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path: root/drivers/of/of_reserved_mem.c
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Diffstat (limited to 'drivers/of/of_reserved_mem.c')
-rw-r--r--drivers/of/of_reserved_mem.c125
1 files changed, 123 insertions, 2 deletions
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 7ec94cfcbd..8236ecae29 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -12,6 +12,7 @@
#define pr_fmt(fmt) "OF: reserved mem: " fmt
#include <linux/err.h>
+#include <linux/libfdt.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
@@ -58,8 +59,8 @@ static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
/*
* fdt_reserved_mem_save_node() - save fdt node for second pass initialization
*/
-void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
- phys_addr_t base, phys_addr_t size)
+static void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
+ phys_addr_t base, phys_addr_t size)
{
struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
@@ -77,6 +78,126 @@ void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
return;
}
+static int __init early_init_dt_reserve_memory(phys_addr_t base,
+ phys_addr_t size, bool nomap)
+{
+ if (nomap) {
+ /*
+ * If the memory is already reserved (by another region), we
+ * should not allow it to be marked nomap, but don't worry
+ * if the region isn't memory as it won't be mapped.
+ */
+ if (memblock_overlaps_region(&memblock.memory, base, size) &&
+ memblock_is_region_reserved(base, size))
+ return -EBUSY;
+
+ return memblock_mark_nomap(base, size);
+ }
+ return memblock_reserve(base, size);
+}
+
+/*
+ * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
+ */
+static int __init __reserved_mem_reserve_reg(unsigned long node,
+ const char *uname)
+{
+ int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+ phys_addr_t base, size;
+ int len;
+ const __be32 *prop;
+ int first = 1;
+ bool nomap;
+
+ prop = of_get_flat_dt_prop(node, "reg", &len);
+ if (!prop)
+ return -ENOENT;
+
+ if (len && len % t_len != 0) {
+ pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
+ uname);
+ return -EINVAL;
+ }
+
+ nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+ while (len >= t_len) {
+ base = dt_mem_next_cell(dt_root_addr_cells, &prop);
+ size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+ if (size &&
+ early_init_dt_reserve_memory(base, size, nomap) == 0)
+ pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
+ uname, &base, (unsigned long)(size / SZ_1M));
+ else
+ pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
+ uname, &base, (unsigned long)(size / SZ_1M));
+
+ len -= t_len;
+ if (first) {
+ fdt_reserved_mem_save_node(node, uname, base, size);
+ first = 0;
+ }
+ }
+ return 0;
+}
+
+/*
+ * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
+ * in /reserved-memory matches the values supported by the current implementation,
+ * also check if ranges property has been provided
+ */
+static int __init __reserved_mem_check_root(unsigned long node)
+{
+ const __be32 *prop;
+
+ prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+ if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
+ return -EINVAL;
+
+ prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+ if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
+ return -EINVAL;
+
+ prop = of_get_flat_dt_prop(node, "ranges", NULL);
+ if (!prop)
+ return -EINVAL;
+ return 0;
+}
+
+/*
+ * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
+ */
+int __init fdt_scan_reserved_mem(void)
+{
+ int node, child;
+ const void *fdt = initial_boot_params;
+
+ node = fdt_path_offset(fdt, "/reserved-memory");
+ if (node < 0)
+ return -ENODEV;
+
+ if (__reserved_mem_check_root(node) != 0) {
+ pr_err("Reserved memory: unsupported node format, ignoring\n");
+ return -EINVAL;
+ }
+
+ fdt_for_each_subnode(child, fdt, node) {
+ const char *uname;
+ int err;
+
+ if (!of_fdt_device_is_available(fdt, child))
+ continue;
+
+ uname = fdt_get_name(fdt, child, NULL);
+
+ err = __reserved_mem_reserve_reg(child, uname);
+ if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL))
+ fdt_reserved_mem_save_node(child, uname, 0, 0);
+ }
+ return 0;
+}
+
/*
* __reserved_mem_alloc_in_range() - allocate reserved memory described with
* 'alloc-ranges'. Choose bottom-up/top-down depending on nearby existing