Staging
v0.5.2
v0.5.2
https://github.com/torvalds/linux
Tip revision: 30a0b95b1335e12efef89dd78518ed3e4a71a763 authored by Linus Torvalds on 30 October 2022, 22:19:28 UTC
Linux 6.1-rc3
Linux 6.1-rc3
Tip revision: 30a0b95
init.c
// SPDX-License-Identifier: GPL-2.0
/*
* Initialize MMU support.
*
* Copyright (C) 1998-2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/dma-map-ops.h>
#include <linux/dmar.h>
#include <linux/efi.h>
#include <linux/elf.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/sched/signal.h>
#include <linux/mmzone.h>
#include <linux/module.h>
#include <linux/personality.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/proc_fs.h>
#include <linux/bitops.h>
#include <linux/kexec.h>
#include <linux/swiotlb.h>
#include <asm/dma.h>
#include <asm/efi.h>
#include <asm/io.h>
#include <asm/numa.h>
#include <asm/patch.h>
#include <asm/pgalloc.h>
#include <asm/sal.h>
#include <asm/sections.h>
#include <asm/tlb.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
#include <asm/mca.h>
extern void ia64_tlb_init (void);
unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
struct page *zero_page_memmap_ptr; /* map entry for zero page */
EXPORT_SYMBOL(zero_page_memmap_ptr);
void
__ia64_sync_icache_dcache (pte_t pte)
{
unsigned long addr;
struct page *page;
page = pte_page(pte);
addr = (unsigned long) page_address(page);
if (test_bit(PG_arch_1, &page->flags))
return; /* i-cache is already coherent with d-cache */
flush_icache_range(addr, addr + page_size(page));
set_bit(PG_arch_1, &page->flags); /* mark page as clean */
}
/*
* Since DMA is i-cache coherent, any (complete) pages that were written via
* DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
* flush them when they get mapped into an executable vm-area.
*/
void arch_dma_mark_clean(phys_addr_t paddr, size_t size)
{
unsigned long pfn = PHYS_PFN(paddr);
do {
set_bit(PG_arch_1, &pfn_to_page(pfn)->flags);
} while (++pfn <= PHYS_PFN(paddr + size - 1));
}
inline void
ia64_set_rbs_bot (void)
{
unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16;
if (stack_size > MAX_USER_STACK_SIZE)
stack_size = MAX_USER_STACK_SIZE;
current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
}
/*
* This performs some platform-dependent address space initialization.
* On IA-64, we want to setup the VM area for the register backing
* store (which grows upwards) and install the gateway page which is
* used for signal trampolines, etc.
*/
void
ia64_init_addr_space (void)
{
struct vm_area_struct *vma;
ia64_set_rbs_bot();
/*
* If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
* the problem. When the process attempts to write to the register backing store
* for the first time, it will get a SEGFAULT in this case.
*/
vma = vm_area_alloc(current->mm);
if (vma) {
vma_set_anonymous(vma);
vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
vma->vm_end = vma->vm_start + PAGE_SIZE;
vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
mmap_write_lock(current->mm);
if (insert_vm_struct(current->mm, vma)) {
mmap_write_unlock(current->mm);
vm_area_free(vma);
return;
}
mmap_write_unlock(current->mm);
}
/* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
if (!(current->personality & MMAP_PAGE_ZERO)) {
vma = vm_area_alloc(current->mm);
if (vma) {
vma_set_anonymous(vma);
vma->vm_end = PAGE_SIZE;
vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO |
VM_DONTEXPAND | VM_DONTDUMP;
mmap_write_lock(current->mm);
if (insert_vm_struct(current->mm, vma)) {
mmap_write_unlock(current->mm);
vm_area_free(vma);
return;
}
mmap_write_unlock(current->mm);
}
}
}
void
free_initmem (void)
{
free_reserved_area(ia64_imva(__init_begin), ia64_imva(__init_end),
-1, "unused kernel");
}
void __init
free_initrd_mem (unsigned long start, unsigned long end)
{
/*
* EFI uses 4KB pages while the kernel can use 4KB or bigger.
* Thus EFI and the kernel may have different page sizes. It is
* therefore possible to have the initrd share the same page as
* the end of the kernel (given current setup).
*
* To avoid freeing/using the wrong page (kernel sized) we:
* - align up the beginning of initrd
* - align down the end of initrd
*
* | |
* |=============| a000
* | |
* | |
* | | 9000
* |/////////////|
* |/////////////|
* |=============| 8000
* |///INITRD////|
* |/////////////|
* |/////////////| 7000
* | |
* |KKKKKKKKKKKKK|
* |=============| 6000
* |KKKKKKKKKKKKK|
* |KKKKKKKKKKKKK|
* K=kernel using 8KB pages
*
* In this example, we must free page 8000 ONLY. So we must align up
* initrd_start and keep initrd_end as is.
