MIPS: Remove get_fs/set_fs

All get_fs/set_fs calls in MIPS code are gone, so remove implementation
of it.  With the clear separation of user/kernel space access we no
longer need the EVA special handling, so get rid of that, too.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>

3 files changed, 146 insertions, 313 deletions

diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
index 8e69e0a35ee9..0c3550c82b72 100644
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -221,10 +221,6 @@ struct nlm_cop2_state {
 #define COP2_INIT
 #endif
 
-typedef struct {
-	unsigned long seg;
-} mm_segment_t;
-
 #ifdef CONFIG_CPU_HAS_MSA
 # define ARCH_MIN_TASKALIGN	16
 # define FPU_ALIGN		__aligned(16)
diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
index e2c352da3877..0b17aaa9e012 100644
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -28,11 +28,6 @@ struct thread_info {
 	unsigned long		tp_value;	/* thread pointer */
 	__u32			cpu;		/* current CPU */
 	int			preempt_count;	/* 0 => preemptable, <0 => BUG */
-	mm_segment_t		addr_limit;	/*
-						 * thread address space limit:
-						 * 0x7fffffff for user-thead
-						 * 0xffffffff for kernel-thread
-						 */
 	struct pt_regs		*regs;
 	long			syscall;	/* syscall number */
 };
@@ -46,7 +41,6 @@ struct thread_info {
 	.flags		= _TIF_FIXADE,		\
 	.cpu		= 0,			\
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
-	.addr_limit	= KERNEL_DS,		\
 }
 
 /*
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index c5cab0b8f902..91bc7fb7dca1 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -16,13 +16,6 @@
 #include <asm/asm-eva.h>
 #include <asm/extable.h>
 
-/*
- * 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.
- */
 #ifdef CONFIG_32BIT
 
 #define __UA_LIMIT 0x80000000UL
@@ -50,38 +43,6 @@ extern u64 __ua_limit;
 #endif /* CONFIG_64BIT */
 
 /*
- * USER_DS is a bitmask that has the bits set that may not be set in a valid
- * userspace address.  Note that we limit 32-bit userspace to 0x7fff8000 but
- * the arithmetic we're doing only works if the limit is a power of two, so
- * we use 0x80000000 here on 32-bit kernels.  If a process passes an invalid
- * address in this range it's the process's problem, not ours :-)
- */
-
-#define KERNEL_DS	((mm_segment_t) { 0UL })
-#define USER_DS		((mm_segment_t) { __UA_LIMIT })
-
-#define get_fs()	(current_thread_info()->addr_limit)
-#define set_fs(x)	(current_thread_info()->addr_limit = (x))
-
-#define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
-
-/*
- * eva_kernel_access() - determine whether kernel memory access on an EVA system
- *
- * Determines whether memory accesses should be performed to kernel memory
- * on a system using Extended Virtual Addressing (EVA).
- *
- * Return: true if a kernel memory access on an EVA system, else false.
- */
-static inline bool eva_kernel_access(void)
-{
-	if (!IS_ENABLED(CONFIG_EVA))
-		return false;
-
-	return uaccess_kernel();
-}
-
-/*
  * Is a address valid? This does a straightforward calculation rather
  * than tests.
  *
@@ -118,7 +79,7 @@ static inline bool eva_kernel_access(void)
 static inline int __access_ok(const void __user *p, unsigned long size)
 {
 	unsigned long addr = (unsigned long)p;
-	return (get_fs().seg & (addr | (addr + size) | __ua_size(size))) == 0;
+	return (__UA_LIMIT & (addr | (addr + size) | __ua_size(size))) == 0;
 }
 
 #define access_ok(addr, size)					\
@@ -215,43 +176,6 @@ static inline int __access_ok(const void __user *p, unsigned long size)
 struct __large_struct { unsigned long buf[100]; };
 #define __m(x) (*(struct __large_struct __user *)(x))
 
