[PATCH] s390 (7/7): system call speedup part 2.

From: Martin Schwidefsky
Date: Fri Mar 26 2004 - 13:41:01 EST

System call speedup part 2.

diffstat:
include/asm-s390/elf.h | 26 +
include/asm-s390/lowcore.h | 27 +
include/asm-s390/mmu_context.h | 22 -
include/asm-s390/processor.h | 9
include/asm-s390/ptrace.h | 10
include/asm-s390/system.h | 19 +
include/asm-s390/uaccess.h | 603 +++++++++++++----------------------------
7 files changed, 278 insertions(+), 438 deletions(-)

diff -urN linux-2.6/include/asm-s390/elf.h linux-2.6-s390/include/asm-s390/elf.h
--- linux-2.6/include/asm-s390/elf.h Thu Mar 11 03:55:44 2004
+++ linux-2.6-s390/include/asm-s390/elf.h Fri Mar 26 18:26:00 2004
@@ -155,9 +155,31 @@
/* regs is struct pt_regs, pr_reg is elf_gregset_t (which is
now struct_user_regs, they are different) */

-#define ELF_CORE_COPY_REGS(pr_reg, regs) \
- memcpy(&pr_reg,regs,sizeof(elf_gregset_t)); \
+static inline int dump_regs(struct pt_regs *ptregs, elf_gregset_t *regs)
+{
+ memcpy(&regs->psw, &ptregs->psw, sizeof(regs->psw)+sizeof(regs->gprs));
+ regs->orig_gpr2 = ptregs->orig_gpr2;
+ return 1;
+}

+#define ELF_CORE_COPY_REGS(pr_reg, regs) dump_regs(regs, &pr_reg);
+
+static inline int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
+{
+ dump_regs(__KSTK_PTREGS(tsk), regs);
+ memcpy(regs->acrs, tsk->thread.acrs, sizeof(regs->acrs));
+ return 1;
+}
+
+#define ELF_CORE_COPY_TASK_REGS(tsk, regs) dump_task_regs(tsk, regs)
+
+static inline int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
+{
+ memcpy(fpregs, &tsk->thread.fp_regs, sizeof(elf_fpregset_t));
+ return 1;
+}
+
+#define ELF_CORE_COPY_FPREGS(tsk, fpregs) dump_task_fpu(tsk, fpregs)


/* This yields a mask that user programs can use to figure out what
diff -urN linux-2.6/include/asm-s390/lowcore.h linux-2.6-s390/include/asm-s390/lowcore.h
--- linux-2.6/include/asm-s390/lowcore.h Fri Mar 26 18:24:56 2004
+++ linux-2.6-s390/include/asm-s390/lowcore.h Fri Mar 26 18:26:00 2004
@@ -64,7 +64,10 @@

#ifndef __s390x__
#define __LC_KERNEL_STACK 0xC40
-#define __LC_ASYNC_STACK 0xC44
+#define __LC_THREAD_INFO 0xC44
+#define __LC_ASYNC_STACK 0xC48
+#define __LC_KERNEL_ASCE 0xC4C
+#define __LC_USER_ASCE 0xC50
#define __LC_CPUID 0xC60
#define __LC_CPUADDR 0xC68
#define __LC_IPLDEV 0xC7C
@@ -73,13 +76,16 @@
#define __LC_INT_CLOCK 0xC98
#else /* __s390x__ */
#define __LC_KERNEL_STACK 0xD40
-#define __LC_ASYNC_STACK 0xD48
+#define __LC_THREAD_INFO 0xD48
+#define __LC_ASYNC_STACK 0xD50
+#define __LC_KERNEL_ASCE 0xD58
+#define __LC_USER_ASCE 0xD60
#define __LC_CPUID 0xD90
#define __LC_CPUADDR 0xD98
#define __LC_IPLDEV 0xDB8
#define __LC_JIFFY_TIMER 0xDC0
#define __LC_CURRENT 0xDD8
-#define __LC_INT_CLOCK 0xDE8
+#define __LC_INT_CLOCK 0xDe8
#endif /* __s390x__ */

