diff options
Diffstat (limited to 'arch/riscv/lib/uaccess.S')
| -rw-r--r-- | arch/riscv/lib/uaccess.S | 121 |
1 files changed, 74 insertions, 47 deletions
diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index bceb0629e440..4efea1b3326c 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -1,26 +1,64 @@ #include <linux/linkage.h> -#include <asm-generic/export.h> +#include <linux/export.h> #include <asm/asm.h> +#include <asm/asm-extable.h> #include <asm/csr.h> +#include <asm/hwcap.h> +#include <asm/alternative-macros.h> .macro fixup op reg addr lbl 100: \op \reg, \addr - .section __ex_table,"a" - .balign RISCV_SZPTR - RISCV_PTR 100b, \lbl - .previous + _asm_extable 100b, \lbl .endm -ENTRY(__asm_copy_to_user) -ENTRY(__asm_copy_from_user) +SYM_FUNC_START(__asm_copy_to_user) +#ifdef CONFIG_RISCV_ISA_V + ALTERNATIVE("j fallback_scalar_usercopy", "nop", 0, RISCV_ISA_EXT_ZVE32X, CONFIG_RISCV_ISA_V) + REG_L t0, riscv_v_usercopy_threshold + bltu a2, t0, fallback_scalar_usercopy + li a3, 1 + tail enter_vector_usercopy +#endif +SYM_FUNC_END(__asm_copy_to_user) +EXPORT_SYMBOL(__asm_copy_to_user) +SYM_FUNC_ALIAS(__asm_copy_from_user, __asm_copy_to_user) +EXPORT_SYMBOL(__asm_copy_from_user) +SYM_FUNC_START(fallback_scalar_usercopy) /* Enable access to user memory */ - li t6, SR_SUM - csrs CSR_STATUS, t6 + li t6, SR_SUM + csrs CSR_STATUS, t6 + mv t6, ra + + call fallback_scalar_usercopy_sum_enabled + + /* Disable access to user memory */ + mv ra, t6 + li t6, SR_SUM + csrc CSR_STATUS, t6 + ret +SYM_FUNC_END(fallback_scalar_usercopy) + +SYM_FUNC_START(__asm_copy_to_user_sum_enabled) +#ifdef CONFIG_RISCV_ISA_V + ALTERNATIVE("j fallback_scalar_usercopy_sum_enabled", "nop", 0, RISCV_ISA_EXT_ZVE32X, CONFIG_RISCV_ISA_V) + REG_L t0, riscv_v_usercopy_threshold + bltu a2, t0, fallback_scalar_usercopy_sum_enabled + li a3, 0 + tail enter_vector_usercopy +#endif +SYM_FUNC_END(__asm_copy_to_user_sum_enabled) +SYM_FUNC_ALIAS(__asm_copy_from_user_sum_enabled, __asm_copy_to_user_sum_enabled) +EXPORT_SYMBOL(__asm_copy_from_user_sum_enabled) +EXPORT_SYMBOL(__asm_copy_to_user_sum_enabled) - /* Save for return value */ - mv t5, a2 +SYM_FUNC_START(fallback_scalar_usercopy_sum_enabled) + /* + * Save the terminal address which will be used to compute the number + * of bytes copied in case of a fixup exception. + */ + add t5, a0, a2 /* * Register allocation for code below: @@ -30,23 +68,23 @@ ENTRY(__asm_copy_from_user) * t0 - end of uncopied dst */ add t0, a0, a2 - bgtu a0, t0, 5f /* * Use byte copy only if too small. + * SZREG holds 4 for RV32 and 8 for RV64 */ - li a3, 8*SZREG /* size must be larger than size in word_copy */ + li a3, 9*SZREG-1 /* size must >= (word_copy stride + SZREG-1) */ bltu a2, a3, .Lbyte_copy_tail /* - * Copy first bytes until dst is align to word boundary. + * Copy first bytes until dst is aligned to word boundary. * a0 - start of dst * t1 - start of aligned dst */ addi t1, a0, SZREG-1 andi t1, t1, ~(SZREG-1) /* dst is already aligned, skip */ - beq a0, t1, .Lskip_first_bytes + beq a0, t1, .Lskip_align_dst 1: /* a5 - one byte for copying data */ fixup