Hi, Ren,

On Sun, May 1, 2022 at 6:56 PM Guo Ren [off-list ref] wrote:

On Sat, Apr 30, 2022 at 5:23 PM Huacai Chen [off-list ref] wrote:

quoted

This patch adds some library functions for LoongArch, including: delay,
memset, memcpy, memmove, copy_user, strncpy_user, strnlen_user and tlb
dump functions.

Signed-off-by: Huacai Chen <redacted>
---
 arch/loongarch/include/asm/delay.h  |  26 +++++++
 arch/loongarch/include/asm/string.h |  17 +++++
 arch/loongarch/lib/clear_user.S     |  43 +++++++++++
 arch/loongarch/lib/copy_user.S      |  47 ++++++++++++
 arch/loongarch/lib/delay.c          |  43 +++++++++++
 arch/loongarch/lib/dump_tlb.c       | 111 ++++++++++++++++++++++++++++
 arch/loongarch/lib/memcpy.S         |  32 ++++++++
 arch/loongarch/lib/memmove.S        |  45 +++++++++++
 arch/loongarch/lib/memset.S         |  30 ++++++++
 9 files changed, 394 insertions(+)
 create mode 100644 arch/loongarch/include/asm/delay.h
 create mode 100644 arch/loongarch/include/asm/string.h
 create mode 100644 arch/loongarch/lib/clear_user.S
 create mode 100644 arch/loongarch/lib/copy_user.S
 create mode 100644 arch/loongarch/lib/delay.c
 create mode 100644 arch/loongarch/lib/dump_tlb.c
 create mode 100644 arch/loongarch/lib/memcpy.S
 create mode 100644 arch/loongarch/lib/memmove.S
 create mode 100644 arch/loongarch/lib/memset.S

diff --git a/arch/loongarch/include/asm/delay.h b/arch/loongarch/include/asm/delay.h
new file mode 100644
index 000000000000..016b3aca65cb
--- /dev/null
+++ b/arch/loongarch/include/asm/delay.h

@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_DELAY_H
+#define _ASM_DELAY_H
+
+#include <linux/param.h>
+
+extern void __delay(unsigned long loops);
+extern void __ndelay(unsigned long ns);
+extern void __udelay(unsigned long us);
+
+#define ndelay(ns) __ndelay(ns)
+#define udelay(us) __udelay(us)
+
+/* make sure "usecs *= ..." in udelay do not overflow. */
+#if HZ >= 1000
+#define MAX_UDELAY_MS  1
+#elif HZ <= 200
+#define MAX_UDELAY_MS  5
+#else
+#define MAX_UDELAY_MS  (1000 / HZ)
+#endif
+
+#endif /* _ASM_DELAY_H */

diff --git a/arch/loongarch/include/asm/string.h b/arch/loongarch/include/asm/string.h
new file mode 100644
index 000000000000..7b29cc9c70aa
--- /dev/null
+++ b/arch/loongarch/include/asm/string.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_STRING_H
+#define _ASM_STRING_H
+
+#define __HAVE_ARCH_MEMSET
+extern void *memset(void *__s, int __c, size_t __count);
+
+#define __HAVE_ARCH_MEMCPY
+extern void *memcpy(void *__to, __const__ void *__from, size_t __n);
+
+#define __HAVE_ARCH_MEMMOVE
+extern void *memmove(void *__dest, __const__ void *__src, size_t __n);
+
+#endif /* _ASM_STRING_H */

diff --git a/arch/loongarch/lib/clear_user.S b/arch/loongarch/lib/clear_user.S
new file mode 100644
index 000000000000..b8168d22ac80
--- /dev/null
+++ b/arch/loongarch/lib/clear_user.S

