Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 58a522f..573463d 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -1,35 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2012 Regents of the University of California
- *
- *   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, version 2.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *   GNU General Public License for more details.
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
  */
 
 #include <linux/init.h>
 #include <linux/mm.h>
-#include <linux/bootmem.h>
-#include <linux/initrd.h>
 #include <linux/memblock.h>
+#include <linux/initrd.h>
 #include <linux/swap.h>
 #include <linux/sizes.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
 
+#include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
 #include <asm/pgtable.h>
 #include <asm/io.h>
 
+#include "../kernel/head.h"
+
+unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
+							__page_aligned_bss;
+EXPORT_SYMBOL(empty_zero_page);
+
+extern char _start[];
+
 static void __init zone_sizes_init(void)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
 
 #ifdef CONFIG_ZONE_DMA32
-	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G, max_low_pfn));
+	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G,
+			(unsigned long) PFN_PHYS(max_low_pfn)));
 #endif
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 
@@ -41,13 +45,6 @@
 	memset((void *)empty_zero_page, 0, PAGE_SIZE);
 }
 
-void __init paging_init(void)
-{
-	setup_zero_page();
-	local_flush_tlb_all();
-	zone_sizes_init();
-}
-
 void __init mem_init(void)
 {
 #ifdef CONFIG_FLATMEM
@@ -55,18 +52,417 @@
 #endif /* CONFIG_FLATMEM */
 
 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
-	free_all_bootmem();
+	memblock_free_all();
 
