sh: Drop support for memory hotplug and memory hotremove

Support for memory hotplug was restricted to 64-bit platforms in
7ec58a2 ("mm/memory_hotplug: restrict CONFIG_MEMORY_HOTPLUG
to 64 bit") while sh is a pure 32-bit platform since the removal
of sh5 support. Thus, drop support for memory hotplug and the
associated memory hotremove on this platform.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20240518115808.8888-2-osalvador@suse.de
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

Author: osalvadorvilardaga

arch/sh/Kconfig

@@ -3,8 +3,6 @@ config SUPERH
 	def_bool y
 	select ARCH_32BIT_OFF_T
 	select ARCH_HAS_CPU_CACHE_ALIASING
-	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM && MMU
-	select ARCH_ENABLE_MEMORY_HOTREMOVE if SPARSEMEM && MMU
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG if (GUSA_RB || CPU_SH4A)
 	select ARCH_HAS_BINFMT_FLAT if !MMU
 	select ARCH_HAS_CPU_FINALIZE_INIT

arch/sh/mm/Kconfig

@@ -144,10 +144,6 @@ config ARCH_SPARSEMEM_DEFAULT
 config ARCH_SELECT_MEMORY_MODEL
 	def_bool y
 
-config ARCH_MEMORY_PROBE
-	def_bool y
-	depends on MEMORY_HOTPLUG
-
 config IOREMAP_FIXED
        def_bool y
        depends on X2TLB

arch/sh/mm/init.c

@@ -395,31 +395,3 @@ void __init mem_init(void)
 
 	mem_init_done = 1;
 }
-
-#ifdef CONFIG_MEMORY_HOTPLUG
-int arch_add_memory(int nid, u64 start, u64 size,
-		    struct mhp_params *params)
-{
-	unsigned long start_pfn = PFN_DOWN(start);
-	unsigned long nr_pages = size >> PAGE_SHIFT;
-	int ret;
-
-	if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
-		return -EINVAL;
-
-	/* We only have ZONE_NORMAL, so this is easy.. */
-	ret = __add_pages(nid, start_pfn, nr_pages, params);
-	if (unlikely(ret))
-		printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
-
-	return ret;
-}
-
-void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
-{
-	unsigned long start_pfn = PFN_DOWN(start);
-	unsigned long nr_pages = size >> PAGE_SHIFT;
-
-	__remove_pages(start_pfn, nr_pages, altmap);
-}
-#endif /* CONFIG_MEMORY_HOTPLUG */