Blackfin SPORT UART: rewrite inline assembly

Hopefuly the new version is easier to read, but in the process it declares
proper clobber lists and better constraints so that GCC can do a better
job at allocating free registers.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 29 insertions, 25 deletions

diff --git a/drivers/serial/bfin_sport_uart.c b/drivers/serial/bfin_sport_uart.c
index 6687ccd422b7..34b4ae0fe760 100644
--- a/drivers/serial/bfin_sport_uart.c
+++ b/drivers/serial/bfin_sport_uart.c
@@ -101,15 +101,16 @@ static inline void tx_one_byte(struct sport_uart_port *up, unsigned int value)
 {
         pr_debug("%s value:%x\n", __func__, value);
         /* Place a Start and Stop bit */
-        __asm__ volatile (
-                "R2 = b#01111111100;\n\t"
-                "R3 = b#10000000001;\n\t"
-                "%0 <<= 2;\n\t"
-                "%0 = %0 & R2;\n\t"
-                "%0 = %0 | R3;\n\t"
-                :"=r"(value)
-                :"0"(value)
-                :"R2", "R3");
+        __asm__ __volatile__ (
+                "R2 = b#01111111100;"
+                "R3 = b#10000000001;"
+                "%0 <<= 2;"
+                "%0 = %0 & R2;"
+                "%0 = %0 | R3;"
+                : "=d"(value)
+                : "d"(value)
+                : "ASTAT", "R2", "R3"
+        );
         pr_debug("%s value:%x\n", __func__, value);
 
         SPORT_PUT_TX(up, value);
@@ -118,27 +119,30 @@ static inline void tx_one_byte(struct sport_uart_port *up, unsigned int value)
 static inline unsigned int rx_one_byte(struct sport_uart_port *up)
 {
         unsigned int value, extract;
+        u32 tmp_mask1, tmp_mask2, tmp_shift, tmp;
 
         value = SPORT_GET_RX32(up);
         pr_debug("%s value:%x\n", __func__, value);
 
         /* Extract 8 bits data */
-        __asm__ volatile (
-                "R5 = 0;\n\t"
-                "P0 = 8;\n\t"
-                "R1 = 0x1801(Z);\n\t"
-                "R3 = 0x0300(Z);\n\t"
-                "R4 = 0;\n\t"
-                "LSETUP(loop_s, loop_e) LC0 = P0;\nloop_s:\t"
-                "R2 = extract(%1, R1.L)(Z);\n\t"
-                "R2 <<= R4;\n\t"
-                "R5 = R5 | R2;\n\t"
-                "R1 = R1 - R3;\nloop_e:\t"
-                "R4 += 1;\n\t"
-                "%0 = R5;\n\t"
-                :"=r"(extract)
-                :"r"(value)
-                :"P0", "R1", "R2","R3","R4", "R5");
+        __asm__ __volatile__ (
+                "%[extr] = 0;"
+                "%[mask1] = 0x1801(Z);"
+                "%[mask2] = 0x0300(Z);"
+                "%[shift] = 0;"
+                "LSETUP(.Lloop_s, .Lloop_e) LC0 = %[lc];"
+                ".Lloop_s:"
+                "%[tmp] = extract(%[val], %[mask1].L)(Z);"
+                "%[tmp] <<= %[shift];"
+                "%[extr] = %[extr] | %[tmp];"
+                "%[mask1] = %[mask1] - %[mask2];"
+                ".Lloop_e:"
+                "%[shift] += 1;"
+                : [val]"=d"(value), [extr]"=d"(extract), [shift]"=d"(tmp_shift), [tmp]"=d"(tmp),
+                  [mask1]"=d"(tmp_mask1), [mask2]"=d"(tmp_mask2)
+                : "d"(value), [lc]"a"(8)
+                : "ASTAT", "LB0", "LC0", "LT0"
+        );
 
         pr_debug("      extract:%x\n", extract);
         return extract;