target/arm/arm-semi: Factor out implementation of SYS_FLEN

Factor out the implementation of SYS_FLEN via the new
function tables.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-13-peter.maydell@linaro.org

target/arm/arm-semi.c

@@ -391,6 +391,7 @@ typedef uint32_t sys_readfn(ARMCPU *cpu, GuestFD *gf,
 typedef uint32_t sys_isattyfn(ARMCPU *cpu, GuestFD *gf);
 typedef uint32_t sys_seekfn(ARMCPU *cpu, GuestFD *gf,
                             target_ulong offset);
+typedef uint32_t sys_flenfn(ARMCPU *cpu, GuestFD *gf);
 
 static uint32_t host_closefn(ARMCPU *cpu, GuestFD *gf)
 {
@@ -454,6 +455,17 @@ static uint32_t host_seekfn(ARMCPU *cpu, GuestFD *gf, target_ulong offset)
     return 0;
 }
 
+static uint32_t host_flenfn(ARMCPU *cpu, GuestFD *gf)
+{
+    CPUARMState *env = &cpu->env;
+    struct stat buf;
+    uint32_t ret = set_swi_errno(env, fstat(gf->hostfd, &buf));
+    if (ret == (uint32_t)-1) {
+        return -1;
+    }
+    return buf.st_size;
+}
+
 static uint32_t gdb_closefn(ARMCPU *cpu, GuestFD *gf)
 {
     return arm_gdb_syscall(cpu, arm_semi_cb, "close,%x", gf->hostfd);
@@ -486,12 +498,19 @@ static uint32_t gdb_seekfn(ARMCPU *cpu, GuestFD *gf, target_ulong offset)
                            gf->hostfd, offset);
 }
 
+static uint32_t gdb_flenfn(ARMCPU *cpu, GuestFD *gf)
+{
+    return arm_gdb_syscall(cpu, arm_semi_flen_cb, "fstat,%x,%x",
+                           gf->hostfd, arm_flen_buf(cpu));
+}
+
 typedef struct GuestFDFunctions {
     sys_closefn *closefn;
     sys_writefn *writefn;
     sys_readfn *readfn;
     sys_isattyfn *isattyfn;
     sys_seekfn *seekfn;
+    sys_flenfn *flenfn;
 } GuestFDFunctions;
 
 static const GuestFDFunctions guestfd_fns[] = {
@@ -501,13 +520,15 @@ static const GuestFDFunctions guestfd_fns[] = {
         .readfn = host_readfn,
         .isattyfn = host_isattyfn,
         .seekfn = host_seekfn,
+        .flenfn = host_flenfn,
     },
     [GuestFDGDB] = {
         .closefn = gdb_closefn,
         .writefn = gdb_writefn,
         .readfn = gdb_readfn,
         .isattyfn = gdb_isattyfn,
         .seekfn = gdb_seekfn,
+        .flenfn = gdb_flenfn,
     },
 };
 
@@ -687,16 +708,7 @@ target_ulong do_arm_semihosting(CPUARMState *env)
             return set_swi_errno(env, -1);
         }
 
-        if (use_gdb_syscalls()) {
-            return arm_gdb_syscall(cpu, arm_semi_flen_cb, "fstat,%x,%x",
-                                   gf->hostfd, arm_flen_buf(cpu));
-        } else {
-            struct stat buf;
-            ret = set_swi_errno(env, fstat(gf->hostfd, &buf));
-            if (ret == (uint32_t)-1)
-                return -1;
-            return buf.st_size;
-        }
+        return guestfd_fns[gf->type].flenfn(cpu, gf);
     case TARGET_SYS_TMPNAM:
         qemu_log_mask(LOG_UNIMP, "%s: SYS_TMPNAM not implemented", __func__);
         return -1;