@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/export.h>
+#include <asm/regdef.h>
+
+.macro fixup_ex from, to, offset, fix
+.if \fix
+       .section .fixup, "ax"
+\to:   addi.d  v0, a1, \offset
+       jr      ra
+       .previous
+.endif
+       .section __ex_table, "a"
+       PTR     \from\()b, \to\()b
+       .previous
+.endm
+
+/*
+ * unsigned long __clear_user(void *addr, size_t size)
+ *
+ * a0: addr
+ * a1: size
+ */
+SYM_FUNC_START(__clear_user)
+       beqz    a1, 2f
+
+1:     st.b    zero, a0, 0
+       addi.d  a0, a0, 1
+       addi.d  a1, a1, -1
+       bgt     a1, zero, 1b
+
+2:     move    v0, a1
+       jr      ra
+
+       fixup_ex 1, 3, 0, 1
+SYM_FUNC_END(__clear_user)
+
+EXPORT_SYMBOL(__clear_user)

diff --git a/arch/loongarch/lib/copy_user.S b/arch/loongarch/lib/copy_user.S
new file mode 100644
index 000000000000..43ed26304954
--- /dev/null
+++ b/arch/loongarch/lib/copy_user.S

@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/export.h>
+#include <asm/regdef.h>
+
+.macro fixup_ex from, to, offset, fix
+.if \fix
+       .section .fixup, "ax"
+\to:   addi.d  v0, a2, \offset
+       jr      ra
+       .previous
+.endif
+       .section __ex_table, "a"
+       PTR     \from\()b, \to\()b
+       .previous
+.endm
+
+/*
+ * unsigned long __copy_user(void *to, const void *from, size_t n)
+ *
+ * a0: to
+ * a1: from
+ * a2: n
+ */
+SYM_FUNC_START(__copy_user)
+       beqz    a2, 3f
+
+1:     ld.b    t0, a1, 0
+2:     st.b    t0, a0, 0
+       addi.d  a0, a0, 1
+       addi.d  a1, a1, 1
+       addi.d  a2, a2, -1
+       bgt     a2, zero, 1b
+
+3:     move    v0, a2
+       jr      ra
+
+       fixup_ex 1, 4, 0, 1
+       fixup_ex 2, 4, 0, 0
+SYM_FUNC_END(__copy_user)
+
+EXPORT_SYMBOL(__copy_user)

diff --git a/arch/loongarch/lib/delay.c b/arch/loongarch/lib/delay.c
new file mode 100644
index 000000000000..5d856694fcfe
--- /dev/null
+++ b/arch/loongarch/lib/delay.c

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/smp.h>
+#include <linux/timex.h>
+
+#include <asm/compiler.h>
+#include <asm/processor.h>
+
+void __delay(unsigned long cycles)
+{
+       u64 t0 = get_cycles();
+
+       while ((unsigned long)(get_cycles() - t0) < cycles)
+               cpu_relax();
+}
+EXPORT_SYMBOL(__delay);
+
+/*
+ * Division by multiplication: you don't have to worry about
+ * loss of precision.
+ *
+ * Use only for very small delays ( < 1 msec). Should probably use a
+ * lookup table, really, as the multiplications take much too long with
+ * short delays.  This is a "reasonable" implementation, though (and the
+ * first constant multiplications gets optimized away if the delay is
+ * a constant)
+ */
+
+void __udelay(unsigned long us)
+{
+       __delay((us * 0x000010c7ull * HZ * lpj_fine) >> 32);
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long ns)
+{
+       __delay((ns * 0x00000005ull * HZ * lpj_fine) >> 32);
+}
+EXPORT_SYMBOL(__ndelay);

diff --git a/arch/loongarch/lib/dump_tlb.c b/arch/loongarch/lib/dump_tlb.c
new file mode 100644
index 000000000000..cda2c6bc7f09
--- /dev/null
+++ b/arch/loongarch/lib/dump_tlb.c

