summaryrefslogtreecommitdiffstats
path: root/arch/parisc/mm/init.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/parisc/mm/init.c')
-rw-r--r--arch/parisc/mm/init.c893
1 files changed, 893 insertions, 0 deletions
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
new file mode 100644
index 000000000..b0c43f3b0
--- /dev/null
+++ b/arch/parisc/mm/init.c
@@ -0,0 +1,893 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/parisc/mm/init.c
+ *
+ * Copyright (C) 1995 Linus Torvalds
+ * Copyright 1999 SuSE GmbH
+ * changed by Philipp Rumpf
+ * Copyright 1999 Philipp Rumpf (prumpf@tux.org)
+ * Copyright 2004 Randolph Chung (tausq@debian.org)
+ * Copyright 2006-2007 Helge Deller (deller@gmx.de)
+ *
+ */
+
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/memblock.h>
+#include <linux/gfp.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/initrd.h>
+#include <linux/swap.h>
+#include <linux/unistd.h>
+#include <linux/nodemask.h> /* for node_online_map */
+#include <linux/pagemap.h> /* for release_pages */
+#include <linux/compat.h>
+
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/pdc_chassis.h>
+#include <asm/mmzone.h>
+#include <asm/sections.h>
+#include <asm/msgbuf.h>
+#include <asm/sparsemem.h>
+
+extern int data_start;
+extern void parisc_kernel_start(void); /* Kernel entry point in head.S */
+
+#if CONFIG_PGTABLE_LEVELS == 3
+pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE)));
+#endif
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE)));
+pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE)));
+
+static struct resource data_resource = {
+ .name = "Kernel data",
+ .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+};
+
+static struct resource code_resource = {
+ .name = "Kernel code",
+ .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+};
+
+static struct resource pdcdata_resource = {
+ .name = "PDC data (Page Zero)",
+ .start = 0,
+ .end = 0x9ff,
+ .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
+};
+
+static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init;
+
+/* The following array is initialized from the firmware specific
+ * information retrieved in kernel/inventory.c.
+ */
+
+physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata;
+int npmem_ranges __initdata;
+
+#ifdef CONFIG_64BIT
+#define MAX_MEM (1UL << MAX_PHYSMEM_BITS)
+#else /* !CONFIG_64BIT */
+#define MAX_MEM (3584U*1024U*1024U)
+#endif /* !CONFIG_64BIT */
+
+static unsigned long mem_limit __read_mostly = MAX_MEM;
+
+static void __init mem_limit_func(void)
+{
+ char *cp, *end;
+ unsigned long limit;
+
+ /* We need this before __setup() functions are called */
+
+ limit = MAX_MEM;
+ for (cp = boot_command_line; *cp; ) {
+ if (memcmp(cp, "mem=", 4) == 0) {
+ cp += 4;
+ limit = memparse(cp, &end);
+ if (end != cp)
+ break;
+ cp = end;
+ } else {
+ while (*cp != ' ' && *cp)
+ ++cp;
+ while (*cp == ' ')
+ ++cp;
+ }
+ }
+
+ if (limit < mem_limit)
+ mem_limit = limit;
+}
+
+#define MAX_GAP (0x40000000UL >> PAGE_SHIFT)
+
+static void __init setup_bootmem(void)
+{
+ unsigned long mem_max;
+#ifndef CONFIG_SPARSEMEM
+ physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1];
+ int npmem_holes;
+#endif
+ int i, sysram_resource_count;
+
+ disable_sr_hashing(); /* Turn off space register hashing */
+
+ /*
+ * Sort the ranges. Since the number of ranges is typically
+ * small, and performance is not an issue here, just do
+ * a simple insertion sort.
+ */
+
+ for (i = 1; i < npmem_ranges; i++) {
+ int j;
+
+ for (j = i; j > 0; j--) {
+ if (pmem_ranges[j-1].start_pfn <
+ pmem_ranges[j].start_pfn) {
+
+ break;
+ }
+ swap(pmem_ranges[j-1], pmem_ranges[j]);
+ }
+ }
+
+#ifndef CONFIG_SPARSEMEM
+ /*
+ * Throw out ranges that are too far apart (controlled by
+ * MAX_GAP).
