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fdtdec: Support parsing multiple /memory nodes

PATCH New Marek Vasut 4 participants 6 messages Nov 29, 2017 – Dec 7, 2017 Library code

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#0 lore raw

PATCH 1/1 fdtdec: Support parsing multiple /memory nodes

It is legal to have multiple /memory nodes in a device tree . Currently, fdtdec_setup_memory_size() only supports parsing the first node . This patch extends the function such that if a particular /memory node does no longer have further "reg" entries and CONFIG_NR_DRAM_BANKS still allows for more DRAM banks, the code moves on to the next memory node and checks it's "reg"s. This makes it possible to handle both systems with single memory node with multiple entries and systems with multiple memory nodes with single entry.

---
 lib/fdtdec.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)
lib/fdtdec.c +18 -6
index c4582eacca..46df0f15f9 100644
@@ -1176,21 +1176,33 @@ int fdtdec_setup_memory_size(void)
 #if defined(CONFIG_NR_DRAM_BANKS)
 int fdtdec_setup_memory_banksize(void)
 {
-	int bank, ret, mem;
+	int bank, ret, mem, reg = 0;
 	struct fdt_resource res;
 
-	mem = fdt_path_offset(gd->fdt_blob, "/memory");
+	mem = fdt_node_offset_by_prop_value(gd->fdt_blob, -1, "device_type",
+					    "memory", 7);
 	if (mem < 0) {
 		debug("%s: Missing /memory node\n", __func__);
 		return -EINVAL;
 	}
 
 	for (bank = 0; bank < CONFIG_NR_DRAM_BANKS; bank++) {
-		ret = fdt_get_resource(gd->fdt_blob, mem, "reg", bank, &res);
-		if (ret == -FDT_ERR_NOTFOUND)
-			break;
-		if (ret != 0)
+		ret = fdt_get_resource(gd->fdt_blob, mem, "reg", reg++, &res);
+		if (ret == -FDT_ERR_NOTFOUND) {
+			reg = 0;
+			mem = fdt_node_offset_by_prop_value(gd->fdt_blob, mem,
+							    "device_type",
+							    "memory", 7);
+			if (mem == -FDT_ERR_NOTFOUND)
+				break;
+
+			ret = fdt_get_resource(gd->fdt_blob, mem, "reg", reg++, &res);
+			if (ret == -FDT_ERR_NOTFOUND)
+				break;
+		}
+		if (ret != 0) {
 			return -EINVAL;
+		}
 
 		gd->bd->bi_dram[bank].start = (phys_addr_t)res.start;
 		gd->bd->bi_dram[bank].size =
Signature · 1 line
2.15.0
#1 lore raw

PATCH 1/1 fdtdec: Support parsing multiple /memory nodes

Quoted 9 lines · Marek Vasut

It is legal to have multiple /memory nodes in a device tree . Currently, fdtdec_setup_memory_size() only supports parsing the first node . This patch extends the function such that if a particular /memory node does no longer have further "reg" entries and CONFIG_NR_DRAM_BANKS still allows for more DRAM banks, the code moves on to the next memory node and checks it's "reg"s. This makes it possible to handle both systems with single memory node with multiple entries and systems with multiple memory nodes with single entry.

Quoted 3 lines

https://www.devicetree.org/downloads/devicetree-specification-v0.1-20160524.pdf
says that multiple nodes can be used, so this is the correct fix here. Thanks!

Signature · 8 lines
Tom
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#2 lore raw

PATCH 1/1 fdtdec: Support parsing multiple /memory nodes

Quoted 11 lines · Tom Rini
Quoted 9 lines · Marek Vasut

It is legal to have multiple /memory nodes in a device tree . Currently, fdtdec_setup_memory_size() only supports parsing the first node . This patch extends the function such that if a particular /memory node does no longer have further "reg" entries and CONFIG_NR_DRAM_BANKS still allows for more DRAM banks, the code moves on to the next memory node and checks it's "reg"s. This makes it possible to handle both systems with single memory node with multiple entries and systems with multiple memory nodes with single entry.

Quoted 6 lines
Quoted 3 lines

https://www.devicetree.org/downloads/devicetree-specification-v0.1-20160524.pdf
says that multiple nodes can be used, so this is the correct fix here.

I am not a big fan of this kind of practice, but that's how our DTs are, so it cannot be helped and we have to support this :-(

Quoted 3 lines

Thanks!

Thanks.

Signature · 2 lines
Best regards,
Marek Vasut
#3 lore raw

PATCH 1/1 fdtdec: Support parsing multiple /memory nodes

In reply to Marek Vasut
Quoted 9 lines · Marek Vasut

It is legal to have multiple /memory nodes in a device tree . Currently, fdtdec_setup_memory_size() only supports parsing the first node . This patch extends the function such that if a particular /memory node does no longer have further "reg" entries and CONFIG_NR_DRAM_BANKS still allows for more DRAM banks, the code moves on to the next memory node and checks it's "reg"s. This makes it possible to handle both systems with single memory node with multiple entries and systems with multiple memory nodes with single entry.

Quoted 6 lines
---
 lib/fdtdec.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

Oh for a test of this code!

#4 lore raw

PATCH 1/1 fdtdec: Support parsing multiple /memory nodes

Hi,

Quoted 17 lines · Simon Glass
Quoted 9 lines · Marek Vasut

It is legal to have multiple /memory nodes in a device tree . Currently, fdtdec_setup_memory_size() only supports parsing the first node . This patch extends the function such that if a particular /memory node does no longer have further "reg" entries and CONFIG_NR_DRAM_BANKS still allows for more DRAM banks, the code moves on to the next memory node and checks it's "reg"s. This makes it possible to handle both systems with single memory node with multiple entries and systems with multiple memory nodes with single entry.

Quoted 6 lines
---
 lib/fdtdec.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)
Quoted 3 lines

Oh for a test of this code!

This is in my queue but seems to have already made it to mainline.

Regards,
Simon

#5 lore raw

PATCH 1/1 fdtdec: Support parsing multiple /memory nodes

In reply to Marek Vasut

Hi,

Quoted 7 lines · On Wed, 29 Nov 2017 03:45:45 +0100 Marek Vasut wrote:

It is legal to have multiple /memory nodes in a device tree . Currently, fdtdec_setup_memory_size() only supports parsing the first node . This patch extends the function such that if a particular /memory node does no longer have further "reg" entries and CONFIG_NR_DRAM_BANKS still allows for more DRAM banks, the code moves on to the next memory node and checks it's "reg"s. This makes it possible to handle both systems

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s/it's/its/
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Lothar Waßmann