Changes in boot/arch/riscv64/src/ucb.c [ae8d7b0:8b6aa39] in mainline

File:

• boot/arch/riscv64/src/ucb.c (modified) (2 diffs)

boot/arch/riscv64/src/ucb.c

@@ -31 +31 @@
 #include <macros.h>
 
-volatile uint64_t tohost __attribute__((section(".htif")));
-volatile uint64_t fromhost __attribute__((section(".htif")));
-
-static void poll_fromhost()
-{
-        uint64_t val = fromhost;
-        if (!val)
-                return;
-        
-        fromhost = 0;
-}
-
 void htif_cmd(uint8_t device, uint8_t cmd, uint64_t payload)
 {
@@ -48 +36 @@
             (((uint64_t) cmd) << 48) |
             (payload & UINT64_C(0xffffffffffff));
+        uint64_t retval;
         
-        while (tohost)
-                poll_fromhost();
-        
-        tohost = val;
+        do {
+                asm volatile (
+                        "csrrw %[retval], " STRING(CSR_MTOHOST) ", %[val]\n"
+                        : [retval] "=r" (retval)
+                        : [val] "r" (val)
+                );
+        } while (retval != 0);
 }