Adding upstream version 5.10.209.upstream/5.10.209

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

1 files changed, 481 insertions, 0 deletions

diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
new file mode 100644
index 000000000..3a653f0a4
--- /dev/null
+++ b/arch/m68k/mm/motorola.c
@@ -0,0 +1,481 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/m68k/mm/motorola.c
+ *
+ * Routines specific to the Motorola MMU, originally from:
+ * linux/arch/m68k/init.c
+ * which are Copyright (C) 1995 Hamish Macdonald
+ *
+ * Moved 8/20/1999 Sam Creasey
+ */
+
+#include <linux/module.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/gfp.h>
+
+#include <asm/setup.h>
+#include <linux/uaccess.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/dma.h>
+#ifdef CONFIG_ATARI
+#include <asm/atari_stram.h>
+#endif
+#include <asm/sections.h>
+
+#undef DEBUG
+
+#ifndef mm_cachebits
+/*
+ * Bits to add to page descriptors for "normal" caching mode.
+ * For 68020/030 this is 0.
+ * For 68040, this is _PAGE_CACHE040 (cachable, copyback)
+ */
+unsigned long mm_cachebits;
+EXPORT_SYMBOL(mm_cachebits);
+#endif
+
+/* Prior to calling these routines, the page should have been flushed
+ * from both the cache and ATC, or the CPU might not notice that the
+ * cache setting for the page has been changed. -jskov
+ */
+static inline void nocache_page(void *vaddr)
+{
+	unsigned long addr = (unsigned long)vaddr;
+
+	if (CPU_IS_040_OR_060) {
+		pte_t *ptep = virt_to_kpte(addr);
+
+		*ptep = pte_mknocache(*ptep);
+	}
+}
+
+static inline void cache_page(void *vaddr)
+{
+	unsigned long addr = (unsigned long)vaddr;
+
+	if (CPU_IS_040_OR_060) {
+		pte_t *ptep = virt_to_kpte(addr);
+
+		*ptep = pte_mkcache(*ptep);
+	}
+}
+
+/*
+ * Motorola 680x0 user's manual recommends using uncached memory for address
+ * translation tables.
+ *
+ * Seeing how the MMU can be external on (some of) these chips, that seems like
+ * a very important recommendation to follow. Provide some helpers to combat
+ * 'variation' amongst the users of this.
+ */
+
+void mmu_page_ctor(void *page)
+{
+	__flush_page_to_ram(page);
+	flush_tlb_kernel_page(page);
+	nocache_page(page);
+}
+
+void mmu_page_dtor(void *page)
+{
+	cache_page(page);
+}
+
+/* ++andreas: {get,free}_pointer_table rewritten to use unused fields from
+   struct page instead of separately kmalloced struct.  Stolen from
+   arch/sparc/mm/srmmu.c ... */
+
+typedef struct list_head ptable_desc;
+
+static struct list_head ptable_list[2] = {
+	LIST_HEAD_INIT(ptable_list[0]),
+	LIST_HEAD_INIT(ptable_list[1]),
+};
+
+#define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page(page)->lru))
+#define PD_PAGE(ptable) (list_entry(ptable, struct page, lru))
+#define PD_MARKBITS(dp) (*(unsigned int *)&PD_PAGE(dp)->index)
+
+static const int ptable_shift[2] = {
+	7+2, /* PGD, PMD */
+	6+2, /* PTE */
+};
+
+#define ptable_size(type) (1U << ptable_shift[type])
+#define ptable_mask(type) ((1U << (PAGE_SIZE / ptable_size(type))) - 1)
+
+void __init init_pointer_table(void *table, int type)
+{
+	ptable_desc *dp;
+	unsigned long ptable = (unsigned long)table;
+	unsigned long page = ptable & PAGE_MASK;
+	unsigned int mask = 1U << ((ptable - page)/ptable_size(type));
+
+	dp = PD_PTABLE(page);
+	if (!(PD_MARKBITS(dp) & mask)) {
+		PD_MARKBITS(dp) = ptable_mask(type);
+		list_add(dp, &ptable_list[type]);
+	}
+
+	PD_MARKBITS(dp) &= ~mask;
+	pr_debug("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp));
+
+	/* unreserve the page so it's possible to free that page */
+	__ClearPageReserved(PD_PAGE(dp));
+	init_page_count(PD_PAGE(dp));
+
+	return;
+}
+
+void *get_pointer_table(int type)
+{
+	ptable_desc *dp = ptable_list[type].next;
+	unsigned int mask = list_empty(&ptable_list[type]) ? 0 : PD_MARKBITS(dp);
+	unsigned int tmp, off;
+
+	/*
+	 * For a pointer table for a user process address space, a
+	 * table is taken from a page allocated for the purpose.  Each
+	 * page can hold 8 pointer tables.  The page is remapped in
+	 * virtual address space to be noncacheable.
