MIPS: Netlogic: Read memory from DRAM BARs

Read the memory from the Bridge DRAM BARs, if it is not passed in
from the device tree. This will allow us to remove memory configuration
from built in device trees.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5743/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 58 insertions, 0 deletions

diff --git a/arch/mips/netlogic/xlp/nlm_hal.c b/arch/mips/netlogic/xlp/nlm_hal.c
index 87560e4db35..6f2c21008dd 100644
--- a/arch/mips/netlogic/xlp/nlm_hal.c
+++ b/arch/mips/netlogic/xlp/nlm_hal.c
@@ -44,6 +44,7 @@
 #include <asm/netlogic/haldefs.h>
 #include <asm/netlogic/xlp-hal/iomap.h>
 #include <asm/netlogic/xlp-hal/xlp.h>
+#include <asm/netlogic/xlp-hal/bridge.h>
 #include <asm/netlogic/xlp-hal/pic.h>
 #include <asm/netlogic/xlp-hal/sys.h>
 
@@ -142,3 +143,37 @@ unsigned int nlm_get_cpu_frequency(void)
 {
 	return nlm_get_core_frequency(0, 0);
 }
+
+/*
+ * Fills upto 8 pairs of entries containing the DRAM map of a node
+ * if n < 0, get dram map for all nodes
+ */
+int xlp_get_dram_map(int n, uint64_t *dram_map)
+{
+	uint64_t bridgebase, base, lim;
+	uint32_t val;
+	int i, node, rv;
+
+	/* Look only at mapping on Node 0, we don't handle crazy configs */
+	bridgebase = nlm_get_bridge_regbase(0);
+	rv = 0;
+	for (i = 0; i < 8; i++) {
+		val = nlm_read_bridge_reg(bridgebase,
+					BRIDGE_DRAM_NODE_TRANSLN(i));
+		node = (val >> 1) & 0x3;
+		if (n >= 0 && n != node)
+			continue;
+		val = nlm_read_bridge_reg(bridgebase, BRIDGE_DRAM_BAR(i));
+		val = (val >>  12) & 0xfffff;
+		base = (uint64_t) val << 20;
+		val = nlm_read_bridge_reg(bridgebase, BRIDGE_DRAM_LIMIT(i));
+		val = (val >>  12) & 0xfffff;
+		if (val == 0)   /* BAR not used */
+			continue;
+		lim = ((uint64_t)val + 1) << 20;
+		dram_map[rv] = base;
+		dram_map[rv + 1] = lim;
+		rv += 2;
+	}
+	return rv;
+}
diff --git a/arch/mips/netlogic/xlp/setup.c b/arch/mips/netlogic/xlp/setup.c
index 7b638f7be49..7718368e459 100644
--- a/arch/mips/netlogic/xlp/setup.c
+++ b/arch/mips/netlogic/xlp/setup.c
@@ -73,6 +73,23 @@ static void nlm_fixup_mem(void)
 	}
 }
 
+static void __init xlp_init_mem_from_bars(void)
+{
+	uint64_t map[16];
+	int i, n;
+
+	n = xlp_get_dram_map(-1, map);	/* -1: info for all nodes */
+	for (i = 0; i < n; i += 2) {
+		/* exclude 0x1000_0000-0x2000_0000, u-boot device */
+		if (map[i] <= 0x10000000 && map[i+1] > 0x10000000)
+			map[i+1] = 0x10000000;
+		if (map[i] > 0x10000000 && map[i] < 0x20000000)
+			map[i] = 0x20000000;
+
+		add_memory_region(map[i], map[i+1] - map[i], BOOT_MEM_RAM);
+	}
+}
+
 void __init plat_mem_setup(void)
 {
 	panic_timeout	= 5;
@@ -82,6 +99,12 @@ void __init plat_mem_setup(void)
 
 	/* memory and bootargs from DT */
 	early_init_devtree(initial_boot_params);
+
+	if (boot_mem_map.nr_map == 0) {
+		pr_info("Using DRAM BARs for memory map.\n");
+		xlp_init_mem_from_bars();
+	}
+	/* Calculate and setup wired entries for mapped kernel */
 	nlm_fixup_mem();
 }