Merge tag 'devicetree-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-2.6-microblaze.git] / drivers / of / fdt.c

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 0f30496..a8f5b65 100644 (file)
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -973,16 +973,24 @@ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
 
 static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
 
+/*
+ * The main usage of linux,usable-memory-range is for crash dump kernel.
+ * Originally, the number of usable-memory regions is one. Now there may
+ * be two regions, low region and high region.
+ * To make compatibility with existing user-space and older kdump, the low
+ * region is always the last range of linux,usable-memory-range if exist.
+ */
+#define MAX_USABLE_RANGES              2
+
 /**
  * early_init_dt_check_for_usable_mem_range - Decode usable memory range
  * location from flat tree
  */
 void __init early_init_dt_check_for_usable_mem_range(void)
 {
-       const __be32 *prop;
-       int len;
-       phys_addr_t cap_mem_addr;
-       phys_addr_t cap_mem_size;
+       struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
+       const __be32 *prop, *endp;
+       int len, i;
        unsigned long node = chosen_node_offset;
 
        if ((long)node < 0)
@@ -991,16 +999,21 @@ void __init early_init_dt_check_for_usable_mem_range(void)
        pr_debug("Looking for usable-memory-range property... ");
 
        prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
-       if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
+       if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
                return;
 
-       cap_mem_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
-       cap_mem_size = dt_mem_next_cell(dt_root_size_cells, &prop);
+       endp = prop + (len / sizeof(__be32));
+       for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
+               rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);
+               rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);
 
-       pr_debug("cap_mem_start=%pa cap_mem_size=%pa\n", &cap_mem_addr,
-                &cap_mem_size);
+               pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
+                        i, &rgn[i].base, &rgn[i].size);
+       }
 
-       memblock_cap_memory_range(cap_mem_addr, cap_mem_size);
+       memblock_cap_memory_range(rgn[0].base, rgn[0].size);
+       for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
+               memblock_add(rgn[i].base, rgn[i].size);
 }
 
 #ifdef CONFIG_SERIAL_EARLYCON