*/
start = PAGE_ALIGN(start);
end = end & PAGE_MASK;
if (start < end)
printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
for (; start < end; start += PAGE_SIZE) {
if (!virt_addr_valid(start))
continue;
free_reserved_page(virt_to_page(start));
}
}
/*
* This installs a clean page in the kernel's page table.
*/
static struct page * __init
put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = pgd_offset_k(address); /* note: this is NOT pgd_offset()! */
{
p4d = p4d_alloc(&init_mm, pgd, address);
if (!p4d)
goto out;
pud = pud_alloc(&init_mm, p4d, address);
if (!pud)
goto out;
pmd = pmd_alloc(&init_mm, pud, address);
if (!pmd)
goto out;
pte = pte_alloc_kernel(pmd, address);
if (!pte)
goto out;
if (!pte_none(*pte))
goto out;
set_pte(pte, mk_pte(page, pgprot));
}
out:
/* no need for flush_tlb */
return page;
}
static void __init
setup_gate (void)
{
struct page *page;
/*
* Map the gate page twice: once read-only to export the ELF
* headers etc. and once execute-only page to enable
* privilege-promotion via "epc":
*/
page = virt_to_page(ia64_imva(__start_gate_section));
put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
#ifdef HAVE_BUGGY_SEGREL
page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
#else
put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
/* Fill in the holes (if any) with read-only zero pages: */
{
unsigned long addr;
for (addr = GATE_ADDR + PAGE_SIZE;
addr < GATE_ADDR + PERCPU_PAGE_SIZE;
addr += PAGE_SIZE)
{
put_kernel_page(ZERO_PAGE(0), addr,
PAGE_READONLY);
put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
PAGE_READONLY);
}
}
#endif
ia64_patch_gate();
}
static struct vm_area_struct gate_vma;
static int __init gate_vma_init(void)
{
vma_init(&gate_vma, NULL);
gate_vma.vm_start = FIXADDR_USER_START;
gate_vma.vm_end = FIXADDR_USER_END;
gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
gate_vma.vm_page_prot = __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX);
return 0;
}
__initcall(gate_vma_init);
struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
return &gate_vma;
}
int in_gate_area_no_mm(unsigned long addr)
{
if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
return 1;
return 0;
}
int in_gate_area(struct mm_struct *mm, unsigned long addr)
{
return in_gate_area_no_mm(addr);
}
void ia64_mmu_init(void *my_cpu_data)
{
unsigned long pta, impl_va_bits;
extern void tlb_init(void);
#ifdef CONFIG_DISABLE_VHPT
# define VHPT_ENABLE_BIT 0
#else
# define VHPT_ENABLE_BIT 1
#endif
/*
* Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
* address space. The IA-64 architecture guarantees that at least 50 bits of
* virtual address space are implemented but if we pick a large enough page size
* (e.g., 64KB), the mapped address space is big enough that it will overlap with
* VMLPT. I assume that once we run on machines big enough to warrant 64KB pages,
* IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
* problem in practice. Alternatively, we could truncate the top of the mapped
* address space to not permit mappings that would overlap with the VMLPT.
* --davidm 00/12/06
*/
# define pte_bits 3
# define mapped_space_bits (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
/*
* The virtual page table has to cover the entire implemented address space within
* a region even though not all of this space may be mappable. The reason for
* this is that the Access bit and Dirty bit fault handlers perform
* non-speculative accesses to the virtual page table, so the address range of the
* virtual page table itself needs to be covered by virtual page table.
*/
# define vmlpt_bits (impl_va_bits - PAGE_SHIFT + pte_bits)
# define POW2(n) (1ULL << (n))
impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
if (impl_va_bits < 51 || impl_va_bits > 61)
panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
/*
* mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
* which must fit into "vmlpt_bits - pte_bits" slots. Second half of
* the test makes sure that our mapped space doesn't overlap the
* unimplemented hole in the middle of the region.
*/
if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
(mapped_space_bits > impl_va_bits - 1))
panic("Cannot build a big enough virtual-linear page table"
" to cover mapped address space.\n"
" Try using a smaller page size.\n");
/* place the VMLPT at the end of each page-table mapped region: */
pta = POW2(61) - POW2(vmlpt_bits);
/*
* Set the (virtually mapped linear) page table address. Bit
* 8 selects between the short and long format, bits 2-7 the
* size of the table, and bit 0 whether the VHPT walker is
* enabled.
