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-rw-r--r--arch/arm/xen/p2m.c210
1 files changed, 210 insertions, 0 deletions
diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
new file mode 100644
index 000000000..309648c17
--- /dev/null
+++ b/arch/arm/xen/p2m.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/memblock.h>
+#include <linux/gfp.h>
+#include <linux/export.h>
+#include <linux/spinlock.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/grant_table.h>
+#include <xen/page.h>
+#include <xen/swiotlb-xen.h>
+
+#include <asm/cacheflush.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_phys;
+};
+
+static rwlock_t p2m_lock;
+struct rb_root phys_to_mach = RB_ROOT;
+EXPORT_SYMBOL_GPL(phys_to_mach);
+
+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->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;
+ struct xen_p2m_entry *entry;
+ unsigned long irqflags;
+
+ read_lock_irqsave(&p2m_lock, irqflags);
+ n = phys_to_mach.rb_node;
+ while (n) {
+ entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
+ if (entry->pfn <= pfn &&
+ entry->pfn + entry->nr_pages > pfn) {
+ unsigned long mfn = entry->mfn + (pfn - entry->pfn);
+ read_unlock_irqrestore(&p2m_lock, irqflags);
+ return mfn;
+ }
+ 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);
+
+int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
+ struct gnttab_map_grant_ref *kmap_ops,
+ struct page **pages, unsigned int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ struct gnttab_unmap_grant_ref unmap;
+ int rc;
+
+ if (map_ops[i].status)
+ continue;
+ if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
+ map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT)))
+ continue;
+
+ /*
+ * Signal an error for this slot. This in turn requires
+ * immediate unmapping.
+ */
+ map_ops[i].status = GNTST_general_error;
+ unmap.host_addr = map_ops[i].host_addr,
+ unmap.handle = map_ops[i].handle;
+ map_ops[i].handle = INVALID_GRANT_HANDLE;
+ if (map_ops[i].flags & GNTMAP_device_map)
+ unmap.dev_bus_addr = map_ops[i].dev_bus_addr;
+ else
+ unmap.dev_bus_addr = 0;
+
+ /*
+ * Pre-populate the status field, to be recognizable in
+ * the log message below.
+ */
+ unmap.status = 1;
+
+ rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+ &unmap, 1);
+ if (rc || unmap.status != GNTST_okay)
+ pr_err_once("gnttab unmap failed: rc=%d st=%d\n",
+ rc, unmap.status);
+ }
+
+ return 0;
+}
+
+int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
+ struct gnttab_unmap_grant_ref *kunmap_ops,
+ struct page **pages, unsigned int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT,
+ INVALID_P2M_ENTRY);
+ }
+
+ return 0;
+}
+
+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;
+
+ if (mfn == INVALID_P2M_ENTRY) {
+ write_lock_irqsave(&p2m_lock, irqflags);
+ n = phys_to_mach.rb_node;
+ 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_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(*p2m_entry), GFP_NOWAIT);
+ if (!p2m_entry)
+ return false;
+
+ p2m_entry->pfn = pfn;
+ p2m_entry->nr_pages = nr_pages;
+ p2m_entry->mfn = mfn;
+
+ write_lock_irqsave(&p2m_lock, irqflags);
+ rc = xen_add_phys_to_mach_entry(p2m_entry);
+ if (rc < 0) {
+ write_unlock_irqrestore(&p2m_lock, irqflags);
+ kfree(p2m_entry);
+ 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);
+
+static int p2m_init(void)
+{
+ rwlock_init(&p2m_lock);
+ return 0;
+}
+arch_initcall(p2m_init);