Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 04ccb27..be941d3 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  PowerPC version
  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
@@ -9,12 +10,6 @@
  *
  *  Derived from "arch/i386/mm/init.c"
  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version
- *  2 of the License, or (at your option) any later version.
- *
  */
 
 #include <linux/export.h>
@@ -27,12 +22,11 @@
 #include <linux/mm.h>
 #include <linux/stddef.h>
 #include <linux/init.h>
-#include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <linux/highmem.h>
 #include <linux/initrd.h>
 #include <linux/pagemap.h>
 #include <linux/suspend.h>
-#include <linux/memblock.h>
 #include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
@@ -55,7 +49,7 @@
 #include <asm/swiotlb.h>
 #include <asm/rtas.h>
 
-#include "mmu_decl.h"
+#include <mm/mmu_decl.h>
 
 #ifndef CPU_FTR_COHERENT_ICACHE
 #define CPU_FTR_COHERENT_ICACHE	0	/* XXX for now */
@@ -70,22 +64,14 @@
 EXPORT_SYMBOL(kmap_pte);
 pgprot_t kmap_prot;
 EXPORT_SYMBOL(kmap_prot);
-#define TOP_ZONE ZONE_HIGHMEM
 
 static inline pte_t *virt_to_kpte(unsigned long vaddr)
 {
 	return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
 			vaddr), vaddr), vaddr);
 }
-#else
-#define TOP_ZONE ZONE_NORMAL
 #endif
 
-int page_is_ram(unsigned long pfn)
-{
-	return memblock_is_memory(__pfn_to_phys(pfn));
-}
-
 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 			      unsigned long size, pgprot_t vma_prot)
 {
@@ -118,8 +104,8 @@
 	return -ENODEV;
 }
 
-int __meminit arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
-		bool want_memblock)
+int __ref arch_add_memory(int nid, u64 start, u64 size,
+			struct mhp_restrictions *restrictions)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
@@ -134,75 +120,36 @@
 			start, start + size, rc);
 		return -EFAULT;
 	}
-	flush_inval_dcache_range(start, start + size);
+	flush_dcache_range(start, start + size);
 
-	return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
+	return __add_pages(nid, start_pfn, nr_pages, restrictions);
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
-int __meminit arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+void __ref arch_remove_memory(int nid, u64 start, u64 size,
+			     struct vmem_altmap *altmap)
 {
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
-	struct page *page;
+	struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap);
 	int ret;
 
-	/*
-	 * If we have an altmap then we need to skip over any reserved PFNs
-	 * when querying the zone.
-	 */
-	page = pfn_to_page(start_pfn);
-	if (altmap)
-		page += vmem_altmap_offset(altmap);
-
-	ret = __remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
-	if (ret)
-		return ret;
+	__remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
 
 	/* Remove htab bolted mappings for this section of memory */
 	start = (unsigned long)__va(start);
-	flush_inval_dcache_range(start, start + size);
+	flush_dcache_range(start, start + size);
 	ret = remove_section_mapping(start, start + size);
+	WARN_ON_ONCE(ret);
 
 	/* Ensure all vmalloc mappings are flushed in case they also
 	 * hit that section of memory
 	 */
 	vm_unmap_aliases();
 
-	resize_hpt_for_hotplug(memblock_phys_mem_size());
-
-	return ret;
+	if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)
+		pr_warn("Hash collision while resizing HPT\n");
 }
 #endif
-#endif /* CONFIG_MEMORY_HOTPLUG */
-
-/*
- * walk_memory_resource() needs to make sure there is no holes in a given
- * memory range.  PPC64 does not maintain the memory layout in /proc/iomem.
- * Instead it maintains it in memblock.memory structures.  Walk through the
- * memory regions, find holes and callback for contiguous regions.
- */
-int
-walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
-		void *arg, int (*func)(unsigned long, unsigned long, void *))
-{
-	struct memblock_region *reg;
-	unsigned long end_pfn = start_pfn + nr_pages;
-	unsigned long tstart, tend;
-	int ret = -1;
-
-	for_each_memblock(memory, reg) {
-		tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
-		tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
-		if (tstart >= tend)
-			continue;
-		ret = (*func)(tstart, tend - tstart, arg);
-		if (ret)
-			break;
-	}
-	return ret;
-}
-EXPORT_SYMBOL_GPL(walk_system_ram_range);
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 void __init mem_topology_setup(void)
@@ -247,54 +194,19 @@
 }
 #endif
 
-static bool zone_limits_final;
-
 /*
- * The memory zones past TOP_ZONE are managed by generic mm code.
- * These should be set to zero since that's what every other
- * architecture does.
- */
-static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
-	[0            ... TOP_ZONE        ] = ~0UL,
-	[TOP_ZONE + 1 ... MAX_NR_ZONES - 1] = 0
-};
-
-/*
- * Restrict the specified zone and all more restrictive zones
- * to be below the specified pfn.  May not be called after
- * paging_init().
- */
-void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
-{
-	int i;
-
-	if (WARN_ON(zone_limits_final))
-		return;
-
-	for (i = zone; i >= 0; i--) {
-		if (max_zone_pfns[i] > pfn_limit)
-			max_zone_pfns[i] = pfn_limit;
-	}
-}
-
-/*
- * Find the least restrictive zone that is entirely below the
- * specified pfn limit.  Returns < 0 if no suitable zone is found.
+ * Zones usage:
  *
- * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
- * systems -- the DMA limit can be higher than any possible real pfn.
+ * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
+ * everything else. GFP_DMA32 page allocations automatically fall back to
+ * ZONE_DMA.
+ *
+ * By using 31-bit unconditionally, we can exploit ARCH_ZONE_DMA_BITS to
+ * inform the generic DMA mapping code.  32-bit only devices (if not handled
+ * by an IOMMU anyway) will take a first dip into ZONE_NORMAL and get
+ * otherwise served by ZONE_DMA.
  */
-int dma_pfn_limit_to_zone(u64 pfn_limit)
-{
-	int i;
-
-	for (i = TOP_ZONE; i >= 0; i--) {
-		if (max_zone_pfns[i] <= pfn_limit)
-			return i;
-	}
-
-	return -EPERM;
-}
+static unsigned long max_zone_pfns[MAX_NR_ZONES];
 
