xen/arm: mm: Initialize page-tables earlier

Since commit f60658c6ae "xen/arm: Stop relocating Xen", the function
setup_page_tables() does not require any information from the FDT.

So the initialization of the page-tables can be done much earlier in the
boot process. The earliest setup_page_tables() can be called is after
traps have been initialized, so we can get backtrace if an error
occurred.

Moving the initialization of the page-tables also avoid the dance to map
the FDT again in the new set of page-tables.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Andrii Anisov <andrii_anisov@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index bce7433f239e06c03064afef9f68b6311e337112..2ad12da5d1c3f309dbd7517622dc978b14af5e32 100644 (file)
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -522,7 +522,6 @@ static inline lpae_t pte_of_xenaddr(vaddr_t va)
     return mfn_to_xen_entry(maddr_to_mfn(ma), MT_NORMAL);
 }
 
-/* Map the FDT in the early boot page table */
 void * __init early_fdt_map(paddr_t fdt_paddr)
 {
     /* We are using 2MB superpage for mapping the FDT */
@@ -545,7 +544,7 @@ void * __init early_fdt_map(paddr_t fdt_paddr)
     /* The FDT is mapped using 2MB superpage */
     BUILD_BUG_ON(BOOT_FDT_VIRT_START % SZ_2M);
 
-    create_mappings(boot_second, BOOT_FDT_VIRT_START, paddr_to_pfn(base_paddr),
+    create_mappings(xen_second, BOOT_FDT_VIRT_START, paddr_to_pfn(base_paddr),
                     SZ_2M >> PAGE_SHIFT, SZ_2M);
 
     offset = fdt_paddr % SECOND_SIZE;
@@ -560,7 +559,7 @@ void * __init early_fdt_map(paddr_t fdt_paddr)
 
     if ( (offset + size) > SZ_2M )
     {
-        create_mappings(boot_second, BOOT_FDT_VIRT_START + SZ_2M,
+        create_mappings(xen_second, BOOT_FDT_VIRT_START + SZ_2M,
                         paddr_to_pfn(base_paddr + SZ_2M),
                         SZ_2M >> PAGE_SHIFT, SZ_2M);
     }
@@ -671,12 +670,6 @@ void __init setup_pagetables(unsigned long boot_phys_offset)
     pte.pt.table = 1;
     xen_second[second_table_offset(FIXMAP_ADDR(0))] = pte;
 
-    /* ... DTB */
-    pte = boot_second[second_table_offset(BOOT_FDT_VIRT_START)];
-    xen_second[second_table_offset(BOOT_FDT_VIRT_START)] = pte;
-    pte = boot_second[second_table_offset(BOOT_FDT_VIRT_START + SZ_2M)];
-    xen_second[second_table_offset(BOOT_FDT_VIRT_START + SZ_2M)] = pte;
-
 #ifdef CONFIG_ARM_64
     ttbr = (uintptr_t) xen_pgtable + phys_offset;
 #else

diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index b577f8e6361ec5c48e669feaa74ab1df550add2e..a635dfce59f0eaeb446a844eff293e9914dec8d9 100644 (file)
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -755,6 +755,8 @@ void __init start_xen(unsigned long boot_phys_offset,
     /* Initialize traps early allow us to get backtrace when an error occurred */
     init_traps();
 
+    setup_pagetables(boot_phys_offset);
+
     smp_clear_cpu_maps();
 
     device_tree_flattened = early_fdt_map(fdt_paddr);
@@ -776,8 +778,6 @@ void __init start_xen(unsigned long boot_phys_offset,
                              (paddr_t)(uintptr_t)(_end - _start + 1), false);
     BUG_ON(!xen_bootmodule);
 
-    setup_pagetables(boot_phys_offset);
-
     setup_mm(fdt_paddr, fdt_size);
 
     /* Parse the ACPI tables for possible boot-time configuration */