cbmem: Add initial allocation support

Add support to allocate a region just below CBMEM root.  This region is
reserved for FSP 1.1 to use for its stack and variables.

BRANCH=none
BUG=None
TEST=Build and run on Braswell

Change-Id: I1d4b36ab366e6f8e036335c56c1756f2dfaab3f5
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: http://review.coreboot.org/10148
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/include/cbmem.h

@@ -146,12 +146,30 @@ struct cbmem_entry;
  */
 
 #define DYN_CBMEM_ALIGN_SIZE (4096)
+#define CBMEM_ROOT_SIZE      DYN_CBMEM_ALIGN_SIZE
+
+/* The root region is at least DYN_CBMEM_ALIGN_SIZE . */
+#define CBMEM_ROOT_MIN_SIZE DYN_CBMEM_ALIGN_SIZE
+#define CBMEM_LG_ALIGN CBMEM_ROOT_MIN_SIZE
+
+/* Small allocation parameters. */
+#define CBMEM_SM_ROOT_SIZE 1024
+#define CBMEM_SM_ALIGN 32
+
+/* Determine the size for CBMEM root and the small allocations */
+static inline size_t cbmem_overhead_size(void)
+{
+   return 2 * CBMEM_ROOT_MIN_SIZE;
+}
 
 /* By default cbmem is attempted to be recovered. Returns 0 if cbmem was
  * recovered or 1 if cbmem had to be reinitialized. */
 int cbmem_initialize(void);
+int cbmem_initialize_id_size(u32 id, u64 size);
+
 /* Initialize cbmem to be empty. */
 void cbmem_initialize_empty(void);
+void cbmem_initialize_empty_id_size(u32 id, u64 size);
 
 /* Return the top address for dynamic cbmem. The address returned needs to
  * be consistent across romstage and ramstage, and it is required to be

src/lib/imd_cbmem.c

@@ -30,13 +30,6 @@
 #include <arch/acpi.h>
 #endif
 
-/* The root region is at least DYN_CBMEM_ALIGN_SIZE . */
-#define ROOT_MIN_SIZE DYN_CBMEM_ALIGN_SIZE
-#define LG_ALIGN ROOT_MIN_SIZE
-/* Small allocation parameters. */
-#define SM_ROOT_SIZE 1024
-#define SM_ALIGN 32
-
 static inline struct imd *cbmem_get_imd(void)
 {
 	/* Only supply a backing store for imd in ramstage. */
@@ -115,6 +108,11 @@ static struct imd *imd_init_backing_with_recover(struct imd *backing)
 }
 
 void cbmem_initialize_empty(void)
+{
+	cbmem_initialize_empty_id_size(0, 0);
+}
+
+void cbmem_initialize_empty_id_size(u32 id, u64 size)
 {
 	struct imd *imd;
 	struct imd imd_backing;
@@ -127,12 +125,16 @@ void cbmem_initialize_empty(void)
 
 	printk(BIOS_DEBUG, "CBMEM:\n");
 
-	if (imd_create_tiered_empty(imd, ROOT_MIN_SIZE, LG_ALIGN,
+	if (imd_create_tiered_empty(imd, CBMEM_ROOT_MIN_SIZE, CBMEM_LG_ALIGN,
-					SM_ROOT_SIZE, SM_ALIGN)) {
+					CBMEM_SM_ROOT_SIZE, CBMEM_SM_ALIGN)) {
 		printk(BIOS_DEBUG, "failed.\n");
 		return;
 	}
 
+	/* Add the specified range first */
+	if (size)
+		cbmem_add(id, size);
+
 	/* Complete migration to CBMEM. */
 	cbmem_run_init_hooks();
 }
@@ -145,6 +147,11 @@ static inline int cbmem_fail_recovery(void)
 }
 
 int cbmem_initialize(void)
+{
+	return cbmem_initialize_id_size(0, 0);
+}
+
+int cbmem_initialize_id_size(u32 id, u64 size)
 {
 	struct imd *imd;
 	struct imd imd_backing;
@@ -167,6 +174,10 @@ int cbmem_initialize(void)
 	imd_lockdown(imd);
 #endif
 
+	/* Add the specified range first */
+	if (size)
+		cbmem_add(id, size);
+
 	/* Complete migration to CBMEM. */
 	cbmem_run_init_hooks();