summaryrefslogtreecommitdiff
path: root/arch/microblaze/mm
diff options
context:
space:
mode:
Diffstat (limited to 'arch/microblaze/mm')
-rw-r--r--arch/microblaze/mm/Makefile2
-rw-r--r--arch/microblaze/mm/fault.c304
-rw-r--r--arch/microblaze/mm/init.c169
-rw-r--r--arch/microblaze/mm/mmu_context.c70
-rw-r--r--arch/microblaze/mm/pgtable.c286
5 files changed, 821 insertions, 10 deletions
diff --git a/arch/microblaze/mm/Makefile b/arch/microblaze/mm/Makefile
index bf9e4479a1fd..6c8a924d9e26 100644
--- a/arch/microblaze/mm/Makefile
+++ b/arch/microblaze/mm/Makefile
@@ -3,3 +3,5 @@
#
obj-y := init.o
+
+obj-$(CONFIG_MMU) += pgtable.o mmu_context.o fault.o
diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c
new file mode 100644
index 000000000000..5e67cd1fab40
--- /dev/null
+++ b/arch/microblaze/mm/fault.c
@@ -0,0 +1,304 @@
+/*
+ * arch/microblaze/mm/fault.c
+ *
+ * Copyright (C) 2007 Xilinx, Inc. All rights reserved.
+ *
+ * Derived from "arch/ppc/mm/fault.c"
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Derived from "arch/i386/mm/fault.c"
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * Modified by Cort Dougan and Paul Mackerras.
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file COPYING in the main directory of this
+ * archive for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+#include <asm/mmu_context.h>
+#include <asm/system.h>
+#include <linux/uaccess.h>
+#include <asm/exceptions.h>
+
+#if defined(CONFIG_KGDB)
+int debugger_kernel_faults = 1;
+#endif
+
+static unsigned long pte_misses; /* updated by do_page_fault() */
+static unsigned long pte_errors; /* updated by do_page_fault() */
+
+/*
+ * Check whether the instruction at regs->pc is a store using
+ * an update addressing form which will update r1.
+ */
+static int store_updates_sp(struct pt_regs *regs)
+{
+ unsigned int inst;
+
+ if (get_user(inst, (unsigned int *)regs->pc))
+ return 0;
+ /* check for 1 in the rD field */
+ if (((inst >> 21) & 0x1f) != 1)
+ return 0;
+ /* check for store opcodes */
+ if ((inst & 0xd0000000) == 0xd0000000)
+ return 1;
+ return 0;
+}
+
+
+/*
+ * bad_page_fault is called when we have a bad access from the kernel.
+ * It is called from do_page_fault above and from some of the procedures
+ * in traps.c.
+ */
+static void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
+{
+ const struct exception_table_entry *fixup;
+/* MS: no context */
+ /* Are we prepared to handle this fault? */
+ fixup = search_exception_tables(regs->pc);
+ if (fixup) {
+ regs->pc = fixup->fixup;
+ return;
+ }
+
+ /* kernel has accessed a bad area */
+#if defined(CONFIG_KGDB)
+ if (debugger_kernel_faults)
+ debugger(regs);
+#endif
+ die("kernel access of bad area", regs, sig);
+}
+
+/*
+ * The error_code parameter is ESR for a data fault,
+ * 0 for an instruction fault.