 	mem_init_print_info(NULL);
 }
 
-void free_initmem(void)
-{
-	free_initmem_default(0);
-}
-
 #ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
+static void __init setup_initrd(void)
 {
+	unsigned long size;
+
+	if (initrd_start >= initrd_end) {
+		pr_info("initrd not found or empty");
+		goto disable;
+	}
+	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
+		pr_err("initrd extends beyond end of memory");
+		goto disable;
+	}
+
+	size = initrd_end - initrd_start;
+	memblock_reserve(__pa(initrd_start), size);
+	initrd_below_start_ok = 1;
+
+	pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
+		(void *)(initrd_start), size);
+	return;
+disable:
+	pr_cont(" - disabling initrd\n");
+	initrd_start = 0;
+	initrd_end = 0;
 }
 #endif /* CONFIG_BLK_DEV_INITRD */
+
+static phys_addr_t dtb_early_pa __initdata;
+
+void __init setup_bootmem(void)
+{
+	struct memblock_region *reg;
+	phys_addr_t mem_size = 0;
+	phys_addr_t vmlinux_end = __pa(&_end);
+	phys_addr_t vmlinux_start = __pa(&_start);
+
+	/* Find the memory region containing the kernel */
+	for_each_memblock(memory, reg) {
+		phys_addr_t end = reg->base + reg->size;
+
+		if (reg->base <= vmlinux_end && vmlinux_end <= end) {
+			mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
+
+			/*
+			 * Remove memblock from the end of usable area to the
+			 * end of region
+			 */
+			if (reg->base + mem_size < end)
+				memblock_remove(reg->base + mem_size,
+						end - reg->base - mem_size);
+		}
+	}
+	BUG_ON(mem_size == 0);
+
+	/* Reserve from the start of the kernel to the end of the kernel */
+	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
+
+	set_max_mapnr(PFN_DOWN(mem_size));
+	max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	setup_initrd();
+#endif /* CONFIG_BLK_DEV_INITRD */
+
+	/*
+	 * Avoid using early_init_fdt_reserve_self() since __pa() does
+	 * not work for DTB pointers that are fixmap addresses
+	 */
+	memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
+
+	early_init_fdt_scan_reserved_mem();
+	memblock_allow_resize();
+	memblock_dump_all();
+
+	for_each_memblock(memory, reg) {
+		unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
+		unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
+
+		memblock_set_node(PFN_PHYS(start_pfn),
+				  PFN_PHYS(end_pfn - start_pfn),
+				  &memblock.memory, 0);
+	}
+}
+
+unsigned long va_pa_offset;
+EXPORT_SYMBOL(va_pa_offset);
+unsigned long pfn_base;
+EXPORT_SYMBOL(pfn_base);
+
+void *dtb_early_va;
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
+pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
+pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
+static bool mmu_enabled;
+
+#define MAX_EARLY_MAPPING_SIZE	SZ_128M
+
+pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
+
+void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
+{
+	unsigned long addr = __fix_to_virt(idx);
+	pte_t *ptep;
+
+	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
+
+	ptep = &fixmap_pte[pte_index(addr)];
+
+	if (pgprot_val(prot)) {
+		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
+	} else {
+		pte_clear(&init_mm, addr, ptep);
+		local_flush_tlb_page(addr);
+	}
+}
+
+static pte_t *__init get_pte_virt(phys_addr_t pa)
+{
+	if (mmu_enabled) {
+		clear_fixmap(FIX_PTE);
+		return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
+	} else {
+		return (pte_t *)((uintptr_t)pa);
+	}
+}
+
+static phys_addr_t __init alloc_pte(uintptr_t va)
+{
+	/*
+	 * We only create PMD or PGD early mappings so we
+	 * should never reach here with MMU disabled.
+	 */
+	BUG_ON(!mmu_enabled);
+
+	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+}
+
+static void __init create_pte_mapping(pte_t *ptep,
+				      uintptr_t va, phys_addr_t pa,
+				      phys_addr_t sz, pgprot_t prot)
+{
+	uintptr_t pte_index = pte_index(va);
+
+	BUG_ON(sz != PAGE_SIZE);
+
+	if (pte_none(ptep[pte_index]))
+		ptep[pte_index] = pfn_pte(PFN_DOWN(pa), prot);
+}
+
+#ifndef __PAGETABLE_PMD_FOLDED
+
+pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
+pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
+
+#if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
+#define NUM_EARLY_PMDS		1UL
+#else
+#define NUM_EARLY_PMDS		(1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
+#endif
+pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
+
+static pmd_t *__init get_pmd_virt(phys_addr_t pa)
+{
+	if (mmu_enabled) {
+		clear_fixmap(FIX_PMD);
+		return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
+	} else {
+		return (pmd_t *)((uintptr_t)pa);
+	}
+}
+
+static phys_addr_t __init alloc_pmd(uintptr_t va)
+{
+	uintptr_t pmd_num;
+
+	if (mmu_enabled)
+		return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+
+	pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
+	BUG_ON(pmd_num >= NUM_EARLY_PMDS);
+	return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
+}
+
+static void __init create_pmd_mapping(pmd_t *pmdp,
+				      uintptr_t va, phys_addr_t pa,
+				      phys_addr_t sz, pgprot_t prot)
+{
+	pte_t *ptep;
+	phys_addr_t pte_phys;
+	uintptr_t pmd_index = pmd_index(va);
+
+	if (sz == PMD_SIZE) {
+		if (pmd_none(pmdp[pmd_index]))
+			pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pa), prot);
+		return;
+	}
+
+	if (pmd_none(pmdp[pmd_index])) {
+		pte_phys = alloc_pte(va);
+		pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
+		ptep = get_pte_virt(pte_phys);
+		memset(ptep, 0, PAGE_SIZE);
+	} else {
+		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_index]));
+		ptep = get_pte_virt(pte_phys);
+	}
+
+	create_pte_mapping(ptep, va, pa, sz, prot);
+}
+
+#define pgd_next_t		pmd_t
+#define alloc_pgd_next(__va)	alloc_pmd(__va)
+#define get_pgd_next_virt(__pa)	get_pmd_virt(__pa)
+#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
