Merge branch 'x86-trampoline-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 trampoline rework from H. Peter Anvin:
 "This code reworks all the "trampoline"/"realmode" code (various bits
  that need to live in the first megabyte of memory, most but not all of
  which runs in real mode at some point) in the kernel into a single
  object.  The main reason for doing this is that it eliminates the last
  place in the kernel where we needed pages to be mapped RWX.  This code
  separates all that code into proper R/RW/RX pages."

Fix up conflicts in arch/x86/kernel/Makefile (mca removed next to reboot
code), and arch/x86/kernel/reboot.c (reboot code moved around in one
branch, modified in this one), and arch/x86/tools/relocs.c (mostly same
code came in earlier due to working around the ld bugs just before the
3.4 release).

Also remove stale x86-relocs entry from scripts/.gitignore as per Peter
Anvin.

* commit '61f5446169046c217a5479517edac3a890c3bee7': (36 commits)
  x86, realmode: Move end signature into header.S
  x86, relocs: When printing an error, say relative or absolute
  x86, relocs: More relocations which may end up as absolute
  x86, relocs: Workaround for binutils 2.22.52.0.1 section bug
  xen-acpi-processor: Add missing #include <xen/xen.h>
  acpi, bgrd: Add missing <linux/io.h> to drivers/acpi/bgrt.c
  x86, realmode: Change EFER to a single u64 field
  x86, realmode: Move kernel/realmode.c to realmode/init.c
  x86, realmode: Move not-common bits out of trampoline_common.S
  x86, realmode: Mask out EFER.LMA when saving trampoline EFER
  x86, realmode: Fix no cache bits test in reboot_32.S
  x86, realmode: Make sure all generated files are listed in targets
  x86, realmode: build fix: remove duplicate build
  x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline
  x86, realmode: fixes compilation issue in tboot.c
  x86, realmode: move relocs from scripts/ to arch/x86/tools
  x86, realmode: header for trampoline code
  x86, realmode: flattened rm hierachy
  x86, realmode: don't copy real_mode_header
  x86, realmode: fix 64-bit wakeup sequence
  ...

1 files changed, 115 insertions, 0 deletions

diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
new file mode 100644
index 000000000000..cbca565af5bd
--- /dev/null
+++ b/arch/x86/realmode/init.c
@@ -0,0 +1,115 @@
+#include <linux/io.h>
+#include <linux/memblock.h>
+
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+#include <asm/realmode.h>
+
+struct real_mode_header *real_mode_header;
+u32 *trampoline_cr4_features;
+
+void __init setup_real_mode(void)
+{
+	phys_addr_t mem;
+	u16 real_mode_seg;
+	u32 *rel;
+	u32 count;
+	u32 *ptr;
+	u16 *seg;
+	int i;
+	unsigned char *base;
+	struct trampoline_header *trampoline_header;
+	size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
+#ifdef CONFIG_X86_64
+	u64 *trampoline_pgd;
+	u64 efer;
+#endif
+
+	/* Has to be in very low memory 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");
+
+	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);
+
+	memcpy(base, real_mode_blob, size);
+
+	real_mode_seg = __pa(base) >> 4;
+	rel = (u32 *) real_mode_relocs;
+
+	/* 16-bit segment relocations. */
+	count = rel[0];
+	rel = &rel[1];
+	for (i = 0; i < count; i++) {
+		seg = (u16 *) (base + rel[i]);
+		*seg = real_mode_seg;
+	}
+
+	/* 32-bit linear relocations. */
+	count = rel[i];
+	rel =  &rel[i + 1];
+	for (i = 0; i < count; i++) {
+		ptr = (u32 *) (base + rel[i]);
+		*ptr += __pa(base);
+	}
+
+	/* Must be perfomed *after* relocation. */
+	trampoline_header = (struct trampoline_header *)
+		__va(real_mode_header->trampoline_header);
+
+#ifdef CONFIG_X86_32
+	trampoline_header->start = __pa(startup_32_smp);
+	trampoline_header->gdt_limit = __BOOT_DS + 7;
+	trampoline_header->gdt_base = __pa(boot_gdt);
+#else
+	/*
+	 * Some AMD processors will #GP(0) if EFER.LMA is set in WRMSR
+	 * so we need to mask it out.
+	 */
+	rdmsrl(MSR_EFER, efer);
+	trampoline_header->efer = efer & ~EFER_LMA;
+
+	trampoline_header->start = (u64) secondary_startup_64;
+	trampoline_cr4_features = &trampoline_header->cr4;
+	*trampoline_cr4_features = read_cr4();
+
+	trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
+	trampoline_pgd[0] = __pa(level3_ident_pgt) + _KERNPG_TABLE;
+	trampoline_pgd[511] = __pa(level3_kernel_pgt) + _KERNPG_TABLE;
+#endif
+}
+
+/*
+ * set_real_mode_permissions() gets called very early, to guarantee the
+ * availability of low memory.  This is before the proper kernel page
+ * tables are set up, so we cannot set page permissions in that
+ * function.  Thus, we use an arch_initcall instead.
+ */
+static int __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);
+
+	size_t ro_size =
+		PAGE_ALIGN(real_mode_header->ro_end) -
+		__pa(base);
+
+	size_t text_size =
+		PAGE_ALIGN(real_mode_header->ro_end) -
+		real_mode_header->text_start;
+
+	unsigned long text_start =
+		(unsigned long) __va(real_mode_header->text_start);
+
+	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);
+
+	return 0;
+}
+
+arch_initcall(set_real_mode_permissions);