#define __LC_PANIC_MAGIC 0xE00
@@ -99,7 +105,6 @@
#include <linux/config.h>
#include <asm/processor.h>
#include <linux/types.h>
-#include <asm/atomic.h>
#include <asm/sigp.h>

void restart_int_handler(void);
@@ -167,9 +172,12 @@
/* System info area */
__u32 save_area[16]; /* 0xc00 */
__u32 kernel_stack; /* 0xc40 */
- __u32 async_stack; /* 0xc44 */
+ __u32 thread_info; /* 0xc44 */
+ __u32 async_stack; /* 0xc48 */
+ __u32 kernel_asce; /* 0xc4c */
+ __u32 user_asce; /* 0xc50 */
+ __u8 pad10[0xc60-0xc54]; /* 0xc54 */
/* entry.S sensitive area start */
- __u8 pad10[0xc60-0xc48]; /* 0xc5c */
struct cpuinfo_S390 cpu_data; /* 0xc60 */
__u32 ipl_device; /* 0xc7c */
/* entry.S sensitive area end */
@@ -245,9 +253,12 @@
__u64 save_area[16]; /* 0xc00 */
__u8 pad9[0xd40-0xc80]; /* 0xc80 */
__u64 kernel_stack; /* 0xd40 */
- __u64 async_stack; /* 0xd48 */
+ __u64 thread_info; /* 0xd48 */
+ __u64 async_stack; /* 0xd50 */
+ __u64 kernel_asce; /* 0xd58 */
+ __u64 user_asce; /* 0xd60 */
+ __u8 pad10[0xd80-0xd68]; /* 0xd68 */
/* entry.S sensitive area start */
- __u8 pad10[0xd80-0xd50]; /* 0xd64 */
struct cpuinfo_S390 cpu_data; /* 0xd80 */
__u32 ipl_device; /* 0xdb8 */
__u32 pad11; /* 0xdbc */
diff -urN linux-2.6/include/asm-s390/mmu_context.h linux-2.6-s390/include/asm-s390/mmu_context.h
--- linux-2.6/include/asm-s390/mmu_context.h Thu Mar 11 03:55:26 2004
+++ linux-2.6-s390/include/asm-s390/mmu_context.h Fri Mar 26 18:26:00 2004
@@ -24,22 +24,19 @@
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
- unsigned long pgd;
-
if (prev != next) {
#ifndef __s390x__
- pgd = (__pa(next->pgd)&PAGE_MASK) |
+ S390_lowcore.user_asce = (__pa(next->pgd)&PAGE_MASK) |
(_SEGMENT_TABLE|USER_STD_MASK);
- /* Load page tables */
- asm volatile(" lctl 7,7,%0\n" /* secondary space */
- " lctl 13,13,%0\n" /* home space */
- : : "m" (pgd) );
+ /* Load home space page table origin. */
+ asm volatile("lctl 13,13,%0"
+ : : "m" (S390_lowcore.user_asce) );
#else /* __s390x__ */
- pgd = (__pa(next->pgd)&PAGE_MASK) | (_REGION_TABLE|USER_STD_MASK);
- /* Load page tables */
- asm volatile(" lctlg 7,7,%0\n" /* secondary space */
- " lctlg 13,13,%0\n" /* home space */
- : : "m" (pgd) );
+ S390_lowcore.user_asce = (__pa(next->pgd) & PAGE_MASK) |
+ (_REGION_TABLE|USER_STD_MASK);
+ /* Load home space page table origin. */
+ asm volatile("lctlg 13,13,%0"
+ : : "m" (S390_lowcore.user_asce) );
#endif /* __s390x__ */
}
cpu_set(smp_processor_id(), next->cpu_vm_mask);
@@ -51,6 +48,7 @@
struct mm_struct *next)
{
switch_mm(prev, next, current);
+ set_fs(current->thread.mm_segment);
}