-/*
- * Yuck.  We need two variants, one for 64bit operation and one
- * for 32 bit mode and old iron.
- */
-#ifndef CONFIG_EVA
-#define __get_kernel_common(val, size, ptr) __get_user_common(val, size, ptr)
-#else
-/*
- * Kernel specific functions for EVA. We need to use normal load instructions
- * to read data from kernel when operating in EVA mode. We use these macros to
- * avoid redefining __get_user_asm for EVA.
- */
-#undef _loadd
-#undef _loadw
-#undef _loadh
-#undef _loadb
-#ifdef CONFIG_32BIT
-#define _loadd			_loadw
-#else
-#define _loadd(reg, addr)	"ld " reg ", " addr
-#endif
-#define _loadw(reg, addr)	"lw " reg ", " addr
-#define _loadh(reg, addr)	"lh " reg ", " addr
-#define _loadb(reg, addr)	"lb " reg ", " addr
-
-#define __get_kernel_common(val, size, ptr)				\
-do {									\
-	switch (size) {							\
-	case 1: __get_data_asm(val, _loadb, ptr); break;		\
-	case 2: __get_data_asm(val, _loadh, ptr); break;		\
-	case 4: __get_data_asm(val, _loadw, ptr); break;		\
-	case 8: __GET_DW(val, _loadd, ptr); break;			\
-	default: __get_user_unknown(); break;				\
-	}								\
-} while (0)
-#endif
-
 #ifdef CONFIG_32BIT
 #define __GET_DW(val, insn, ptr) __get_data_asm_ll32(val, insn, ptr)
 #endif
@@ -276,12 +200,9 @@ do {									\
 ({									\
 	int __gu_err;							\
 									\
-	if (eva_kernel_access()) {					\
-		__get_kernel_common((x), size, ptr);			\
-	} else {							\
-		__chk_user_ptr(ptr);					\
-		__get_user_common((x), size, ptr);			\
-	}								\
+	__chk_user_ptr(ptr);						\
+	__get_user_common((x), size, ptr);				\
+									\
 	__gu_err;							\
 })
 
@@ -291,11 +212,8 @@ do {									\
 	const __typeof__(*(ptr)) __user * __gu_ptr = (ptr);		\
 									\
 	might_fault();							\
-	if (likely(access_ok( __gu_ptr, size))) {		\
-		if (eva_kernel_access())				\
-			__get_kernel_common((x), size, __gu_ptr);	\
-		else							\
-			__get_user_common((x), size, __gu_ptr);		\
+	if (likely(access_ok(__gu_ptr, size))) {			\
+		__get_user_common((x), size, __gu_ptr);			\
 	} else								\
 		(x) = 0;						\
 									\
@@ -361,46 +279,31 @@ do {									\
 do {									\
 	int __gu_err;							\
 									\
-	__get_kernel_common(*((type *)(dst)), sizeof(type),		\
-			    (__force type *)(src));			\
+	switch (sizeof(type)) {						\
+	case 1:								\
+		__get_data_asm(*(type *)(dst), kernel_lb,		\
+			       (__force type *)(src));			\
+		break;							\
+	case 2:								\
+		__get_data_asm(*(type *)(dst), kernel_lh,		\
+			       (__force type *)(src));			\
+		break;							\
+	case 4:								\
+		 __get_data_asm(*(type *)(dst), kernel_lw,		\
+			       (__force type *)(src));			\
+		break;							\
+	case 8:								\
+		__GET_DW(*(type *)(dst), kernel_ld,			\
+			 (__force type *)(src));			\
+		break;							\
+	default:							\
+		__get_user_unknown();					\
+		break;							\
+	}								\
 	if (unlikely(__gu_err))						\
 		goto err_label;						\
 } while (0)
 
-#ifndef CONFIG_EVA
-#define __put_kernel_common(ptr, size) __put_user_common(ptr, size)
-#else
-/*
- * Kernel specific functions for EVA. We need to use normal load instructions
- * to read data from kernel when operating in EVA mode. We use these macros to
- * avoid redefining __get_data_asm for EVA.
- */
-#undef _stored
-#undef _storew
-#undef _storeh
-#undef _storeb
-#ifdef CONFIG_32BIT
-#define _stored			_storew
-#else
-#define _stored(reg, addr)	"ld " reg ", " addr
-#endif
-
-#define _storew(reg, addr)	"sw " reg ", " addr
-#define _storeh(reg, addr)	"sh " reg ", " addr
-#define _storeb(reg, addr)	"sb " reg ", " addr
-
-#define __put_kernel_common(ptr, size)					\
-do {									\
-	switch (size) {							\
-	case 1: __put_data_asm(_storeb, ptr); break;			\
-	case 2: __put_data_asm(_storeh, ptr); break;			\
-	case 4: __put_data_asm(_storew, ptr); break;			\
-	case 8: __PUT_DW(_stored, ptr); break;				\
-	default: __put_user_unknown(); break;				\
-	}								\
-} while(0)
-#endif
-
 /*
  * Yuck.  We need two variants, one for 64bit operation and one
  * for 32 bit mode and old iron.
@@ -429,12 +332,9 @@ do {									\
 	int __pu_err = 0;						\
 									\
 	__pu_val = (x);							\
-	if (eva_kernel_access()) {					\
-		__put_kernel_common(ptr, size);				\
-	} else {							\
-		__chk_user_ptr(ptr);					\
-		__put_user_common(ptr, size);				\
-	}								\
+	__chk_user_ptr(ptr);						\
+	__put_user_common(ptr, size);					\
+									\
 	__pu_err;							\
 })
 
