[PATCH v3 7/9] xen/ppc: Enable bootfdt and boot allocator

[Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx>]

Enable usage of bootfdt for populating the boot info struct from the
firmware-provided device tree.  Also enable the Xen boot page allocator.

Includes minor changes to bootfdt.c's boot_fdt_info() to tolerate the
scenario in which the FDT overlaps a reserved memory region, as is the
case on PPC when booted directly from skiboot.

Signed-off-by: Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx>
---
 xen/arch/ppc/include/asm/setup.h |  5 +++++
 xen/arch/ppc/setup.c             | 21 ++++++++++++++++++++-
 xen/common/device-tree/bootfdt.c | 11 +++++++++--
 3 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/xen/arch/ppc/include/asm/setup.h b/xen/arch/ppc/include/asm/setup.h
index 1b2d29c5b6..fe27f61fc3 100644
--- a/xen/arch/ppc/include/asm/setup.h
+++ b/xen/arch/ppc/include/asm/setup.h
@@ -115,4 +115,9 @@ const char *boot_module_kind_as_string(bootmodule_kind 
kind);
 struct bootcmdline *boot_cmdline_find_by_kind(bootmodule_kind kind);
 void populate_boot_allocator(void);
 
+/*
+ * bootfdt.c
+ */
+size_t boot_fdt_info(const void *fdt, paddr_t paddr);
+
 #endif /* __ASM_PPC_SETUP_H__ */
diff --git a/xen/arch/ppc/setup.c b/xen/arch/ppc/setup.c
index 101bdd8bb6..946167a56f 100644
--- a/xen/arch/ppc/setup.c
+++ b/xen/arch/ppc/setup.c
@@ -1,12 +1,14 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
 #include <xen/init.h>
 #include <xen/lib.h>
+#include <xen/libfdt/libfdt.h>
 #include <xen/mm.h>
 #include <public/version.h>
 #include <asm/boot.h>
 #include <asm/early_printk.h>
 #include <asm/mm.h>
 #include <asm/processor.h>
+#include <asm/setup.h>
 
 /* Xen stack for bringing up the first CPU. */
 unsigned char __initdata cpu0_boot_stack[STACK_SIZE] __aligned(STACK_SIZE);
@@ -24,6 +26,9 @@ void __init noreturn start_xen(unsigned long r3, unsigned 
long r4,
                                unsigned long r5, unsigned long r6,
                                unsigned long r7)
 {
+    void *boot_fdt;
+    struct bootmodule *xen_bootmodule;
+
     if ( r5 )
     {
         /* Unsupported OpenFirmware boot protocol */
@@ -32,11 +37,25 @@ void __init noreturn start_xen(unsigned long r3, unsigned 
long r4,
     else
     {
         /* kexec boot protocol */
-        boot_opal_init((void *)r3);
+        boot_fdt = (void *)r3;
+        boot_opal_init(boot_fdt);
     }
 
     setup_exceptions();
 
+    device_tree_flattened = boot_fdt;
+    boot_fdt_info(boot_fdt, r3);
+
+    /*
+     * Xen relocates itself at the ppc64 entrypoint, so we need to manually 
mark
+     * the kernel module.
+     */
+    xen_bootmodule = add_boot_module(BOOTMOD_XEN, __pa(_start),
+                                     PAGE_ALIGN(__pa(_end)), false);
+    BUG_ON(!xen_bootmodule);
+
+    populate_boot_allocator();
+
     setup_initial_pagetables();
 
     early_printk("Hello, ppc64le!\n");
diff --git a/xen/common/device-tree/bootfdt.c b/xen/common/device-tree/bootfdt.c
index 35dbdf3384..1985648b31 100644
--- a/xen/common/device-tree/bootfdt.c
+++ b/xen/common/device-tree/bootfdt.c
@@ -543,12 +543,19 @@ size_t __init boot_fdt_info(const void *fdt, paddr_t 
paddr)
     if ( ret < 0 )
         panic("No valid device tree\n");
 
-    add_boot_module(BOOTMOD_FDT, paddr, fdt_totalsize(fdt), false);
-
     ret = device_tree_for_each_node(fdt, 0, early_scan_node, NULL);
     if ( ret )
         panic("Early FDT parsing failed (%d)\n", ret);
 
+    /*
+     * Add module for the FDT itself after the device tree has been parsed. 
This
+     * is required on ppc64le where the device tree passed to Xen may have been
+     * allocated by skiboot, in which case it will exist within a reserved
+     * region and this call will fail. This is fine, however, since either way
+     * the allocator will know not to step on the device tree.
+     */
+    add_boot_module(BOOTMOD_FDT, paddr, fdt_totalsize(fdt), false);
+
     /*
      * On Arm64 setup_directmap_mappings() expects to be called with the lowest
      * bank in memory first. There is no requirement that the DT will provide
-- 
2.30.2