+ */
+void do_page_fault(struct pt_regs *regs, unsigned long address,
+ unsigned long error_code)
+{
+ struct vm_area_struct *vma;
+ struct mm_struct *mm = current->mm;
+ siginfo_t info;
+ int code = SEGV_MAPERR;
+ int is_write = error_code & ESR_S;
+ int fault;
+
+ regs->ear = address;
+ regs->esr = error_code;
+
+ /* On a kernel SLB miss we can only check for a valid exception entry */
+ if (kernel_mode(regs) && (address >= TASK_SIZE)) {
+ printk(KERN_WARNING "kernel task_size exceed");
+ _exception(SIGSEGV, regs, code, address);
+ }
+
+ /* for instr TLB miss and instr storage exception ESR_S is undefined */
+ if ((error_code & 0x13) == 0x13 || (error_code & 0x11) == 0x11)
+ is_write = 0;
+
+#if defined(CONFIG_KGDB)
+ if (debugger_fault_handler && regs->trap == 0x300) {
+ debugger_fault_handler(regs);
+ return;
+ }
+#endif /* CONFIG_KGDB */
+
+ if (in_atomic() || mm == NULL) {
+ /* FIXME */
+ if (kernel_mode(regs)) {
+ printk(KERN_EMERG
+ "Page fault in kernel mode - Oooou!!! pid %d\n",
+ current->pid);
+ _exception(SIGSEGV, regs, code, address);
+ return;
+ }
+ /* in_atomic() in user mode is really bad,
+ as is current->mm == NULL. */
+ printk(KERN_EMERG "Page fault in user mode with "
+ "in_atomic(), mm = %p\n", mm);
+ printk(KERN_EMERG "r15 = %lx MSR = %lx\n",
+ regs->r15, regs->msr);
+ die("Weird page fault", regs, SIGSEGV);
+ }
+
+ /* When running in the kernel we expect faults to occur only to
+ * addresses in user space. All other faults represent errors in the
+ * kernel and should generate an OOPS. Unfortunately, in the case of an
+ * erroneous fault occurring in a code path which already holds mmap_sem
+ * we will deadlock attempting to validate the fault against the
+ * address space. Luckily the kernel only validly references user
+ * space from well defined areas of code, which are listed in the
+ * exceptions table.
+ *
+ * As the vast majority of faults will be valid we will only perform
+ * the source reference check when there is a possibility of a deadlock.
+ * Attempt to lock the address space, if we cannot we then validate the
+ * source. If this is invalid we can skip the address space check,
+ * thus avoiding the deadlock.
+ */
+ if (!down_read_trylock(&mm->mmap_sem)) {
+ if (kernel_mode(regs) && !search_exception_tables(regs->pc))
+ goto bad_area_nosemaphore;
+
+ down_read(&mm->mmap_sem);
+ }
+
+ vma = find_vma(mm, address);
+ if (!vma)
+ goto bad_area;
+
+ if (vma->vm_start <= address)
+ goto good_area;
+
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ goto bad_area;
+
+ if (!is_write)
+ goto bad_area;
+
+ /*
+ * N.B. The ABI allows programs to access up to
+ * a few hundred bytes below the stack pointer (TBD).
+ * The kernel signal delivery code writes up to about 1.5kB
+ * below the stack pointer (r1) before decrementing it.
+ * The exec code can write slightly over 640kB to the stack
+ * before setting the user r1. Thus we allow the stack to
+ * expand to 1MB without further checks.
+ */
+ if (address + 0x100000 < vma->vm_end) {
+
+ /* get user regs even if this fault is in kernel mode */
+ struct pt_regs *uregs = current->thread.regs;
+ if (uregs == NULL)
+ goto bad_area;
+
+ /*
+ * A user-mode access to an address a long way below
+ * the stack pointer is only valid if the instruction
+ * is one which would update the stack pointer to the
+ * address accessed if the instruction completed,
+ * i.e. either stwu rs,n(r1) or stwux rs,r1,rb
+ * (or the byte, halfword, float or double forms).
+ *
+ * If we don't check this then any write to the area
+ * between the last mapped region and the stack will
+ * expand the stack rather than segfaulting.
+ */
+ if (address + 2048 < uregs->r1
+ && (kernel_mode(regs) || !store_updates_sp(regs)))
+ goto bad_area;
+ }
+ if (expand_stack(vma, address))
+ goto bad_area;
+
+good_area:
+ code = SEGV_ACCERR;
+
+ /* a write */
+ if (is_write) {
+ if (!(vma->vm_flags & VM_WRITE))
+ goto bad_area;
+ /* a read */
+ } else {
+ /* protection fault */
+ if (error_code & 0x08000000)
+ goto bad_area;
+ if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+ goto bad_area;
+ }
+
+ /*
+ * If for any reason at all we couldn't handle the fault,
+ * make sure we exit gracefully rather than endlessly redo
+ * the fault.
