Commit 42a2b54c authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

uml: clean up TASK_SIZE usage



Clean up the calculation and use of the usable address space size on the host.

task_size is gone, replaced with TASK_SIZE, which is calculated from
CONFIG_TOP_ADDR.  get_kmem_end and set_task_sizes_skas are also gone.

host_task_size, which refers to the entire address space usable by the UML
kernel and which may be larger than the address space usable by a UML process,
since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR.

STACK_TOP is now TASK_SIZE minus the two stub pages.
Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b7c000cb
......@@ -29,9 +29,20 @@
#define _AC(X, Y) __AC(X, Y)
#endif
/*
* The "- 1"'s are to avoid gcc complaining about integer overflows
* and unrepresentable decimal constants. With 3-level page tables,
* TASK_SIZE is 0x80000000, which gets turned into its signed decimal
* equivalent in asm-offsets.s. gcc then complains about that being
* unsigned only in C90. To avoid that, UM_TASK_SIZE is defined as
* TASK_SIZE - 1. To compensate, we need to add the 1 back here.
* However, adding it back to UM_TASK_SIZE produces more gcc
* complaints. So, I adjust the thing being subtracted from
* UM_TASK_SIZE instead. Bah.
*/
#define STUB_CODE _AC((unsigned long), \
UML_CONFIG_TOP_ADDR - 2 * UM_KERN_PAGE_SIZE)
#define STUB_DATA _AC((unsigned long), UML_CONFIG_TOP_ADDR - UM_KERN_PAGE_SIZE)
UM_TASK_SIZE - (2 * UM_KERN_PAGE_SIZE - 1))
#define STUB_DATA _AC((unsigned long), UM_TASK_SIZE - (UM_KERN_PAGE_SIZE - 1))
#define STUB_START _AC(, STUB_CODE)
#ifndef __ASSEMBLY__
......
......@@ -39,3 +39,6 @@ DEFINE(UM_HZ, HZ);
DEFINE(UM_USEC_PER_SEC, USEC_PER_SEC);
DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC);
DEFINE(UM_NSEC_PER_USEC, NSEC_PER_USEC);
/* See as-layout.h for an explanation of the "- 1". Bah. */
DEFINE(UM_TASK_SIZE, TASK_SIZE - 1);
......@@ -46,9 +46,6 @@ extern int iomem_size;
#define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 << 22) - 1))
extern unsigned long host_task_size;
extern unsigned long task_size;
extern int init_mem_user(void);
extern void setup_memory(void *entry);
extern unsigned long find_iomem(char *driver, unsigned long *len_out);
......@@ -62,6 +59,5 @@ extern unsigned long phys_offset(unsigned long phys);
extern void unmap_physmem(void);
extern void map_memory(unsigned long virt, unsigned long phys,
unsigned long len, int r, int w, int x);
extern unsigned long get_kmem_end(void);
#endif
......@@ -19,7 +19,7 @@
void flush_thread(void)
{
void *data = NULL;
unsigned long end = proc_mm ? task_size : STUB_START;
unsigned long end = proc_mm ? TASK_SIZE : STUB_START;
int ret;
arch_flush_thread(&current->thread.arch);
......
......@@ -18,11 +18,8 @@ EXPORT_SYMBOL(set_signals);
EXPORT_SYMBOL(get_signals);
EXPORT_SYMBOL(kernel_thread);
EXPORT_SYMBOL(sys_waitpid);
EXPORT_SYMBOL(task_size);
EXPORT_SYMBOL(flush_tlb_range);
EXPORT_SYMBOL(host_task_size);
EXPORT_SYMBOL(arch_validate);
EXPORT_SYMBOL(get_kmem_end);
EXPORT_SYMBOL(high_physmem);
EXPORT_SYMBOL(empty_zero_page);
......
......@@ -55,16 +55,6 @@ int __init init_maps(unsigned long physmem, unsigned long iomem,
return 0;
}
/* Changed during early boot */
static unsigned long kmem_top = 0;
unsigned long get_kmem_end(void)
{
if (kmem_top == 0)
kmem_top = host_task_size - 1024 * 1024;
return kmem_top;
}
void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
int r, int w, int x)
{
......
......@@ -511,7 +511,7 @@ void flush_tlb_mm(struct mm_struct *mm)
if (atomic_read(&mm->mm_users) == 0)
return;
end = proc_mm ? task_size : STUB_START;
end = proc_mm ? TASK_SIZE : STUB_START;
fix_range(mm, 0, end, 0);
}
......
......@@ -101,8 +101,6 @@ const struct seq_operations cpuinfo_op = {
};
/* Set in linux_main */
unsigned long host_task_size;
unsigned long task_size;
unsigned long uml_physmem;
unsigned long uml_reserved; /* Also modified in mem_init */
unsigned long start_vm;
......@@ -234,20 +232,6 @@ EXPORT_SYMBOL(end_iomem);
extern char __binary_start;
static unsigned long set_task_sizes_skas(unsigned long *task_size_out)
{
/* Round up to the nearest 4M */
unsigned long host_task_size = ROUND_4M((unsigned long)
&host_task_size);
if (!skas_needs_stub)
*task_size_out = host_task_size;
else
*task_size_out = STUB_START & PGDIR_MASK;
return host_task_size;
}
int __init linux_main(int argc, char **argv)
{
unsigned long avail, diff;
......@@ -278,8 +262,6 @@ int __init linux_main(int argc, char **argv)
printf("UML running in %s mode\n", mode);
host_task_size = set_task_sizes_skas(&task_size);
brk_start = (unsigned long) sbrk(0);
/*
......@@ -304,7 +286,7 @@ int __init linux_main(int argc, char **argv)
highmem = 0;
iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC;
max_physmem = CONFIG_TOP_ADDR - uml_physmem - iomem_size - MIN_VMALLOC;
/*
* Zones have to begin on a 1 << MAX_ORDER page boundary,
......@@ -336,7 +318,7 @@ int __init linux_main(int argc, char **argv)
}
virtmem_size = physmem_size;
avail = get_kmem_end() - start_vm;
avail = CONFIG_TOP_ADDR - start_vm;
if (physmem_size > avail)
virtmem_size = avail;
end_vm = start_vm + virtmem_size;
......
......@@ -13,11 +13,9 @@
extern unsigned long stacksizelim;
extern unsigned long host_task_size;
#define STACK_ROOM (stacksizelim)
#define STACK_TOP task_size
#define STACK_TOP (TASK_SIZE - 2 * PAGE_SIZE)
#define STACK_TOP_MAX STACK_TOP
......
......@@ -56,9 +56,8 @@ extern void __set_fixmap (enum fixed_addresses idx,
* the start of the fixmap, and leave one page empty
* at the top of mem..
*/
extern unsigned long get_kmem_end(void);
#define FIXADDR_TOP (get_kmem_end() - 0x2000)
#define FIXADDR_TOP (CONFIG_TOP_ADDR - 2 * PAGE_SIZE)
#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
......
......@@ -94,9 +94,7 @@ static inline void mm_copy_segments(struct mm_struct *from_mm,
/*
* User space process size: 3GB (default).
*/
extern unsigned long task_size;
#define TASK_SIZE (task_size)
#define TASK_SIZE (CONFIG_TOP_ADDR & PGDIR_MASK)
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
......
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