Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 226 insertions, 0 deletions

diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c
new file mode 100644
index 000000000..c5e262229
--- /dev/null
+++ b/arch/m68k/mm/mcfmmu.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Based upon linux/arch/m68k/mm/sun3mmu.c
+ * Based upon linux/arch/ppc/mm/mmu_context.c
+ *
+ * Implementations of mm routines specific to the Coldfire MMU.
+ *
+ * Copyright (c) 2008 Freescale Semiconductor, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/mmu_context.h>
+#include <asm/mcf_pgalloc.h>
+#include <asm/tlbflush.h>
+
+#define KMAPAREA(x)	((x >= VMALLOC_START) && (x < KMAP_END))
+
+mm_context_t next_mmu_context;
+unsigned long context_map[LAST_CONTEXT / BITS_PER_LONG + 1];
+atomic_t nr_free_contexts;
+struct mm_struct *context_mm[LAST_CONTEXT+1];
+unsigned long num_pages;
+
+/*
+ * ColdFire paging_init derived from sun3.
+ */
+void __init paging_init(void)
+{
+	pgd_t *pg_dir;
+	pte_t *pg_table;
+	unsigned long address, size;
+	unsigned long next_pgtable, bootmem_end;
+	unsigned long zones_size[MAX_NR_ZONES];
+	enum zone_type zone;
+	int i;
+
+	empty_zero_page = (void *) alloc_bootmem_pages(PAGE_SIZE);
+	memset((void *) empty_zero_page, 0, PAGE_SIZE);
+
+	pg_dir = swapper_pg_dir;
+	memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
+
+	size = num_pages * sizeof(pte_t);
+	size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
+	next_pgtable = (unsigned long) alloc_bootmem_pages(size);
+
+	bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
+	pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
+
+	address = PAGE_OFFSET;
+	while (address < (unsigned long)high_memory) {
+		pg_table = (pte_t *) next_pgtable;
+		next_pgtable += PTRS_PER_PTE * sizeof(pte_t);
+		pgd_val(*pg_dir) = (unsigned long) pg_table;
+		pg_dir++;
+
+		/* now change pg_table to kernel virtual addresses */
+		for (i = 0; i < PTRS_PER_PTE; ++i, ++pg_table) {
+			pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
+			if (address >= (unsigned long) high_memory)
+				pte_val(pte) = 0;
+
+			set_pte(pg_table, pte);
+			address += PAGE_SIZE;
+		}
+	}
+
+	current->mm = NULL;
+
+	for (zone = 0; zone < MAX_NR_ZONES; zone++)
+		zones_size[zone] = 0x0;
+	zones_size[ZONE_DMA] = num_pages;
+	free_area_init(zones_size);
+}
+
+int cf_tlb_miss(struct pt_regs *regs, int write, int dtlb, int extension_word)
+{
+	unsigned long flags, mmuar, mmutr;
+	struct mm_struct *mm;
+	pgd_t *pgd;
+	pmd_t *pmd;
+	pte_t *pte;
+	int asid;
+
+	local_irq_save(flags);
+
+	mmuar = (dtlb) ? mmu_read(MMUAR) :
+		regs->pc + (extension_word * sizeof(long));
+
+	mm = (!user_mode(regs) && KMAPAREA(mmuar)) ? &init_mm : current->mm;
+	if (!mm) {
+		local_irq_restore(flags);
+		return -1;
+	}
+
+	pgd = pgd_offset(mm, mmuar);
+	if (pgd_none(*pgd))  {
+		local_irq_restore(flags);
+		return -1;
+	}
+
+	pmd = pmd_offset(pgd, mmuar);
+	if (pmd_none(*pmd)) {
+		local_irq_restore(flags);
+		return -1;
+	}
+
+	pte = (KMAPAREA(mmuar)) ? pte_offset_kernel(pmd, mmuar)
+				: pte_offset_map(pmd, mmuar);
+	if (pte_none(*pte) || !pte_present(*pte)) {
