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+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_IA64_UACCESS_H
+#define _ASM_IA64_UACCESS_H
+
+/*
+ * This file defines various macros to transfer memory areas across
+ * the user/kernel boundary. This needs to be done carefully because
+ * this code is executed in kernel mode and uses user-specified
+ * addresses. Thus, we need to be careful not to let the user to
+ * trick us into accessing kernel memory that would normally be
+ * inaccessible. This code is also fairly performance sensitive,
+ * so we want to spend as little time doing safety checks as
+ * possible.
+ *
+ * To make matters a bit more interesting, these macros sometimes also
+ * called from within the kernel itself, in which case the address
+ * validity check must be skipped. The get_fs() macro tells us what
+ * to do: if get_fs()==USER_DS, checking is performed, if
+ * get_fs()==KERNEL_DS, checking is bypassed.
+ *
+ * Note that even if the memory area specified by the user is in a
+ * valid address range, it is still possible that we'll get a page
+ * fault while accessing it. This is handled by filling out an
+ * exception handler fixup entry for each instruction that has the
+ * potential to fault. When such a fault occurs, the page fault
+ * handler checks to see whether the faulting instruction has a fixup
+ * associated and, if so, sets r8 to -EFAULT and clears r9 to 0 and
+ * then resumes execution at the continuation point.
+ *
+ * Based on <asm-alpha/uaccess.h>.
+ *
+ * Copyright (C) 1998, 1999, 2001-2004 Hewlett-Packard Co
+ * David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+
+#include <linux/compiler.h>
+#include <linux/page-flags.h>
+
+#include <asm/intrinsics.h>
+#include <linux/pgtable.h>
+#include <asm/io.h>
+#include <asm/extable.h>
+
+/*
+ * When accessing user memory, we need to make sure the entire area really is
+ * in user-level space. We also need to make sure that the address doesn't
+ * point inside the virtually mapped linear page table.
+ */
+static inline int __access_ok(const void __user *p, unsigned long size)
+{
+ unsigned long limit = TASK_SIZE;
+ unsigned long addr = (unsigned long)p;
+
+ return likely((size <= limit) && (addr <= (limit - size)) &&
+ likely(REGION_OFFSET(addr) < RGN_MAP_LIMIT));
+}
+#define __access_ok __access_ok
+#include <asm-generic/access_ok.h>
+
+/*
+ * These are the main single-value transfer routines. They automatically
+ * use the right size if we just have the right pointer type.
+ *
+ * Careful to not
+ * (a) re-use the arguments for side effects (sizeof/typeof is ok)
+ * (b) require any knowledge of processes at this stage
+ */
+#define put_user(x, ptr) __put_user_check((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)))
+#define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)))
+
+/*
+ * The "__xxx" versions do not do address space checking, useful when
+ * doing multiple accesses to the same area (the programmer has to do the
+ * checks by hand with "access_ok()")
+ */
+#define __put_user(x, ptr) __put_user_nocheck((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)))
+#define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+#ifdef ASM_SUPPORTED
+ struct __large_struct { unsigned long buf[100]; };
+# define __m(x) (*(struct __large_struct __user *)(x))
+
+/* We need to declare the __ex_table section before we can use it in .xdata. */
+asm (".section \"__ex_table\", \"a\"\n\t.previous");
+
+# define __get_user_size(val, addr, n, err) \
+do { \
+ register long __gu_r8 asm ("r8") = 0; \
+ register long __gu_r9 asm ("r9"); \
+ asm ("\n[1:]\tld"#n" %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n" \
+ "\t.xdata4 \"__ex_table\", 1b-., 1f-.+4\n" \
+ "[1:]" \
+ : "=r"(__gu_r9), "=r"(__gu_r8) : "m"(__m(addr)), "1"(__gu_r8)); \
+ (err) = __gu_r8; \
+ (val) = __gu_r9; \
+} while (0)
+
+/*
+ * The "__put_user_size()" macro tells gcc it reads from memory instead of writing it. This
+ * is because they do not write to any memory gcc knows about, so there are no aliasing
+ * issues.
+ */
+# define __put_user_size(val, addr, n, err) \
+do { \
+ register long __pu_r8 asm ("r8") = 0; \
+ asm volatile ("\n[1:]\tst"#n" %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \
+ "\t.xdata4 \"__ex_table\", 1b-., 1f-.\n" \
+ "[1:]" \
+ : "=r"(__pu_r8) : "m"(__m(addr)), "rO"(val), "0"(__pu_r8)); \
+ (err) = __pu_r8; \
+} while (0)
+
+#else /* !ASM_SUPPORTED */
+# define RELOC_TYPE 2 /* ip-rel */
+# define __get_user_size(val, addr, n, err) \
+do { \
+ __ld_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE); \
+ (err) = ia64_getreg(_IA64_REG_R8); \
+ (val) = ia64_getreg(_IA64_REG_R9); \
+} while (0)
+# define __put_user_size(val, addr, n, err) \
+do { \
+ __st_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE, \
+ (__force unsigned long) (val)); \
+ (err) = ia64_getreg(_IA64_REG_R8); \
+} while (0)
+#endif /* !ASM_SUPPORTED */
+
+extern void __get_user_unknown (void);
+
+/*
+ * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
+ * could clobber r8 and r9 (among others). Thus, be careful not to evaluate it while
+ * using r8/r9.