#endif
diff -urN linux-2.6/include/asm-s390/processor.h linux-2.6-s390/include/asm-s390/processor.h
--- linux-2.6/include/asm-s390/processor.h Thu Mar 11 03:55:27 2004
+++ linux-2.6-s390/include/asm-s390/processor.h Fri Mar 26 18:26:00 2004
@@ -82,10 +82,10 @@
*/
struct thread_struct {
s390_fp_regs fp_regs;
- unsigned int ar2; /* kernel access register 2 */
- unsigned int ar4; /* kernel access register 4 */
+ unsigned int acrs[NUM_ACRS];
unsigned long ksp; /* kernel stack pointer */
unsigned long user_seg; /* HSTD */
+ mm_segment_t mm_segment;
unsigned long prot_addr; /* address of protection-excep. */
unsigned int error_code; /* error-code of last prog-excep. */
unsigned int trap_no;
@@ -106,9 +106,10 @@

#define INIT_THREAD {{0,{{0},{0},{0},{0},{0},{0},{0},{0},{0},{0}, \
{0},{0},{0},{0},{0},{0}}}, \
- 0, 0, \
+ {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, \
sizeof(init_stack) + (unsigned long) &init_stack, \
__SWAPPER_PG_DIR, \
+ {0}, \
0,0,0, \
(per_struct) {{{{0,}}},0,0,0,0,{{0,}}}, \
0, 0 \
@@ -167,7 +168,7 @@

unsigned long get_wchan(struct task_struct *p);
#define __KSTK_PTREGS(tsk) ((struct pt_regs *) \
- (((unsigned long) tsk->thread_info + THREAD_SIZE - sizeof(struct pt_regs)) & -8L))
+ ((unsigned long) tsk->thread_info + THREAD_SIZE - sizeof(struct pt_regs)))
#define KSTK_EIP(tsk) (__KSTK_PTREGS(tsk)->psw.addr)
#define KSTK_ESP(tsk) (__KSTK_PTREGS(tsk)->gprs[15])

diff -urN linux-2.6/include/asm-s390/ptrace.h linux-2.6-s390/include/asm-s390/ptrace.h
--- linux-2.6/include/asm-s390/ptrace.h Fri Mar 26 18:24:56 2004
+++ linux-2.6-s390/include/asm-s390/ptrace.h Fri Mar 26 18:26:00 2004
@@ -286,10 +286,7 @@
((NEW) & (PSW_MASK_CC|PSW_MASK_PM)))

/*
- * The first entries in pt_regs and user_regs_struct
- * are common for the two structures. The s390_regs structure
- * covers the common parts. It simplifies copying the common part
- * between the three structures.
+ * The s390_regs structure is used to define the elf_gregset_t.
*/
typedef struct
{
@@ -299,6 +296,7 @@
unsigned long orig_gpr2;
} s390_regs;

+#ifdef __KERNEL__
/*
* The pt_regs struct defines the way the registers are stored on
* the stack during a system call.
@@ -307,11 +305,11 @@
{
psw_t psw;
unsigned long gprs[NUM_GPRS];
- unsigned int acrs[NUM_ACRS];
unsigned long orig_gpr2;
unsigned short ilc;
unsigned short trap;
-} __attribute__ ((packed));
+};
+#endif

/*
* Now for the program event recording (trace) definitions.
diff -urN linux-2.6/include/asm-s390/system.h linux-2.6-s390/include/asm-s390/system.h
--- linux-2.6/include/asm-s390/system.h Thu Mar 11 03:55:54 2004
+++ linux-2.6-s390/include/asm-s390/system.h Fri Mar 26 18:26:00 2004
@@ -83,14 +83,33 @@
: : "a" (fpregs), "m" (*fpregs) );
}

+static inline void save_access_regs(unsigned int *acrs)
+{
+ asm volatile ("stam 0,15,0(%0)" : : "a" (acrs) : "memory" );
+}
+
+static inline void restore_access_regs(unsigned int *acrs)
+{
+ asm volatile ("lam 0,15,0(%0)" : : "a" (acrs) );
+}
+
#define switch_to(prev,next,last) do { \
if (prev == next) \
break; \
save_fp_regs(&prev->thread.fp_regs); \
restore_fp_regs(&next->thread.fp_regs); \
+ save_access_regs(&prev->thread.acrs[0]); \
+ restore_access_regs(&next->thread.acrs[0]); \
prev = __switch_to(prev,next); \
} while (0)