+ */
+survive:
+ fault = handle_mm_fault(mm, vma, address, is_write);
+ if (unlikely(fault & VM_FAULT_ERROR)) {
+ if (fault & VM_FAULT_OOM)
+ goto out_of_memory;
+ else if (fault & VM_FAULT_SIGBUS)
+ goto do_sigbus;
+ BUG();
+ }
+ if (fault & VM_FAULT_MAJOR)
+ current->maj_flt++;
+ else
+ current->min_flt++;
+ up_read(&mm->mmap_sem);
+ /*
+ * keep track of tlb+htab misses that are good addrs but
+ * just need pte's created via handle_mm_fault()
+ * -- Cort
+ */
+ pte_misses++;
+ return;
+
+bad_area:
+ up_read(&mm->mmap_sem);
+
+bad_area_nosemaphore:
+ pte_errors++;
+
+ /* User mode accesses cause a SIGSEGV */
+ if (user_mode(regs)) {
+ _exception(SIGSEGV, regs, code, address);
+/* info.si_signo = SIGSEGV;
+ info.si_errno = 0;
+ info.si_code = code;
+ info.si_addr = (void *) address;
+ force_sig_info(SIGSEGV, &info, current);*/
+ return;
+ }
+
+ bad_page_fault(regs, address, SIGSEGV);
+ return;
+
+/*
+ * We ran out of memory, or some other thing happened to us that made
+ * us unable to handle the page fault gracefully.
+ */
+out_of_memory:
+ if (current->pid == 1) {
+ yield();
+ down_read(&mm->mmap_sem);
+ goto survive;
+ }
+ up_read(&mm->mmap_sem);
+ printk(KERN_WARNING "VM: killing process %s\n", current->comm);
+ if (user_mode(regs))
+ do_exit(SIGKILL);
+ bad_page_fault(regs, address, SIGKILL);
+ return;
+
+do_sigbus:
+ up_read(&mm->mmap_sem);
+ if (user_mode(regs)) {
+ info.si_signo = SIGBUS;
+ info.si_errno = 0;
+ info.si_code = BUS_ADRERR;
+ info.si_addr = (void __user *)address;
+ force_sig_info(SIGBUS, &info, current);
+ return;
+ }
+ bad_page_fault(regs, address, SIGBUS);
+}
diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index b0c8213cd6cf..b5a701cd71e0 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -23,8 +23,16 @@
#include <asm/sections.h>
#include <asm/tlb.h>
+#ifndef CONFIG_MMU
unsigned int __page_offset;
-/* EXPORT_SYMBOL(__page_offset); */
+EXPORT_SYMBOL(__page_offset);
+
+#else
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+int mem_init_done;
+static int init_bootmem_done;
+#endif /* CONFIG_MMU */
char *klimit = _end;
@@ -32,28 +40,26 @@ char *klimit = _end;
* Initialize the bootmem system and give it all the memory we
* have available.
*/
-unsigned int memory_start;
-unsigned int memory_end; /* due to mm/nommu.c */
-unsigned int memory_size;
+unsigned long memory_start;
+unsigned long memory_end; /* due to mm/nommu.c */
+unsigned long memory_size;
/*
* paging_init() sets up the page tables - in fact we've already done this.
*/
static void __init paging_init(void)
{
- int i;
unsigned long zones_size[MAX_NR_ZONES];
+ /* Clean every zones */
+ memset(zones_size, 0, sizeof(zones_size));
+
/*
* old: we can DMA to/from any address.put all page into ZONE_DMA
* We use only ZONE_NORMAL
*/
zones_size[ZONE_NORMAL] = max_mapnr;
- /* every other zones are empty */
- for (i = 1; i < MAX_NR_ZONES; i++)
- zones_size[i] = 0;
-
free_area_init(zones_size);
}
@@ -61,6 +67,7 @@ void __init setup_memory(void)
{
int i;
unsigned long map_size;
+#ifndef CONFIG_MMU
u32 kernel_align_start, kernel_align_size;
/* Find main memory where is the kernel */
@@ -93,6 +100,7 @@ void __init setup_memory(void)
__func__, kernel_align_start, kernel_align_start
+ kernel_align_size, kernel_align_size);
+#endif
/*
* Kernel:
* start: base phys address of kernel - page align
@@ -121,9 +129,13 @@ void __init setup_memory(void)
* for 4GB of memory, using 4kB pages), plus 1 page
* (in case the address isn't page-aligned).