@@ -445,11 +345,8 @@ do {									\
 	int __pu_err = -EFAULT;						\
 									\
 	might_fault();							\
-	if (likely(access_ok( __pu_addr, size))) {	\
-		if (eva_kernel_access())				\
-			__put_kernel_common(__pu_addr, size);		\
-		else							\
-			__put_user_common(__pu_addr, size);		\
+	if (likely(access_ok(__pu_addr, size))) {			\
+		__put_user_common(__pu_addr, size);			\
 	}								\
 									\
 	__pu_err;							\
@@ -501,7 +398,23 @@ do {									\
 	int __pu_err = 0;						\
 									\
 	__pu_val = *(__force type *)(src);				\
-	__put_kernel_common(((type *)(dst)), sizeof(type));		\
+	switch (sizeof(type)) {						\
+	case 1:								\
+		__put_data_asm(kernel_sb, (type *)(dst));		\
+		break;							\
+	case 2:								\
+		__put_data_asm(kernel_sh, (type *)(dst));		\
+		break;							\
+	case 4:								\
+		__put_data_asm(kernel_sw, (type *)(dst))		\
+		break;							\
+	case 8:								\
+		__PUT_DW(kernel_sd, (type *)(dst));			\
+		break;							\
+	default:							\
+		__put_user_unknown();					\
+		break;							\
+	}								\
 	if (unlikely(__pu_err))						\
 		goto err_label;						\
 } while (0)
@@ -529,124 +442,85 @@ do {									\
 #define DADDI_SCRATCH "$0"
 #endif
 
-extern size_t __copy_user(void *__to, const void *__from, size_t __n);
-
-#define __invoke_copy_from(func, to, from, n)				\
-({									\
-	register void *__cu_to_r __asm__("$4");				\
-	register const void __user *__cu_from_r __asm__("$5");		\
-	register long __cu_len_r __asm__("$6");				\
-									\
-	__cu_to_r = (to);						\
-	__cu_from_r = (from);						\
-	__cu_len_r = (n);						\
-	__asm__ __volatile__(						\
-	".set\tnoreorder\n\t"						\
-	__MODULE_JAL(func)						\
-	".set\tnoat\n\t"						\
-	__UA_ADDU "\t$1, %1, %2\n\t"					\
-	".set\tat\n\t"							\
-	".set\treorder"							\
-	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
-	:								\
-	: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",	\
-	  DADDI_SCRATCH, "memory");					\
-	__cu_len_r;							\
-})
-
-#define __invoke_copy_to(func, to, from, n)				\
-({									\
-	register void __user *__cu_to_r __asm__("$4");			\
-	register const void *__cu_from_r __asm__("$5");			\
-	register long __cu_len_r __asm__("$6");				\
-									\
-	__cu_to_r = (to);						\
-	__cu_from_r = (from);						\
-	__cu_len_r = (n);						\
-	__asm__ __volatile__(						\
-	__MODULE_JAL(func)						\
-	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
-	:								\
-	: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",	\
-	  DADDI_SCRATCH, "memory");					\
-	__cu_len_r;							\
-})
-
-#define __invoke_copy_from_kernel(to, from, n)				\
-	__invoke_copy_from(__copy_user, to, from, n)
-
-#define __invoke_copy_to_kernel(to, from, n)				\
-	__invoke_copy_to(__copy_user, to, from, n)
-
-#define ___invoke_copy_in_kernel(to, from, n)				\
-	__invoke_copy_from(__copy_user, to, from, n)
-
-#ifndef CONFIG_EVA
-#define __invoke_copy_from_user(to, from, n)				\
-	__invoke_copy_from(__copy_user, to, from, n)
-
-#define __invoke_copy_to_user(to, from, n)				\
-	__invoke_copy_to(__copy_user, to, from, n)
-
-#define ___invoke_copy_in_user(to, from, n)				\
-	__invoke_copy_from(__copy_user, to, from, n)
-
-#else
-
-/* EVA specific functions */
-
-extern size_t __copy_from_user_eva(void *__to, const void *__from,
-				   size_t __n);
-extern size_t __copy_to_user_eva(void *__to, const void *__from,
-				 size_t __n);
-extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
-
-/*
- * Source or destination address is in userland. We need to go through
- * the TLB
- */
-#define __invoke_copy_from_user(to, from, n)				\
-	__invoke_copy_from(__copy_from_user_eva, to, from, n)
-
-#define __invoke_copy_to_user(to, from, n)				\
-	__invoke_copy_to(__copy_to_user_eva, to, from, n)
-
-#define ___invoke_copy_in_user(to, from, n)				\
-	__invoke_copy_from(__copy_in_user_eva, to, from, n)
-
-#endif /* CONFIG_EVA */
+extern size_t __raw_copy_from_user(void *__to, const void *__from, size_t __n);
+extern size_t __raw_copy_to_user(void *__to, const void *__from, size_t __n);
+extern size_t __raw_copy_in_user(void *__to, const void *__from, size_t __n);
 
