Please double-check the usedbit issue below otherwise I'll ACK this.
-JX
On Jan 11, 2007, at 4:51 PM, Hollis Blanchard wrote:
# HG changeset patch
# User Hollis Blanchard <[EMAIL PROTECTED]>
# Date 1168550320 21600
# Node ID d98b2fbc100cfec5678a787ba7bfd0b065254793
# Parent dbc74db14a4b39d359365fcf8257216d968fa269
[POWERPC][XEN] Mark heap memory based on boot_of.c's allocator.
- Explain why we have another allocator (that wasn't so hard now
was it?).
- Create and export boot_of_mem_avail() to allow later code to
iterate over the
allocator bitmap.
- Use boot_of_mem_avail() to place memory in the heap, instead of
using globals
and making assumptions about the ordering of reserved areas.
Signed-off-by: Hollis Blanchard <[EMAIL PROTECTED]>
diff -r dbc74db14a4b -r d98b2fbc100c xen/arch/powerpc/boot_of.c
--- a/xen/arch/powerpc/boot_of.c Tue Dec 12 14:35:07 2006 -0600
+++ b/xen/arch/powerpc/boot_of.c Thu Jan 11 15:18:40 2007 -0600
@@ -43,6 +43,14 @@ static int of_out;
static int of_out;
static ulong eomem;
+/* Track memory during early boot with a limited per-page bitmap.
We need an
+ * allocator to tell us where we can place RTAS, our copy of the
device tree.
+ * We could examine the "available" properties in memory nodes,
but we
+ * apparently can't depend on firmware to update those when we
call "claim". So
+ * we need to track it ourselves.
+ * We can't dynamically allocate the bitmap, because we would need
something
+ * to tell us where it's safe to allocate...
+ */
#define MEM_AVAILABLE_PAGES ((32 << 20) >> PAGE_SHIFT)
static DECLARE_BITMAP(mem_available_pages, MEM_AVAILABLE_PAGES);
@@ -530,6 +538,33 @@ static ulong boot_of_alloc(ulong size)
pos = pos + i;
}
+}
+
+int boot_of_mem_avail(int pos, ulong *startpage, ulong *endpage)
If you'd like to hide the bitmap, then perhaps the first arg should
be a start address and return the address of the next "used" page?
+{
+ ulong freebit;
+ ulong usedbit;
+
+ /* find first free page. */
+ freebit = find_next_zero_bit(mem_available_pages,
MEM_AVAILABLE_PAGES, pos);
+ if (freebit >= MEM_AVAILABLE_PAGES) {
+ /* We know everything after MEM_AVAILABLE_PAGES is still
free. */
+ *startpage = MEM_AVAILABLE_PAGES << PAGE_SHIFT;
+ *endpage = ~0UL;
+ return -1;
+ }
+ *startpage = freebit << PAGE_SHIFT;
+
+ /* now find first used page after that. */
+ usedbit = find_next_bit(mem_available_pages,
MEM_AVAILABLE_PAGES, freebit);
+ if (usedbit >= MEM_AVAILABLE_PAGES) {
+ /* We know everything after MEM_AVAILABLE_PAGES is still
free. */
+ *endpage = ~0UL;
+ return -1;
+ }
+ *endpage = usedbit << PAGE_SHIFT;
I'm not 100% but the code below looks like require that end represent
a free page so "usedbit - 1"?
+
+ return usedbit;
}
static ulong boot_of_mem_init(void)
diff -r dbc74db14a4b -r d98b2fbc100c xen/arch/powerpc/memory.c
--- a/xen/arch/powerpc/memory.c Tue Dec 12 14:35:07 2006 -0600
+++ b/xen/arch/powerpc/memory.c Thu Jan 11 15:18:40 2007 -0600
@@ -42,8 +42,6 @@ unsigned long xenheap_phys_end;
unsigned long xenheap_phys_end;
static uint nr_pages;
static ulong xenheap_size;
-static ulong save_start;
-static ulong save_end;
struct membuf {
ulong start;
@@ -51,30 +49,6 @@ struct membuf {
};
typedef void (*walk_mem_fn)(struct membuf *, uint);
-
-static ulong free_xenheap(ulong start, ulong end)
-{
- start = ALIGN_UP(start, PAGE_SIZE);
- end = ALIGN_DOWN(end, PAGE_SIZE);
-
- DBG("%s: 0x%lx - 0x%lx\n", __func__, start, end);
-
- /* need to do this better */
- if (save_start <= end && save_start >= start) {
- DBG("%s: Go around the saved area: 0x%lx - 0x%lx\n",
- __func__, save_start, save_end);
- init_xenheap_pages(start, ALIGN_DOWN(save_start, PAGE_SIZE));
- xenheap_size += ALIGN_DOWN(save_start, PAGE_SIZE) - start;
-
- init_xenheap_pages(ALIGN_UP(save_end, PAGE_SIZE), end);