+ */
+
+ for (i = 1; i < npmem_ranges; i++) {
+ if (pmem_ranges[i].start_pfn -
+ (pmem_ranges[i-1].start_pfn +
+ pmem_ranges[i-1].pages) > MAX_GAP) {
+ npmem_ranges = i;
+ printk("Large gap in memory detected (%ld pages). "
+ "Consider turning on CONFIG_SPARSEMEM\n",
+ pmem_ranges[i].start_pfn -
+ (pmem_ranges[i-1].start_pfn +
+ pmem_ranges[i-1].pages));
+ break;
+ }
+ }
+#endif
+
+ /* Print the memory ranges */
+ pr_info("Memory Ranges:\n");
+
+ for (i = 0; i < npmem_ranges; i++) {
+ struct resource *res = &sysram_resources[i];
+ unsigned long start;
+ unsigned long size;
+
+ size = (pmem_ranges[i].pages << PAGE_SHIFT);
+ start = (pmem_ranges[i].start_pfn << PAGE_SHIFT);
+ pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n",
+ i, start, start + (size - 1), size >> 20);
+
+ /* request memory resource */
+ res->name = "System RAM";
+ res->start = start;
+ res->end = start + size - 1;
+ res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+ request_resource(&iomem_resource, res);
+ }
+
+ sysram_resource_count = npmem_ranges;
+
+ /*
+ * For 32 bit kernels we limit the amount of memory we can
+ * support, in order to preserve enough kernel address space
+ * for other purposes. For 64 bit kernels we don't normally
+ * limit the memory, but this mechanism can be used to
+ * artificially limit the amount of memory (and it is written
+ * to work with multiple memory ranges).
+ */
+
+ mem_limit_func(); /* check for "mem=" argument */
+
+ mem_max = 0;
+ for (i = 0; i < npmem_ranges; i++) {
+ unsigned long rsize;
+
+ rsize = pmem_ranges[i].pages << PAGE_SHIFT;
+ if ((mem_max + rsize) > mem_limit) {
+ printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20);
+ if (mem_max == mem_limit)
+ npmem_ranges = i;
+ else {
+ pmem_ranges[i].pages = (mem_limit >> PAGE_SHIFT)
+ - (mem_max >> PAGE_SHIFT);
+ npmem_ranges = i + 1;
+ mem_max = mem_limit;
+ }
+ break;
+ }
+ mem_max += rsize;
+ }
+
+ printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20);
+
+#ifndef CONFIG_SPARSEMEM
+ /* Merge the ranges, keeping track of the holes */
+ {
+ unsigned long end_pfn;
+ unsigned long hole_pages;
+
+ npmem_holes = 0;
+ end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages;
+ for (i = 1; i < npmem_ranges; i++) {
+
+ hole_pages = pmem_ranges[i].start_pfn - end_pfn;
+ if (hole_pages) {
+ pmem_holes[npmem_holes].start_pfn = end_pfn;
+ pmem_holes[npmem_holes++].pages = hole_pages;
+ end_pfn += hole_pages;
+ }
+ end_pfn += pmem_ranges[i].pages;
+ }
+
+ pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn;
+ npmem_ranges = 1;
+ }
+#endif
+
+ /*
+ * Initialize and free the full range of memory in each range.
+ */
+
+ max_pfn = 0;
+ for (i = 0; i < npmem_ranges; i++) {
+ unsigned long start_pfn;
+ unsigned long npages;
+ unsigned long start;
+ unsigned long size;
+
+ start_pfn = pmem_ranges[i].start_pfn;
+ npages = pmem_ranges[i].pages;
+
+ start = start_pfn << PAGE_SHIFT;
+ size = npages << PAGE_SHIFT;
+
+ /* add system RAM memblock */
+ memblock_add(start, size);
+
+ if ((start_pfn + npages) > max_pfn)
+ max_pfn = start_pfn + npages;
+ }
+
+ /*
+ * We can't use memblock top-down allocations because we only
+ * created the initial mapping up to KERNEL_INITIAL_SIZE in
+ * the assembly bootup code.
