@@ -52,6 +52,7 @@ obj-y += pci.o
obj-y += percpu.o
obj-y += physdev.o x86_64/physdev.o
obj-y += platform_hypercall.o x86_64/platform_hypercall.o
+obj-bin-y += pmap.init.o
obj-y += psr.o
obj-y += setup.o
obj-y += shutdown.o
new file mode 100644
@@ -0,0 +1,87 @@
+#include <xen/init.h>
+#include <xen/mm.h>
+#include <xen/spinlock.h>
+
+#include <asm/bitops.h>
+#include <asm/fixmap.h>
+#include <asm/flushtlb.h>
+
+/*
+ * Simple mapping infrastructure to map / unmap pages in fixed map.
+ * This is used to set up the page table for mapcache, which is used
+ * by map domain page infrastructure.
+ *
+ * This structure is not protected by any locks, so it must not be used after
+ * smp bring-up.
+ */
+
+/* Bitmap to track which slot is used */
+static unsigned long __initdata inuse;
+
+void *__init pmap_map(mfn_t mfn)
+{
+ unsigned long flags;
+ unsigned int idx;
+ void *linear = NULL;
+ enum fixed_addresses slot;
+ l1_pgentry_t *pl1e;
+
+ BUILD_BUG_ON(sizeof(inuse) * BITS_PER_LONG < NUM_FIX_PMAP);
+
+ ASSERT(system_state < SYS_STATE_smp_boot);
+
+ local_irq_save(flags);
+
+ idx = find_first_zero_bit(&inuse, NUM_FIX_PMAP);
+ if ( idx == NUM_FIX_PMAP )
+ panic("Out of PMAP slots\n");
+
+ __set_bit(idx, &inuse);
+
+ slot = idx + FIX_PMAP_BEGIN;
+ ASSERT(slot >= FIX_PMAP_BEGIN && slot <= FIX_PMAP_END);
+
+ linear = fix_to_virt(slot);
+ /*
+ * We cannot use set_fixmap() here. We use PMAP when there is no direct map,
+ * so map_pages_to_xen() called by set_fixmap() needs to map pages on
+ * demand, which then calls pmap() again, resulting in a loop. Modify the
+ * PTEs directly instead. The same is true for pmap_unmap().
+ */
+ pl1e = &l1_fixmap[l1_table_offset((unsigned long)linear)];
+ l1e_write_atomic(pl1e, l1e_from_mfn(mfn, PAGE_HYPERVISOR));
+
+ local_irq_restore(flags);
+
+ return linear;
+}
+
+void __init pmap_unmap(void *p)
+{
+ unsigned long flags;
+ unsigned int idx;
+ l1_pgentry_t *pl1e;
+ enum fixed_addresses slot = __virt_to_fix((unsigned long)p);
+
+ ASSERT(system_state < SYS_STATE_smp_boot);
+ ASSERT(slot >= FIX_PMAP_BEGIN && slot <= FIX_PMAP_END);
+
+ idx = slot - FIX_PMAP_BEGIN;
+ local_irq_save(flags);
+
+ __clear_bit(idx, &inuse);
+ pl1e = &l1_fixmap[l1_table_offset((unsigned long)p)];
+ l1e_write_atomic(pl1e, l1e_empty());
+ flush_tlb_one_local(p);
+
+ local_irq_restore(flags);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
@@ -24,6 +24,7 @@
#include <xen/kexec.h>
#include <asm/apicdef.h>
#include <asm/msi.h>
+#include <asm/pmap.h>
#include <acpi/apei.h>
/*
@@ -49,6 +50,8 @@ enum fixed_addresses {
FIX_XEN_SHARED_INFO,
#endif /* CONFIG_XEN_GUEST */
/* Everything else should go further down. */
+ FIX_PMAP_BEGIN,
+ FIX_PMAP_END = FIX_PMAP_BEGIN + NUM_FIX_PMAP - 1,
FIX_APIC_BASE,
FIX_IO_APIC_BASE_0,
FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS-1,
new file mode 100644
@@ -0,0 +1,10 @@
+#ifndef __X86_PMAP_H__
+#define __X86_PMAP_H__
+
+/* Large enough for mapping 5 levels of page tables with some headroom */
+#define NUM_FIX_PMAP 8
+
+void *pmap_map(mfn_t mfn);
+void pmap_unmap(void *p);
+
+#endif /* __X86_PMAP_H__ */