2 files changed, 22 insertions, 0 deletions
diff --git a/compote.c b/compote.c
index 190aff6..49a3ea9 100644
--- a/compote.c
+++ b/compote.c
@@ -20,6 +20,7 @@
 #include <strings.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <string.h>
 #include <errno.h>
 #include <stdio.h>
 #include <fcntl.h>
@@ -96,6 +97,17 @@ int compote_mo_new(compote_context_t *ctx, compote_mo_t **mop, uint64_t nbytes)
 
     mo->foffset = arg.foffset;
     mo->nbytes = nbytes;
+
+    mo->ptr = mmap(NULL, mo->nbytes, PROT_READ | PROT_WRITE,
+                   MAP_SHARED, ctx->fd, mo->foffset);
+    if (mo->ptr == MAP_FAILED) {
+        mo->ptr = NULL;
+        compote_mo_del(ctx, &mo);
+        return -errno;
+    }
+
+    memset(mo->ptr, 0, mo->nbytes);
+
     *mop = mo;
     return 0;
 }
@@ -111,6 +123,7 @@ void compote_mo_del(compote_context_t *ctx, compote_mo_t **mop)
     }
 
     arg.foffset = mo->foffset;
+    munmap(mo->ptr, mo->nbytes);
     compote_context_ioctl(ctx, COMPOTE_IOCTL_MEM_FREE, &arg);
     free(mo);
 }
diff --git a/compote.h b/compote.h
index 4c5bb18..b7811fb 100644
--- a/compote.h
+++ b/compote.h
@@ -35,4 +35,13 @@ int compote_context_ioctl(compote_context_t *ctx, int command, void *arg);
 int compote_mo_new(compote_context_t *ctx, compote_mo_t **mop, uint64_t nbytes);
 void compote_mo_del(compote_context_t *ctx, compote_mo_t **mop);
 
+static inline uint64_t compote_mo_gpu_addr(compote_mo_t *mo)
+{
+    if (mo == NULL || mo->ptr == NULL) {
+        return -1UL;
+    }
+
+    return (unsigned long)mo->ptr;
+}
+
 #endif // COMPOTE_H