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path: root/drivers/of/fdt.c
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Diffstat (limited to 'drivers/of/fdt.c')
-rw-r--r--drivers/of/fdt.c187
1 files changed, 49 insertions, 138 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index bf502ba8da95..a8a04f27915b 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -8,6 +8,7 @@
#define pr_fmt(fmt) "OF: fdt: " fmt
+#include <linux/acpi.h>
#include <linux/crash_dump.h>
#include <linux/crc32.h>
#include <linux/kernel.h>
@@ -16,7 +17,6 @@
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
-#include <linux/of_reserved_mem.h>
#include <linux/sizes.h>
#include <linux/string.h>
#include <linux/errno.h>
@@ -33,6 +33,13 @@
#include "of_private.h"
/*
+ * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by
+ * cmd_dt_S_dtb in scripts/Makefile.lib
+ */
+extern uint8_t __dtb_empty_root_begin[];
+extern uint8_t __dtb_empty_root_end[];
+
+/*
* of_fdt_limit_memory - limit the number of regions in the /memory node
* @limit: maximum entries
*
@@ -80,7 +87,7 @@ void __init of_fdt_limit_memory(int limit)
}
}
-static bool of_fdt_device_is_available(const void *blob, unsigned long node)
+bool of_fdt_device_is_available(const void *blob, unsigned long node)
{
const char *status = fdt_getprop(blob, node, "status", NULL);
@@ -476,126 +483,6 @@ void *initial_boot_params __ro_after_init;
static u32 of_fdt_crc32;
-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
- */
-static 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;
-}
-
/*
* fdt_reserve_elfcorehdr() - reserves memory for elf core header
*
@@ -1318,6 +1205,21 @@ bool __init early_init_dt_scan(void *params)
return true;
}
+static void *__init copy_device_tree(void *fdt)
+{
+ int size;
+ void *dt;
+
+ size = fdt_totalsize(fdt);
+ dt = early_init_dt_alloc_memory_arch(size,
+ roundup_pow_of_two(FDT_V17_SIZE));
+
+ if (dt)
+ memcpy(dt, fdt, size);
+
+ return dt;
+}
+
/**
* unflatten_device_tree - create tree of device_nodes from flat blob
*
@@ -1328,7 +1230,29 @@ bool __init early_init_dt_scan(void *params)
*/
void __init unflatten_device_tree(void)
{
- __unflatten_device_tree(initial_boot_params, NULL, &of_root,
+ void *fdt = initial_boot_params;
+
+ /* Don't use the bootloader provided DTB if ACPI is enabled */
+ if (!acpi_disabled)
+ fdt = NULL;
+
+ /*
+ * Populate an empty root node when ACPI is enabled or bootloader
+ * doesn't provide one.
+ */
+ if (!fdt) {
+ fdt = (void *) __dtb_empty_root_begin;
+ /* fdt_totalsize() will be used for copy size */
+ if (fdt_totalsize(fdt) >
+ __dtb_empty_root_end - __dtb_empty_root_begin) {
+ pr_err("invalid size in dtb_empty_root\n");
+ return;
+ }
+ of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt));
+ fdt = copy_device_tree(fdt);
+ }
+
+ __unflatten_device_tree(fdt, NULL, &of_root,
early_init_dt_alloc_memory_arch, false);
/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
@@ -1350,22 +1274,9 @@ void __init unflatten_device_tree(void)
*/
void __init unflatten_and_copy_device_tree(void)
{
- int size;
- void *dt;
+ if (initial_boot_params)
+ initial_boot_params = copy_device_tree(initial_boot_params);
- if (!initial_boot_params) {
- pr_warn("No valid device tree found, continuing without\n");
- return;
- }
-
- size = fdt_totalsize(initial_boot_params);
- dt = early_init_dt_alloc_memory_arch(size,
- roundup_pow_of_two(FDT_V17_SIZE));
-
- if (dt) {
- memcpy(dt, initial_boot_params, size);
- initial_boot_params = dt;
- }
unflatten_device_tree();
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-27 01:02:15 +0300