arch/tile: core support for Tilera 32-bit chips.

This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.

This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 164 insertions, 0 deletions

diff --git a/arch/tile/mm/elf.c b/arch/tile/mm/elf.c
new file mode 100644
index 0000000..818c9be
--- /dev/null
+++ b/arch/tile/mm/elf.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/binfmts.h>
+#include <linux/compat.h>
+#include <linux/mman.h>
+#include <linux/elf.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+
+/* Notify a running simulator, if any, that an exec just occurred. */
+static void sim_notify_exec(const char *binary_name)
+{
+	unsigned char c;
+	do {
+		c = *binary_name++;
+		__insn_mtspr(SPR_SIM_CONTROL,
+			     (SIM_CONTROL_OS_EXEC
+			      | (c << _SIM_CONTROL_OPERATOR_BITS)));
+
+	} while (c);
+}
+
+static int notify_exec(void)
+{
+	int retval = 0;  /* failure */
+	struct vm_area_struct *vma = current->mm->mmap;
+	while (vma) {
+		if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file)
+			break;
+		vma = vma->vm_next;
+	}
+	if (vma) {
+		char *buf = (char *) __get_free_page(GFP_KERNEL);
+		if (buf) {
+			char *path = d_path(&vma->vm_file->f_path,
+					    buf, PAGE_SIZE);
+			if (!IS_ERR(path)) {
+				sim_notify_exec(path);
+				retval = 1;
+			}
+			free_page((unsigned long)buf);
+		}
+	}
+	return retval;
+}
+
+/* Notify a running simulator, if any, that we loaded an interpreter. */
+static void sim_notify_interp(unsigned long load_addr)
+{
+	size_t i;
+	for (i = 0; i < sizeof(load_addr); i++) {
+		unsigned char c = load_addr >> (i * 8);
+		__insn_mtspr(SPR_SIM_CONTROL,
+			     (SIM_CONTROL_OS_INTERP
+			      | (c << _SIM_CONTROL_OPERATOR_BITS)));
+	}
+}
+
+
+/* Kernel address of page used to map read-only kernel data into userspace. */
+static void *vdso_page;
+
+/* One-entry array used for install_special_mapping. */
+static struct page *vdso_pages[1];
+
+int __init vdso_setup(void)
+{
+	extern char __rt_sigreturn[], __rt_sigreturn_end[];
+	vdso_page = (void *)get_zeroed_page(GFP_ATOMIC);
+	memcpy(vdso_page, __rt_sigreturn, __rt_sigreturn_end - __rt_sigreturn);
+	vdso_pages[0] = virt_to_page(vdso_page);
+	return 0;
+}
+device_initcall(vdso_setup);
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+	if (vma->vm_private_data == vdso_pages)
+		return "[vdso]";
+#ifndef __tilegx__
+	if (vma->vm_start == MEM_USER_INTRPT)
+		return "[intrpt]";
+#endif
+	return NULL;
+}
+
+int arch_setup_additional_pages(struct linux_binprm *bprm,
+				int executable_stack)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long vdso_base;
+	int retval = 0;
+
+	/*
+	 * Notify the simulator that an exec just occurred.
+	 * If we can't find the filename of the mapping, just use
+	 * whatever was passed as the linux_binprm filename.
+	 */
+	if (!notify_exec())
+		sim_notify_exec(bprm->filename);
+
+	down_write(&mm->mmap_sem);
+
+	/*
+	 * MAYWRITE to allow gdb to COW and set breakpoints
+	 *
+	 * Make sure the vDSO gets into every core dump.  Dumping its
+	 * contents makes post-mortem fully interpretable later
+	 * without matching up the same kernel and hardware config to
+	 * see what PC values meant.
+	 */
+	vdso_base = VDSO_BASE;
+	retval = install_special_mapping(mm, vdso_base, PAGE_SIZE,
+					 VM_READ|VM_EXEC|
+					 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
+					 VM_ALWAYSDUMP,
+					 vdso_pages);
+
+#ifndef __tilegx__
+	/*
+	 * Set up a user-interrupt mapping here; the user can't
+	 * create one themselves since it is above TASK_SIZE.
+	 * We make it unwritable by default, so the model for adding
+	 * interrupt vectors always involves an mprotect.
+	 */
+	if (!retval) {
+		unsigned long addr = MEM_USER_INTRPT;
+		addr = mmap_region(NULL, addr, INTRPT_SIZE,
+				   MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE,
+				   VM_READ|VM_EXEC|
+				   VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 0);
+		if (addr > (unsigned long) -PAGE_SIZE)
+			retval = (int) addr;
+	}
+#endif
+
+	up_write(&mm->mmap_sem);
+
+	return retval;
+}
+
+
+void elf_plat_init(struct pt_regs *regs, unsigned long load_addr)
+{
+	/* Zero all registers. */
+	memset(regs, 0, sizeof(*regs));
+
+	/* Report the interpreter's load address. */
+	sim_notify_interp(load_addr);
+}