+#define prepare_arch_switch(rq, next) do { } while(0)
+#define task_running(rq, p) ((rq)->curr == (p))
+#define finish_arch_switch(rq, prev) do { \
+ set_fs(current->thread.mm_segment); \
+ spin_unlock_irq(&(rq)->lock); \
+} while (0)
+
#define nop() __asm__ __volatile__ ("nop")

#define xchg(ptr,x) \
diff -urN linux-2.6/include/asm-s390/uaccess.h linux-2.6-s390/include/asm-s390/uaccess.h
--- linux-2.6/include/asm-s390/uaccess.h Thu Mar 11 03:55:23 2004
+++ linux-2.6-s390/include/asm-s390/uaccess.h Fri Mar 26 18:26:00 2004
@@ -36,10 +36,27 @@
#define USER_DS MAKE_MM_SEG(1)

#define get_ds() (KERNEL_DS)
-#define get_fs() ({ mm_segment_t __x; \
- asm volatile("ear %0,4":"=a" (__x)); \
- __x;})
-#define set_fs(x) ({asm volatile("sar 4,%0"::"a" ((x).ar4));})
+#define get_fs() (current->thread.mm_segment)
+
+#ifdef __s390x__
+#define set_fs(x) \
+({ \
+ unsigned long __pto; \
+ current->thread.mm_segment = (x); \
+ __pto = current->thread.mm_segment.ar4 ? \
+ S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
+ asm volatile ("lctlg 7,7,%0" : : "m" (__pto) ); \
+})
+#else
+#define set_fs(x) \
+({ \
+ unsigned long __pto; \
+ current->thread.mm_segment = (x); \
+ __pto = current->thread.mm_segment.ar4 ? \
+ S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
+ asm volatile ("lctl 7,7,%0" : : "m" (__pto) ); \
+})
+#endif

#define segment_eq(a,b) ((a).ar4 == (b).ar4)

@@ -71,126 +88,64 @@
unsigned long insn, fixup;
};

-/*
- * Standard fixup section for uaccess inline functions.
- * local label 0: is the fault point
- * local label 1: is the return point
- * %0 is the error variable
- * %3 is the error value -EFAULT
- */
#ifndef __s390x__
#define __uaccess_fixup \
".section .fixup,\"ax\"\n" \
- "8: sacf 0\n" \
- " lhi %0,%h3\n" \
- " bras 4,9f\n" \
- " .long 1b\n" \
- "9: l 4,0(4)\n" \
- " br 4\n" \
+ "2: lhi %0,%4\n" \
+ " bras 1,3f\n" \
+ " .long 1b\n" \
+ "3: l 1,0(1)\n" \
+ " br 1\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 4\n" \
- " .long 0b,8b\n" \
+ " .long 0b,2b\n" \
".previous"
+#define __uaccess_clobber "cc", "1"
#else /* __s390x__ */
#define __uaccess_fixup \
".section .fixup,\"ax\"\n" \
- "9: sacf 0\n" \
- " lhi %0,%h3\n" \
- " jg 1b\n" \
+ "2: lghi %0,%4\n" \
+ " jg 1b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 8\n" \
- " .quad 0b,9b\n" \
+ " .quad 0b,2b\n" \
".previous"
+#define __uaccess_clobber "cc"
#endif /* __s390x__ */

