alpha: remove DISCONTIGMEM and NUMA

Patch series "Remove DISCONTIGMEM memory model", v3.

SPARSEMEM memory model was supposed to entirely replace DISCONTIGMEM a
(long) while ago.  The last architectures that used DISCONTIGMEM were
updated to use other memory models in v5.11 and it is about the time to
entirely remove DISCONTIGMEM from the kernel.

This set removes DISCONTIGMEM from alpha, arc and m68k, simplifies memory
model selection in mm/Kconfig and replaces usage of redundant
CONFIG_NEED_MULTIPLE_NODES and CONFIG_FLAT_NODE_MEM_MAP with CONFIG_NUMA
and CONFIG_FLATMEM respectively.

I've also removed NUMA support on alpha that was BROKEN for more than 15
years.

There were also minor updates all over arch/ to remove mentions of
DISCONTIGMEM in comments and #ifdefs.

This patch (of 9):

NUMA is marked broken on alpha for more than 15 years and DISCONTIGMEM was
replaced with SPARSEMEM in v5.11.

Remove both NUMA and DISCONTIGMEM support from alpha.

Link: https://lkml.kernel.org/r/20210608091316.3622-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20210608091316.3622-2-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/Kconfig

@@ -549,29 +549,12 @@ config NR_CPUS
 	  MARVEL support can handle a maximum of 32 CPUs, all the others
 	  with working support have a maximum of 4 CPUs.
 
-config ARCH_DISCONTIGMEM_ENABLE
-	bool "Discontiguous Memory Support"
-	depends on BROKEN
-	help
-	  Say Y to support efficient handling of discontiguous physical memory,
-	  for architectures which are either NUMA (Non-Uniform Memory Access)
-	  or have huge holes in the physical address space for other reasons.
-	  See <file:Documentation/vm/numa.rst> for more.
-
 config ARCH_SPARSEMEM_ENABLE
 	bool "Sparse Memory Support"
 	help
 	  Say Y to support efficient handling of discontiguous physical memory,
 	  for systems that have huge holes in the physical address space.
 
-config NUMA
-	bool "NUMA Support (EXPERIMENTAL)"
-	depends on DISCONTIGMEM && BROKEN
-	help
-	  Say Y to compile the kernel to support NUMA (Non-Uniform Memory
-	  Access).  This option is for configuring high-end multiprocessor
-	  server machines.  If in doubt, say N.
-
 config ALPHA_WTINT
 	bool "Use WTINT" if ALPHA_SRM || ALPHA_GENERIC
 	default y if ALPHA_QEMU
@@ -596,11 +579,6 @@ config ALPHA_WTINT
 
 	  If unsure, say N.
 
-config NODES_SHIFT
-	int
-	default "7"
-	depends on NEED_MULTIPLE_NODES
-
 # LARGE_VMALLOC is racy, if you *really* need it then fix it first
 config ALPHA_LARGE_VMALLOC
 	bool

arch/alpha/include/asm/machvec.h

@@ -99,12 +99,6 @@ struct alpha_machine_vector
 
 	const char *vector_name;
 
-	/* NUMA information */
-	int (*pa_to_nid)(unsigned long);
-	int (*cpuid_to_nid)(int);
-	unsigned long (*node_mem_start)(int);
-	unsigned long (*node_mem_size)(int);
-
 	/* System specific parameters.  */
 	union {
 	    struct {

arch/alpha/include/asm/pgtable.h

@@ -206,7 +206,6 @@ extern unsigned long __zero_page(void);
 #define page_to_pa(page)	(page_to_pfn(page) << PAGE_SHIFT)
 #define pte_pfn(pte)	(pte_val(pte) >> 32)
 