 /*
  * paging_init() sets up the page tables - in fact we've already done this.
@@ -309,11 +221,11 @@
 	unsigned long end = __fix_to_virt(FIX_HOLE);
 
 	for (; v < end; v += PAGE_SIZE)
-		map_kernel_page(v, 0, 0); /* XXX gross */
+		map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
 #endif
 
 #ifdef CONFIG_HIGHMEM
-	map_kernel_page(PKMAP_BASE, 0, 0);	/* XXX gross */
+	map_kernel_page(PKMAP_BASE, 0, __pgprot(0));	/* XXX gross */
 	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 
 	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
@@ -325,11 +237,15 @@
 	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 	       (long int)((top_of_ram - total_ram) >> 20));
 
-#ifdef CONFIG_HIGHMEM
-	limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
+#ifdef CONFIG_ZONE_DMA
+	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn,
+				      1UL << (ARCH_ZONE_DMA_BITS - PAGE_SHIFT));
 #endif
-	limit_zone_pfn(TOP_ZONE, top_of_ram >> PAGE_SHIFT);
-	zone_limits_final = true;
+	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+#ifdef CONFIG_HIGHMEM
+	max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
+#endif
+
 	free_area_init_nodes(max_zone_pfns);
 
 	mark_nonram_nosave();
@@ -349,7 +265,7 @@
 
 	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 	set_max_mapnr(max_pfn);
-	free_all_bootmem();
+	memblock_free_all();
 
 #ifdef CONFIG_HIGHMEM
 	{
@@ -377,17 +293,18 @@
 	mem_init_print_info(NULL);
 #ifdef CONFIG_PPC32
 	pr_info("Kernel virtual memory layout:\n");
+#ifdef CONFIG_KASAN
+	pr_info("  * 0x%08lx..0x%08lx  : kasan shadow mem\n",
+		KASAN_SHADOW_START, KASAN_SHADOW_END);
+#endif
 	pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 #ifdef CONFIG_HIGHMEM
 	pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 		PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 #endif /* CONFIG_HIGHMEM */
-#ifdef CONFIG_NOT_COHERENT_CACHE
-	pr_info("  * 0x%08lx..0x%08lx  : consistent mem\n",
-		IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
-#endif /* CONFIG_NOT_COHERENT_CACHE */
-	pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
-		ioremap_bot, IOREMAP_TOP);
+	if (ioremap_bot != IOREMAP_TOP)
+		pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
+			ioremap_bot, IOREMAP_TOP);
 	pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 		VMALLOC_START, VMALLOC_END);
 #endif /* CONFIG_PPC32 */
@@ -401,13 +318,6 @@
 	free_initmem_default(POISON_FREE_INITMEM);
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void __init free_initrd_mem(unsigned long start, unsigned long end)
-{
-	free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
 /*
  * This is called when a page has been modified by the kernel.
  * It just marks the page as not i-cache clean.  We do the i-cache
@@ -494,62 +404,6 @@
 EXPORT_SYMBOL(flush_icache_user_range);
 
 /*
- * This is called at the end of handling a user page fault, when the
- * fault has been handled by updating a PTE in the linux page tables.
- * We use it to preload an HPTE into the hash table corresponding to
- * the updated linux PTE.
- * 
- * This must always be called with the pte lock held.
- */
-void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
-		      pte_t *ptep)
-{
-#ifdef CONFIG_PPC_STD_MMU
-	/*
-	 * We don't need to worry about _PAGE_PRESENT here because we are
-	 * called with either mm->page_table_lock held or ptl lock held
-	 */
-	unsigned long access, trap;
-
-	if (radix_enabled()) {
-		prefetch((void *)address);
-		return;
-	}
-
-	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
-	if (!pte_young(*ptep) || address >= TASK_SIZE)
-		return;
-
-	/* We try to figure out if we are coming from an instruction
-	 * access fault and pass that down to __hash_page so we avoid
-	 * double-faulting on execution of fresh text. We have to test
-	 * for regs NULL since init will get here first thing at boot
-	 *
-	 * We also avoid filling the hash if not coming from a fault
-	 */
-
-	trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
-	switch (trap) {
-	case 0x300:
-		access = 0UL;
-		break;
-	case 0x400:
-		access = _PAGE_EXEC;
-		break;
-	default:
-		return;
-	}
-
-	hash_preload(vma->vm_mm, address, access, trap);
-#endif /* CONFIG_PPC_STD_MMU */
-#if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
-	&& defined(CONFIG_HUGETLB_PAGE)
-	if (is_vm_hugetlb_page(vma))
-		book3e_hugetlb_preload(vma, address, *ptep);
-#endif
-}
-
-/*
  * System memory should not be in /proc/iomem but various tools expect it
  * (eg kdump).
  */
@@ -597,3 +451,9 @@
 	return 0;
 }
 #endif /* CONFIG_STRICT_DEVMEM */
+
+/*
+ * This is defined in kernel/resource.c but only powerpc needs to export it, for
+ * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
+ */
+EXPORT_SYMBOL_GPL(walk_system_ram_range);