MIPS: malta: malta-memory: Add support for the 'ememsize' variable

The 'ememsize' variable is used to denote the real RAM which is
present on the Malta board. This is different compared to 'memsize'
which is capped to 256MB. The 'ememsize' is used to get the actual
physical memory when setting up the Malta memory layout. This only
makes sense in case the core operates in the EVA mode, and it's
ignored otherwise.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

arch/mips/include/asm/fw/fw.h

@@ -38,7 +38,7 @@ extern int *_fw_envp;
 
 extern void fw_init_cmdline(void);
 extern char *fw_getcmdline(void);
-extern fw_memblock_t *fw_getmdesc(void);
+extern fw_memblock_t *fw_getmdesc(int);
 extern void fw_meminit(void);
 extern char *fw_getenv(char *name);
 extern unsigned long fw_getenvl(char *name);

arch/mips/mti-malta/malta-memory.c

@@ -24,22 +24,30 @@ static fw_memblock_t mdesc[FW_MAX_MEMBLOCKS];
 /* determined physical memory size, not overridden by command line args	 */
 unsigned long physical_memsize = 0L;
 
-fw_memblock_t * __init fw_getmdesc(void)
+fw_memblock_t * __init fw_getmdesc(int eva)
 {
-	char *memsize_str, *ptr;
-	unsigned int memsize;
+	char *memsize_str, *ememsize_str __maybe_unused = NULL, *ptr;
+	unsigned long memsize, ememsize __maybe_unused = 0;
 	static char cmdline[COMMAND_LINE_SIZE] __initdata;
-	long val;
 	int tmp;
 
 	/* otherwise look in the environment */
+
 	memsize_str = fw_getenv("memsize");
-	if (!memsize_str) {
+	if (memsize_str)
+		tmp = kstrtol(memsize_str, 0, &memsize);
+	if (eva) {
+	/* Look for ememsize for EVA */
+		ememsize_str = fw_getenv("ememsize");
+		if (ememsize_str)
+			tmp = kstrtol(ememsize_str, 0, &ememsize);
+	}
+	if (!memsize && !ememsize) {
 		pr_warn("memsize not set in YAMON, set to default (32Mb)\n");
 		physical_memsize = 0x02000000;
 	} else {
-		tmp = kstrtol(memsize_str, 0, &val);
-		physical_memsize = (unsigned long)val;
+		/* If ememsize is set, then set physical_memsize to that */
+		physical_memsize = ememsize ? : memsize;
 	}
 
 #ifdef CONFIG_CPU_BIG_ENDIAN
@@ -54,12 +62,22 @@ fw_memblock_t * __init fw_getmdesc(void)
 	ptr = strstr(cmdline, "memsize=");
 	if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
 		ptr = strstr(ptr, " memsize=");
+	/* And now look for ememsize */
+	if (eva) {
+		ptr = strstr(cmdline, "ememsize=");
+		if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
+			ptr = strstr(ptr, " ememsize=");
+	}
 
 	if (ptr)
-		memsize = memparse(ptr + 8, &ptr);
+		memsize = memparse(ptr + 8 + (eva ? 1 : 0), &ptr);
 	else
 		memsize = physical_memsize;
 
+	/* Last 64K for HIGHMEM arithmetics */
+	if (memsize > 0x7fff0000)
+		memsize = 0x7fff0000;
+
 	memset(mdesc, 0, sizeof(mdesc));
 
 	mdesc[0].type = fw_dontuse;
@@ -109,7 +127,7 @@ void __init fw_meminit(void)
 {
 	fw_memblock_t *p;
 
-	p = fw_getmdesc();
+	p = fw_getmdesc(config_enabled(CONFIG_EVA));
 
 	while (p->size) {
 		long type;