-#ifndef CONFIG_DISCONTIGMEM
 #define pte_page(pte)	pfn_to_page(pte_pfn(pte))
 #define mk_pte(page, pgprot)						\
 ({									\
@@ -215,7 +214,6 @@ extern unsigned long __zero_page(void);
 	pte_val(pte) = (page_to_pfn(page) << 32) | pgprot_val(pgprot);	\
 	pte;								\
 })
-#endif
 
 extern inline pte_t pfn_pte(unsigned long physpfn, pgprot_t pgprot)
 { pte_t pte; pte_val(pte) = (PHYS_TWIDDLE(physpfn) << 32) | pgprot_val(pgprot); return pte; }
@@ -330,9 +328,7 @@ extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
 
-#ifndef CONFIG_DISCONTIGMEM
 #define kern_addr_valid(addr)	(1)
-#endif
 
 #define pte_ERROR(e) \
 	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))

arch/alpha/include/asm/topology.h

@@ -7,45 +7,6 @@
 #include <linux/numa.h>
 #include <asm/machvec.h>
 
-#ifdef CONFIG_NUMA
-static inline int cpu_to_node(int cpu)
-{
-	int node;
-
-	if (!alpha_mv.cpuid_to_nid)
-		return 0;
-
-	node = alpha_mv.cpuid_to_nid(cpu);
-
-#ifdef DEBUG_NUMA
-	BUG_ON(node < 0);
-#endif
-
-	return node;
-}
-
-extern struct cpumask node_to_cpumask_map[];
-/* FIXME: This is dumb, recalculating every time.  But simple. */
-static const struct cpumask *cpumask_of_node(int node)
-{
-	int cpu;
-
-	if (node == NUMA_NO_NODE)
-		return cpu_all_mask;
-
-	cpumask_clear(&node_to_cpumask_map[node]);
-
-	for_each_online_cpu(cpu) {
-		if (cpu_to_node(cpu) == node)
-			cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
-	}
-
-	return &node_to_cpumask_map[node];
-}
-
-#define cpumask_of_pcibus(bus)	(cpu_online_mask)
-
-#endif /* !CONFIG_NUMA */
 # include <asm-generic/topology.h>
 
 #endif /* _ASM_ALPHA_TOPOLOGY_H */

arch/alpha/kernel/core_marvel.c

@@ -287,8 +287,7 @@ io7_init_hose(struct io7 *io7, int port)
 	/*
 	 * Set up window 0 for scatter-gather 8MB at 8MB.
 	 */
-	hose->sg_isa = iommu_arena_new_node(marvel_cpuid_to_nid(io7->pe),
-					    hose, 0x00800000, 0x00800000, 0);
+	hose->sg_isa = iommu_arena_new_node(0, hose, 0x00800000, 0x00800000, 0);
 	hose->sg_isa->align_entry = 8;	/* cache line boundary */
 	csrs->POx_WBASE[0].csr = 
 		hose->sg_isa->dma_base | wbase_m_ena | wbase_m_sg;
@@ -305,8 +304,7 @@ io7_init_hose(struct io7 *io7, int port)
 	/*
 	 * Set up window 2 for scatter-gather (up-to) 1GB at 3GB.
 	 */
-	hose->sg_pci = iommu_arena_new_node(marvel_cpuid_to_nid(io7->pe),
-					    hose, 0xc0000000, 0x40000000, 0);
+	hose->sg_pci = iommu_arena_new_node(0, hose, 0xc0000000, 0x40000000, 0);
 	hose->sg_pci->align_entry = 8;	/* cache line boundary */
 	csrs->POx_WBASE[2].csr = 
 		hose->sg_pci->dma_base | wbase_m_ena | wbase_m_sg;
@@ -843,53 +841,8 @@ EXPORT_SYMBOL(marvel_ioportmap);
 EXPORT_SYMBOL(marvel_ioread8);
 EXPORT_SYMBOL(marvel_iowrite8);
 #endif
-
-/*
- * NUMA Support
- */
-/**********
- * FIXME - for now each cpu is a node by itself 
- *              -- no real support for striped mode 
- **********
- */
-int
-marvel_pa_to_nid(unsigned long pa)
-{
-	int cpuid;
 
