From d0b2f91bede3bd5e3d24dd6803e56eee959c1797 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Thu, 20 Oct 2016 00:10:27 -0300
Subject: Linux-libre 4.8.2-gnu

---
 arch/x86/realmode/init.c      | 52 ++++++++++++++++++++++++++++++++-----------
 arch/x86/realmode/rm/Makefile |  2 +-
 2 files changed, 40 insertions(+), 14 deletions(-)

(limited to 'arch/x86/realmode')

diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index 0b7a63d98..5db706f14 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -1,32 +1,49 @@
 #include <linux/io.h>
+#include <linux/slab.h>
 #include <linux/memblock.h>
 
 #include <asm/cacheflush.h>
 #include <asm/pgtable.h>
 #include <asm/realmode.h>
+#include <asm/tlbflush.h>
 
 struct real_mode_header *real_mode_header;
 u32 *trampoline_cr4_features;
 
+/* Hold the pgd entry used on booting additional CPUs */
+pgd_t trampoline_pgd_entry;
+
+void __init set_real_mode_mem(phys_addr_t mem, size_t size)
+{
+	void *base = __va(mem);
+
+	real_mode_header = (struct real_mode_header *) base;
+	printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
+	       base, (unsigned long long)mem, size);
+}
+
 void __init reserve_real_mode(void)
 {
 	phys_addr_t mem;
-	unsigned char *base;
-	size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
+	size_t size = real_mode_size_needed();
+
+	if (!size)
+		return;
+
+	WARN_ON(slab_is_available());
 
 	/* Has to be under 1M so we can execute real-mode AP code. */
 	mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
-	if (!mem)
-		panic("Cannot allocate trampoline\n");
+	if (!mem) {
+		pr_info("No sub-1M memory is available for the trampoline\n");
+		return;
+	}
 
-	base = __va(mem);
 	memblock_reserve(mem, size);
-	real_mode_header = (struct real_mode_header *) base;
-	printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
-	       base, (unsigned long long)mem, size);
+	set_real_mode_mem(mem, size);
 }
 
-void __init setup_real_mode(void)
+static void __init setup_real_mode(void)
 {
 	u16 real_mode_seg;
 	const u32 *rel;
@@ -81,10 +98,10 @@ void __init setup_real_mode(void)
 
 	trampoline_header->start = (u64) secondary_startup_64;
 	trampoline_cr4_features = &trampoline_header->cr4;
-	*trampoline_cr4_features = __read_cr4();
+	*trampoline_cr4_features = mmu_cr4_features;
 
 	trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
-	trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd;
+	trampoline_pgd[0] = trampoline_pgd_entry.pgd;
 	trampoline_pgd[511] = init_level4_pgt[511].pgd;
 #endif
 }
@@ -97,7 +114,7 @@ void __init setup_real_mode(void)
  * need to mark it executable at do_pre_smp_initcalls() at least,
  * thus run it as a early_initcall().
  */
-static int __init set_real_mode_permissions(void)
+static void __init set_real_mode_permissions(void)
 {
 	unsigned char *base = (unsigned char *) real_mode_header;
 	size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
@@ -116,7 +133,16 @@ static int __init set_real_mode_permissions(void)
 	set_memory_nx((unsigned long) base, size >> PAGE_SHIFT);
 	set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);
 	set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);
+}
+
+static int __init init_real_mode(void)
+{
+	if (!real_mode_header)
+		panic("Real mode trampoline was not allocated");
+
+	setup_real_mode();
+	set_real_mode_permissions();
 
 	return 0;
 }
-early_initcall(set_real_mode_permissions);
+early_initcall(init_real_mode);
diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index c556c5ae8..25012abc3 100644
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -48,7 +48,7 @@ targets += realmode.lds
 $(obj)/realmode.lds: $(obj)/pasyms.h
 
 LDFLAGS_realmode.elf := --emit-relocs -T
-CPPFLAGS_realmode.lds += -P -C -I$(obj)
+CPPFLAGS_realmode.lds += -P -C -I$(objtree)/$(obj)
 
 targets += realmode.elf
 $(obj)/realmode.elf: $(obj)/realmode.lds $(REALMODE_OBJS) FORCE
-- 
cgit v1.2.3-54-g00ecf