MIPS: Fix little endian microMIPS MSA encodings

When the toolchain doesn't support MSA we encode MSA instructions
explicitly in assembly. Unfortunately we use .word for both MIPS and
microMIPS encodings which is wrong, since 32-bit microMIPS instructions
are made up from a pair of halfwords.

- The most significant halfword always comes first, so for little endian
  builds the halves will be emitted in the wrong order.

- 32-bit alignment isn't guaranteed, so the assembler may insert a
  16-bit nop instruction to pad the instruction stream to a 32-bit
  boundary.

Use the new instruction encoding macros to encode microMIPS MSA
instructions correctly.

Fixes: d96cc3d1ec5d ("MIPS: Add microMIPS MSA support.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <Paul.Burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13312/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/include/asm/asmmacro.h b/arch/mips/include/asm/asmmacro.h
index 6741673..56584a6 100644 (file)
--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -19,6 +19,28 @@
 #include <asm/asmmacro-64.h>
 #endif
 
+/*
+ * Helper macros for generating raw instruction encodings.
+ */
+#ifdef CONFIG_CPU_MICROMIPS
+       .macro  insn32_if_mm enc
+       .insn
+       .hword ((\enc) >> 16)
+       .hword ((\enc) & 0xffff)
+       .endm
+
+       .macro  insn_if_mips enc
+       .endm
+#else
+       .macro  insn32_if_mm enc
+       .endm
+
+       .macro  insn_if_mips enc
+       .insn
+       .word (\enc)
+       .endm
+#endif
+
 #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
        .macro  local_irq_enable reg=t0
        ei
@@ -341,38 +363,6 @@
        .endm
 #else
 
-#ifdef CONFIG_CPU_MICROMIPS
-#define CFC_MSA_INSN           0x587e0056
-#define CTC_MSA_INSN           0x583e0816
-#define LDB_MSA_INSN           0x58000807
-#define LDH_MSA_INSN           0x58000817
-#define LDW_MSA_INSN           0x58000827
-#define LDD_MSA_INSN           0x58000837
-#define STB_MSA_INSN           0x5800080f
-#define STH_MSA_INSN           0x5800081f
-#define STW_MSA_INSN           0x5800082f
-#define STD_MSA_INSN           0x5800083f
-#define COPY_SW_MSA_INSN       0x58b00056
-#define COPY_SD_MSA_INSN       0x58b80056
-#define INSERT_W_MSA_INSN      0x59300816
-#define INSERT_D_MSA_INSN      0x59380816
-#else
-#define CFC_MSA_INSN           0x787e0059
-#define CTC_MSA_INSN           0x783e0819
-#define LDB_MSA_INSN           0x78000820
-#define LDH_MSA_INSN           0x78000821
-#define LDW_MSA_INSN           0x78000822
-#define LDD_MSA_INSN           0x78000823
-#define STB_MSA_INSN           0x78000824
-#define STH_MSA_INSN           0x78000825
-#define STW_MSA_INSN           0x78000826
-#define STD_MSA_INSN           0x78000827
-#define COPY_SW_MSA_INSN       0x78b00059
-#define COPY_SD_MSA_INSN       0x78b80059
-#define INSERT_W_MSA_INSN      0x79300819
-#define INSERT_D_MSA_INSN      0x79380819
-#endif
-
        /*
         * Temporary until all toolchains in use include MSA support.
         */
@@ -380,8 +370,8 @@
        .set    push
        .set    noat
        SET_HARDFLOAT
-       .insn
-       .word   CFC_MSA_INSN | (\cs << 11)
+       insn_if_mips 0x787e0059 | (\cs << 11)
+       insn32_if_mm 0x587e0056 | (\cs << 11)
        move    \rd, $1
        .set    pop
        .endm
@@ -391,7 +381,8 @@
        .set    noat
        SET_HARDFLOAT
        move    $1, \rs
-       .word   CTC_MSA_INSN | (\cd << 6)
+       insn_if_mips 0x783e0819 | (\cd << 6)
+       insn32_if_mm 0x583e0816 | (\cd << 6)
        .set    pop
        .endm
 
@@ -400,7 +391,8 @@
        .set    noat
        SET_HARDFLOAT
        PTR_ADDU $1, \base, \off
-       .word   LDB_MSA_INSN | (\wd << 6)
+       insn_if_mips 0x78000820 | (\wd << 6)
+       insn32_if_mm 0x58000807 | (\wd << 6)
        .set    pop
        .endm
 
@@ -409,7 +401,8 @@
        .set    noat
        SET_HARDFLOAT
        PTR_ADDU $1, \base, \off
-       .word   LDH_MSA_INSN | (\wd << 6)
+       insn_if_mips 0x78000821 | (\wd << 6)
+       insn32_if_mm 0x58000817 | (\wd << 6)
        .set    pop
        .endm
 
@@ -418,7 +411,8 @@
        .set    noat
        SET_HARDFLOAT
        PTR_ADDU $1, \base, \off
-       .word   LDW_MSA_INSN | (\wd << 6)
+       insn_if_mips 0x78000822 | (\wd << 6)
+       insn32_if_mm 0x58000827 | (\wd << 6)
        .set    pop
        .endm
 
@@ -427,7 +421,8 @@
        .set    noat
        SET_HARDFLOAT
        PTR_ADDU $1, \base, \off
-       .word   LDD_MSA_INSN | (\wd << 6)
+       insn_if_mips 0x78000823 | (\wd << 6)
+       insn32_if_mm 0x58000837 | (\wd << 6)
        .set    pop
        .endm
 