-	if ((pa >> 43) & 1) 	/* I/O */ 
-		cpuid = (~(pa >> 35) & 0xff);
-	else			/* mem */
-		cpuid = ((pa >> 34) & 0x3) | ((pa >> (37 - 2)) & (0x1f << 2));
-
-	return marvel_cpuid_to_nid(cpuid);
-}
-
-int
-marvel_cpuid_to_nid(int cpuid)
-{
-	return cpuid;
-}
-
-unsigned long
-marvel_node_mem_start(int nid)
-{
-	unsigned long pa;
-
-	pa = (nid & 0x3) | ((nid & (0x1f << 2)) << 1);
-	pa <<= 34;
-
-	return pa;
-}
-
-unsigned long
-marvel_node_mem_size(int nid)
-{
-	return 16UL * 1024 * 1024 * 1024; /* 16GB */
-}
-
-
-/* 
+/*
  * AGP GART Support.
  */
 #include <linux/agp_backend.h>

arch/alpha/kernel/core_wildfire.c

@@ -434,39 +434,12 @@ wildfire_write_config(struct pci_bus *bus, unsigned int devfn, int where,
 	return PCIBIOS_SUCCESSFUL;
 }
 
-struct pci_ops wildfire_pci_ops = 
+struct pci_ops wildfire_pci_ops =
 {
 	.read =		wildfire_read_config,
 	.write =	wildfire_write_config,
 };
 
-
-/*
- * NUMA Support
- */
-int wildfire_pa_to_nid(unsigned long pa)
-{
-	return pa >> 36;
-}
-
-int wildfire_cpuid_to_nid(int cpuid)
-{
-	/* assume 4 CPUs per node */
-	return cpuid >> 2;
-}
-
-unsigned long wildfire_node_mem_start(int nid)
-{
-	/* 64GB per node */
-	return (unsigned long)nid * (64UL * 1024 * 1024 * 1024);
-}
-
-unsigned long wildfire_node_mem_size(int nid)
-{
-	/* 64GB per node */
-	return 64UL * 1024 * 1024 * 1024;
-}
-
 #if DEBUG_DUMP_REGS
 
 static void __init

arch/alpha/kernel/pci_iommu.c

@@ -71,33 +71,6 @@ iommu_arena_new_node(int nid, struct pci_controller *hose, dma_addr_t base,
 	if (align < mem_size)
 		align = mem_size;
 
-
-#ifdef CONFIG_DISCONTIGMEM
-
-	arena = memblock_alloc_node(sizeof(*arena), align, nid);
-	if (!NODE_DATA(nid) || !arena) {
-		printk("%s: couldn't allocate arena from node %d\n"
-		       "    falling back to system-wide allocation\n",
-		       __func__, nid);
-		arena = memblock_alloc(sizeof(*arena), SMP_CACHE_BYTES);
-		if (!arena)
-			panic("%s: Failed to allocate %zu bytes\n", __func__,
-			      sizeof(*arena));
-	}
-
-	arena->ptes = memblock_alloc_node(sizeof(*arena), align, nid);
-	if (!NODE_DATA(nid) || !arena->ptes) {
-		printk("%s: couldn't allocate arena ptes from node %d\n"
-		       "    falling back to system-wide allocation\n",
-		       __func__, nid);
-		arena->ptes = memblock_alloc(mem_size, align);
-		if (!arena->ptes)
-			panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
-			      __func__, mem_size, align);
-	}
-
-#else /* CONFIG_DISCONTIGMEM */
-
 	arena = memblock_alloc(sizeof(*arena), SMP_CACHE_BYTES);
 	if (!arena)
 		panic("%s: Failed to allocate %zu bytes\n", __func__,
@@ -107,8 +80,6 @@ iommu_arena_new_node(int nid, struct pci_controller *hose, dma_addr_t base,
 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 		      __func__, mem_size, align);
 
-#endif /* CONFIG_DISCONTIGMEM */
-
 	spin_lock_init(&arena->lock);
 	arena->hose = hose;
 	arena->dma_base = base;