/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*/
-#ifndef __s390x__
-
-#define __put_user_asm_8(x, ptr, err) \
-({ \
- register __typeof__(x) const * __from asm("2"); \
- register __typeof__(*(ptr)) * __to asm("4"); \
- __from = &(x); \
- __to = (ptr); \
- __asm__ __volatile__ ( \
- " sacf 512\n" \
- "0: mvc 0(8,%1),0(%2)\n" \
- " sacf 0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "=&d" (err) \
- : "a" (__to),"a" (__from),"K" (-EFAULT),"0" (0),\
- "m" (x) : "cc" ); \
-})
-
-#else /* __s390x__ */
-
-#define __put_user_asm_8(x, ptr, err) \
-({ \
- register __typeof__(*(ptr)) * __ptr asm("4"); \
- __ptr = (ptr); \
- __asm__ __volatile__ ( \
- " sacf 512\n" \
- "0: stg %2,0(%1)\n" \
- " sacf 0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "=&d" (err) \
- : "a" (__ptr), "d" (x), "K" (-EFAULT), "0" (0) \
- : "cc" ); \
-})
-
-#endif /* __s390x__ */
-
-#define __put_user_asm_4(x, ptr, err) \
-({ \
- register __typeof__(*(ptr)) * __ptr asm("4"); \
- __ptr = (ptr); \
- __asm__ __volatile__ ( \
- " sacf 512\n" \
- "0: st %2,0(%1)\n" \
- " sacf 0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "=&d" (err) \
- : "a" (__ptr), "d" (x), "K" (-EFAULT), "0" (0) \
- : "cc" ); \
-})
-
-#define __put_user_asm_2(x, ptr, err) \
+#if __GNUC__ > 2
+#define __put_user_asm(x, ptr, err) \
({ \
- register __typeof__(*(ptr)) * __ptr asm("4"); \
- __ptr = (ptr); \
- __asm__ __volatile__ ( \
- " sacf 512\n" \
- "0: sth %2,0(%1)\n" \
- " sacf 0\n" \
+ err = 0; \
+ asm volatile( \
+ "0: mvcs 0(%1,%2),%3,%0\n" \
"1:\n" \
__uaccess_fixup \
- : "=&d" (err) \
- : "a" (__ptr), "d" (x), "K" (-EFAULT), "0" (0) \
- : "cc" ); \
+ : "+&d" (err) \
+ : "d" (sizeof(*(ptr))), "a" (ptr), "Q" (x), \
+ "K" (-EFAULT) \
+ : __uaccess_clobber ); \
})
-
-#define __put_user_asm_1(x, ptr, err) \
+#else
+#define __put_user_asm(x, ptr, err) \
({ \
- register __typeof__(*(ptr)) * __ptr asm("4"); \
- __ptr = (ptr); \
- __asm__ __volatile__ ( \
- " sacf 512\n" \
- "0: stc %2,0(%1)\n" \
- " sacf 0\n" \
+ err = 0; \
+ asm volatile( \
+ "0: mvcs 0(%1,%2),0(%3),%0\n" \
"1:\n" \
__uaccess_fixup \
- : "=&d" (err) \
- : "a" (__ptr), "d" (x), "K" (-EFAULT), "0" (0) \
- : "cc" ); \
+ : "+&d" (err) \
+ : "d" (sizeof(*(ptr))), "a" (ptr), "a" (&(x)), \
+ "K" (-EFAULT), "m" (x) \
+ : __uaccess_clobber ); \
})
+#endif

#define __put_user(x, ptr) \
({ \
@@ -198,16 +153,10 @@
int __pu_err; \
switch (sizeof (*(ptr))) { \
case 1: \
- __put_user_asm_1(__x, ptr, __pu_err); \
- break; \
case 2: \
- __put_user_asm_2(__x, ptr, __pu_err); \
- break; \
case 4: \
- __put_user_asm_4(__x, ptr, __pu_err); \
- break; \
case 8: \
- __put_user_asm_8(__x, ptr, __pu_err); \
+ __put_user_asm(__x, ptr, __pu_err); \
break; \
default: \
__pu_err = __put_user_bad(); \
@@ -225,90 +174,33 @@

extern int __put_user_bad(void);