@@ -436,7 +431,8 @@
        .set    noat
        SET_HARDFLOAT
        PTR_ADDU $1, \base, \off
-       .word   STB_MSA_INSN | (\wd << 6)
+       insn_if_mips 0x78000824 | (\wd << 6)
+       insn32_if_mm 0x5800080f | (\wd << 6)
        .set    pop
        .endm
 
@@ -445,7 +441,8 @@
        .set    noat
        SET_HARDFLOAT
        PTR_ADDU $1, \base, \off
-       .word   STH_MSA_INSN | (\wd << 6)
+       insn_if_mips 0x78000825 | (\wd << 6)
+       insn32_if_mm 0x5800081f | (\wd << 6)
        .set    pop
        .endm
 
@@ -454,7 +451,8 @@
        .set    noat
        SET_HARDFLOAT
        PTR_ADDU $1, \base, \off
-       .word   STW_MSA_INSN | (\wd << 6)
+       insn_if_mips 0x78000826 | (\wd << 6)
+       insn32_if_mm 0x5800082f | (\wd << 6)
        .set    pop
        .endm
 
@@ -463,7 +461,8 @@
        .set    noat
        SET_HARDFLOAT
        PTR_ADDU $1, \base, \off
-       .word   STD_MSA_INSN | (\wd << 6)
+       insn_if_mips 0x78000827 | (\wd << 6)
+       insn32_if_mm 0x5800083f | (\wd << 6)
        .set    pop
        .endm
 
@@ -471,8 +470,8 @@
        .set    push
        .set    noat
        SET_HARDFLOAT
-       .insn
-       .word   COPY_SW_MSA_INSN | (\n << 16) | (\ws << 11)
+       insn_if_mips 0x78b00059 | (\n << 16) | (\ws << 11)
+       insn32_if_mm 0x58b00056 | (\n << 16) | (\ws << 11)
        .set    pop
        .endm
 
@@ -480,8 +479,8 @@
        .set    push
        .set    noat
        SET_HARDFLOAT
-       .insn
-       .word   COPY_SD_MSA_INSN | (\n << 16) | (\ws << 11)
+       insn_if_mips 0x78b80059 | (\n << 16) | (\ws << 11)
+       insn32_if_mm 0x58b80056 | (\n << 16) | (\ws << 11)
        .set    pop
        .endm
 
@@ -489,7 +488,8 @@
        .set    push
        .set    noat
        SET_HARDFLOAT
-       .word   INSERT_W_MSA_INSN | (\n << 16) | (\wd << 6)
+       insn_if_mips 0x79300819 | (\n << 16) | (\wd << 6)
+       insn32_if_mm 0x59300816 | (\n << 16) | (\wd << 6)
        .set    pop
        .endm
 
@@ -497,7 +497,8 @@
        .set    push
        .set    noat
        SET_HARDFLOAT
-       .word   INSERT_D_MSA_INSN | (\n << 16) | (\wd << 6)
+       insn_if_mips 0x79380819 | (\n << 16) | (\wd << 6)
+       insn32_if_mm 0x59380816 | (\n << 16) | (\wd << 6)
        .set    pop
        .endm
 #endif

diff --git a/arch/mips/include/asm/msa.h b/arch/mips/include/asm/msa.h
index 6e4effa..ddf496c 100644 (file)
--- a/arch/mips/include/asm/msa.h
+++ b/arch/mips/include/asm/msa.h
@@ -192,13 +192,6 @@ static inline void write_msa_##name(unsigned int val)              \
  * allow compilation with toolchains that do not support MSA. Once all
  * toolchains in use support MSA these can be removed.
  */
-#ifdef CONFIG_CPU_MICROMIPS
-#define CFC_MSA_INSN   0x587e0056
-#define CTC_MSA_INSN   0x583e0816
-#else
-#define CFC_MSA_INSN   0x787e0059
-#define CTC_MSA_INSN   0x783e0819
-#endif
 
 #define __BUILD_MSA_CTL_REG(name, cs)                          \
 static inline unsigned int read_msa_##name(void)               \
@@ -207,11 +200,12 @@ static inline unsigned int read_msa_##name(void)          \
        __asm__ __volatile__(                                   \
        "       .set    push\n"                                 \
        "       .set    noat\n"                                 \
-       "       .insn\n"                                        \
-       "       .word   %1 | (" #cs " << 11)\n"                 \
+       "       # cfcmsa $1, $%1\n"                             \
+       _ASM_INSN_IF_MIPS(0x787e0059 | %1 << 11)                \
+       _ASM_INSN32_IF_MM(0x587e0056 | %1 << 11)                \
        "       move    %0, $1\n"                               \
        "       .set    pop\n"                                  \
-       : "=r"(reg) : "i"(CFC_MSA_INSN));                       \
+       : "=r"(reg) : "i"(cs));                                 \
        return reg;                                             \
 }                                                              \
                                                                \
@@ -221,10 +215,11 @@ static inline void write_msa_##name(unsigned int val)             \
        "       .set    push\n"                                 \
        "       .set    noat\n"                                 \
        "       move    $1, %0\n"                               \
-       "       .insn\n"                                        \
-       "       .word   %1 | (" #cs " << 6)\n"                  \
+       "       # ctcmsa $%1, $1\n"                             \
+       _ASM_INSN_IF_MIPS(0x783e0819 | %1 << 6)                 \
+       _ASM_INSN32_IF_MM(0x583e0816 | %1 << 6)                 \
        "       .set    pop\n"                                  \
-       : : "r"(val), "i"(CTC_MSA_INSN));                       \
+       : : "r"(val), "i"(cs));                                 \
 }
 
 #endif /* !TOOLCHAIN_SUPPORTS_MSA */