From: "Pratyush Yadav (Google)" In a future patch, mm init will use kho_scratch_overlap() for deciding the migrate type of pageblocks it initializes. The earliest user currently is free_area_init(). kho_scratch_overlap() relies on kho_scratch pointer being initialized. Introduce kho_memory_init_early() to do this. kho_populate() would normally be a good place to do this, but unfortunately, phys_to_virt() does not work at that point on ARM64. So we need yet another initialization function. Signed-off-by: Pratyush Yadav (Google) --- include/linux/kexec_handover.h | 3 +++ kernel/liveupdate/kexec_handover.c | 15 +++++++++++++-- mm/mm_init.c | 1 + 3 files changed, 17 insertions(+), 2 deletions(-) diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h index 40cb95a80981..18ba417f1ada 100644 --- a/include/linux/kexec_handover.h +++ b/include/linux/kexec_handover.h @@ -33,6 +33,7 @@ void kho_remove_subtree(void *blob); int kho_retrieve_subtree(const char *name, phys_addr_t *phys, size_t *size); void kho_memory_init(void); +void kho_memory_init_early(void); void kho_populate(phys_addr_t fdt_phys, u64 fdt_len, phys_addr_t scratch_phys, u64 scratch_len); @@ -110,6 +111,8 @@ static inline int kho_retrieve_subtree(const char *name, phys_addr_t *phys, static inline void kho_memory_init(void) { } +static inline void kho_memory_init_early(void) { } + static inline void kho_populate(phys_addr_t fdt_phys, u64 fdt_len, phys_addr_t scratch_phys, u64 scratch_len) { diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index b3b97a6ff9c8..2ddfc804cdf7 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -1534,8 +1534,6 @@ static void __init kho_mem_retrieve(void) const void *fdt = kho_get_fdt(); int err; - kho_scratch = phys_to_virt(kho_in.scratch_phys); - /* * kho_get_mem_map() should always succeed. If it fails, kho_populate() * catches that and never sets kho_in.scratch_phys, which stops memory @@ -1756,6 +1754,19 @@ static __init int kho_init(void) } fs_initcall(kho_init); +void __init kho_memory_init_early(void) +{ + if (!is_kho_boot()) + return; + + /* + * kho_scratch_overlap() needs kho_scratch to be initialized. It + * is used by free_area_init() on KHO boots, so initialize it + * early. + */ + kho_scratch = phys_to_virt(kho_in.scratch_phys); +} + void __init kho_memory_init(void) { if (kho_in.scratch_phys) diff --git a/mm/mm_init.c b/mm/mm_init.c index 0f64909e8d20..84d4b1c997bc 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -2687,6 +2687,7 @@ void __init __weak mem_init(void) void __init mm_core_init_early(void) { + kho_memory_init_early(); hugetlb_cma_reserve(); hugetlb_bootmem_alloc(); -- 2.55.0.571.g244d577d93-goog