Currently, the serialized memory map is tracked via kho_out.preserved_mem_map and copied to the FDT during finalization. This double tracking is redundant.
Remove preserved_mem_map from kho_out. Instead, maintain the physical address of the head chunk directly in the preserved-memory-map FDT property. Introduce kho_update_memory_map() to manage this property. This function handles: 1. Retrieving and freeing any existing serialized map (handling the abort/retry case). 2. Updating the FDT property with the new chunk address. This establishes the FDT as the single source of truth for the handover state. Signed-off-by: Pasha Tatashin <[email protected]> --- kernel/liveupdate/kexec_handover.c | 43 ++++++++++++++++++------------ 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index aea58e5a6b49..f1c3dd1ef680 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -117,9 +117,6 @@ struct kho_out { struct mutex fdts_lock; struct kho_mem_track track; - /* First chunk of serialized preserved memory map */ - struct khoser_mem_chunk *preserved_mem_map; - struct kho_debugfs dbg; }; @@ -380,6 +377,27 @@ static void kho_mem_ser_free(struct khoser_mem_chunk *first_chunk) } } +/* + * Update memory map property, if old one is found discard it via + * kho_mem_ser_free(). + */ +static void kho_update_memory_map(struct khoser_mem_chunk *first_chunk) +{ + void *ptr; + u64 phys; + + ptr = fdt_getprop_w(kho_out.fdt, 0, PROP_PRESERVED_MEMORY_MAP, NULL); + + /* Check and discard previous memory map */ + memcpy(&phys, ptr, sizeof(u64)); + if (phys) + kho_mem_ser_free((struct khoser_mem_chunk *)phys_to_virt(phys)); + + /* Update with the new value */ + phys = first_chunk ? (u64)virt_to_phys(first_chunk) : 0; + memcpy(ptr, &phys, sizeof(u64)); +} + static int kho_mem_serialize(struct kho_out *kho_out) { struct khoser_mem_chunk *first_chunk = NULL; @@ -420,7 +438,7 @@ static int kho_mem_serialize(struct kho_out *kho_out) } } - kho_out->preserved_mem_map = first_chunk; + kho_update_memory_map(first_chunk); return 0; @@ -1136,8 +1154,7 @@ int kho_abort(void) if (!kho_out.finalized) return -ENOENT; - kho_mem_ser_free(kho_out.preserved_mem_map); - kho_out.preserved_mem_map = NULL; + kho_update_memory_map(NULL); kho_out.finalized = false; return 0; @@ -1147,21 +1164,15 @@ static int __kho_finalize(void) { void *root = kho_out.fdt; struct kho_sub_fdt *fdt; - u64 *preserved_mem_map; + u64 empty_mem_map = 0; int err; err = fdt_create(root, PAGE_SIZE); err |= fdt_finish_reservemap(root); err |= fdt_begin_node(root, ""); err |= fdt_property_string(root, "compatible", KHO_FDT_COMPATIBLE); - /** - * Reserve the preserved-memory-map property in the root FDT, so - * that all property definitions will precede subnodes created by - * KHO callers. - */ - err |= fdt_property_placeholder(root, PROP_PRESERVED_MEMORY_MAP, - sizeof(*preserved_mem_map), - (void **)&preserved_mem_map); + err |= fdt_property(root, PROP_PRESERVED_MEMORY_MAP, &empty_mem_map, + sizeof(empty_mem_map)); if (err) goto err_exit; @@ -1184,8 +1195,6 @@ static int __kho_finalize(void) if (err) goto err_exit; - *preserved_mem_map = (u64)virt_to_phys(kho_out.preserved_mem_map); - return 0; err_exit: -- 2.52.0.rc1.455.g30608eb744-goog
