Fix early page allocation on Xen

The Xen target was completely ignored when porting the biosmem and
vm_page physical memory allocators. Let's fix this.

* i386/Makefrag.am (libkernel_a_SOURCES): Add i386/i386at/biosmem.{c,h}.
* i386/i386/vm_page.h (VM_PAGE_MAX_SEGS, VM_PAGE_DIRECTMAP_LIMIT,
VM_PAGE_HIGHMEM_LIMIT): Define for Xen.
* i386/i386at/biosmem.c: Include mach/xen.h.
(biosmem_panic_setup_msg): Comment out for Xen since it's unused.
(biosmem_map_build, biosmem_map_build_simple,
biosmem_save_cmdline_sizes, biosmem_find_boot_data_update,
biosmem_find_boot_data, biosmem_setup_allocator): Likewise.
(biosmem_bootstrap_common): New function.
(biosmem_xen_bootstrap): Likewise, for Xen.
(biosmem_bootalloc): Perform bottom-up allocations for Xen.
* i386/i386at/biosmem.h (biosmem_xen_bootstrap): New prototype, for Xen.
* i386/i386at/model_dep.c (i386at_init): Call biosmem_xen_bootstrap instead
of biosmem_bootstrap on Xen.
* i386/include/mach/i386/vm_types.h (phys_addr_t): Define as an unsigned
64-bits integer when PAE is enabled.

6 files changed, 102 insertions, 12 deletions

diff --git a/i386/Makefrag.am b/i386/Makefrag.am
index e6cfedd7..0c5faa32 100644
--- a/i386/Makefrag.am
+++ b/i386/Makefrag.am
@@ -20,6 +20,8 @@
 libkernel_a_SOURCES += \
 	i386/i386at/autoconf.c \
 	i386/i386at/autoconf.h \
+	i386/i386at/biosmem.c \
+	i386/i386at/biosmem.h \
 	i386/i386at/conf.c \
 	i386/i386at/cons_conf.c \
 	i386/i386at/idt.h \
@@ -29,8 +31,6 @@ libkernel_a_SOURCES += \
 
 if PLATFORM_at
 libkernel_a_SOURCES += \
-	i386/i386at/biosmem.c \
-	i386/i386at/biosmem.h \
 	i386/i386at/boothdr.S \
 	i386/i386at/com.c \
 	i386/i386at/com.h \
diff --git a/i386/i386/vm_param.h b/i386/i386/vm_param.h
index da3126c0..3769ef70 100644
--- a/i386/i386/vm_param.h
+++ b/i386/i386/vm_param.h
@@ -108,6 +108,14 @@
  */
 #define VM_PAGE_DMA_LIMIT       DECL_CONST(0x1000000, UL)
 
+#ifdef MACH_XEN
+/* TODO Completely check Xen physical/virtual layout */
+#define VM_PAGE_MAX_SEGS 3
+#define VM_PAGE_DIRECTMAP_LIMIT (VM_MAX_KERNEL_ADDRESS \
+				 - VM_MIN_KERNEL_ADDRESS \
+				 - VM_KERNEL_MAP_SIZE)
+#define VM_PAGE_HIGHMEM_LIMIT   DECL_CONST(0x10000000000000, ULL)
+#else /* MACH_XEN */
 #ifdef __LP64__
 #define VM_PAGE_MAX_SEGS 4
 #define VM_PAGE_DMA32_LIMIT     DECL_CONST(0x100000000, UL)
@@ -125,6 +133,7 @@
 #define VM_PAGE_HIGHMEM_LIMIT   DECL_CONST(0xfffff000, UL)
 #endif /* PAE */
 #endif /* __LP64__ */
+#endif /* MACH_XEN */
 
