@@ -18,6 +18,11 @@
#include <linux/memblock.h>
#include <linux/mutex.h>
+#ifdef CONFIG_KEXEC_HANDOVER
+#include <linux/libfdt.h>
+#include <linux/kexec_handover.h>
+#endif /* CONFIG_KEXEC_HANDOVER */
+
#include <asm/sections.h>
#include <linux/io.h>
@@ -2475,6 +2480,201 @@ int reserve_mem_release_by_name(const char *name)
return 1;
}
+#ifdef CONFIG_KEXEC_HANDOVER
+#define MEMBLOCK_KHO_FDT "memblock"
+#define MEMBLOCK_KHO_NODE_COMPATIBLE "memblock-v1"
+#define RESERVE_MEM_KHO_NODE_COMPATIBLE "reserve-mem-v1"
+static struct page *kho_fdt;
+
+static int reserve_mem_kho_finalize(struct kho_serialization *ser)
+{
+ int err = 0, i;
+
+ if (!reserved_mem_count)
+ return NOTIFY_DONE;
+
+ if (IS_ERR(kho_fdt)) {
+ err = PTR_ERR(kho_fdt);
+ pr_err("memblock FDT was not prepared successfully: %d\n", err);
+ return notifier_from_errno(err);
+ }
+
+ for (i = 0; i < reserved_mem_count; i++) {
+ struct reserve_mem_table *map = &reserved_mem_table[i];
+
+ err |= kho_preserve_phys(ser, map->start, map->size);
+ }
+
+ err |= kho_preserve_folio(ser, page_folio(kho_fdt));
+ err |= kho_add_subtree(ser, MEMBLOCK_KHO_FDT, page_to_virt(kho_fdt));
+
+ return notifier_from_errno(err);
+}
+
+static int reserve_mem_kho_notifier(struct notifier_block *self,
+ unsigned long cmd, void *v)
+{
+ switch (cmd) {
+ case KEXEC_KHO_FINALIZE:
+ return reserve_mem_kho_finalize((struct kho_serialization *)v);
+ case KEXEC_KHO_ABORT:
+ return NOTIFY_DONE;
+ default:
+ return NOTIFY_BAD;
+ }
+}
+
+static struct notifier_block reserve_mem_kho_nb = {
+ .notifier_call = reserve_mem_kho_notifier,
+};
+
+static void __init prepare_kho_fdt(void)
+{
+ int err = 0, i;
+ void *fdt;
+
+ if (!reserved_mem_count)
+ return;
+
+ kho_fdt = alloc_page(GFP_KERNEL);
+ if (!kho_fdt) {
+ kho_fdt = ERR_PTR(-ENOMEM);
+ return;
+ }
+
+ fdt = page_to_virt(kho_fdt);
+
+ err |= fdt_create(fdt, PAGE_SIZE);
+ err |= fdt_finish_reservemap(fdt);
+
+ err |= fdt_begin_node(fdt, "");
+ err |= fdt_property_string(fdt, "compatible", MEMBLOCK_KHO_NODE_COMPATIBLE);
+ for (i = 0; i < reserved_mem_count; i++) {
+ struct reserve_mem_table *map = &reserved_mem_table[i];
+
+ err |= fdt_begin_node(fdt, map->name);
+ err |= fdt_property_string(fdt, "compatible", RESERVE_MEM_KHO_NODE_COMPATIBLE);
+ err |= fdt_property(fdt, "start", &map->start, sizeof(map->start));
+ err |= fdt_property(fdt, "size", &map->size, sizeof(map->size));
+ err |= fdt_end_node(fdt);
+ }
+ err |= fdt_end_node(fdt);
+
+ err |= fdt_finish(fdt);
+
+ if (err) {
+ pr_err("failed to prepare memblock FDT for KHO: %d\n", err);
+ put_page(kho_fdt);
+ kho_fdt = ERR_PTR(-EINVAL);
+ }
+}
+
+static int __init reserve_mem_init(void)
+{
+ if (!kho_is_enabled())
+ return 0;
+
+ prepare_kho_fdt();
+
+ return register_kho_notifier(&reserve_mem_kho_nb);
+}
+late_initcall(reserve_mem_init);
+