+	 */
+	if (mask == 0) {
+		void *page;
+		ptable_desc *new;
+
+		if (!(page = (void *)get_zeroed_page(GFP_KERNEL)))
+			return NULL;
+
+		if (type == TABLE_PTE) {
+			/*
+			 * m68k doesn't have SPLIT_PTE_PTLOCKS for not having
+			 * SMP.
+			 */
+			pgtable_pte_page_ctor(virt_to_page(page));
+		}
+
+		mmu_page_ctor(page);
+
+		new = PD_PTABLE(page);
+		PD_MARKBITS(new) = ptable_mask(type) - 1;
+		list_add_tail(new, dp);
+
+		return (pmd_t *)page;
+	}
+
+	for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += ptable_size(type))
+		;
+	PD_MARKBITS(dp) = mask & ~tmp;
+	if (!PD_MARKBITS(dp)) {
+		/* move to end of list */
+		list_move_tail(dp, &ptable_list[type]);
+	}
+	return page_address(PD_PAGE(dp)) + off;
+}
+
+int free_pointer_table(void *table, int type)
+{
+	ptable_desc *dp;
+	unsigned long ptable = (unsigned long)table;
+	unsigned long page = ptable & PAGE_MASK;
+	unsigned int mask = 1U << ((ptable - page)/ptable_size(type));
+
+	dp = PD_PTABLE(page);
+	if (PD_MARKBITS (dp) & mask)
+		panic ("table already free!");
+
+	PD_MARKBITS (dp) |= mask;
+
+	if (PD_MARKBITS(dp) == ptable_mask(type)) {
+		/* all tables in page are free, free page */
+		list_del(dp);
+		mmu_page_dtor((void *)page);
+		if (type == TABLE_PTE)
+			pgtable_pte_page_dtor(virt_to_page(page));
+		free_page (page);
+		return 1;
+	} else if (ptable_list[type].next != dp) {
+		/*
+		 * move this descriptor to the front of the list, since
+		 * it has one or more free tables.
+		 */
+		list_move(dp, &ptable_list[type]);
+	}
+	return 0;
+}
+
+/* size of memory already mapped in head.S */
+extern __initdata unsigned long m68k_init_mapped_size;
+
+extern unsigned long availmem;
+
+static pte_t *last_pte_table __initdata = NULL;
+
+static pte_t * __init kernel_page_table(void)
+{
+	pte_t *pte_table = last_pte_table;
+
+	if (PAGE_ALIGNED(last_pte_table)) {
+		pte_table = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
+		if (!pte_table) {
+			panic("%s: Failed to allocate %lu bytes align=%lx\n",
+					__func__, PAGE_SIZE, PAGE_SIZE);
+		}
+
+		clear_page(pte_table);
+		mmu_page_ctor(pte_table);
+
+		last_pte_table = pte_table;
+	}
+
+	last_pte_table += PTRS_PER_PTE;
+
+	return pte_table;
+}
+
+static pmd_t *last_pmd_table __initdata = NULL;
+
+static pmd_t * __init kernel_ptr_table(void)
+{
+	if (!last_pmd_table) {
+		unsigned long pmd, last;
+		int i;
+
+		/* Find the last ptr table that was used in head.S and
+		 * reuse the remaining space in that page for further
+		 * ptr tables.