-#ifndef __s390x__
-
-#define __get_user_asm_8(x, ptr, err) \
+#if __GNUC__ > 2
+#define __get_user_asm(x, ptr, err) \
({ \
- register __typeof__(*(ptr)) const * __from asm("4"); \
- register __typeof__(x) * __to asm("2"); \
- __from = (ptr); \
- __to = &(x); \
- __asm__ __volatile__ ( \
- " sacf 512\n" \
- "0: mvc 0(8,%2),0(%4)\n" \
- " sacf 0\n" \
+ err = 0; \
+ asm volatile ( \
+ "0: mvcp %O1(%2,%R1),0(%3),%0\n" \
"1:\n" \
__uaccess_fixup \
- : "=&d" (err), "=m" (x) \
- : "a" (__to),"K" (-EFAULT),"a" (__from),"0" (0) \
- : "cc" ); \
+ : "+&d" (err), "=Q" (x) \
+ : "d" (sizeof(*(ptr))), "a" (ptr), \
+ "K" (-EFAULT) \
+ : __uaccess_clobber ); \
})
-
-#else /* __s390x__ */
-
-#define __get_user_asm_8(x, ptr, err) \
-({ \
- register __typeof__(*(ptr)) const * __ptr asm("4"); \
- __ptr = (ptr); \
- __asm__ __volatile__ ( \
- " sacf 512\n" \
- "0: lg %1,0(%2)\n" \
- " sacf 0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "=&d" (err), "=d" (x) \
- : "a" (__ptr), "K" (-EFAULT), "0" (0) \
- : "cc" ); \
-})
-
-#endif /* __s390x__ */
-
-
-#define __get_user_asm_4(x, ptr, err) \
-({ \
- register __typeof__(*(ptr)) const * __ptr asm("4"); \
- __ptr = (ptr); \
- __asm__ __volatile__ ( \
- " sacf 512\n" \
- "0: l %1,0(%2)\n" \
- " sacf 0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "=&d" (err), "=d" (x) \
- : "a" (__ptr), "K" (-EFAULT), "0" (0) \
- : "cc" ); \
-})
-
-#define __get_user_asm_2(x, ptr, err) \
-({ \
- register __typeof__(*(ptr)) const * __ptr asm("4"); \
- __ptr = (ptr); \
- __asm__ __volatile__ ( \
- " sacf 512\n" \
- "0: lh %1,0(%2)\n" \
- " sacf 0\n" \
- "1:\n" \
- __uaccess_fixup \
- : "=&d" (err), "=d" (x) \
- : "a" (__ptr), "K" (-EFAULT), "0" (0) \
- : "cc" ); \
-})
-
-#define __get_user_asm_1(x, ptr, err) \
+#else
+#define __get_user_asm(x, ptr, err) \
({ \
- register __typeof__(*(ptr)) const * __ptr asm("4"); \
- __ptr = (ptr); \
- __asm__ __volatile__ ( \
- " sr %1,%1\n" \
- " sacf 512\n" \
- "0: ic %1,0(%2)\n" \
- " sacf 0\n" \
+ err = 0; \
+ asm volatile ( \
+ "0: mvcp 0(%2,%5),0(%3),%0\n" \
"1:\n" \
__uaccess_fixup \
- : "=&d" (err), "=&d" (x) \
- : "a" (__ptr), "K" (-EFAULT), "0" (0) \
- : "cc" ); \
+ : "+&d" (err), "=m" (x) \
+ : "d" (sizeof(*(ptr))), "a" (ptr), \
+ "K" (-EFAULT), "a" (&(x)) \
+ : __uaccess_clobber ); \
})
+#endif

#define __get_user(x, ptr) \
({ \
@@ -316,16 +208,10 @@
int __gu_err; \
switch (sizeof(*(ptr))) { \
case 1: \
- __get_user_asm_1(__x, ptr, __gu_err); \
- break; \
case 2: \
- __get_user_asm_2(__x, ptr, __gu_err); \
- break; \
case 4: \
- __get_user_asm_4(__x, ptr, __gu_err); \
- break; \
case 8: \
- __get_user_asm_8(__x, ptr, __gu_err); \
+ __get_user_asm(__x, ptr, __gu_err); \
break; \
default: \
__x = 0; \
@@ -344,149 +230,123 @@

extern int __get_user_bad(void);

-/*
- * access register are set up, that 4 points to secondary (user),
- * 2 to primary (kernel)
- */
-
-extern long __copy_to_user_asm(const void *from, long n, const void *to);
+extern long __copy_to_user_asm(const void *from, long n, void *to);

-#define __copy_to_user(to, from, n) \
-({ \
- __copy_to_user_asm(from, n, to); \
-})
+/**
+ * __copy_to_user: - Copy a block of 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.
+ */
+static inline unsigned long
+__copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ return __copy_to_user_asm(from, n, to);
+}

