From 300709fbefd19ff7293c7d0ded9b56e69216e634 Mon Sep 17 00:00:00 2001 From: Sumanth Korikkar Date: Fri, 10 Oct 2025 10:51:47 +0200 Subject: mm/memory_hotplug: Remove MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers were introduced to prepare the transition of memory to and from a physically accessible state. This enhancement was crucial for implementing the "memmap on memory" feature for s390. With introduction of dynamic (de)configuration of hotpluggable memory, memory can be brought to accessible state before add_memory(). Memory can be brought to inaccessible state before remove_memory(). Hence, there is no need of MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE memory notifiers anymore. This basically reverts commit c5f1e2d18909 ("mm/memory_hotplug: introduce MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers") Additionally, apply minor adjustments to the function parameters of move_pfn_range_to_zone() and mhp_supports_memmap_on_memory() to ensure compatibility with the latest branch. Acked-by: David Hildenbrand Signed-off-by: Sumanth Korikkar Signed-off-by: Heiko Carstens --- include/linux/memory.h | 9 --------- include/linux/memory_hotplug.h | 18 +----------------- include/linux/memremap.h | 1 - 3 files changed, 1 insertion(+), 27 deletions(-) (limited to 'include/linux') diff --git a/include/linux/memory.h b/include/linux/memory.h index 0c214256216f..ba1515160894 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -96,17 +96,8 @@ int set_memory_block_size_order(unsigned int order); #define MEM_GOING_ONLINE (1<<3) #define MEM_CANCEL_ONLINE (1<<4) #define MEM_CANCEL_OFFLINE (1<<5) -#define MEM_PREPARE_ONLINE (1<<6) -#define MEM_FINISH_OFFLINE (1<<7) struct memory_notify { - /* - * The altmap_start_pfn and altmap_nr_pages fields are designated for - * specifying the altmap range and are exclusively intended for use in - * MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers. - */ - unsigned long altmap_start_pfn; - unsigned long altmap_nr_pages; unsigned long start_pfn; unsigned long nr_pages; }; diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 23f038a16231..f2f16cdd73ee 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -58,22 +58,6 @@ typedef int __bitwise mhp_t; * implies the node id (nid). */ #define MHP_NID_IS_MGID ((__force mhp_t)BIT(2)) -/* - * The hotplugged memory is completely inaccessible while the memory is - * offline. The memory provider will handle MEM_PREPARE_ONLINE / - * MEM_FINISH_OFFLINE notifications and make the memory accessible. - * - * This flag is only relevant when used along with MHP_MEMMAP_ON_MEMORY, - * because the altmap cannot be written (e.g., poisoned) when adding - * memory -- before it is set online. - * - * This allows for adding memory with an altmap that is not currently - * made available by a hypervisor. When onlining that memory, the - * hypervisor can be instructed to make that memory available, and - * the onlining phase will not require any memory allocations, which is - * helpful in low-memory situations. - */ -#define MHP_OFFLINE_INACCESSIBLE ((__force mhp_t)BIT(3)) /* * Extended parameters for memory hotplug: @@ -123,7 +107,7 @@ extern void adjust_present_page_count(struct page *page, long nr_pages); /* VM interface that may be used by firmware interface */ extern int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, - struct zone *zone, bool mhp_off_inaccessible); + struct zone *zone); extern void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages); extern int online_pages(unsigned long pfn, unsigned long nr_pages, struct zone *zone, struct memory_group *group); diff --git a/include/linux/memremap.h b/include/linux/memremap.h index e5951ba12a28..30c7aecbd245 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -25,7 +25,6 @@ struct vmem_altmap { unsigned long free; unsigned long align; unsigned long alloc; - bool inaccessible; }; /* -- cgit v1.2.3 From e950d1f84d3c16e86dd1b6066c3ac3958099fa79 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 19 Nov 2025 15:37:56 +0100 Subject: s390/percpu: Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU Since the rework of the kernel virtual address space [1] the module area and the kernel image are within the same 4GB area. Therefore there is no need for the weak per cpu workaround for modules anymore. Remove it. [1] commit c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") Acked-by: Alexander Gordeev Signed-off-by: Heiko Carstens --- arch/s390/Kconfig | 1 - arch/s390/include/asm/percpu.h | 8 -------- include/linux/percpu-defs.h | 2 +- 3 files changed, 1 insertion(+), 10 deletions(-) (limited to 'include/linux') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 9914db771e45..cb143bf782f8 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -140,7 +140,6 @@ config S390 select ARCH_INLINE_WRITE_UNLOCK_IRQ select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE - select ARCH_MODULE_NEEDS_WEAK_PER_CPU select ARCH_STACKWALK select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_DEBUG_PAGEALLOC diff --git a/arch/s390/include/asm/percpu.h b/arch/s390/include/asm/percpu.h index 965886dfe954..5899f57f17d1 100644 --- a/arch/s390/include/asm/percpu.h +++ b/arch/s390/include/asm/percpu.h @@ -12,14 +12,6 @@ */ #define __my_cpu_offset get_lowcore()->percpu_offset -/* - * For 64 bit module code, the module may be more than 4G above the - * per cpu area, use weak definitions to force the compiler to - * generate external references. - * Therefore, we have enabled CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU - * in the Kconfig. - */ - /* * We use a compare-and-swap loop since that uses less cpu cycles than * disabling and enabling interrupts like the generic variant would do. diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index 12d90360f6db..43c854a273c3 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -52,7 +52,7 @@ __section(".discard") __attribute__((unused)) /* - * s390 and alpha modules require percpu variables to be defined as + * alpha modules require percpu variables to be defined as * weak to force the compiler to generate GOT based external * references for them. This is necessary because percpu sections * will be located outside of the usually addressable area. -- cgit v1.2.3