1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
#include <limits.h>
#include <kernel/pagemgr.H>
#include <util/singleton.H>
#include <kernel/console.H>
#include <sys/vfs.h>
#include <arch/ppc.H>
void PageManager::init()
{
Singleton<PageManager>::instance();
}
void* PageManager::allocatePage(size_t n)
{
PageManager& pmgr = Singleton<PageManager>::instance();
return pmgr._allocatePage(n);
}
void PageManager::freePage(void* p, size_t n)
{
PageManager& pmgr = Singleton<PageManager>::instance();
return pmgr._freePage(p, n);
}
PageManager::PageManager() : iv_pagesAvail(0)
{
// Determine first page of un-allocated memory.
uint64_t addr = (uint64_t) VFS_LAST_ADDRESS;
if (0 != (addr % PAGESIZE))
addr = (addr - (addr % PAGESIZE)) + PAGESIZE;
// Determine number of pages available.
page_t* page = (page_t*)((void*) addr);
size_t length = (MEMLEN - addr) / PAGESIZE;
// Update statistics.
__sync_add_and_fetch(&iv_pagesAvail, length);
// Display.
printk("Initializing PageManager with %zd pages starting at %lx...",
length,
(uint64_t)page);
// Populate L3 cache lines.
uint64_t* cache_line = (uint64_t*) addr;
uint64_t* end_cache_line = (uint64_t*) VmmManager::FULL_MEM_SIZE;
while (cache_line != end_cache_line)
{
dcbz(cache_line);
cache_line++;
}
// Allocate pages to buckets.
size_t page_length = BUCKETS-1;
while(length > 0)
{
while (length < (size_t)(1 << page_length))
page_length--;
first_page[page_length].push(page);
page = (page_t*)((uint64_t)page + (1 << page_length)*PAGESIZE);
length -= (1 << page_length);
}
// @TODO: Venice: Clear 3-8MB region and add to free memory pool.
// Can't do this now due to fake-PNOR driver.
printk("done\n");
}
void* PageManager::_allocatePage(size_t n)
{
size_t which_bucket = 0;
while (n > (size_t)(1 << which_bucket)) which_bucket++;
int retries = 0;
page_t* page = (page_t*)NULL;
while ((page == NULL) && (retries < 3))
{
page = pop_bucket(which_bucket);
retries++;
}
if (NULL == page)
{
// TODO: Add abort instead.
printk("Insufficient memory for allocation of size %zd!\n", n);
while(1);
}
// Update statistics.
__sync_sub_and_fetch(&iv_pagesAvail, n);
return page;
}
void PageManager::_freePage(void* p, size_t n)
{
if ((NULL == p) || (0 == n)) return;
size_t which_bucket = 0;
while (n > (size_t)(1 << which_bucket)) which_bucket++;
push_bucket((page_t*)p, which_bucket);
// Update statistics.
__sync_add_and_fetch(&iv_pagesAvail, n);
return;
}
PageManager::page_t* PageManager::pop_bucket(size_t n)
{
if (n >= BUCKETS) return NULL;
page_t* p = first_page[n].pop();
if (NULL == p)
{
// Couldn't allocate from the correct size bucket, so split up an
// item from the next sized bucket.
p = pop_bucket(n+1);
if (NULL != p)
{
push_bucket((page_t*) (((uint64_t)p) + (PAGESIZE * (1 << n))),
n);
}
}
return p;
}
void PageManager::push_bucket(page_t* p, size_t n)
{
if (n >= BUCKETS) return;
first_page[n].push(p);
}
|