 /*
  * Physical segment indexes.
diff --git a/i386/i386at/biosmem.c b/i386/i386at/biosmem.c
index 5b4fbddc..bf18cf65 100644
--- a/i386/i386at/biosmem.c
+++ b/i386/i386at/biosmem.c
@@ -24,6 +24,7 @@
 #include <kern/macros.h>
 #include <kern/printf.h>
 #include <mach/vm_param.h>
+#include <mach/xen.h>
 #include <mach/machine/multiboot.h>
 #include <sys/types.h>
 #include <vm/vm_page.h>
@@ -108,8 +109,10 @@ static uint32_t biosmem_heap_end __bootdata;
 
 static char biosmem_panic_toobig_msg[] __bootdata
     = "biosmem: too many memory map entries";
+#ifndef MACH_HYP
 static char biosmem_panic_setup_msg[] __bootdata
     = "biosmem: unable to set up the early memory allocator";
+#endif /* MACH_HYP */
 static char biosmem_panic_noseg_msg[] __bootdata
     = "biosmem: unable to find any memory segment";
 static char biosmem_panic_inval_msg[] __bootdata
@@ -117,6 +120,8 @@ static char biosmem_panic_inval_msg[] __bootdata
 static char biosmem_panic_nomem_msg[] __bootdata
     = "biosmem: unable to allocate memory";
 
+#ifndef MACH_HYP
+
 static void __boot
 biosmem_map_build(const struct multiboot_raw_info *mbi)
 {
@@ -161,6 +166,8 @@ biosmem_map_build_simple(const struct multiboot_raw_info *mbi)
     biosmem_map_size = 2;
 }
 
+#endif /* MACH_HYP */
+
 static int __boot
 biosmem_map_entry_is_invalid(const struct biosmem_map_entry *entry)
 {
@@ -375,6 +382,8 @@ biosmem_segment_size(unsigned int seg_index)
     return biosmem_segments[seg_index].end - biosmem_segments[seg_index].start;
 }
 
+#ifndef MACH_HYP
+
 static void __boot
 biosmem_save_cmdline_sizes(struct multiboot_raw_info *mbi)
 {
@@ -530,17 +539,14 @@ biosmem_setup_allocator(struct multiboot_raw_info *mbi)
     biosmem_heap_cur = biosmem_heap_end;
 }
 
-void __boot
-biosmem_bootstrap(struct multiboot_raw_info *mbi)
+#endif /* MACH_HYP */
+
+static void __boot
+biosmem_bootstrap_common(void)
 {
     phys_addr_t phys_start, phys_end, last_addr;
     int error;
 
-    if (mbi->flags & MULTIBOOT_LOADER_MMAP)
-        biosmem_map_build(mbi);
-    else
-        biosmem_map_build_simple(mbi);
-
     biosmem_map_adjust();
 
     phys_start = BIOSMEM_BASE;
@@ -585,6 +591,61 @@ biosmem_bootstrap(struct multiboot_raw_info *mbi)
     biosmem_set_segment(VM_PAGE_SEG_HIGHMEM, phys_start, phys_end);
 
 out:
+    /* XXX phys_last_addr must be part of the direct physical mapping */
+    phys_last_addr = last_addr;
+}
+
+#ifdef MACH_HYP
+
+void
+biosmem_xen_bootstrap(void)
+{
+    struct biosmem_map_entry *entry;
+
+    entry = biosmem_map;
+    entry->base_addr = 0;
+    entry->length = boot_info.nr_pages << PAGE_SHIFT;
+    entry->type = BIOSMEM_TYPE_AVAILABLE;
+
+    biosmem_map_size = 1;
+
+    biosmem_bootstrap_common();
+
+    biosmem_heap_start = _kvtophys(boot_info.pt_base)
+                         + (boot_info.nr_pt_frames + 3) * 0x1000;
+    biosmem_heap_end = boot_info.nr_pages << PAGE_SHIFT;
+
+#ifndef __LP64__
+    /* TODO Check that this actually makes sense */
+    if (biosmem_heap_end > VM_PAGE_DIRECTMAP_LIMIT)
+        biosmem_heap_end = VM_PAGE_DIRECTMAP_LIMIT;
+#endif /* __LP64__ */
+
+    /*
+     * XXX Allocation on Xen must be bottom-up :
+     * At the "start of day", only 512k are available after the boot
+     * data. The pmap module then creates a 4g mapping so all physical
+     * memory is available, but it uses this allocator to do so.
+     * Therefore, it must return pages from this small 512k regions
+     * first.
+     */
+    biosmem_heap_cur = biosmem_heap_start;
+}
+
+#else /* MACH_HYP */
+
+void __boot
+biosmem_bootstrap(struct multiboot_raw_info *mbi)
+{
+    phys_addr_t phys_start, phys_end, last_addr;
+    int error;
+
+    if (mbi->flags & MULTIBOOT_LOADER_MMAP)
+        biosmem_map_build(mbi);
+    else
+        biosmem_map_build_simple(mbi);
+
+    biosmem_bootstrap_common();
 