+	create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
+#define PTE_PARENT_SIZE		PMD_SIZE
+#define fixmap_pgd_next		fixmap_pmd
+#else
+#define pgd_next_t		pte_t
+#define alloc_pgd_next(__va)	alloc_pte(__va)
+#define get_pgd_next_virt(__pa)	get_pte_virt(__pa)
+#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
+	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
+#define PTE_PARENT_SIZE		PGDIR_SIZE
+#define fixmap_pgd_next		fixmap_pte
+#endif
+
+static void __init create_pgd_mapping(pgd_t *pgdp,
+				      uintptr_t va, phys_addr_t pa,
+				      phys_addr_t sz, pgprot_t prot)
+{
+	pgd_next_t *nextp;
+	phys_addr_t next_phys;
+	uintptr_t pgd_index = pgd_index(va);
+
+	if (sz == PGDIR_SIZE) {
+		if (pgd_val(pgdp[pgd_index]) == 0)
+			pgdp[pgd_index] = pfn_pgd(PFN_DOWN(pa), prot);
+		return;
+	}
+
+	if (pgd_val(pgdp[pgd_index]) == 0) {
+		next_phys = alloc_pgd_next(va);
+		pgdp[pgd_index] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
+		nextp = get_pgd_next_virt(next_phys);
+		memset(nextp, 0, PAGE_SIZE);
+	} else {
+		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_index]));
+		nextp = get_pgd_next_virt(next_phys);
+	}
+
+	create_pgd_next_mapping(nextp, va, pa, sz, prot);
+}
+
+static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
+{
+	uintptr_t map_size = PAGE_SIZE;
+
+	/* Upgrade to PMD/PGDIR mappings whenever possible */
+	if (!(base & (PTE_PARENT_SIZE - 1)) &&
+	    !(size & (PTE_PARENT_SIZE - 1)))
+		map_size = PTE_PARENT_SIZE;
+
+	return map_size;
+}
+
+/*
+ * setup_vm() is called from head.S with MMU-off.
+ *
+ * Following requirements should be honoured for setup_vm() to work
+ * correctly:
+ * 1) It should use PC-relative addressing for accessing kernel symbols.
+ *    To achieve this we always use GCC cmodel=medany.
+ * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
+ *    so disable compiler instrumentation when FTRACE is enabled.
+ *
+ * Currently, the above requirements are honoured by using custom CFLAGS
+ * for init.o in mm/Makefile.
+ */
+
+#ifndef __riscv_cmodel_medany
+#error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
+#endif
+
+asmlinkage void __init setup_vm(uintptr_t dtb_pa)
+{
+	uintptr_t va, end_va;
+	uintptr_t load_pa = (uintptr_t)(&_start);
+	uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
+	uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
+
+	va_pa_offset = PAGE_OFFSET - load_pa;
+	pfn_base = PFN_DOWN(load_pa);
+
+	/*
+	 * Enforce boot alignment requirements of RV32 and
+	 * RV64 by only allowing PMD or PGD mappings.
+	 */
+	BUG_ON(map_size == PAGE_SIZE);
+
+	/* Sanity check alignment and size */
+	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
+	BUG_ON((load_pa % map_size) != 0);
+	BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
+
+	/* Setup early PGD for fixmap */
+	create_pgd_mapping(early_pg_dir, FIXADDR_START,
+			   (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
+
+#ifndef __PAGETABLE_PMD_FOLDED
+	/* Setup fixmap PMD */
+	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
+			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
+	/* Setup trampoline PGD and PMD */
+	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
+			   (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
+	create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
+			   load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
+#else
+	/* Setup trampoline PGD */
+	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
+			   load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
+#endif
+
+	/*
+	 * Setup early PGD covering entire kernel which will allows
+	 * us to reach paging_init(). We map all memory banks later
+	 * in setup_vm_final() below.
+	 */
+	end_va = PAGE_OFFSET + load_sz;
+	for (va = PAGE_OFFSET; va < end_va; va += map_size)
+		create_pgd_mapping(early_pg_dir, va,
+				   load_pa + (va - PAGE_OFFSET),
+				   map_size, PAGE_KERNEL_EXEC);
+
+	/* Create fixed mapping for early FDT parsing */
+	end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
+	for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
+		create_pte_mapping(fixmap_pte, va,
+				   dtb_pa + (va - __fix_to_virt(FIX_FDT)),
+				   PAGE_SIZE, PAGE_KERNEL);
+
+	/* Save pointer to DTB for early FDT parsing */
+	dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
+	/* Save physical address for memblock reservation */
+	dtb_early_pa = dtb_pa;
+}
+
+static void __init setup_vm_final(void)
+{
+	uintptr_t va, map_size;
+	phys_addr_t pa, start, end;
+	struct memblock_region *reg;
+
+	/* Set mmu_enabled flag */
+	mmu_enabled = true;
+
+	/* Setup swapper PGD for fixmap */
+	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
+			   __pa(fixmap_pgd_next),
+			   PGDIR_SIZE, PAGE_TABLE);
+
+	/* Map all memory banks */
+	for_each_memblock(memory, reg) {
+		start = reg->base;
+		end = start + reg->size;
+
+		if (start >= end)
+			break;
+		if (memblock_is_nomap(reg))
+			continue;
+		if (start <= __pa(PAGE_OFFSET) &&
+		    __pa(PAGE_OFFSET) < end)
+			start = __pa(PAGE_OFFSET);
+
+		map_size = best_map_size(start, end - start);
+		for (pa = start; pa < end; pa += map_size) {
+			va = (uintptr_t)__va(pa);
+			create_pgd_mapping(swapper_pg_dir, va, pa,
+					   map_size, PAGE_KERNEL_EXEC);
+		}
+	}
+
+	/* Clear fixmap PTE and PMD mappings */
+	clear_fixmap(FIX_PTE);
+	clear_fixmap(FIX_PMD);
+
+	/* Move to swapper page table */
+	csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | SATP_MODE);
+	local_flush_tlb_all();
+}
+
+void __init paging_init(void)
+{
+	setup_vm_final();
+	memblocks_present();
+	sparse_init();
+	setup_zero_page();
+	zone_sizes_init();
+}
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
+			       struct vmem_altmap *altmap)
+{
+	return vmemmap_populate_basepages(start, end, node);
+}
+#endif