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, 578 insertions, 0 deletions

diff --git a/arch/tile/include/asm/uaccess.h b/arch/tile/include/asm/uaccess.h
new file mode 100644
index 00000000000..f3058afd5a8
--- /dev/null
+++ b/arch/tile/include/asm/uaccess.h
@@ -0,0 +1,578 @@
+/*
+ * 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.
+ */
+
+#ifndef _ASM_TILE_UACCESS_H
+#define _ASM_TILE_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <asm-generic/uaccess-unaligned.h>
+#include <asm/processor.h>
+#include <asm/page.h>
+
+#define VERIFY_READ	0
+#define VERIFY_WRITE	1
+
+/*
+ * The fs value determines whether argument validity checking should be
+ * performed or not.  If get_fs() == USER_DS, checking is performed, with
+ * get_fs() == KERNEL_DS, checking is bypassed.
+ *
+ * For historical reasons, these macros are grossly misnamed.
+ */
+#define MAKE_MM_SEG(a)  ((mm_segment_t) { (a) })
+
+#define KERNEL_DS	MAKE_MM_SEG(-1UL)
+#define USER_DS		MAKE_MM_SEG(PAGE_OFFSET)
+
+#define get_ds()	(KERNEL_DS)
+#define get_fs()	(current_thread_info()->addr_limit)
+#define set_fs(x)	(current_thread_info()->addr_limit = (x))
+
+#define segment_eq(a, b) ((a).seg == (b).seg)
+
+#ifndef __tilegx__
+/*
+ * We could allow mapping all 16 MB at 0xfc000000, but we set up a
+ * special hack in arch_setup_additional_pages() to auto-create a mapping
+ * for the first 16 KB, and it would seem strange to have different
+ * user-accessible semantics for memory at 0xfc000000 and above 0xfc004000.
+ */
+static inline int is_arch_mappable_range(unsigned long addr,
+					 unsigned long size)
+{
+	return (addr >= MEM_USER_INTRPT &&
+		addr < (MEM_USER_INTRPT + INTRPT_SIZE) &&
+		size <= (MEM_USER_INTRPT + INTRPT_SIZE) - addr);
+}
+#define is_arch_mappable_range is_arch_mappable_range
+#else
+#define is_arch_mappable_range(addr, size) 0
+#endif
+
+/*
+ * Test whether a block of memory is a valid user space address.
+ * Returns 0 if the range is valid, nonzero otherwise.
+ */
+int __range_ok(unsigned long addr, unsigned long size);
+
+/**
+ * access_ok: - Checks if a user space pointer is valid
+ * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
+ *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
+ *        to write to a block, it is always safe to read from it.
+ * @addr: User space pointer to start of block to check
+ * @size: Size of block to check
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Checks if a pointer to a block of memory in user space is valid.
+ *
+ * Returns true (nonzero) if the memory block may be valid, false (zero)
+ * if it is definitely invalid.
+ *
+ * Note that, depending on architecture, this function probably just
+ * checks that the pointer is in the user space range - after calling
+ * this function, memory access functions may still return -EFAULT.
+ */
+#define access_ok(type, addr, size) \
+	(likely(__range_ok((unsigned long)addr, size) == 0))
+
+/*
+ * The exception table consists of pairs of addresses: the first is the
+ * address of an instruction that is allowed to fault, and the second is
+ * the address at which the program should continue.  No registers are
+ * modified, so it is entirely up to the continuation code to figure out
+ * what to do.
+ *
+ * All the routines below use bits of fixup code that are out of line
+ * with the main instruction path.  This means when everything is well,
+ * we don't even have to jump over them.  Further, they do not intrude
+ * on our cache or tlb entries.
+ */
+
+struct exception_table_entry {
+	unsigned long insn, fixup;
+};
+
+extern int fixup_exception(struct pt_regs *regs);
+
+/*
+ * We return the __get_user_N function results in a structure,
+ * thus in r0 and r1.  If "err" is zero, "val" is the result
+ * of the read; otherwise, "err" is -EFAULT.
+ *
+ * We rarely need 8-byte values on a 32-bit architecture, but
+ * we size the structure to accommodate.  In practice, for the
+ * the smaller reads, we can zero the high word for free, and
+ * the caller will ignore it by virtue of casting anyway.