*/
+#ifndef CONFIG_MMU
map_size = init_bootmem_node(NODE_DATA(0), PFN_UP(TOPHYS((u32)_end)),
min_low_pfn, max_low_pfn);
-
+#else
+ map_size = init_bootmem_node(&contig_page_data,
+ PFN_UP(TOPHYS((u32)_end)), min_low_pfn, max_low_pfn);
+#endif
lmb_reserve(PFN_UP(TOPHYS((u32)_end)) << PAGE_SHIFT, map_size);
/* free bootmem is whole main memory */
@@ -137,6 +149,9 @@ void __init setup_memory(void)
reserve_bootmem(lmb.reserved.region[i].base,
lmb_size_bytes(&lmb.reserved, i) - 1, BOOTMEM_DEFAULT);
}
+#ifdef CONFIG_MMU
+ init_bootmem_done = 1;
+#endif
paging_init();
}
@@ -191,11 +206,145 @@ void __init mem_init(void)
printk(KERN_INFO "Memory: %luk/%luk available\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
num_physpages << (PAGE_SHIFT-10));
+#ifdef CONFIG_MMU
+ mem_init_done = 1;
+#endif
}
+#ifndef CONFIG_MMU
/* Check against bounds of physical memory */
int ___range_ok(unsigned long addr, unsigned long size)
{
return ((addr < memory_start) ||
((addr + size) > memory_end));
}
+EXPORT_SYMBOL(___range_ok);
+
+#else
+int page_is_ram(unsigned long pfn)
+{
+ return pfn < max_low_pfn;
+}
+
+/*
+ * Check for command-line options that affect what MMU_init will do.
+ */
+static void mm_cmdline_setup(void)
+{
+ unsigned long maxmem = 0;
+ char *p = cmd_line;
+
+ /* Look for mem= option on command line */
+ p = strstr(cmd_line, "mem=");
+ if (p) {
+ p += 4;
+ maxmem = memparse(p, &p);
+ if (maxmem && memory_size > maxmem) {
+ memory_size = maxmem;
+ memory_end = memory_start + memory_size;
+ lmb.memory.region[0].size = memory_size;
+ }
+ }
+}
+
+/*
+ * MMU_init_hw does the chip-specific initialization of the MMU hardware.
+ */
+static void __init mmu_init_hw(void)
+{
+ /*
+ * The Zone Protection Register (ZPR) defines how protection will
+ * be applied to every page which is a member of a given zone. At
+ * present, we utilize only two of the zones.
+ * The zone index bits (of ZSEL) in the PTE are used for software
+ * indicators, except the LSB. For user access, zone 1 is used,
+ * for kernel access, zone 0 is used. We set all but zone 1
+ * to zero, allowing only kernel access as indicated in the PTE.
+ * For zone 1, we set a 01 binary (a value of 10 will not work)
+ * to allow user access as indicated in the PTE. This also allows
+ * kernel access as indicated in the PTE.
+ */
+ __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
+ "mts rzpr, r11;"
+ : : : "r11");
+}
+
+/*
+ * MMU_init sets up the basic memory mappings for the kernel,
+ * including both RAM and possibly some I/O regions,
+ * and sets up the page tables and the MMU hardware ready to go.
