arc: libgloss: Introduce hostlink interface

[newlib-cygwin.git] / libgloss / arc / hl / hl_read.c

diff --git a/libgloss/arc/hl/hl_read.c b/libgloss/arc/hl/hl_read.c
new file mode 100644 (file)
index 0000000..584df1c
--- /dev/null
+++ b/libgloss/arc/hl/hl_read.c
@@ -0,0 +1,105 @@
+/*
+ * hl_read.c -- provide _read().
+ *
+ * Copyright (c) 2024 Synopsys Inc.
+ *
+ * The authors hereby grant permission to use, copy, modify, distribute,
+ * and license this software and its documentation for any purpose, provided
+ * that existing copyright notices are retained in all copies and that this
+ * notice is included verbatim in any distributions. No written agreement,
+ * license, or royalty fee is required for any of the authorized uses.
+ * Modifications to this software may be copyrighted by their authors
+ * and need not follow the licensing terms described here, provided that
+ * the new terms are clearly indicated on the first page of each file where
+ * they apply.
+ *
+ */
+
+#include <errno.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <unistd.h>
+
+#include "hl_toolchain.h"
+#include "hl_api.h"
+
+
+/* Read one chunk.  Implements HL_SYSCALL_READ.  */
+static ssize_t
+_hl_read (int fd, void *buf, size_t count)
+{
+  ssize_t ret;
+  int32_t hl_n;
+  uint32_t host_errno;
+  volatile __uncached char *p;
+
+  p = _hl_message (HL_SYSCALL_READ, "ii:i",
+                  (uint32_t) fd,      /* i */
+                  (uint32_t) count,   /* i */
+                  (uint32_t *) &hl_n  /* :i */);
+
+  if (p == NULL)
+    {
+      errno = ETIMEDOUT;
+      ret = -1;
+    }
+  else if (hl_n < 0)
+    {
+      p = _hl_unpack_int (p, &host_errno);
+      errno = p == NULL ? EIO : host_errno;
+      ret = -1;
+    }
+  else
+    {
+      uint32_t n;
+
+      p = _hl_unpack_ptr (p, buf, &n);
+      ret = n;
+
+      if (p == NULL || n != (uint32_t) hl_n)
+       {
+         errno = EIO;
+         ret = -1;
+       }
+    }
+
+  _hl_delete ();
+
+  return ret;
+}
+
+ssize_t
+_read (int fd, void *buf, size_t count)
+{
+  const uint32_t hl_iochunk = _hl_iochunk_size ();
+  size_t to_read = count;
+  size_t offset = 0;
+  ssize_t ret = 0;
+
+  while (to_read > hl_iochunk)
+    {
+      ret = _hl_read (fd, (char *) buf + offset, hl_iochunk);
+
+      if (ret < 0)
+       return ret;
+
+      offset += ret;
+
+      if (ret != (ssize_t) hl_iochunk)
+       return offset;
+
+      to_read -= hl_iochunk;
+    }
+
+  if (to_read)
+    {
+      ret = _hl_read (fd, (char *) buf + offset, to_read);
+
+      if (ret < 0)
+       return ret;
+
+      ret += offset;
+    }
+
+  return ret;
+}