+ */
+#define __do_get_user(check, x, ptr, size) \
+({ \
+ const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
+ __typeof__ (size) __gu_size = (size); \
+ long __gu_err = -EFAULT; \
+ unsigned long __gu_val = 0; \
+ if (!check || __access_ok(__gu_ptr, size)) \
+ switch (__gu_size) { \
+ case 1: __get_user_size(__gu_val, __gu_ptr, 1, __gu_err); break; \
+ case 2: __get_user_size(__gu_val, __gu_ptr, 2, __gu_err); break; \
+ case 4: __get_user_size(__gu_val, __gu_ptr, 4, __gu_err); break; \
+ case 8: __get_user_size(__gu_val, __gu_ptr, 8, __gu_err); break; \
+ default: __get_user_unknown(); break; \
+ } \
+ (x) = (__force __typeof__(*(__gu_ptr))) __gu_val; \
+ __gu_err; \
+})
+
+#define __get_user_nocheck(x, ptr, size) __do_get_user(0, x, ptr, size)
+#define __get_user_check(x, ptr, size) __do_get_user(1, x, ptr, size)
+
+extern void __put_user_unknown (void);
+
+/*
+ * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
+ * could clobber r8 (among others). Thus, be careful not to evaluate them while using r8.
+ */
+#define __do_put_user(check, x, ptr, size) \
+({ \
+ __typeof__ (x) __pu_x = (x); \
+ __typeof__ (*(ptr)) __user *__pu_ptr = (ptr); \
+ __typeof__ (size) __pu_size = (size); \
+ long __pu_err = -EFAULT; \
+ \
+ if (!check || __access_ok(__pu_ptr, __pu_size)) \
+ switch (__pu_size) { \
+ case 1: __put_user_size(__pu_x, __pu_ptr, 1, __pu_err); break; \
+ case 2: __put_user_size(__pu_x, __pu_ptr, 2, __pu_err); break; \
+ case 4: __put_user_size(__pu_x, __pu_ptr, 4, __pu_err); break; \
+ case 8: __put_user_size(__pu_x, __pu_ptr, 8, __pu_err); break; \
+ default: __put_user_unknown(); break; \
+ } \
+ __pu_err; \
+})
+
+#define __put_user_nocheck(x, ptr, size) __do_put_user(0, x, ptr, size)
+#define __put_user_check(x, ptr, size) __do_put_user(1, x, ptr, size)
+
+/*
+ * Complex access routines
+ */
+extern unsigned long __must_check __copy_user (void __user *to, const void __user *from,
+ unsigned long count);
+
+static inline unsigned long
+raw_copy_to_user(void __user *to, const void *from, unsigned long count)
+{
+ return __copy_user(to, (__force void __user *) from, count);
+}
+
+static inline unsigned long
+raw_copy_from_user(void *to, const void __user *from, unsigned long count)
+{
+ return __copy_user((__force void __user *) to, from, count);
+}
+
+#define INLINE_COPY_FROM_USER
+#define INLINE_COPY_TO_USER
+
+extern unsigned long __do_clear_user (void __user *, unsigned long);
+
+#define __clear_user(to, n) __do_clear_user(to, n)
+
+#define clear_user(to, n) \
+({ \
+ unsigned long __cu_len = (n); \
+ if (__access_ok(to, __cu_len)) \
+ __cu_len = __do_clear_user(to, __cu_len); \
+ __cu_len; \
+})
+
+
+/*
+ * Returns: -EFAULT if exception before terminator, N if the entire buffer filled, else
+ * strlen.
+ */
+extern long __must_check __strncpy_from_user (char *to, const char __user *from, long to_len);
+
+#define strncpy_from_user(to, from, n) \
+({ \
+ const char __user * __sfu_from = (from); \
+ long __sfu_ret = -EFAULT; \
+ if (__access_ok(__sfu_from, 0)) \
+ __sfu_ret = __strncpy_from_user((to), __sfu_from, (n)); \
+ __sfu_ret; \
+})
+
+/*
+ * Returns: 0 if exception before NUL or reaching the supplied limit
+ * (N), a value greater than N if the limit would be exceeded, else
+ * strlen.
+ */
+extern unsigned long __strnlen_user (const char __user *, long);
+
+#define strnlen_user(str, len) \
+({ \
+ const char __user *__su_str = (str); \
+ unsigned long __su_ret = 0; \
+ if (__access_ok(__su_str, 0)) \
+ __su_ret = __strnlen_user(__su_str, len); \
+ __su_ret; \
+})
+
+#define ARCH_HAS_TRANSLATE_MEM_PTR 1
+static __inline__ void *
+xlate_dev_mem_ptr(phys_addr_t p)
+{
+ struct page *page;
+ void *ptr;
+
+ page = pfn_to_page(p >> PAGE_SHIFT);
+ if (PageUncached(page))
+ ptr = (void *)p + __IA64_UNCACHED_OFFSET;
+ else
+ ptr = __va(p);
+
+ return ptr;
+}
+
+#endif /* _ASM_IA64_UACCESS_H */