+ */
+
+/* called from head.S */
+asmlinkage void __init mmu_init(void)
+{
+ unsigned int kstart, ksize;
+
+ if (!lmb.reserved.cnt) {
+ printk(KERN_EMERG "Error memory count\n");
+ machine_restart(NULL);
+ }
+
+ if ((u32) lmb.memory.region[0].size < 0x1000000) {
+ printk(KERN_EMERG "Memory must be greater than 16MB\n");
+ machine_restart(NULL);
+ }
+ /* Find main memory where the kernel is */
+ memory_start = (u32) lmb.memory.region[0].base;
+ memory_end = (u32) lmb.memory.region[0].base +
+ (u32) lmb.memory.region[0].size;
+ memory_size = memory_end - memory_start;
+
+ mm_cmdline_setup(); /* FIXME parse args from command line - not used */
+
+ /*
+ * Map out the kernel text/data/bss from the available physical
+ * memory.
+ */
+ kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
+ /* kernel size */
+ ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
+ lmb_reserve(kstart, ksize);
+
+#if defined(CONFIG_BLK_DEV_INITRD)
+ /* Remove the init RAM disk from the available memory. */
+/* if (initrd_start) {
+ mem_pieces_remove(&phys_avail, __pa(initrd_start),
+ initrd_end - initrd_start, 1);
+ }*/
+#endif /* CONFIG_BLK_DEV_INITRD */
+
+ /* Initialize the MMU hardware */
+ mmu_init_hw();
+
+ /* Map in all of RAM starting at CONFIG_KERNEL_START */
+ mapin_ram();
+
+#ifdef HIGHMEM_START_BOOL
+ ioremap_base = HIGHMEM_START;
+#else
+ ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
+#endif /* CONFIG_HIGHMEM */
+ ioremap_bot = ioremap_base;
+
+ /* Initialize the context management stuff */
+ mmu_context_init();
+}
+
+/* This is only called until mem_init is done. */
+void __init *early_get_page(void)
+{
+ void *p;
+ if (init_bootmem_done) {
+ p = alloc_bootmem_pages(PAGE_SIZE);
+ } else {
+ /*
+ * Mem start + 32MB -> here is limit
+ * because of mem mapping from head.S
+ */
+ p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
+ memory_start + 0x2000000));
+ }
+ return p;
+}
+#endif /* CONFIG_MMU */
diff --git a/arch/microblaze/mm/mmu_context.c b/arch/microblaze/mm/mmu_context.c
new file mode 100644
index 000000000000..26ff82f4fa8f
--- /dev/null
+++ b/arch/microblaze/mm/mmu_context.c
@@ -0,0 +1,70 @@
+/*
+ * This file contains the routines for handling the MMU.
+ *
+ * Copyright (C) 2007 Xilinx, Inc. All rights reserved.
+ *
+ * Derived from arch/ppc/mm/4xx_mmu.c:
+ * -- paulus
+ *
+ * Derived from arch/ppc/mm/init.c:
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
+ * and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ * Copyright (C) 1996 Paul Mackerras
+ * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
+ *
+ * Derived from "arch/i386/mm/init.c"
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/mm.h>
+#include <linux/init.h>
+
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+
+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];
+
+/*
+ * Initialize the context management stuff.
+ */
+void __init mmu_context_init(void)
+{
+ /*
+ * The use of context zero is reserved 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 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 were motivated to do it.
+ */
+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);
+}
diff --git a/arch/microblaze/mm/pgtable.c b/arch/microblaze/mm/pgtable.c
new file mode 100644
index 000000000000..46c4ca5d15c5
--- /dev/null
+++ b/arch/microblaze/mm/pgtable.c
@@ -0,0 +1,286 @@
+/*
+ * This file contains the routines setting up the linux page tables.
+ *
+ * Copyright (C) 2008 Michal Simek
+ * Copyright (C) 2008 PetaLogix
+ *
+ * Copyright (C) 2007 Xilinx, Inc. All rights reserved.