     /*
      * The kernel and modules command lines will be memory mapped later
@@ -592,11 +653,10 @@ out:
      */
     biosmem_save_cmdline_sizes(mbi);
     biosmem_setup_allocator(mbi);
-
-    /* XXX phys_last_addr must be part of the direct physical mapping */
-    phys_last_addr = last_addr;
 }
 
+#endif /* MACH_HYP */
+
 unsigned long __boot
 biosmem_bootalloc(unsigned int nr_pages)
 {
@@ -609,13 +669,22 @@ biosmem_bootalloc(unsigned int nr_pages)
     if (size == 0)
         boot_panic(biosmem_panic_inval_msg);
 
+#ifdef MACH_HYP
+    addr = biosmem_heap_cur;
+#else /* MACH_HYP */
     /* Top-down allocation to avoid unnecessarily filling DMA segments */
     addr = biosmem_heap_cur - size;
+#endif /* MACH_HYP */
 
     if ((addr < biosmem_heap_start) || (addr > biosmem_heap_cur))
         boot_panic(biosmem_panic_nomem_msg);
 
+#ifdef MACH_HYP
+    biosmem_heap_cur += size;
+#else /* MACH_HYP */
     biosmem_heap_cur = addr;
+#endif /* MACH_HYP */
+
     return addr;
 }
 
diff --git a/i386/i386at/biosmem.h b/i386/i386at/biosmem.h
index 0cc4f8a6..1db63f9f 100644
--- a/i386/i386at/biosmem.h
+++ b/i386/i386at/biosmem.h
@@ -47,7 +47,11 @@
  *
  * It is called before paging is enabled.
  */
+#ifdef MACH_HYP
+void biosmem_xen_bootstrap(void);
+#else /* MACH_HYP */
 void biosmem_bootstrap(struct multiboot_raw_info *mbi);
+#endif /* MACH_HYP */
 
 /*
  * Allocate contiguous physical pages during bootstrap.
diff --git a/i386/i386at/model_dep.c b/i386/i386at/model_dep.c
index dbb9d8b6..7638b832 100644
--- a/i386/i386at/model_dep.c
+++ b/i386/i386at/model_dep.c
@@ -286,7 +286,11 @@ i386at_init(void)
 	/*
 	 * Read memory map and load it into the physical page allocator.
 	 */
+#ifdef MACH_HYP
+	biosmem_xen_bootstrap();
+#else /* MACH_HYP */
 	biosmem_bootstrap((struct multiboot_raw_info *) &boot_info);
+#endif /* MACH_HYP */
 
 #ifdef MACH_XEN
 	kernel_cmdline = (char*) boot_info.cmd_line;
diff --git a/i386/include/mach/i386/vm_types.h b/i386/include/mach/i386/vm_types.h
index 41272e39..4a58b1cb 100644
--- a/i386/include/mach/i386/vm_types.h
+++ b/i386/include/mach/i386/vm_types.h
@@ -79,7 +79,11 @@ typedef	vm_offset_t *	vm_offset_array_t;
 /*
  * A type for physical addresses.
  */
+#ifdef PAE
+typedef unsigned long long phys_addr_t;
+#else /* PAE */
 typedef unsigned long phys_addr_t;
+#endif /* PAE */
 
 /*
  * A vm_size_t is the proper type for e.g.