+ */
+struct __get_user {
+	unsigned long long val;
+	int err;
+};
+
+/*
+ * FIXME: we should express these as inline extended assembler, since
+ * they're fundamentally just a variable dereference and some
+ * supporting exception_table gunk.  Note that (a la i386) we can
+ * extend the copy_to_user and copy_from_user routines to call into
+ * such extended assembler routines, though we will have to use a
+ * different return code in that case (1, 2, or 4, rather than -EFAULT).
+ */
+extern struct __get_user __get_user_1(const void *);
+extern struct __get_user __get_user_2(const void *);
+extern struct __get_user __get_user_4(const void *);
+extern struct __get_user __get_user_8(const void *);
+extern int __put_user_1(long, void *);
+extern int __put_user_2(long, void *);
+extern int __put_user_4(long, void *);
+extern int __put_user_8(long long, void *);
+
+/* Unimplemented routines to cause linker failures */
+extern struct __get_user __get_user_bad(void);
+extern int __put_user_bad(void);
+
+/*
+ * Careful: we have to cast the result to the type of the pointer
+ * for sign reasons.
+ */
+/**
+ * __get_user: - Get a simple variable from user space, with less checking.
+ * @x:   Variable to store result.
+ * @ptr: Source address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple variable from user space to kernel
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and the result of
+ * dereferencing @ptr must be assignable to @x without a cast.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ * On error, the variable @x is set to zero.
+ *
+ * Caller must check the pointer with access_ok() before calling this
+ * function.
+ */
+#define __get_user(x, ptr)						\
+({	struct __get_user __ret;					\
+	__typeof__(*(ptr)) const __user *__gu_addr = (ptr);		\
+	__chk_user_ptr(__gu_addr);					\
+	switch (sizeof(*(__gu_addr))) {					\
+	case 1:								\
+		__ret = __get_user_1(__gu_addr);			\
+		break;							\
+	case 2:								\
+		__ret = __get_user_2(__gu_addr);			\
+		break;							\
+	case 4:								\
+		__ret = __get_user_4(__gu_addr);			\
+		break;							\
+	case 8:								\
+		__ret = __get_user_8(__gu_addr);			\
+		break;							\
+	default:							\
+		__ret = __get_user_bad();				\
+		break;							\
+	}								\
+	(x) = (__typeof__(*__gu_addr)) (__typeof__(*__gu_addr - *__gu_addr)) \
+	  __ret.val;			                                \
+	__ret.err;							\
+})
+
+/**
+ * __put_user: - Write a simple value into user space, with less checking.
+ * @x:   Value to copy to user space.
+ * @ptr: Destination address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple value from kernel space to user
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and @x must be assignable
+ * to the result of dereferencing @ptr.
+ *
+ * Caller must check the pointer with access_ok() before calling this
+ * function.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ *
+ * Implementation note: The "case 8" logic of casting to the type of
+ * the result of subtracting the value from itself is basically a way
+ * of keeping all integer types the same, but casting any pointers to
+ * ptrdiff_t, i.e. also an integer type.  This way there are no
+ * questionable casts seen by the compiler on an ILP32 platform.
+ */
+#define __put_user(x, ptr)						\
+({									\
+	int __pu_err = 0;						\
+	__typeof__(*(ptr)) __user *__pu_addr = (ptr);			\
+	typeof(*__pu_addr) __pu_val = (x);				\
+	__chk_user_ptr(__pu_addr);					\
+	switch (sizeof(__pu_val)) {					\
+	case 1:								\
+		__pu_err = __put_user_1((long)__pu_val, __pu_addr);	\
+		break;							\
+	case 2:								\
+		__pu_err = __put_user_2((long)__pu_val, __pu_addr);	\
+		break;							\
+	case 4:								\
+		__pu_err = __put_user_4((long)__pu_val, __pu_addr);	\
+		break;							\
+	case 8:								\
+		__pu_err =						\
+		  __put_user_8((__typeof__(__pu_val - __pu_val))__pu_val,\
+			__pu_addr);					\
+		break;							\
+	default:							\
+		__pu_err = __put_user_bad();				\
+		break;							\
+	}								\
+	__pu_err;							\
+})
+
+/*
+ * The versions of get_user and put_user without initial underscores
+ * check the address of their arguments to make sure they are not
+ * in kernel space.
