[U-Boot] [PATCH v2 2/3] ARM: zynq: Replace board specific with generic memory bank decoding

[Nathan Rossi]

The dram_init and dram_init_banksize functions were using a board
specific implementation for decoding the memory banks from the fdt. This
board specific implementation uses a static variable 'tmp' which makes
these functions unsafe for execution from within the board_init_f
context.

This unsafe use of a static variable was causing a specific bug when
using the zynq_zybo configuration, U-Boot would generate the following
error during image load. This was caused due to dram_init overwriting
the relocations for the 'image' variable within the do_bootm function.
Out of coincidence the un-initialized memory has a compression type
which is the same as the value for the relocation type R_ARM_RELATIVE.

   Uncompressing Invalid Image ... Unimplemented compression type 23

It should be noted that this is just one way the issue could surface,
other cases my not be observed in normal boot flow. Depending on the
size of various sections, and location of relocations within __rel_dyn
and the compiler/linker the outcome of this bug can differ greatly.

This change makes the dram_init* functions use a generic implementation
of decoding and populating memory bank and size data.

Signed-off-by: Nathan Rossi <nathan at nathanrossi.com>
Fixes: 758f29d0f8 ("ARM: zynq: Support systems with more memory banks")
Cc: Michal Simek <monstr at monstr.eu>
---
 board/xilinx/zynq/board.c | 112 ++--------------------------------------------
 1 file changed, 3 insertions(+), 109 deletions(-)

diff --git a/board/xilinx/zynq/board.c b/board/xilinx/zynq/board.c
index 2c86940957..5cd9bbf711 100644
--- a/board/xilinx/zynq/board.c
+++ b/board/xilinx/zynq/board.c
@@ -124,121 +124,15 @@ int zynq_board_read_rom_ethaddr(unsigned char *ethaddr)
 }
 
 #if !defined(CONFIG_SYS_SDRAM_BASE) && !defined(CONFIG_SYS_SDRAM_SIZE)
-/*
- * fdt_get_reg - Fill buffer by information from DT
- */
-static phys_size_t fdt_get_reg(const void *fdt, int nodeoffset, void *buf,
-			       const u32 *cell, int n)
-{
-	int i = 0, b, banks;
-	int parent_offset = fdt_parent_offset(fdt, nodeoffset);
-	int address_cells = fdt_address_cells(fdt, parent_offset);
-	int size_cells = fdt_size_cells(fdt, parent_offset);
-	char *p = buf;
-	u64 val;
-	u64 vals;
-
-	debug("%s: addr_cells=%x, size_cell=%x, buf=%p, cell=%p\n",
-	      __func__, address_cells, size_cells, buf, cell);
-
-	/* Check memory bank setup */
-	banks = n % (address_cells + size_cells);
-	if (banks)
-		panic("Incorrect memory setup cells=%d, ac=%d, sc=%d\n",
-		      n, address_cells, size_cells);
-
-	banks = n / (address_cells + size_cells);
-
-	for (b = 0; b < banks; b++) {
-		debug("%s: Bank #%d:\n", __func__, b);
-		if (address_cells == 2) {
-			val = cell[i + 1];
-			val <<= 32;
-			val |= cell[i];
-			val = fdt64_to_cpu(val);
-			debug("%s: addr64=%llx, ptr=%p, cell=%p\n",
-			      __func__, val, p, &cell[i]);
-			*(phys_addr_t *)p = val;
-		} else {
-			debug("%s: addr32=%x, ptr=%p\n",
-			      __func__, fdt32_to_cpu(cell[i]), p);
-			*(phys_addr_t *)p = fdt32_to_cpu(cell[i]);
-		}
-		p += sizeof(phys_addr_t);
-		i += address_cells;
-
-		debug("%s: pa=%p, i=%x, size=%zu\n", __func__, p, i,
-		      sizeof(phys_addr_t));
-
-		if (size_cells == 2) {
-			vals = cell[i + 1];
-			vals <<= 32;
-			vals |= cell[i];
-			vals = fdt64_to_cpu(vals);
-
-			debug("%s: size64=%llx, ptr=%p, cell=%p\n",
-			      __func__, vals, p, &cell[i]);
-			*(phys_size_t *)p = vals;
-		} else {
-			debug("%s: size32=%x, ptr=%p\n",
-			      __func__, fdt32_to_cpu(cell[i]), p);
-			*(phys_size_t *)p = fdt32_to_cpu(cell[i]);
-		}
-		p += sizeof(phys_size_t);
-		i += size_cells;
-
-		debug("%s: ps=%p, i=%x, size=%zu\n",
-		      __func__, p, i, sizeof(phys_size_t));
-	}
-
-	/* Return the first address size */
-	return *(phys_size_t *)((char *)buf + sizeof(phys_addr_t));
-}
-
-#define FDT_REG_SIZE  sizeof(u32)
-/* Temp location for sharing data for storing */
-/* Up to 64-bit address + 64-bit size */
-static u8 tmp[CONFIG_NR_DRAM_BANKS * 16];
-
 void dram_init_banksize(void)
 {
-	int bank;
-
-	memcpy(&gd->bd->bi_dram[0], &tmp, sizeof(tmp));
-
-	for (bank = 0; bank < CONFIG_NR_DRAM_BANKS; bank++) {
-		debug("Bank #%d: start %llx\n", bank,
-		      (unsigned long long)gd->bd->bi_dram[bank].start);
-		debug("Bank #%d: size %llx\n", bank,
-		      (unsigned long long)gd->bd->bi_dram[bank].size);
-	}
+	fdtdec_setup_memory_banksize();
 }
 
 int dram_init(void)
 {
-	int node, len;
-	const void *blob = gd->fdt_blob;
-	const u32 *cell;
-
-	memset(&tmp, 0, sizeof(tmp));
-
-	/* find or create "/memory" node. */
-	node = fdt_subnode_offset(blob, 0, "memory");
-	if (node < 0) {
-		printf("%s: Can't get memory node\n", __func__);
-		return node;
-	}
-
-	/* Get pointer to cells and lenght of it */
-	cell = fdt_getprop(blob, node, "reg", &len);
-	if (!cell) {
-		printf("%s: Can't get reg property\n", __func__);
-		return -1;
-	}
-
-	gd->ram_size = fdt_get_reg(blob, node, &tmp, cell, len / FDT_REG_SIZE);
-
-	debug("%s: Initial DRAM size %llx\n", __func__, (u64)gd->ram_size);
+	if (fdtdec_setup_memory_size() != 0)
+		return -EINVAL;
 
 	zynq_ddrc_init();
 
-- 
2.10.2