+		local_irq_restore(flags);
+		return -1;
+	}
+
+	if (write) {
+		if (!pte_write(*pte)) {
+			local_irq_restore(flags);
+			return -1;
+		}
+		set_pte(pte, pte_mkdirty(*pte));
+	}
+
+	set_pte(pte, pte_mkyoung(*pte));
+	asid = mm->context & 0xff;
+	if (!pte_dirty(*pte) && !KMAPAREA(mmuar))
+		set_pte(pte, pte_wrprotect(*pte));
+
+	mmutr = (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) | MMUTR_V;
+	if ((mmuar < TASK_UNMAPPED_BASE) || (mmuar >= TASK_SIZE))
+		mmutr |= (pte->pte & CF_PAGE_MMUTR_MASK) >> CF_PAGE_MMUTR_SHIFT;
+	mmu_write(MMUTR, mmutr);
+
+	mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) |
+		((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X);
+
+	if (dtlb)
+		mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA);
+	else
+		mmu_write(MMUOR, MMUOR_ITLB | MMUOR_ACC | MMUOR_UAA);
+
+	local_irq_restore(flags);
+	return 0;
+}
+
+void __init cf_bootmem_alloc(void)
+{
+	unsigned long memstart;
+
+	/* _rambase and _ramend will be naturally page aligned */
+	m68k_memory[0].addr = _rambase;
+	m68k_memory[0].size = _ramend - _rambase;
+
+	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0);
+
+	/* compute total pages in system */
+	num_pages = PFN_DOWN(_ramend - _rambase);
+
+	/* page numbers */
+	memstart = PAGE_ALIGN(_ramstart);
+	min_low_pfn = PFN_DOWN(_rambase);
+	max_pfn = max_low_pfn = PFN_DOWN(_ramend);
+	high_memory = (void *)_ramend;
+
+	/* Reserve kernel text/data/bss */
+	memblock_reserve(_rambase, memstart - _rambase);
+
+	m68k_virt_to_node_shift = fls(_ramend - 1) - 6;
+	module_fixup(NULL, __start_fixup, __stop_fixup);
+
+	/* setup node data */
+	m68k_setup_node(0);
+}
+
+/*
+ * Initialize the context management stuff.
+ * The following was taken from arch/ppc/mmu_context.c
+ */
+void __init cf_mmu_context_init(void)
+{
+	/*
+	 * Some processors have too few contexts to reserve one for
+	 * init_mm, and require using context 0 for a normal task.
+	 * Other processors reserve the use of context zero for the kernel.
+	 * This code assumes FIRST_CONTEXT < 32.
+	 */
+	context_map[0] = (1 << FIRST_CONTEXT) - 1;
+	next_mmu_context = FIRST_CONTEXT;
+	atomic_set(&nr_free_contexts, LAST_CONTEXT - FIRST_CONTEXT + 1);
+}
+
+/*
+ * Steal a context from a task that has one at the moment.
+ * This is only used on 8xx and 4xx and we presently assume that
+ * they don't do SMP.  If they do then thicfpgalloc.hs will have to check
+ * whether the MM we steal is in use.
+ * We also assume that this is only used on systems that don't
+ * use an MMU hash table - this is true for 8xx and 4xx.
+ * This isn't an LRU system, it just frees up each context in
+ * turn (sort-of pseudo-random replacement :).  This would be the
+ * place to implement an LRU scheme if anyone was motivated to do it.
+ *  -- paulus
+ */
+void steal_context(void)
+{
+	struct mm_struct *mm;
+	/*
+	 * free up context `next_mmu_context'
+	 * if we shouldn't free context 0, don't...
+	 */
+	if (next_mmu_context < FIRST_CONTEXT)
+		next_mmu_context = FIRST_CONTEXT;
+	mm = context_mm[next_mmu_context];
+	flush_tlb_mm(mm);
+	destroy_context(mm);
+}
+