+ */
+ memblock_set_bottom_up(true);
+
+ /* IOMMU is always used to access "high mem" on those boxes
+ * that can support enough mem that a PCI device couldn't
+ * directly DMA to any physical addresses.
+ * ISA DMA support will need to revisit this.
+ */
+ max_low_pfn = max_pfn;
+
+ /* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */
+
+#define PDC_CONSOLE_IO_IODC_SIZE 32768
+
+ memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free +
+ PDC_CONSOLE_IO_IODC_SIZE));
+ memblock_reserve(__pa(KERNEL_BINARY_TEXT_START),
+ (unsigned long)(_end - KERNEL_BINARY_TEXT_START));
+
+#ifndef CONFIG_SPARSEMEM
+
+ /* reserve the holes */
+
+ for (i = 0; i < npmem_holes; i++) {
+ memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT),
+ (pmem_holes[i].pages << PAGE_SHIFT));
+ }
+#endif
+
+#ifdef CONFIG_BLK_DEV_INITRD
+ if (initrd_start) {
+ printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end);
+ if (__pa(initrd_start) < mem_max) {
+ unsigned long initrd_reserve;
+
+ if (__pa(initrd_end) > mem_max) {
+ initrd_reserve = mem_max - __pa(initrd_start);
+ } else {
+ initrd_reserve = initrd_end - initrd_start;
+ }
+ initrd_below_start_ok = 1;
+ printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max);
+
+ memblock_reserve(__pa(initrd_start), initrd_reserve);
+ }
+ }
+#endif
+
+ data_resource.start = virt_to_phys(&data_start);
+ data_resource.end = virt_to_phys(_end) - 1;
+ code_resource.start = virt_to_phys(_text);
+ code_resource.end = virt_to_phys(&data_start)-1;
+
+ /* We don't know which region the kernel will be in, so try
+ * all of them.
+ */
+ for (i = 0; i < sysram_resource_count; i++) {
+ struct resource *res = &sysram_resources[i];
+ request_resource(res, &code_resource);
+ request_resource(res, &data_resource);
+ }
+ request_resource(&sysram_resources[0], &pdcdata_resource);
+
+ /* Initialize Page Deallocation Table (PDT) and check for bad memory. */
+ pdc_pdt_init();
+
+ memblock_allow_resize();
+ memblock_dump_all();
+}
+
+static bool kernel_set_to_readonly;
+
+static void __ref map_pages(unsigned long start_vaddr,
+ unsigned long start_paddr, unsigned long size,
+ pgprot_t pgprot, int force)
+{
+ pmd_t *pmd;
+ pte_t *pg_table;
+ unsigned long end_paddr;
+ unsigned long start_pmd;
+ unsigned long start_pte;
+ unsigned long tmp1;
+ unsigned long tmp2;
+ unsigned long address;
+ unsigned long vaddr;
+ unsigned long ro_start;
+ unsigned long ro_end;
+ unsigned long kernel_start, kernel_end;
+
+ ro_start = __pa((unsigned long)_text);
+ ro_end = __pa((unsigned long)&data_start);
+ kernel_start = __pa((unsigned long)&__init_begin);
+ kernel_end = __pa((unsigned long)&_end);
+
+ end_paddr = start_paddr + size;
+
+ /* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */
+ start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1));
+ start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
+
+ address = start_paddr;
+ vaddr = start_vaddr;
+ while (address < end_paddr) {
+ pgd_t *pgd = pgd_offset_k(vaddr);
+ p4d_t *p4d = p4d_offset(pgd, vaddr);
+ pud_t *pud = pud_offset(p4d, vaddr);
+
+#if CONFIG_PGTABLE_LEVELS == 3
+ if (pud_none(*pud)) {
+ pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER,
+ PAGE_SIZE << PMD_TABLE_ORDER);
+ if (!pmd)
+ panic("pmd allocation failed.\n");
+ pud_populate(NULL, pud, pmd);
+ }
+#endif
+
+ pmd = pmd_offset(pud, vaddr);
+ for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) {
+ if (pmd_none(*pmd)) {
+ pg_table = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ if (!pg_table)
+ panic("page table allocation failed\n");
+ pmd_populate_kernel(NULL, pmd, pg_table);
+ }
+
+ pg_table = pte_offset_kernel(pmd, vaddr);
+ for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) {
+ pte_t pte;
+ pgprot_t prot;
+ bool huge = false;
+
+ if (force) {
+ prot = pgprot;
+ } else if (address < kernel_start || address >= kernel_end) {
+ /* outside kernel memory */
+ prot = PAGE_KERNEL;
+ } else if (!kernel_set_to_readonly) {
+ /* still initializing, allow writing to RO memory */
+ prot = PAGE_KERNEL_RWX;
+ huge = true;
+ } else if (address >= ro_start) {
+ /* Code (ro) and Data areas */
+ prot = (address < ro_end) ?
