[PATCH 3/5] hw/mem/cxl_type3: CDAT pre-allocate and check resources prior to work

[Gregory Price <gourry.memverge@gmail.com>]

Makes the size of the allocated cdat table static (6 entries),
flattens the code, and reduces the number of exit conditions

Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
 hw/mem/cxl_type3.c | 52 ++++++++++++++++++++--------------------------
 1 file changed, 22 insertions(+), 30 deletions(-)

diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index 43b2b9e041..0e0ea70387 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -17,6 +17,7 @@
 #include "hw/pci/msix.h"
 
 #define DWORD_BYTE 4
+#define CT3_CDAT_SUBTABLE_SIZE 6
 
 static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
                                 void *priv)
@@ -25,7 +26,6 @@ static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
     g_autofree CDATDslbis *dslbis_nonvolatile = NULL;
     g_autofree CDATDsemts *dsemts_nonvolatile = NULL;
     CXLType3Dev *ct3d = priv;
-    int len = 0;
     int i = 0;
     int next_dsmad_handle = 0;
     int nonvolatile_dsmad = -1;
@@ -33,7 +33,7 @@ static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
     MemoryRegion *mr;
 
     if (!ct3d->hostmem) {
-        return len;
+        return 0;
     }
 
     mr = host_memory_backend_get_memory(ct3d->hostmem);
@@ -41,11 +41,22 @@ static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
         return -EINVAL;
     }
 
+    *cdat_table = g_malloc0(CT3_CDAT_SUBTABLE_SIZE * sizeof(*cdat_table));
+    if (!*cdat_table) {
+        return -ENOMEM;
+    }
+
     /* Non volatile aspects */
     dsmas_nonvolatile = g_malloc(sizeof(*dsmas_nonvolatile));
-    if (!dsmas_nonvolatile) {
+    dslbis_nonvolatile =
+        g_malloc(sizeof(*dslbis_nonvolatile) * dslbis_nonvolatile_num);
+    dsemts_nonvolatile = g_malloc(sizeof(*dsemts_nonvolatile));
+    if (!dsmas_nonvolatile || !dslbis_nonvolatile || !dsemts_nonvolatile) {
+        g_free(*cdat_table);
+        *cdat_table = NULL;
         return -ENOMEM;
     }
+
     nonvolatile_dsmad = next_dsmad_handle++;
     *dsmas_nonvolatile = (CDATDsmas) {
         .header = {
@@ -57,15 +68,8 @@ static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
         .DPA_base = 0,
         .DPA_length = int128_get64(mr->size),
     };
-    len++;
 
     /* For now, no memory side cache, plausiblish numbers */
-    dslbis_nonvolatile =
-        g_malloc(sizeof(*dslbis_nonvolatile) * dslbis_nonvolatile_num);
-    if (!dslbis_nonvolatile) {
-        return -ENOMEM;
-    }
-
     dslbis_nonvolatile[0] = (CDATDslbis) {
         .header = {
             .type = CDAT_TYPE_DSLBIS,
@@ -77,7 +81,6 @@ static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
         .entry_base_unit = 10000, /* 10ns base */
         .entry[0] = 15, /* 150ns */
     };
-    len++;
 
     dslbis_nonvolatile[1] = (CDATDslbis) {
         .header = {
@@ -90,7 +93,6 @@ static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
         .entry_base_unit = 10000,
         .entry[0] = 25, /* 250ns */
     };
-    len++;
 
     dslbis_nonvolatile[2] = (CDATDslbis) {
         .header = {
@@ -103,7 +105,6 @@ static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
         .entry_base_unit = 1000, /* GB/s */
         .entry[0] = 16,
     };
-    len++;
 
     dslbis_nonvolatile[3] = (CDATDslbis) {
         .header = {
@@ -116,9 +117,7 @@ static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
         .entry_base_unit = 1000, /* GB/s */
         .entry[0] = 16,
     };
-    len++;
 
-    dsemts_nonvolatile = g_malloc(sizeof(*dsemts_nonvolatile));
     *dsemts_nonvolatile = (CDATDsemts) {
         .header = {
             .type = CDAT_TYPE_DSEMTS,
@@ -130,26 +129,19 @@ static int ct3_build_cdat_table(CDATSubHeader ***cdat_table,
         .DPA_offset = 0,
         .DPA_length = int128_get64(mr->size),
     };
-    len++;
 
-    *cdat_table = g_malloc0(len * sizeof(*cdat_table));
     /* Header always at start of structure */
-    if (dsmas_nonvolatile) {
-        (*cdat_table)[i++] = g_steal_pointer(&dsmas_nonvolatile);
-    }
-    if (dslbis_nonvolatile) {
-        CDATDslbis *dslbis = g_steal_pointer(&dslbis_nonvolatile);
-        int j;
+    (*cdat_table)[i++] = g_steal_pointer(&dsmas_nonvolatile);
 
-        for (j = 0; j < dslbis_nonvolatile_num; j++) {
-            (*cdat_table)[i++] = (CDATSubHeader *)&dslbis[j];
-        }
-    }
-    if (dsemts_nonvolatile) {
-        (*cdat_table)[i++] = g_steal_pointer(&dsemts_nonvolatile);
+    CDATDslbis *dslbis = g_steal_pointer(&dslbis_nonvolatile);
+    int j;
+    for (j = 0; j < dslbis_nonvolatile_num; j++) {
+        (*cdat_table)[i++] = (CDATSubHeader *)&dslbis[j];
     }
 
-    return len;
+    (*cdat_table)[i++] = g_steal_pointer(&dsemts_nonvolatile);
+
+    return CT3_CDAT_SUBTABLE_SIZE;
 }
 
 static void ct3_free_cdat_table(CDATSubHeader **cdat_table, int num, void *priv)
-- 
2.37.3