 static inline unsigned long
-raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 {
-	if (eva_kernel_access())
-		return __invoke_copy_to_kernel(to, from, n);
-	else
-		return __invoke_copy_to_user(to, from, n);
+	register void *__cu_to_r __asm__("$4");
+	register const void __user *__cu_from_r __asm__("$5");
+	register long __cu_len_r __asm__("$6");
+
+	__cu_to_r = to;
+	__cu_from_r = from;
+	__cu_len_r = n;
+
+	__asm__ __volatile__(
+		".set\tnoreorder\n\t"
+		__MODULE_JAL(__raw_copy_from_user)
+		".set\tnoat\n\t"
+		__UA_ADDU "\t$1, %1, %2\n\t"
+		".set\tat\n\t"
+		".set\treorder"
+		: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)
+		:
+		: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",
+		  DADDI_SCRATCH, "memory");
+
+	return __cu_len_r;
 }
 
 static inline unsigned long
-raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 {
-	if (eva_kernel_access())
-		return __invoke_copy_from_kernel(to, from, n);
-	else
-		return __invoke_copy_from_user(to, from, n);
+	register void __user *__cu_to_r __asm__("$4");
+	register const void *__cu_from_r __asm__("$5");
+	register long __cu_len_r __asm__("$6");
+
+	__cu_to_r = (to);
+	__cu_from_r = (from);
+	__cu_len_r = (n);
+
+	__asm__ __volatile__(
+		__MODULE_JAL(__raw_copy_to_user)
+		: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)
+		:
+		: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",
+		  DADDI_SCRATCH, "memory");
+
+	return __cu_len_r;
 }
 
 #define INLINE_COPY_FROM_USER
 #define INLINE_COPY_TO_USER
 
 static inline unsigned long
-raw_copy_in_user(void __user*to, const void __user *from, unsigned long n)
+raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
 {
-	if (eva_kernel_access())
-		return ___invoke_copy_in_kernel(to, from, n);
-	else
-		return ___invoke_copy_in_user(to, from,	n);
+	register void __user *__cu_to_r __asm__("$4");
+	register const void __user *__cu_from_r __asm__("$5");
+	register long __cu_len_r __asm__("$6");
+
+	__cu_to_r = to;
+	__cu_from_r = from;
+	__cu_len_r = n;
+
+	__asm__ __volatile__(
+		".set\tnoreorder\n\t"
+		__MODULE_JAL(__raw_copy_in_user)
+		".set\tnoat\n\t"
+		__UA_ADDU "\t$1, %1, %2\n\t"
+		".set\tat\n\t"
+		".set\treorder"
+		: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)
+		:
+		: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",
+		  DADDI_SCRATCH, "memory");
+	return __cu_len_r;
 }
 
-extern __kernel_size_t __bzero_kernel(void __user *addr, __kernel_size_t size);
 extern __kernel_size_t __bzero(void __user *addr, __kernel_size_t size);
 