+ PAGE_KERNEL_EXEC : PAGE_KERNEL;
+ huge = true;
+ } else {
+ prot = PAGE_KERNEL;
+ }
+
+ pte = __mk_pte(address, prot);
+ if (huge)
+ pte = pte_mkhuge(pte);
+
+ if (address >= end_paddr)
+ break;
+
+ set_pte(pg_table, pte);
+
+ address += PAGE_SIZE;
+ vaddr += PAGE_SIZE;
+ }
+ start_pte = 0;
+
+ if (address >= end_paddr)
+ break;
+ }
+ start_pmd = 0;
+ }
+}
+
+void __init set_kernel_text_rw(int enable_read_write)
+{
+ unsigned long start = (unsigned long) __init_begin;
+ unsigned long end = (unsigned long) &data_start;
+
+ map_pages(start, __pa(start), end-start,
+ PAGE_KERNEL_RWX, enable_read_write ? 1:0);
+
+ /* force the kernel to see the new page table entries */
+ flush_cache_all();
+ flush_tlb_all();
+}
+
+void free_initmem(void)
+{
+ unsigned long init_begin = (unsigned long)__init_begin;
+ unsigned long init_end = (unsigned long)__init_end;
+ unsigned long kernel_end = (unsigned long)&_end;
+
+ /* Remap kernel text and data, but do not touch init section yet. */
+ kernel_set_to_readonly = true;
+ map_pages(init_end, __pa(init_end), kernel_end - init_end,
+ PAGE_KERNEL, 0);
+
+ /* The init text pages are marked R-X. We have to
+ * flush the icache and mark them RW-
+ *
+ * Do a dummy remap of the data section first (the data
+ * section is already PAGE_KERNEL) to pull in the TLB entries
+ * for map_kernel */
+ map_pages(init_begin, __pa(init_begin), init_end - init_begin,
+ PAGE_KERNEL_RWX, 1);
+ /* now remap at PAGE_KERNEL since the TLB is pre-primed to execute
+ * map_pages */
+ map_pages(init_begin, __pa(init_begin), init_end - init_begin,
+ PAGE_KERNEL, 1);
+
+ /* force the kernel to see the new TLB entries */
+ __flush_tlb_range(0, init_begin, kernel_end);
+
+ /* finally dump all the instructions which were cached, since the
+ * pages are no-longer executable */
+ flush_icache_range(init_begin, init_end);
+
+ free_initmem_default(POISON_FREE_INITMEM);
+
+ /* set up a new led state on systems shipped LED State panel */
+ pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE);
+}
+
+
+#ifdef CONFIG_STRICT_KERNEL_RWX
+void mark_rodata_ro(void)
+{
+ /* rodata memory was already mapped with KERNEL_RO access rights by
+ pagetable_init() and map_pages(). No need to do additional stuff here */
+ unsigned long roai_size = __end_ro_after_init - __start_ro_after_init;
+
+ pr_info("Write protected read-only-after-init data: %luk\n", roai_size >> 10);
+}
+#endif
+
+
+/*
+ * Just an arbitrary offset to serve as a "hole" between mapping areas
+ * (between top of physical memory and a potential pcxl dma mapping
+ * area, and below the vmalloc mapping area).