-#define copy_to_user(to, from, n) \
-({ \
- long err = 0; \
- __typeof__(n) __n = (n); \
- might_sleep(); \
- if (__access_ok(to,__n)) { \
- err = __copy_to_user_asm(from, __n, to); \
- } \
- else \
- err = __n; \
- err; \
-})
+/**
+ * copy_to_user: - Copy a block of data into user space.
+ * @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.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ */
+static inline unsigned long
+copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ might_sleep();
+ if (access_ok(VERIFY_WRITE, to, n))
+ n = __copy_to_user(to, from, n);
+ return n;
+}

extern long __copy_from_user_asm(void *to, long n, const void *from);

-#define __copy_from_user(to, from, n) \
-({ \
- __copy_from_user_asm(to, n, from); \
-})
-
-#define copy_from_user(to, from, n) \
-({ \
- long err = 0; \
- __typeof__(n) __n = (n); \
- might_sleep(); \
- if (__access_ok(from,__n)) { \
- err = __copy_from_user_asm(to, __n, from); \
- } \
- else \
- err = __n; \
- err; \
-})
-
-extern long __copy_in_user_asm(const void *from, long n, void *to);
-
-#define __copy_in_user(to, from, n) \
-({ \
- __copy_in_user_asm(from, n, to); \
-})
-
-#define copy_in_user(to, from, n) \
-({ \
- long err = 0; \
- __typeof__(n) __n = (n); \
- might_sleep(); \
- if (__access_ok(from,__n) && __access_ok(to,__n)) { \
- err = __copy_in_user_asm(from, __n, to); \
- } \
- else \
- err = __n; \
- err; \
-})
+/**
+ * __copy_from_user: - Copy a block of 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.
+ */
+static inline unsigned long
+__copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ return __copy_from_user_asm(to, n, from);
+}

-/*
- * Copy a null terminated string from userspace.
+/**
+ * copy_from_user: - Copy a block of data from user space.
+ * @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.
+ *
+ * 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.
*/
+static inline unsigned long
+copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ might_sleep();
+ if (access_ok(VERIFY_READ, from, n))
+ n = __copy_from_user(to, from, n);
+ else
+ memset(to, 0, n);
+ return n;
+}

-#ifndef __s390x__
+extern long __copy_in_user_asm(const void *from, long n, void *to);

-static inline long
-__strncpy_from_user(char *dst, const char *src, long count)
+static inline unsigned long
+__copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
- int len;
- __asm__ __volatile__ (
- " slr %0,%0\n"
- " lr 2,%1\n"
- " lr 4,%2\n"
- " slr 3,3\n"
- " sacf 512\n"
- "0: ic 3,0(%0,4)\n"
- "1: stc 3,0(%0,2)\n"
- " ltr 3,3\n"
- " jz 2f\n"
- " ahi %0,1\n"
- " clr %0,%3\n"
- " jl 0b\n"
- "2: sacf 0\n"
- ".section .fixup,\"ax\"\n"
- "3: lhi %0,%h4\n"
- " basr 3,0\n"
- " l 3,4f-.(3)\n"
- " br 3\n"
- "4: .long 2b\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- " .align 4\n"
- " .long 0b,3b\n"
- " .long 1b,3b\n"
- ".previous"
- : "=&a" (len)
- : "a" (dst), "d" (src), "d" (count), "K" (-EFAULT)
- : "2", "3", "4", "memory", "cc" );
- return len;
+ __copy_in_user_asm(from, n, to);
}

-#else /* __s390x__ */
-
-static inline long
-__strncpy_from_user(char *dst, const char *src, long count)
+static inline unsigned long
+copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
- long len;
- __asm__ __volatile__ (
- " slgr %0,%0\n"
- " lgr 2,%1\n"
- " lgr 4,%2\n"
- " slr 3,3\n"
- " sacf 512\n"
- "0: ic 3,0(%0,4)\n"
- "1: stc 3,0(%0,2)\n"
- " ltr 3,3\n"
- " jz 2f\n"
- " aghi %0,1\n"
- " cgr %0,%3\n"
- " jl 0b\n"
- "2: sacf 0\n"
- ".section .fixup,\"ax\"\n"
- "3: lghi %0,%h4\n"
- " jg 2b\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- " .align 8\n"
- " .quad 0b,3b\n"
- " .quad 1b,3b\n"
- ".previous"
- : "=&a" (len)
- : "a" (dst), "d" (src), "d" (count), "K" (-EFAULT)
- : "cc", "2" ,"3", "4" );
- return len;
+ might_sleep();
+ if (__access_ok(from,n) && __access_ok(to,n))
+ n = __copy_in_user_asm(from, n, to);
+ return n;
}

