/interface.h>
+
+struct xen_p2m_entry {
+        unsigned long pfn;
+        unsigned long mfn;
+        unsigned long nr_pages;
+        struct rb_node rbnode_mach;
+        struct rb_node rbnode_phys;
+};
+
+rwlock_t p2m_lock;
+struct rb_root phys_to_mach = RB_ROOT;
+static struct rb_root mach_to_phys = RB_ROOT;
+
+static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new)
+{
+        struct rb_node **link = &phys_to_mach.rb_node;
+        struct rb_node *parent = NULL;
+        struct xen_p2m_entry *entry;
+        int rc = 0;
+
+        while (*link) {
+                parent = *link;
+                entry = rb_entry(parent, struct xen_p2m_entry, rbnode_phys);
+
+                if (new->mfn == entry->mfn)
+                        goto err_out;
+                if (new->pfn == entry->pfn)
+                        goto err_out;
+
+                if (new->pfn < entry->pfn)
+                        link = &(*link)->rb_left;
+                else
+                        link = &(*link)->rb_right;
+        }
+        rb_link_node(&new->rbnode_phys, parent, link);
+        rb_insert_color(&new->rbnode_phys, &phys_to_mach);
+        goto out;
+
+err_out:
+        rc = -EINVAL;
+        pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n",
+                        __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn);
+out:
+        return rc;
+}
+
+unsigned long __pfn_to_mfn(unsigned long pfn)
+{
+        struct rb_node *n = phys_to_mach.rb_node;
+        struct xen_p2m_entry *entry;
+        unsigned long irqflags;
+
+        read_lock_irqsave(&p2m_lock, irqflags);
+        while (n) {
+                entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
+                if (entry->pfn <= pfn &&
+                                entry->pfn + entry->nr_pages > pfn) {
+                        read_unlock_irqrestore(&p2m_lock, irqflags);
+                        return entry->mfn + (pfn - entry->pfn);
+                }
+                if (pfn < entry->pfn)
+                        n = n->rb_left;
+                else
+                        n = n->rb_right;
+        }
+        read_unlock_irqrestore(&p2m_lock, irqflags);
+
+        return INVALID_P2M_ENTRY;
+}
+EXPORT_SYMBOL_GPL(__pfn_to_mfn);
+
+static int xen_add_mach_to_phys_entry(struct xen_p2m_entry *new)
+{
+        struct rb_node **link = &mach_to_phys.rb_node;
+        struct rb_node *parent = NULL;
+        struct xen_p2m_entry *entry;
+        int rc = 0;
+
+        while (*link) {
+                parent = *link;
+                entry = rb_entry(parent, struct xen_p2m_entry, rbnode_mach);
+
+                if (new->mfn == entry->mfn)
+                        goto err_out;
+                if (new->pfn == entry->pfn)
+                        goto err_out;
+
+                if (new->mfn < entry->mfn)
+                        link = &(*link)->rb_left;
+                else
+                        link = &(*link)->rb_right;
+        }
+        rb_link_node(&new->rbnode_mach, parent, link);
+        rb_insert_color(&new->rbnode_mach, &mach_to_phys);
+        goto out;
+
+err_out:
+        rc = -EINVAL;
+        pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n",
+                        __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn);
+out:
+        return rc;
+}
+
+unsigned long __mfn_to_pfn(unsigned long mfn)
+{
+        struct rb_node *n = mach_to_phys.rb_node;
+        struct xen_p2m_entry *entry;
+        unsigned long irqflags;
+
+        read_lock_irqsave(&p2m_lock, irqflags);
+        while (n) {
+                entry = rb_entry(n, struct xen_p2m_entry, rbnode_mach);
+                if (entry->mfn <= mfn &&
+                                entry->mfn + entry->nr_pages > mfn) {
+                        read_unlock_irqrestore(&p2m_lock, irqflags);
+                        return entry->pfn + (mfn - entry->mfn);
+                }
+                if (mfn < entry->mfn)
+                        n = n->rb_left;
+                else
+                        n = n->rb_right;
+        }
+        read_unlock_irqrestore(&p2m_lock, irqflags);
+
+        return INVALID_P2M_ENTRY;
+}
+EXPORT_SYMBOL_GPL(__mfn_to_pfn);
+
+bool __set_phys_to_machine_multi(unsigned long pfn,
+                unsigned long mfn, unsigned long nr_pages)
+{
+        int rc;
+        unsigned long irqflags;
+        struct xen_p2m_entry *p2m_entry;
+        struct rb_node *n = phys_to_mach.rb_node;
+
+        if (mfn == INVALID_P2M_ENTRY) {
+                write_lock_irqsave(&p2m_lock, irqflags);
+                while (n) {
+                        p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
+                        if (p2m_entry->pfn <= pfn &&
+                                        p2m_entry->pfn + p2m_entry->nr_pages > pfn) {
+                                rb_erase(&p2m_entry->rbnode_mach, &mach_to_phys);
+                                rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach);
+                                write_unlock_irqrestore(&p2m_lock, irqflags);
+                                kfree(p2m_entry);       
+                                return true;
+                        }
+                        if (pfn < p2m_entry->pfn)
+                                n = n->rb_left;
+                        else
+                                n = n->rb_right;
+                }
+                write_unlock_irqrestore(&p2m_lock, irqflags);
+                return true;
+        }
+
+        p2m_entry = kzalloc(sizeof(struct xen_p2m_entry), GFP_NOWAIT);
+        if (!p2m_entry) {
+                pr_warn("cannot allocate xen_p2m_entry\n");
+                return false;
+        }
+        p2m_entry->pfn = pfn;
+        p2m_entry->nr_pages = nr_pages;
+        p2m_entry->mfn = mfn;
+
+        write_lock_irqsave(&p2m_lock, irqflags);
+        if ((rc = xen_add_phys_to_mach_entry(p2m_entry) < 0) ||
+                (rc = xen_add_mach_to_phys_entry(p2m_entry) < 0)) {
+                write_unlock_irqrestore(&p2m_lock, irqflags);
+                return false;
+        }
+        write_unlock_irqrestore(&p2m_lock, irqflags);
+        return true;
+}
+EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi);
+
+bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
+{
+        return __set_phys_to_machine_multi(pfn, mfn, 1);
+}
+EXPORT_SYMBOL_GPL(__set_phys_to_machine);
+
+int p2m_init(void)
+{
+        rwlock_init(&p2m_lock);
+        return 0;
+}
+arch_initcall(p2m_init);
diff --git a/arch/arm64/xen/Makefile b/arch/arm64/xen/Makefile
index be240404ba96..cd866b0c619b 100644
--- a/arch/arm64/xen/Makefile
+++ b/arch/arm64/xen/Makefile
@@ -1,2 +1,2 @@
-xen-arm-y       += $(addprefix ../../arm/xen/, enlighten.o grant-table.o)
+xen-arm-y       += $(addprefix ../../arm/xen/, enlighten.o grant-table.o p2m.o)
 obj-y           := xen-arm.o hypercall.o