+ */
+#define put_user(x, ptr)						\
+({									\
+	__typeof__(*(ptr)) __user *__Pu_addr = (ptr);			\
+	access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ?	\
+		__put_user((x), (__Pu_addr)) :				\
+		-EFAULT;						\
+})
+
+#define get_user(x, ptr)						\
+({									\
+	__typeof__(*(ptr)) const __user *__Gu_addr = (ptr);		\
+	access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ?	\
+		__get_user((x), (__Gu_addr)) :				\
+		((x) = 0, -EFAULT);					\
+})
+
+/**
+ * __copy_to_user() - copy data into user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @from: Source address, in kernel space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Copy data from kernel space to user space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ *
+ * An alternate version - __copy_to_user_inatomic() - is designed
+ * to be called from atomic context, typically bracketed by calls
+ * to pagefault_disable() and pagefault_enable().
+ */
+extern unsigned long __must_check __copy_to_user_inatomic(
+	void __user *to, const void *from, unsigned long n);
+
+static inline unsigned long __must_check
+__copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	might_fault();
+	return __copy_to_user_inatomic(to, from, n);
+}
+
+static inline unsigned long __must_check
+copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	if (access_ok(VERIFY_WRITE, to, n))
+		n = __copy_to_user(to, from, n);
+	return n;
+}
+
+/**
+ * __copy_from_user() - copy data from user space, with less checking.
+ * @to:   Destination address, in kernel space.
+ * @from: Source address, in user space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Copy data from user space to kernel space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ *
+ * If some data could not be copied, this function will pad the copied
+ * data to the requested size using zero bytes.
+ *
+ * An alternate version - __copy_from_user_inatomic() - is designed
+ * to be called from atomic context, typically bracketed by calls
+ * to pagefault_disable() and pagefault_enable().  This version
+ * does *NOT* pad with zeros.
+ */
+extern unsigned long __must_check __copy_from_user_inatomic(
+	void *to, const void __user *from, unsigned long n);
+extern unsigned long __must_check __copy_from_user_zeroing(
+	void *to, const void __user *from, unsigned long n);
+
+static inline unsigned long __must_check
+__copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+       might_fault();
+       return __copy_from_user_zeroing(to, from, n);
+}
+
+static inline unsigned long __must_check
+_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	if (access_ok(VERIFY_READ, from, n))
+		n = __copy_from_user(to, from, n);
+	else
+		memset(to, 0, n);
+	return n;
+}
+
+#ifdef CONFIG_DEBUG_COPY_FROM_USER
+extern void copy_from_user_overflow(void)
+	__compiletime_warning("copy_from_user() size is not provably correct");
+
+static inline unsigned long __must_check copy_from_user(void *to,
+					  const void __user *from,
+					  unsigned long n)
+{
+	int sz = __compiletime_object_size(to);
+
+	if (likely(sz == -1 || sz >= n))
+		n = _copy_from_user(to, from, n);
+	else
+		copy_from_user_overflow();
+
+	return n;
+}
+#else
+#define copy_from_user _copy_from_user
+#endif
+
+#ifdef __tilegx__
+/**
+ * __copy_in_user() - copy data within user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @from: Source address, in kernel space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Copy data from user space to user space.  Caller must check
+ * the specified blocks with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ */
+extern unsigned long __copy_in_user_asm(
+	void __user *to, const void __user *from, unsigned long n);
+
+static inline unsigned long __must_check
+__copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+	might_sleep();
+	return __copy_in_user_asm(to, from, n);
+}
+
+static inline unsigned long __must_check
+copy_in_user(void __user *to, const void __user *from, unsigned long n)
+{
+	if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
+		n = __copy_in_user(to, from, n);
+	return n;
+}
+#endif
+
+
+/**
+ * strlen_user: - Get the size of a string in user space.
+ * @str: The string to measure.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Get the size of a NUL-terminated string in user space.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ * On exception, returns 0.
+ *
+ * If there is a limit on the length of a valid string, you may wish to
+ * consider using strnlen_user() instead.