-#endif /* __s390x__ */
+/*
+ * Copy a null terminated string from userspace.
+ */
+extern long __strncpy_from_user_asm(char *dst, const char *src, long count);

static inline long
strncpy_from_user(char *dst, const char *src, long count)
@@ -494,104 +354,34 @@
long res = -EFAULT;
might_sleep();
if (access_ok(VERIFY_READ, src, 1))
- res = __strncpy_from_user(dst, src, count);
+ res = __strncpy_from_user_asm(dst, src, count);
return res;
}


-/*
- * Return the size of a string (including the ending 0)
- *
- * Return 0 for error
- */
-#ifndef __s390x__
+extern long __strnlen_user_asm(const char *src, long count);

static inline unsigned long
strnlen_user(const char * src, unsigned long n)
{
might_sleep();
- __asm__ __volatile__ (
- " alr %0,%1\n"
- " slr 0,0\n"
- " lr 4,%1\n"
- " sacf 512\n"
- "0: srst %0,4\n"
- " jo 0b\n"
- " slr %0,%1\n"
- " ahi %0,1\n"
- " sacf 0\n"
- "1:\n"
- ".section .fixup,\"ax\"\n"
- "2: sacf 0\n"
- " slr %0,%0\n"
- " bras 4,3f\n"
- " .long 1b\n"
- "3: l 4,0(4)\n"
- " br 4\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- " .align 4\n"
- " .long 0b,2b\n"
- ".previous"
- : "+&a" (n) : "d" (src)
- : "cc", "0", "4" );
- return n;
+ return __strnlen_user_asm(src, n);
}

-#else /* __s390x__ */
-
-static inline unsigned long
-strnlen_user(const char * src, unsigned long n)
-{
- might_sleep();
-#if 0
- __asm__ __volatile__ (
- " algr %0,%1\n"
- " slgr 0,0\n"
- " lgr 4,%1\n"
- " sacf 512\n"
- "0: srst %0,4\n"
- " jo 0b\n"
- " slgr %0,%1\n"
- " aghi %0,1\n"
- "1: sacf 0\n"
- ".section .fixup,\"ax\"\n"
- "2: slgr %0,%0\n"
- " jg 1b\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- " .align 8\n"
- " .quad 0b,2b\n"
- ".previous"
- : "+&a" (n) : "d" (src)
- : "cc", "0", "4" );
-#else
- __asm__ __volatile__ (
- " lgr 4,%1\n"
- " sacf 512\n"
- "0: cli 0(4),0x00\n"
- " la 4,1(4)\n"
- " je 1f\n"
- " brctg %0,0b\n"
- "1: lgr %0,4\n"
- " slgr %0,%1\n"
- "2: sacf 0\n"
- ".section .fixup,\"ax\"\n"
- "3: slgr %0,%0\n"
- " jg 2b\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- " .align 8\n"
- " .quad 0b,3b\n"
- ".previous"
- : "+&a" (n) : "d" (src)
- : "cc", "4" );
-#endif
- return n;
-}
-
-#endif /* __s390x__ */
-
+/**
+ * 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.
+ */
#define strlen_user(str) strnlen_user(str, ~0UL)

/*
@@ -600,17 +390,18 @@

extern long __clear_user_asm(void *to, long n);

-#define __clear_user(to, n) \
-({ \
- __clear_user_asm(to, n); \
-})
+static inline unsigned long
+__clear_user(void *to, unsigned long n)
+{
+ return __clear_user_asm(to, n);
+}

static inline unsigned long
clear_user(void *to, unsigned long n)
{
might_sleep();
if (access_ok(VERIFY_WRITE, to, n))
- n = __clear_user(to, n);
+ n = __clear_user_asm(to, n);
return n;
}

-
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