+static void *kho_fdt_in __initdata;
+
+static void *__init reserve_mem_kho_retrieve_fdt(void)
+{
+ phys_addr_t fdt_phys;
+ struct folio *fdt_folio;
+ void *fdt;
+ int err;
+
+ err = kho_retrieve_subtree(MEMBLOCK_KHO_FDT, &fdt_phys);
+ if (err) {
+ if (err != -ENOENT)
+ pr_warn("failed to retrieve FDT '%s' from KHO: %d\n",
+ MEMBLOCK_KHO_FDT, err);
+ return ERR_PTR(err);
+ }
+
+ fdt_folio = kho_restore_folio(fdt_phys);
+ if (!fdt_folio) {
+ pr_warn("failed to restore memblock KHO FDT (0x%llx)\n", fdt_phys);
+ return ERR_PTR(-EFAULT);
+ }
+
+ fdt = page_to_virt(folio_page(fdt_folio, 0));
+
+ err = fdt_node_check_compatible(fdt, 0, MEMBLOCK_KHO_NODE_COMPATIBLE);
+ if (err) {
+ pr_warn("FDT '%s' is incompatible with '%s': %d\n",
+ MEMBLOCK_KHO_FDT, MEMBLOCK_KHO_NODE_COMPATIBLE, err);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return fdt;
+}
+
+static bool __init reserve_mem_kho_revive(const char *name, phys_addr_t size,
+ phys_addr_t align)
+{
+ int err, len_start, len_size, offset;
+ const phys_addr_t *p_start, *p_size;
+ const void *fdt;
+
+ if (!kho_fdt_in)
+ kho_fdt_in = reserve_mem_kho_retrieve_fdt();
+
+ if (IS_ERR(kho_fdt_in))
+ return false;
+
+ fdt = kho_fdt_in;
+
+ offset = fdt_subnode_offset(fdt, 0, name);
+ if (offset < 0) {
+ pr_warn("FDT '%s' has no child '%s': %d\n",
+ MEMBLOCK_KHO_FDT, name, offset);
+ return false;
+ }
+ err = fdt_node_check_compatible(fdt, offset, RESERVE_MEM_KHO_NODE_COMPATIBLE);
+ if (err) {
+ pr_warn("Node '%s' is incompatible with '%s': %d\n",
+ name, RESERVE_MEM_KHO_NODE_COMPATIBLE, err);
+ return false;
+ }
+
+ p_start = fdt_getprop(fdt, offset, "start", &len_start);
+ p_size = fdt_getprop(fdt, offset, "size", &len_size);
+ if (!p_start || len_start != sizeof(*p_start) || !p_size ||
+ len_size != sizeof(*p_size)) {
+ return false;
+ }
+
+ if (*p_start & (align - 1)) {
+ pr_warn("KHO reserve-mem '%s' has wrong alignment (0x%lx, 0x%lx)\n",
+ name, (long)align, (long)*p_start);
+ return false;
+ }
+
+ if (*p_size != size) {
+ pr_warn("KHO reserve-mem '%s' has wrong size (0x%lx != 0x%lx)\n",
+ name, (long)*p_size, (long)size);
+ return false;
+ }
+
+ reserved_mem_add(*p_start, size, name);
+ pr_info("Revived memory reservation '%s' from KHO\n", name);
+
+ return true;
+}
+#else
+static bool __init reserve_mem_kho_revive(const char *name, phys_addr_t size,
+ phys_addr_t align)
+{
+ return false;
+}
+#endif /* CONFIG_KEXEC_HANDOVER */
+
/*
* Parse reserve_mem=nn:align:name
*/
@@ -2530,6 +2730,11 @@ static int __init reserve_mem(char *p)
if (reserve_mem_find_by_name(name, &start, &tmp))
return -EBUSY;
+ /* Pick previous allocations up from KHO if available */
+ if (reserve_mem_kho_revive(name, size, align))
+ return 1;
+
+ /* TODO: Allocation must be outside of scratch region */
start = memblock_phys_alloc(size, align);
if (!start)
return -ENOMEM;