+ *
+ * The current 32K value just means that there will be a 32K "hole"
+ * between mapping areas. That means that any out-of-bounds memory
+ * accesses will hopefully be caught. The vmalloc() routines leaves
+ * a hole of 4kB between each vmalloced area for the same reason.
+ */
+
+ /* Leave room for gateway page expansion */
+#if KERNEL_MAP_START < GATEWAY_PAGE_SIZE
+#error KERNEL_MAP_START is in gateway reserved region
+#endif
+#define MAP_START (KERNEL_MAP_START)
+
+#define VM_MAP_OFFSET (32*1024)
+#define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \
+ & ~(VM_MAP_OFFSET-1)))
+
+void *parisc_vmalloc_start __ro_after_init;
+EXPORT_SYMBOL(parisc_vmalloc_start);
+
+#ifdef CONFIG_PA11
+unsigned long pcxl_dma_start __ro_after_init;
+#endif
+
+void __init mem_init(void)
+{
+ /* Do sanity checks on IPC (compat) structures */
+ BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48);
+#ifndef CONFIG_64BIT
+ BUILD_BUG_ON(sizeof(struct semid64_ds) != 80);
+ BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104);
+ BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104);
+#endif
+#ifdef CONFIG_COMPAT
+ BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm));
+ BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80);
+ BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104);
+ BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104);
+#endif
+
+ /* Do sanity checks on page table constants */
+ BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t));
+ BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t));
+ BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t));
+ BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD
+ > BITS_PER_LONG);
+#if CONFIG_PGTABLE_LEVELS == 3
+ BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PMD);
+#else
+ BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PGD);
+#endif
+
+#ifdef CONFIG_64BIT
+ /* avoid ldil_%L() asm statements to sign-extend into upper 32-bits */
+ BUILD_BUG_ON(__PAGE_OFFSET >= 0x80000000);
+ BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000);
+#endif
+
+ high_memory = __va((max_pfn << PAGE_SHIFT));
+ set_max_mapnr(max_low_pfn);
+ memblock_free_all();
+
+#ifdef CONFIG_PA11
+ if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
+ pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
+ parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start
+ + PCXL_DMA_MAP_SIZE);
+ } else
+#endif
+ parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START);
+
+#if 0
+ /*
+ * Do not expose the virtual kernel memory layout to userspace.
+ * But keep code for debugging purposes.
+ */
+ printk("virtual kernel memory layout:\n"
+ " vmalloc : 0x%px - 0x%px (%4ld MB)\n"
+ " fixmap : 0x%px - 0x%px (%4ld kB)\n"
+ " memory : 0x%px - 0x%px (%4ld MB)\n"
+ " .init : 0x%px - 0x%px (%4ld kB)\n"
+ " .data : 0x%px - 0x%px (%4ld kB)\n"
+ " .text : 0x%px - 0x%px (%4ld kB)\n",
+
+ (void*)VMALLOC_START, (void*)VMALLOC_END,
+ (VMALLOC_END - VMALLOC_START) >> 20,
+
+ (void *)FIXMAP_START, (void *)(FIXMAP_START + FIXMAP_SIZE),
+ (unsigned long)(FIXMAP_SIZE / 1024),
+
+ __va(0), high_memory,
+ ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
+
+ __init_begin, __init_end,
+ ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10,
+
+ _etext, _edata,
+ ((unsigned long)_edata - (unsigned long)_etext) >> 10,
+
+ _text, _etext,
+ ((unsigned long)_etext - (unsigned long)_text) >> 10);
+#endif
+}
+
+unsigned long *empty_zero_page __ro_after_init;
+EXPORT_SYMBOL(empty_zero_page);
+
+/*
+ * pagetable_init() sets up the page tables
+ *
+ * Note that gateway_init() places the Linux gateway page at page 0.
+ * Since gateway pages cannot be dereferenced this has the desirable
+ * side effect of trapping those pesky NULL-reference errors in the
+ * kernel.