 /*
@@ -672,28 +546,16 @@ __clear_user(void __user *addr, __kernel_size_t size)
 #define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"
 #endif /* CONFIG_CPU_MICROMIPS */
 
-	if (eva_kernel_access()) {
-		__asm__ __volatile__(
-			"move\t$4, %1\n\t"
-			"move\t$5, $0\n\t"
-			"move\t$6, %2\n\t"
-			__MODULE_JAL(__bzero_kernel)
-			"move\t%0, $6"
-			: "=r" (res)
-			: "r" (addr), "r" (size)
-			: bzero_clobbers);
-	} else {
-		might_fault();
-		__asm__ __volatile__(
-			"move\t$4, %1\n\t"
-			"move\t$5, $0\n\t"
-			"move\t$6, %2\n\t"
-			__MODULE_JAL(__bzero)
-			"move\t%0, $6"
-			: "=r" (res)
-			: "r" (addr), "r" (size)
-			: bzero_clobbers);
-	}
+	might_fault();
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		"move\t$5, $0\n\t"
+		"move\t$6, %2\n\t"
+		__MODULE_JAL(__bzero)
+		"move\t%0, $6"
+		: "=r" (res)
+		: "r" (addr), "r" (size)
+		: bzero_clobbers);
 
 	return res;
 }
@@ -707,7 +569,6 @@ __clear_user(void __user *addr, __kernel_size_t size)
 	__cl_size;							\
 })
 
-extern long __strncpy_from_kernel_asm(char *__to, const char __user *__from, long __len);
 extern long __strncpy_from_user_asm(char *__to, const char __user *__from, long __len);
 
 /*
@@ -733,33 +594,23 @@ strncpy_from_user(char *__to, const char __user *__from, long __len)
 {
 	long res;
 
-	if (eva_kernel_access()) {
-		__asm__ __volatile__(
-			"move\t$4, %1\n\t"
-			"move\t$5, %2\n\t"
-			"move\t$6, %3\n\t"
-			__MODULE_JAL(__strncpy_from_kernel_asm)
-			"move\t%0, $2"
-			: "=r" (res)
-			: "r" (__to), "r" (__from), "r" (__len)
-			: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
-	} else {
-		might_fault();
-		__asm__ __volatile__(
-			"move\t$4, %1\n\t"
-			"move\t$5, %2\n\t"
-			"move\t$6, %3\n\t"
-			__MODULE_JAL(__strncpy_from_user_asm)
-			"move\t%0, $2"
-			: "=r" (res)
-			: "r" (__to), "r" (__from), "r" (__len)
-			: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
-	}
+	if (!access_ok(__from, __len))
+		return -EFAULT;
+
+	might_fault();
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		"move\t$5, %2\n\t"
+		"move\t$6, %3\n\t"
+		__MODULE_JAL(__strncpy_from_user_asm)
+		"move\t%0, $2"
+		: "=r" (res)
+		: "r" (__to), "r" (__from), "r" (__len)
+		: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
 
 	return res;
 }
 
-extern long __strnlen_kernel_asm(const char __user *s, long n);
 extern long __strnlen_user_asm(const char __user *s, long n);
 
 /*
@@ -779,26 +630,18 @@ static inline long strnlen_user(const char __user *s, long n)
 {
 	long res;
 
+	if (!access_ok(s, n))
+		return -0;
+
 	might_fault();
-	if (eva_kernel_access()) {
-		__asm__ __volatile__(
-			"move\t$4, %1\n\t"
-			"move\t$5, %2\n\t"
-			__MODULE_JAL(__strnlen_kernel_asm)
-			"move\t%0, $2"
-			: "=r" (res)
-			: "r" (s), "r" (n)
-			: "$2", "$4", "$5", __UA_t0, "$31");
-	} else {
-		__asm__ __volatile__(
-			"move\t$4, %1\n\t"
-			"move\t$5, %2\n\t"
-			__MODULE_JAL(__strnlen_user_asm)
-			"move\t%0, $2"
-			: "=r" (res)
-			: "r" (s), "r" (n)
-			: "$2", "$4", "$5", __UA_t0, "$31");
-	}
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		"move\t$5, %2\n\t"
+		__MODULE_JAL(__strnlen_user_asm)
+		"move\t%0, $2"
+		: "=r" (res)
+		: "r" (s), "r" (n)
+		: "$2", "$4", "$5", __UA_t0, "$31");
 
 	return res;
 }