+ *
+ * Derived from arch/ppc/mm/pgtable.c:
+ * -- paulus
+ *
+ * Derived from arch/ppc/mm/init.c:
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
+ * and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ * Copyright (C) 1996 Paul Mackerras
+ * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
+ *
+ * Derived from "arch/i386/mm/init.c"
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file COPYING in the main directory of this
+ * archive for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <linux/io.h>
+#include <asm/mmu.h>
+#include <asm/sections.h>
+
+#define flush_HPTE(X, va, pg) _tlbie(va)
+
+unsigned long ioremap_base;
+unsigned long ioremap_bot;
+
+/* The maximum lowmem defaults to 768Mb, but this can be configured to
+ * another value.
+ */
+#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
+
+#ifndef CONFIG_SMP
+struct pgtable_cache_struct quicklists;
+#endif
+
+static void __iomem *__ioremap(phys_addr_t addr, unsigned long size,
+ unsigned long flags)
+{
+ unsigned long v, i;
+ phys_addr_t p;
+ int err;
+
+ /*
+ * Choose an address to map it to.
+ * Once the vmalloc system is running, we use it.
+ * Before then, we use space going down from ioremap_base
+ * (ioremap_bot records where we're up to).
+ */
+ p = addr & PAGE_MASK;
+ size = PAGE_ALIGN(addr + size) - p;
+
+ /*
+ * Don't allow anybody to remap normal RAM that we're using.
+ * mem_init() sets high_memory so only do the check after that.
+ *
+ * However, allow remap of rootfs: TBD
+ */
+ if (mem_init_done &&
+ p >= memory_start && p < virt_to_phys(high_memory) &&
+ !(p >= virt_to_phys((unsigned long)&__bss_stop) &&
+ p < virt_to_phys((unsigned long)__bss_stop))) {
+ printk(KERN_WARNING "__ioremap(): phys addr "PTE_FMT
+ " is RAM lr %p\n", (unsigned long)p,
+ __builtin_return_address(0));
+ return NULL;
+ }
+
+ if (size == 0)
+ return NULL;
+
+ /*
+ * Is it already mapped? If the whole area is mapped then we're
+ * done, otherwise remap it since we want to keep the virt addrs for
+ * each request contiguous.
+ *
+ * We make the assumption here that if the bottom and top
+ * of the range we want are mapped then it's mapped to the
+ * same virt address (and this is contiguous).
+ * -- Cort
+ */
+
+ if (mem_init_done) {
+ struct vm_struct *area;
+ area = get_vm_area(size, VM_IOREMAP);
+ if (area == NULL)
+ return NULL;
+ v = VMALLOC_VMADDR(area->addr);
+ } else {
+ v = (ioremap_bot -= size);
+ }
+
+ if ((flags & _PAGE_PRESENT) == 0)
+ flags |= _PAGE_KERNEL;
+ if (flags & _PAGE_NO_CACHE)
+ flags |= _PAGE_GUARDED;
+
+ err = 0;
+ for (i = 0; i < size && err == 0; i += PAGE_SIZE)
+ err = map_page(v + i, p + i, flags);
+ if (err) {
+ if (mem_init_done)
+ vfree((void *)v);
+ return NULL;
+ }
+
+ return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
+}
+
+void __iomem *ioremap(phys_addr_t addr, unsigned long size)
+{
+ return __ioremap(addr, size, _PAGE_NO_CACHE);
+}
+EXPORT_SYMBOL(ioremap);
+
+void iounmap(void *addr)
+{
+ if (addr > high_memory && (unsigned long) addr < ioremap_bot)
+ vfree((void *) (PAGE_MASK & (unsigned long) addr));
+}
+EXPORT_SYMBOL(iounmap);
+
+
+int map_page(unsigned long va, phys_addr_t pa, int flags)
+{
+ pmd_t *pd;
+ pte_t *pg;
+ int err = -ENOMEM;
+ /* spin_lock(&init_mm.page_table_lock); */
+ /* Use upper 10 bits of VA to index the first level map */