*/
ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
ia64_tlb_init();
#ifdef CONFIG_HUGETLB_PAGE
ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
ia64_srlz_d();
#endif
}
int __init register_active_ranges(u64 start, u64 len, int nid)
{
u64 end = start + len;
#ifdef CONFIG_KEXEC
if (start > crashk_res.start && start < crashk_res.end)
start = crashk_res.end;
if (end > crashk_res.start && end < crashk_res.end)
end = crashk_res.start;
#endif
if (start < end)
memblock_add_node(__pa(start), end - start, nid, MEMBLOCK_NONE);
return 0;
}
int
find_max_min_low_pfn (u64 start, u64 end, void *arg)
{
unsigned long pfn_start, pfn_end;
#ifdef CONFIG_FLATMEM
pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
#else
pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
#endif
min_low_pfn = min(min_low_pfn, pfn_start);
max_low_pfn = max(max_low_pfn, pfn_end);
return 0;
}
/*
* Boot command-line option "nolwsys" can be used to disable the use of any light-weight
* system call handler. When this option is in effect, all fsyscalls will end up bubbling
* down into the kernel and calling the normal (heavy-weight) syscall handler. This is
* useful for performance testing, but conceivably could also come in handy for debugging
* purposes.
*/
static int nolwsys __initdata;
static int __init
nolwsys_setup (char *s)
{
nolwsys = 1;
return 1;
}
__setup("nolwsys", nolwsys_setup);
void __init
mem_init (void)
{
int i;
BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
/*
* This needs to be called _after_ the command line has been parsed but
* _before_ any drivers that may need the PCI DMA interface are
* initialized or bootmem has been freed.
*/
do {
#ifdef CONFIG_INTEL_IOMMU
detect_intel_iommu();
if (iommu_detected)
break;
#endif
swiotlb_init(true, SWIOTLB_VERBOSE);
} while (0);
#ifdef CONFIG_FLATMEM
BUG_ON(!mem_map);
#endif
set_max_mapnr(max_low_pfn);
high_memory = __va(max_low_pfn * PAGE_SIZE);
memblock_free_all();
/*
* For fsyscall entrypoints with no light-weight handler, use the ordinary
* (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
* code can tell them apart.
*/
for (i = 0; i < NR_syscalls; ++i) {
extern unsigned long fsyscall_table[NR_syscalls];
extern unsigned long sys_call_table[NR_syscalls];
if (!fsyscall_table[i] || nolwsys)
fsyscall_table[i] = sys_call_table[i] | 1;
}
setup_gate();
}
#ifdef CONFIG_MEMORY_HOTPLUG
int arch_add_memory(int nid, u64 start, u64 size,
struct mhp_params *params)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
int ret;
if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
return -EINVAL;
ret = __add_pages(nid, start_pfn, nr_pages, params);
if (ret)
printk("%s: Problem encountered in __add_pages() as ret=%d\n",
__func__, ret);
return ret;
}
void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
__remove_pages(start_pfn, nr_pages, altmap);
}
#endif
static const pgprot_t protection_map[16] = {
[VM_NONE] = PAGE_NONE,
[VM_READ] = PAGE_READONLY,
[VM_WRITE] = PAGE_READONLY,
[VM_WRITE | VM_READ] = PAGE_READONLY,
[VM_EXEC] = __pgprot(__ACCESS_BITS | _PAGE_PL_3 |
_PAGE_AR_X_RX),
[VM_EXEC | VM_READ] = __pgprot(__ACCESS_BITS | _PAGE_PL_3 |
_PAGE_AR_RX),
[VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC,
[VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC,
[VM_SHARED] = PAGE_NONE,
[VM_SHARED | VM_READ] = PAGE_READONLY,
[VM_SHARED | VM_WRITE] = PAGE_SHARED,
[VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
[VM_SHARED | VM_EXEC] = __pgprot(__ACCESS_BITS | _PAGE_PL_3 |
_PAGE_AR_X_RX),
[VM_SHARED | VM_EXEC | VM_READ] = __pgprot(__ACCESS_BITS | _PAGE_PL_3 |
_PAGE_AR_RX),
[VM_SHARED | VM_EXEC | VM_WRITE] = __pgprot(__ACCESS_BITS | _PAGE_PL_3 |
_PAGE_AR_RWX),
[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __pgprot(__ACCESS_BITS | _PAGE_PL_3 |
_PAGE_AR_RWX)
};
DECLARE_VM_GET_PAGE_PROT