lb a5, 0(a1), 10f @@ -55,7 +93,7 @@ ENTRY(__asm_copy_from_user) addi a0, a0, 1 /* dst */ bltu a0, t1, 1b /* t1 - start of aligned dst */ -.Lskip_first_bytes: +.Lskip_align_dst: /* * Now dst is aligned. * Use shift-copy if src is misaligned. @@ -72,10 +110,9 @@ ENTRY(__asm_copy_from_user) * * a0 - start of aligned dst * a1 - start of aligned src - * a3 - a1 & mask:(SZREG-1) * t0 - end of aligned dst */ - addi t0, t0, -(8*SZREG-1) /* not to over run */ + addi t0, t0, -(8*SZREG) /* not to over run */ 2: fixup REG_L a4, 0(a1), 10f fixup REG_L a5, SZREG(a1), 10f @@ -95,9 +132,9 @@ ENTRY(__asm_copy_from_user) fixup REG_S t4, 7*SZREG(a0), 10f addi a0, a0, 8*SZREG addi a1, a1, 8*SZREG - bltu a0, t0, 2b + bleu a0, t0, 2b - addi t0, t0, 8*SZREG-1 /* revert to original value */ + addi t0, t0, 8*SZREG /* revert to original value */ j .Lbyte_copy_tail .Lshift_copy: @@ -107,7 +144,7 @@ ENTRY(__asm_copy_from_user) * For misaligned copy we still perform aligned word copy, but * we need to use the value fetched from the previous iteration and * do some shifts. - * This is safe because reading less than a word size. + * This is safe because reading is less than a word size. * * a0 - start of aligned dst * a1 - start of src @@ -117,7 +154,7 @@ ENTRY(__asm_copy_from_user) */ /* calculating aligned word boundary for dst */ andi t1, t0, ~(SZREG-1) - /* Converting unaligned src to aligned arc */ + /* Converting unaligned src to aligned src */ andi a1, a1, ~(SZREG-1) /* @@ -125,11 +162,11 @@ ENTRY(__asm_copy_from_user) * t3 - prev shift * t4 - current shift */ - slli t3, a3, LGREG + slli t3, a3, 3 /* converting bytes in a3 to bits */ li a5, SZREG*8 sub t4, a5, t3 - /* Load the first word to combine with seceond word */ + /* Load the first word to combine with second word */ fixup REG_L a5, 0(a1), 10f 3: @@ -161,7 +198,7 @@ ENTRY(__asm_copy_from_user) * a1 - start of remaining src * t0 - end of remaining dst */ - bgeu a0, t0, 5f + bgeu a0, t0, .Lout_copy_user /* check if end of copy */ 4: fixup lb a5, 0(a1), 10f addi a1, a1, 1 /* src */ @@ -169,18 +206,15 @@ ENTRY(__asm_copy_from_user) addi a0, a0, 1 /* dst */ bltu a0, t0, 4b /* t0 - end of dst */ -5: - /* Disable access to user memory */ - csrc CSR_STATUS, t6 +.Lout_copy_user: li a0, 0 ret -ENDPROC(__asm_copy_to_user) -ENDPROC(__asm_copy_from_user) -EXPORT_SYMBOL(__asm_copy_to_user) -EXPORT_SYMBOL(__asm_copy_from_user) - +10: + sub a0, t5, a0 + ret +SYM_FUNC_END(fallback_scalar_usercopy_sum_enabled) -ENTRY(__clear_user) +SYM_FUNC_START(__clear_user) /* Enable access to user memory */ li t6, SR_SUM @@ -219,19 +253,12 @@ ENTRY(__clear_user) addi a0, a0, 1 bltu a0, a3, 5b j 3b -ENDPROC(__clear_user) -EXPORT_SYMBOL(__clear_user) - .section .fixup,"ax" - .balign 4 - /* Fixup code for __copy_user(10) and __clear_user(11) */ -10: - /* Disable access to user memory */ - csrs CSR_STATUS, t6 - mv a0, t5 - ret + /* Exception fixup code */ 11: - csrs CSR_STATUS, t6 - mv a0, a1 + /* Disable access to user memory */ + csrc CSR_STATUS, t6 + sub a0, a3, a0 ret - .previous +SYM_FUNC_END(__clear_user) +EXPORT_SYMBOL(__clear_user) |