+		 */
+		last = (unsigned long)kernel_pg_dir;
+		for (i = 0; i < PTRS_PER_PGD; i++) {
+			pud_t *pud = (pud_t *)(&kernel_pg_dir[i]);
+
+			if (!pud_present(*pud))
+				continue;
+			pmd = pgd_page_vaddr(kernel_pg_dir[i]);
+			if (pmd > last)
+				last = pmd;
+		}
+
+		last_pmd_table = (pmd_t *)last;
+#ifdef DEBUG
+		printk("kernel_ptr_init: %p\n", last_pmd_table);
+#endif
+	}
+
+	last_pmd_table += PTRS_PER_PMD;
+	if (PAGE_ALIGNED(last_pmd_table)) {
+		last_pmd_table = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
+		if (!last_pmd_table)
+			panic("%s: Failed to allocate %lu bytes align=%lx\n",
+			      __func__, PAGE_SIZE, PAGE_SIZE);
+
+		clear_page(last_pmd_table);
+		mmu_page_ctor(last_pmd_table);
+	}
+
+	return last_pmd_table;
+}
+
+static void __init map_node(int node)
+{
+	unsigned long physaddr, virtaddr, size;
+	pgd_t *pgd_dir;
+	p4d_t *p4d_dir;
+	pud_t *pud_dir;
+	pmd_t *pmd_dir;
+	pte_t *pte_dir;
+
+	size = m68k_memory[node].size;
+	physaddr = m68k_memory[node].addr;
+	virtaddr = (unsigned long)phys_to_virt(physaddr);
+	physaddr |= m68k_supervisor_cachemode |
+		    _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY;
+	if (CPU_IS_040_OR_060)
+		physaddr |= _PAGE_GLOBAL040;
+
+	while (size > 0) {
+#ifdef DEBUG
+		if (!(virtaddr & (PMD_SIZE-1)))
+			printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK,
+				virtaddr);
+#endif
+		pgd_dir = pgd_offset_k(virtaddr);
+		if (virtaddr && CPU_IS_020_OR_030) {
+			if (!(virtaddr & (PGDIR_SIZE-1)) &&
+			    size >= PGDIR_SIZE) {
+#ifdef DEBUG
+				printk ("[very early term]");
+#endif
+				pgd_val(*pgd_dir) = physaddr;
+				size -= PGDIR_SIZE;
+				virtaddr += PGDIR_SIZE;
+				physaddr += PGDIR_SIZE;
+				continue;
+			}
+		}
+		p4d_dir = p4d_offset(pgd_dir, virtaddr);
+		pud_dir = pud_offset(p4d_dir, virtaddr);
+		if (!pud_present(*pud_dir)) {
+			pmd_dir = kernel_ptr_table();
+#ifdef DEBUG
+			printk ("[new pointer %p]", pmd_dir);
+#endif
+			pud_set(pud_dir, pmd_dir);
+		} else
+			pmd_dir = pmd_offset(pud_dir, virtaddr);
+
+		if (CPU_IS_020_OR_030) {
+			if (virtaddr) {
+#ifdef DEBUG
+				printk ("[early term]");
+#endif
+				pmd_val(*pmd_dir) = physaddr;
+				physaddr += PMD_SIZE;
+			} else {
+				int i;
+#ifdef DEBUG
+				printk ("[zero map]");
+#endif
+				pte_dir = kernel_page_table();
+				pmd_set(pmd_dir, pte_dir);
+
+				pte_val(*pte_dir++) = 0;
+				physaddr += PAGE_SIZE;
+				for (i = 1; i < PTRS_PER_PTE; physaddr += PAGE_SIZE, i++)
+					pte_val(*pte_dir++) = physaddr;
+			}
+			size -= PMD_SIZE;
+			virtaddr += PMD_SIZE;
+		} else {
+			if (!pmd_present(*pmd_dir)) {
+#ifdef DEBUG
+				printk ("[new table]");
+#endif
+				pte_dir = kernel_page_table();
+				pmd_set(pmd_dir, pte_dir);
+			}
+			pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
+
+			if (virtaddr) {
+				if (!pte_present(*pte_dir))
+					pte_val(*pte_dir) = physaddr;
+			} else
+				pte_val(*pte_dir) = 0;
+			size -= PAGE_SIZE;
+			virtaddr += PAGE_SIZE;
+			physaddr += PAGE_SIZE;
+		}
+
+	}
+#ifdef DEBUG
+	printk("\n");
+#endif
+}
+
+/*
+ * paging_init() continues the virtual memory environment setup which
+ * was begun by the code in arch/head.S.