@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 1994, 1995 by Waldorf Electronics, written by Ralf Baechle.
+ * Copyright (C) 1999 by Silicon Graphics, Inc.
+ */
+#include <linux/kernel.h>
+#include <linux/mm.h>
+
+#include <asm/loongarch.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/tlb.h>
+
+void dump_tlb_regs(void)
+{
+       const int field = 2 * sizeof(unsigned long);
+
+       pr_info("Index    : %0x\n", read_csr_tlbidx());
+       pr_info("PageSize : %0x\n", read_csr_pagesize());
+       pr_info("EntryHi  : %0*llx\n", field, read_csr_entryhi());
+       pr_info("EntryLo0 : %0*llx\n", field, read_csr_entrylo0());
+       pr_info("EntryLo1 : %0*llx\n", field, read_csr_entrylo1());
+}
+
+static void dump_tlb(int first, int last)
+{
+       unsigned long s_entryhi, entryhi, asid;
+       unsigned long long entrylo0, entrylo1, pa;
+       unsigned int index;
+       unsigned int s_index, s_asid;
+       unsigned int pagesize, c0, c1, i;
+       unsigned long asidmask = cpu_asid_mask(&current_cpu_data);
+       int pwidth = 11;
+       int vwidth = 11;
+       int asidwidth = DIV_ROUND_UP(ilog2(asidmask) + 1, 4);
+
+       s_entryhi = read_csr_entryhi();
+       s_index = read_csr_tlbidx();
+       s_asid = read_csr_asid();
+
+       for (i = first; i <= last; i++) {
+               write_csr_index(i);
+               tlb_read();
+               pagesize = read_csr_pagesize();
+               entryhi  = read_csr_entryhi();
+               entrylo0 = read_csr_entrylo0();
+               entrylo1 = read_csr_entrylo1();
+               index = read_csr_tlbidx();
+               asid = read_csr_asid();
+
+               /* EHINV bit marks entire entry as invalid */
+               if (index & CSR_TLBIDX_EHINV)
+                       continue;
+               /*
+                * ASID takes effect in absence of G (global) bit.
+                */
+               if (!((entrylo0 | entrylo1) & ENTRYLO_G) &&
+                   asid != s_asid)
+                       continue;
+
+               /*
+                * Only print entries in use
+                */
+               pr_info("Index: %2d pgsize=%x ", i, (1 << pagesize));
+
+               c0 = (entrylo0 & ENTRYLO_C) >> ENTRYLO_C_SHIFT;
+               c1 = (entrylo1 & ENTRYLO_C) >> ENTRYLO_C_SHIFT;
+
+               pr_cont("va=%0*lx asid=%0*lx",
+                       vwidth, (entryhi & ~0x1fffUL), asidwidth, asid & asidmask);
+
+               /* NR/NX are in awkward places, so mask them off separately */
+               pa = entrylo0 & ~(ENTRYLO_NR | ENTRYLO_NX);
+               pa = pa & PAGE_MASK;
+               pr_cont("\n\t[");
+               pr_cont("ri=%d xi=%d ",
+                       (entrylo0 & ENTRYLO_NR) ? 1 : 0,
+                       (entrylo0 & ENTRYLO_NX) ? 1 : 0);
+               pr_cont("pa=%0*llx c=%d d=%d v=%d g=%d plv=%lld] [",
+                       pwidth, pa, c0,
+                       (entrylo0 & ENTRYLO_D) ? 1 : 0,
+                       (entrylo0 & ENTRYLO_V) ? 1 : 0,
+                       (entrylo0 & ENTRYLO_G) ? 1 : 0,
+                       (entrylo0 & ENTRYLO_PLV) >> ENTRYLO_PLV_SHIFT);
+               /* NR/NX are in awkward places, so mask them off separately */
+               pa = entrylo1 & ~(ENTRYLO_NR | ENTRYLO_NX);
+               pa = pa & PAGE_MASK;
+               pr_cont("ri=%d xi=%d ",
+                       (entrylo1 & ENTRYLO_NR) ? 1 : 0,
+                       (entrylo1 & ENTRYLO_NX) ? 1 : 0);
+               pr_cont("pa=%0*llx c=%d d=%d v=%d g=%d plv=%lld]\n",
+                       pwidth, pa, c1,
+                       (entrylo1 & ENTRYLO_D) ? 1 : 0,
+                       (entrylo1 & ENTRYLO_V) ? 1 : 0,
+                       (entrylo1 & ENTRYLO_G) ? 1 : 0,
+                       (entrylo1 & ENTRYLO_PLV) >> ENTRYLO_PLV_SHIFT);
+       }
+       pr_info("\n");
+
+       write_csr_entryhi(s_entryhi);
+       write_csr_tlbidx(s_index);
+       write_csr_asid(s_asid);
+}
+
+void dump_tlb_all(void)
+{
+       dump_tlb(0, current_cpu_data.tlbsize - 1);
+}

diff --git a/arch/loongarch/lib/memcpy.S b/arch/loongarch/lib/memcpy.S
new file mode 100644
index 000000000000..d53f1148d26b
--- /dev/null
+++ b/arch/loongarch/lib/memcpy.S