+ */
+static void __init pagetable_init(void)
+{
+ int range;
+
+ /* Map each physical memory range to its kernel vaddr */
+
+ for (range = 0; range < npmem_ranges; range++) {
+ unsigned long start_paddr;
+ unsigned long end_paddr;
+ unsigned long size;
+
+ start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT;
+ size = pmem_ranges[range].pages << PAGE_SHIFT;
+ end_paddr = start_paddr + size;
+
+ map_pages((unsigned long)__va(start_paddr), start_paddr,
+ size, PAGE_KERNEL, 0);
+ }
+
+#ifdef CONFIG_BLK_DEV_INITRD
+ if (initrd_end && initrd_end > mem_limit) {
+ printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end);
+ map_pages(initrd_start, __pa(initrd_start),
+ initrd_end - initrd_start, PAGE_KERNEL, 0);
+ }
+#endif
+
+ empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ if (!empty_zero_page)
+ panic("zero page allocation failed.\n");
+
+}
+
+static void __init gateway_init(void)
+{
+ unsigned long linux_gateway_page_addr;
+ /* FIXME: This is 'const' in order to trick the compiler
+ into not treating it as DP-relative data. */
+ extern void * const linux_gateway_page;
+
+ linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK;
+
+ /*
+ * Setup Linux Gateway page.
+ *
+ * The Linux gateway page will reside in kernel space (on virtual
+ * page 0), so it doesn't need to be aliased into user space.
+ */
+
+ map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page),
+ PAGE_SIZE, PAGE_GATEWAY, 1);
+}
+
+static void __init parisc_bootmem_free(void)
+{
+ unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
+
+ max_zone_pfn[0] = memblock_end_of_DRAM();
+
+ free_area_init(max_zone_pfn);
+}
+
+void __init paging_init(void)
+{
+ setup_bootmem();
+ pagetable_init();
+ gateway_init();
+ flush_cache_all_local(); /* start with known state */
+ flush_tlb_all_local(NULL);
+
+ sparse_init();
+ parisc_bootmem_free();
+}
+
+#ifdef CONFIG_PA20
+
+/*
+ * Currently, all PA20 chips have 18 bit protection IDs, which is the
+ * limiting factor (space ids are 32 bits).
+ */
+
+#define NR_SPACE_IDS 262144
+
+#else
+
+/*
+ * Currently we have a one-to-one relationship between space IDs and
+ * protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only
+ * support 15 bit protection IDs, so that is the limiting factor.
+ * PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's
+ * probably not worth the effort for a special case here.
+ */
+
+#define NR_SPACE_IDS 32768
+
+#endif /* !CONFIG_PA20 */
+
+#define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2)
+#define SID_ARRAY_SIZE (NR_SPACE_IDS / (8 * sizeof(long)))
+
+static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */
+static unsigned long dirty_space_id[SID_ARRAY_SIZE];
+static unsigned long space_id_index;
+static unsigned long free_space_ids = NR_SPACE_IDS - 1;
+static unsigned long dirty_space_ids;
+
+static DEFINE_SPINLOCK(sid_lock);
+
+unsigned long alloc_sid(void)
+{
+ unsigned long index;
+
+ spin_lock(&sid_lock);
+
+ if (free_space_ids == 0) {
+ if (dirty_space_ids != 0) {
+ spin_unlock(&sid_lock);
+ flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */
+ spin_lock(&sid_lock);
+ }
+ BUG_ON(free_space_ids == 0);
+ }
+
+ free_space_ids--;
+
+ index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index);
+ space_id[BIT_WORD(index)] |= BIT_MASK(index);