+ */
+extern long strnlen_user_asm(const char __user *str, long n);
+static inline long __must_check strnlen_user(const char __user *str, long n)
+{
+	might_fault();
+	return strnlen_user_asm(str, n);
+}
+#define strlen_user(str) strnlen_user(str, LONG_MAX)
+
+/**
+ * strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
+ * @dst:   Destination address, in kernel space.  This buffer must be at
+ *         least @count bytes long.
+ * @src:   Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ * Caller must check the specified block with access_ok() before calling
+ * this function.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+extern long strncpy_from_user_asm(char *dst, const char __user *src, long);
+static inline long __must_check __strncpy_from_user(
+	char *dst, const char __user *src, long count)
+{
+	might_fault();
+	return strncpy_from_user_asm(dst, src, count);
+}
+static inline long __must_check strncpy_from_user(
+	char *dst, const char __user *src, long count)
+{
+	if (access_ok(VERIFY_READ, src, 1))
+		return __strncpy_from_user(dst, src, count);
+	return -EFAULT;
+}
+
+/**
+ * clear_user: - Zero a block of memory in user space.
+ * @mem:   Destination address, in user space.
+ * @len:   Number of bytes to zero.
+ *
+ * Zero a block of memory in user space.
+ *
+ * Returns number of bytes that could not be cleared.
+ * On success, this will be zero.
+ */
+extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
+static inline unsigned long __must_check __clear_user(
+	void __user *mem, unsigned long len)
+{
+	might_fault();
+	return clear_user_asm(mem, len);
+}
+static inline unsigned long __must_check clear_user(
+	void __user *mem, unsigned long len)
+{
+	if (access_ok(VERIFY_WRITE, mem, len))
+		return __clear_user(mem, len);
+	return len;
+}
+
+/**
+ * flush_user: - Flush a block of memory in user space from cache.
+ * @mem:   Destination address, in user space.
+ * @len:   Number of bytes to flush.
+ *
+ * Returns number of bytes that could not be flushed.
+ * On success, this will be zero.
+ */
+extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
+static inline unsigned long __must_check __flush_user(
+	void __user *mem, unsigned long len)
+{
+	int retval;
+
+	might_fault();
+	retval = flush_user_asm(mem, len);
+	mb_incoherent();
+	return retval;
+}
+
+static inline unsigned long __must_check flush_user(
+	void __user *mem, unsigned long len)
+{
+	if (access_ok(VERIFY_WRITE, mem, len))
+		return __flush_user(mem, len);
+	return len;
+}
+
+/**
+ * inv_user: - Invalidate a block of memory in user space from cache.
+ * @mem:   Destination address, in user space.
+ * @len:   Number of bytes to invalidate.
+ *
+ * Returns number of bytes that could not be invalidated.
+ * On success, this will be zero.
+ *
+ * Note that on Tile64, the "inv" operation is in fact a
+ * "flush and invalidate", so cache write-backs will occur prior
+ * to the cache being marked invalid.
+ */
+extern unsigned long inv_user_asm(void __user *mem, unsigned long len);
+static inline unsigned long __must_check __inv_user(
+	void __user *mem, unsigned long len)
+{
+	int retval;
+
+	might_fault();
+	retval = inv_user_asm(mem, len);
+	mb_incoherent();
+	return retval;
+}
+static inline unsigned long __must_check inv_user(
+	void __user *mem, unsigned long len)
+{
+	if (access_ok(VERIFY_WRITE, mem, len))
+		return __inv_user(mem, len);
+	return len;
+}
+
+/**
+ * finv_user: - Flush-inval a block of memory in user space from cache.
+ * @mem:   Destination address, in user space.
+ * @len:   Number of bytes to invalidate.
+ *
+ * Returns number of bytes that could not be flush-invalidated.
+ * On success, this will be zero.
+ */
+extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
+static inline unsigned long __must_check __finv_user(
+	void __user *mem, unsigned long len)
+{
+	int retval;
+
+	might_fault();
+	retval = finv_user_asm(mem, len);
+	mb_incoherent();
+	return retval;
+}
+static inline unsigned long __must_check finv_user(
+	void __user *mem, unsigned long len)
+{
+	if (access_ok(VERIFY_WRITE, mem, len))
+		return __finv_user(mem, len);
+	return len;
+}
+
+#endif /* _ASM_TILE_UACCESS_H */