+ pd = pmd_offset(pgd_offset_k(va), va);
+ /* Use middle 10 bits of VA to index the second-level map */
+ pg = pte_alloc_kernel(pd, va); /* from powerpc - pgtable.c */
+ /* pg = pte_alloc_kernel(&init_mm, pd, va); */
+
+ if (pg != NULL) {
+ err = 0;
+ set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
+ __pgprot(flags)));
+ if (mem_init_done)
+ flush_HPTE(0, va, pmd_val(*pd));
+ /* flush_HPTE(0, va, pg); */
+
+ }
+ /* spin_unlock(&init_mm.page_table_lock); */
+ return err;
+}
+
+void __init adjust_total_lowmem(void)
+{
+/* TBD */
+#if 0
+ unsigned long max_low_mem = MAX_LOW_MEM;
+
+ if (total_lowmem > max_low_mem) {
+ total_lowmem = max_low_mem;
+#ifndef CONFIG_HIGHMEM
+ printk(KERN_INFO "Warning, memory limited to %ld Mb, use "
+ "CONFIG_HIGHMEM to reach %ld Mb\n",
+ max_low_mem >> 20, total_memory >> 20);
+ total_memory = total_lowmem;
+#endif /* CONFIG_HIGHMEM */
+ }
+#endif
+}
+
+static void show_tmem(unsigned long tmem)
+{
+ volatile unsigned long a;
+ a = a + tmem;
+}
+
+/*
+ * Map in all of physical memory starting at CONFIG_KERNEL_START.
+ */
+void __init mapin_ram(void)
+{
+ unsigned long v, p, s, f;
+
+ v = CONFIG_KERNEL_START;
+ p = memory_start;
+ show_tmem(memory_size);
+ for (s = 0; s < memory_size; s += PAGE_SIZE) {
+ f = _PAGE_PRESENT | _PAGE_ACCESSED |
+ _PAGE_SHARED | _PAGE_HWEXEC;
+ if ((char *) v < _stext || (char *) v >= _etext)
+ f |= _PAGE_WRENABLE;
+ else
+ /* On the MicroBlaze, no user access
+ forces R/W kernel access */
+ f |= _PAGE_USER;
+ map_page(v, p, f);
+ v += PAGE_SIZE;
+ p += PAGE_SIZE;
+ }
+}
+
+/* is x a power of 2? */
+#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0))
+
+/*
+ * Set up a mapping for a block of I/O.
+ * virt, phys, size must all be page-aligned.
+ * This should only be called before ioremap is called.
+ */
+void __init io_block_mapping(unsigned long virt, phys_addr_t phys,
+ unsigned int size, int flags)
+{
+ int i;
+
+ if (virt > CONFIG_KERNEL_START && virt < ioremap_bot)
+ ioremap_bot = ioremap_base = virt;
+
+ /* Put it in the page tables. */
+ for (i = 0; i < size; i += PAGE_SIZE)
+ map_page(virt + i, phys + i, flags);
+}
+
+/* Scan the real Linux page tables and return a PTE pointer for
+ * a virtual address in a context.
+ * Returns true (1) if PTE was found, zero otherwise. The pointer to
+ * the PTE pointer is unmodified if PTE is not found.
+ */
+static int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep)
+{
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pte_t *pte;
+ int retval = 0;
+
+ pgd = pgd_offset(mm, addr & PAGE_MASK);
+ if (pgd) {
+ pmd = pmd_offset(pgd, addr & PAGE_MASK);
+ if (pmd_present(*pmd)) {
+ pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
+ if (pte) {
+ retval = 1;
+ *ptep = pte;
+ }
+ }
+ }
+ return retval;
+}
+
+/* Find physical address for this virtual address. Normally used by
+ * I/O functions, but anyone can call it.
+ */
+unsigned long iopa(unsigned long addr)
+{
+ unsigned long pa;
+
+ pte_t *pte;
+ struct mm_struct *mm;
+
+ /* Allow mapping of user addresses (within the thread)
+ * for DMA if necessary.
+ */
+ if (addr < TASK_SIZE)
+ mm = current->mm;
+ else
+ mm = &init_mm;
+
+ pa = 0;
+ if (get_pteptr(mm, addr, &pte))
+ pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
+
+ return pa;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-04 06:56:34 +0000