+ space_id_index = index;
+
+ spin_unlock(&sid_lock);
+
+ return index << SPACEID_SHIFT;
+}
+
+void free_sid(unsigned long spaceid)
+{
+ unsigned long index = spaceid >> SPACEID_SHIFT;
+ unsigned long *dirty_space_offset, mask;
+
+ dirty_space_offset = &dirty_space_id[BIT_WORD(index)];
+ mask = BIT_MASK(index);
+
+ spin_lock(&sid_lock);
+
+ BUG_ON(*dirty_space_offset & mask); /* attempt to free space id twice */
+
+ *dirty_space_offset |= mask;
+ dirty_space_ids++;
+
+ spin_unlock(&sid_lock);
+}
+
+
+#ifdef CONFIG_SMP
+static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array)
+{
+ int i;
+
+ /* NOTE: sid_lock must be held upon entry */
+
+ *ndirtyptr = dirty_space_ids;
+ if (dirty_space_ids != 0) {
+ for (i = 0; i < SID_ARRAY_SIZE; i++) {
+ dirty_array[i] = dirty_space_id[i];
+ dirty_space_id[i] = 0;
+ }
+ dirty_space_ids = 0;
+ }
+
+ return;
+}
+
+static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array)
+{
+ int i;
+
+ /* NOTE: sid_lock must be held upon entry */
+
+ if (ndirty != 0) {
+ for (i = 0; i < SID_ARRAY_SIZE; i++) {
+ space_id[i] ^= dirty_array[i];
+ }
+
+ free_space_ids += ndirty;
+ space_id_index = 0;
+ }
+}
+
+#else /* CONFIG_SMP */
+
+static void recycle_sids(void)
+{
+ int i;
+
+ /* NOTE: sid_lock must be held upon entry */
+
+ if (dirty_space_ids != 0) {
+ for (i = 0; i < SID_ARRAY_SIZE; i++) {
+ space_id[i] ^= dirty_space_id[i];
+ dirty_space_id[i] = 0;
+ }
+
+ free_space_ids += dirty_space_ids;
+ dirty_space_ids = 0;
+ space_id_index = 0;
+ }
+}
+#endif
+
+/*
+ * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is
+ * purged, we can safely reuse the space ids that were released but
+ * not flushed from the tlb.
+ */
+
+#ifdef CONFIG_SMP
+
+static unsigned long recycle_ndirty;
+static unsigned long recycle_dirty_array[SID_ARRAY_SIZE];
+static unsigned int recycle_inuse;
+
+void flush_tlb_all(void)
+{
+ int do_recycle;
+
+ do_recycle = 0;
+ spin_lock(&sid_lock);
+ __inc_irq_stat(irq_tlb_count);
+ if (dirty_space_ids > RECYCLE_THRESHOLD) {
+ BUG_ON(recycle_inuse); /* FIXME: Use a semaphore/wait queue here */
+ get_dirty_sids(&recycle_ndirty,recycle_dirty_array);
+ recycle_inuse++;
+ do_recycle++;
+ }
+ spin_unlock(&sid_lock);
+ on_each_cpu(flush_tlb_all_local, NULL, 1);
+ if (do_recycle) {
+ spin_lock(&sid_lock);
+ recycle_sids(recycle_ndirty,recycle_dirty_array);
+ recycle_inuse = 0;
+ spin_unlock(&sid_lock);
+ }
+}
+#else
+void flush_tlb_all(void)
+{
+ spin_lock(&sid_lock);
+ __inc_irq_stat(irq_tlb_count);
+ flush_tlb_all_local(NULL);
+ recycle_sids();
+ spin_unlock(&sid_lock);
+}
+#endif
+
+static const pgprot_t protection_map[16] = {
+ [VM_NONE] = PAGE_NONE,
+ [VM_READ] = PAGE_READONLY,
+ [VM_WRITE] = PAGE_NONE,
+ [VM_WRITE | VM_READ] = PAGE_READONLY,
+ [VM_EXEC] = PAGE_EXECREAD,
+ [VM_EXEC | VM_READ] = PAGE_EXECREAD,
+ [VM_EXEC | VM_WRITE] = PAGE_EXECREAD,
+ [VM_EXEC | VM_WRITE | VM_READ] = PAGE_EXECREAD,
+ [VM_SHARED] = PAGE_NONE,
+ [VM_SHARED | VM_READ] = PAGE_READONLY,
+ [VM_SHARED | VM_WRITE] = PAGE_WRITEONLY,
+ [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
+ [VM_SHARED | VM_EXEC] = PAGE_EXECREAD,
+ [VM_SHARED | VM_EXEC | VM_READ] = PAGE_EXECREAD,
+ [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_RWX,
+ [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_RWX
+};
+DECLARE_VM_GET_PAGE_PROT