+ */
+void __init paging_init(void)
+{
+	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
+	unsigned long min_addr, max_addr;
+	unsigned long addr;
+	int i;
+
+#ifdef DEBUG
+	printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem);
+#endif
+
+	/* Fix the cache mode in the page descriptors for the 680[46]0.  */
+	if (CPU_IS_040_OR_060) {
+		int i;
+#ifndef mm_cachebits
+		mm_cachebits = _PAGE_CACHE040;
+#endif
+		for (i = 0; i < 16; i++)
+			pgprot_val(protection_map[i]) |= _PAGE_CACHE040;
+	}
+
+	min_addr = m68k_memory[0].addr;
+	max_addr = min_addr + m68k_memory[0].size;
+	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0);
+	for (i = 1; i < m68k_num_memory;) {
+		if (m68k_memory[i].addr < min_addr) {
+			printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n",
+				m68k_memory[i].addr, m68k_memory[i].size);
+			printk("Fix your bootloader or use a memfile to make use of this area!\n");
+			m68k_num_memory--;
+			memmove(m68k_memory + i, m68k_memory + i + 1,
+				(m68k_num_memory - i) * sizeof(struct m68k_mem_info));
+			continue;
+		}
+		memblock_add_node(m68k_memory[i].addr, m68k_memory[i].size, i);
+		addr = m68k_memory[i].addr + m68k_memory[i].size;
+		if (addr > max_addr)
+			max_addr = addr;
+		i++;
+	}
+	m68k_memoffset = min_addr - PAGE_OFFSET;
+	m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6;
+
+	module_fixup(NULL, __start_fixup, __stop_fixup);
+	flush_icache();
+
+	high_memory = phys_to_virt(max_addr);
+
+	min_low_pfn = availmem >> PAGE_SHIFT;
+	max_pfn = max_low_pfn = max_addr >> PAGE_SHIFT;
+
+	/* Reserve kernel text/data/bss and the memory allocated in head.S */
+	memblock_reserve(m68k_memory[0].addr, availmem - m68k_memory[0].addr);
+
+	/*
+	 * Map the physical memory available into the kernel virtual
+	 * address space. Make sure memblock will not try to allocate
+	 * pages beyond the memory we already mapped in head.S
+	 */
+	memblock_set_bottom_up(true);
+
+	for (i = 0; i < m68k_num_memory; i++) {
+		m68k_setup_node(i);
+		map_node(i);
+	}
+
+	flush_tlb_all();
+
+	/*
+	 * initialize the bad page table and bad page to point
+	 * to a couple of allocated pages
+	 */
+	empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+	if (!empty_zero_page)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+		      __func__, PAGE_SIZE, PAGE_SIZE);
+
+	/*
+	 * Set up SFC/DFC registers
+	 */
+	set_fs(KERNEL_DS);
+
+#ifdef DEBUG
+	printk ("before free_area_init\n");
+#endif
+	for (i = 0; i < m68k_num_memory; i++)
+		if (node_present_pages(i))
+			node_set_state(i, N_NORMAL_MEMORY);
+
+	max_zone_pfn[ZONE_DMA] = memblock_end_of_DRAM();
+	free_area_init(max_zone_pfn);
+}