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <asm/asmmacro.h>
+#include <asm/export.h>
+#include <asm/regdef.h>
+
+/*
+ * void *memcpy(void *dst, const void *src, size_t n)
+ *
+ * a0: dst
+ * a1: src
+ * a2: n
+ */
+SYM_FUNC_START(memcpy)
+       move    a3, a0
+       beqz    a2, 2f
+
+1:     ld.b    t0, a1, 0
+       st.b    t0, a0, 0
+       addi.d  a0, a0, 1
+       addi.d  a1, a1, 1
+       addi.d  a2, a2, -1
+       bgt     a2, zero, 1b
+
+2:     move    v0, a3
+       jr      ra
+SYM_FUNC_END(memcpy)
+
+EXPORT_SYMBOL(memcpy)

diff --git a/arch/loongarch/lib/memmove.S b/arch/loongarch/lib/memmove.S
new file mode 100644
index 000000000000..18907d83a83b
--- /dev/null
+++ b/arch/loongarch/lib/memmove.S

@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <asm/asmmacro.h>
+#include <asm/export.h>
+#include <asm/regdef.h>
+
+/*
+ * void *rmemcpy(void *dst, const void *src, size_t n)
+ *
+ * a0: dst
+ * a1: src
+ * a2: n
+ */
+SYM_FUNC_START(rmemcpy)
+       move    a3, a0
+       beqz    a2, 2f
+
+       add.d   a0, a0, a2
+       add.d   a1, a1, a2
+
+1:     ld.b    t0, a1, -1
+       st.b    t0, a0, -1
+       addi.d  a0, a0, -1
+       addi.d  a1, a1, -1
+       addi.d  a2, a2, -1
+       bgt     a2, zero, 1b
+
+2:     move    v0, a3
+       jr      ra
+SYM_FUNC_END(rmemcpy)

Why not directly use:

I want to use "alternative" to provide multi-versions, but now I can
use the generic implemation.

Huacai

lib/string.c:
#ifndef __HAVE_ARCH_MEMCPY
/**
 * memcpy - Copy one area of memory to another
 * @dest: Where to copy to
 * @src: Where to copy from
 * @count: The size of the area.
 *
 * You should not use this function to access IO space, use memcpy_toio()
 * or memcpy_fromio() instead.
 */
void *memcpy(void *dest, const void *src, size_t count)
{
        char *tmp = dest;
        const char *s = src;

        while (count--)
                *tmp++ = *s++;
        return dest;
}
EXPORT_SYMBOL(memcpy);
#endif

Do you want to try a C's string implementation?
https://lore.kernel.org/linux-csky/202204051450.UN2k1raL-lkp@intel.com/T/#Z2e.:..:20220404142354.2792428-1-guoren::40kernel.org:1arch:csky:lib:string.c (local)

quoted

+
+SYM_FUNC_START(memmove)
+       blt     a0, a1, 1f      /* dst < src, memcpy */
+       blt     a1, a0, 2f      /* src < dst, rmemcpy */
+       jr      ra              /* dst == src, return */
+
+1:     b       memcpy
+
+2:     b       rmemcpy
+SYM_FUNC_END(memmove)
+
+EXPORT_SYMBOL(memmove)

diff --git a/arch/loongarch/lib/memset.S b/arch/loongarch/lib/memset.S
new file mode 100644
index 000000000000..3fc3e7da5263
--- /dev/null
+++ b/arch/loongarch/lib/memset.S

@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <asm/asmmacro.h>
+#include <asm/export.h>
+#include <asm/regdef.h>
+
+/*
+ * void *memset(void *s, int c, size_t n)
+ *
+ * a0: s
+ * a1: c
+ * a2: n
+ */
+SYM_FUNC_START(memset)
+       move    a3, a0
+       beqz    a2, 2f
+
+1:     st.b    a1, a0, 0
+       addi.d  a0, a0, 1
+       addi.d  a2, a2, -1
+       bgt     a2, zero, 1b
+
+2:     move    v0, a3
+       jr      ra
+SYM_FUNC_END(memset)
+
+EXPORT_SYMBOL(memset)
--

2.27.0

--
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/