- xenheap_size += end - ALIGN_UP(save_end, PAGE_SIZE);
- } else {
- init_xenheap_pages(start, end);
- xenheap_size += end - start;
- }
-
- return ALIGN_UP(end, PAGE_SIZE);
-}
static void set_max_page(struct membuf *mb, uint entries)
{
@@ -113,6 +87,7 @@ static void heap_init(struct membuf *mb,
start_blk = xenheap_phys_end;
}
+ DBG("boot free: %016lx - %016lx\n", start_blk, end_blk);
init_boot_pages(start_blk, end_blk);
total_pages += (end_blk - start_blk) >> PAGE_SHIFT;
}
@@ -141,72 +116,31 @@ static void ofd_walk_mem(void *m, walk_m
}
}
-static void setup_xenheap(module_t *mod, int mcount)
-{
- int i;
- ulong freemem;
-
- freemem = ALIGN_UP((ulong)_end, PAGE_SIZE);
-
- for (i = 0; i < mcount; i++) {
- u32 s;
-
- if (mod[i].mod_end == mod[i].mod_start)
- continue;
-
- s = ALIGN_DOWN(mod[i].mod_start, PAGE_SIZE);
-
- if (mod[i].mod_start > (ulong)_start &&
- mod[i].mod_start < (ulong)_end) {
- /* mod was linked in */
- continue;
- }
-
- if (s < freemem)
- panic("module addresses must assend\n");
-
- free_xenheap(freemem, s);
- freemem = ALIGN_UP(mod[i].mod_end, PAGE_SIZE);
-
- }
-
- /* the rest of the xenheap, starting at the end of modules */
- free_xenheap(freemem, xenheap_phys_end);
-}
-
void memory_init(module_t *mod, int mcount)
{
ulong eomem;
ulong heap_start;
+ ulong bitmap_start;
+ ulong bitmap_end;
ulong xh_pages;
+ ulong start;
+ ulong end;
+ int pos = 0;
/* lets find out how much memory there is and set max_page */
max_page = 0;
printk("Physical RAM map:\n");
ofd_walk_mem((void *)oftree, set_max_page);
eomem = max_page << PAGE_SHIFT;
-
- if (eomem == 0){
+ if (eomem == 0) {
panic("ofd_walk_mem() failed\n");
}
- /* find the portion of memory we need to keep safe */
- save_start = oftree;
- save_end = oftree_end;
- if (rtas_base) {
- if (save_start > rtas_base)
- save_start = rtas_base;
- if (save_end < rtas_end)
- save_end = rtas_end;
- }
-
- /* minimum heap has to reach to the end of all Xen required
memory */
- xh_pages = ALIGN_UP(save_end, PAGE_SIZE) >> PAGE_SHIFT;
- xh_pages += opt_xenheap_megabytes << (20 - PAGE_SHIFT);
+ xh_pages = opt_xenheap_megabytes << (20 - PAGE_SHIFT);
/* While we are allocating HTABS from The Xen Heap we need it to
* be larger */
- xh_pages += nr_pages >> 5;
+ xh_pages += nr_pages >> 5;
xenheap_phys_end = xh_pages << PAGE_SHIFT;
printk("End of Xen Area: %luMiB (%luKiB)\n",
@@ -214,16 +148,22 @@ void memory_init(module_t *mod, int mcou
printk("End of RAM: %luMiB (%luKiB)\n", eomem >> 20, eomem >>
10);
- /* Architecturally the first 4 pages are exception hendlers, we
- * will also be copying down some code there */
+ /* Architecturally the first 4 pages are exception handlers. */
heap_start = 4 << PAGE_SHIFT;
- if (oftree < (ulong)_start)
- heap_start = ALIGN_UP(oftree_end, PAGE_SIZE);
-
all the images below are in the bitmap, so can;t you use
boot_of_mem_avail() to figure this out?
+ /* Avoid anything else in low memory. */
+ if (rtas_end < (ulong)_start)
+ heap_start = max_t(ulong, heap_start, rtas_end);
+ if (oftree_end < (ulong)_start)
+ heap_start = max_t(ulong, heap_start, oftree_end);
+
+ /* Install the boot allocator bitmap low. */
+ bitmap_start = heap_start;
heap_start = init_boot_allocator(heap_start);
- if (heap_start > (ulong)_start) {
+ bitmap_end = heap_start;
+ printk("boot allocator @ %lx - %lx\n", bitmap_start, bitmap_end);
+ if (bitmap_end > (ulong)_start) {
panic("space below _start (%p) is not enough memory "
- "for heap (0x%lx)\n", _start, heap_start);
+ "for heap (0x%lx)\n", _start, bitmap_end);
}
/* allow everything else to be allocated */
@@ -242,12 +182,37 @@ void memory_init(module_t *mod, int mcou
numa_initmem_init(0, max_page);
+ /* Domain heap gets all the unclaimed memory. */
end_boot_allocator();
- /* Add memory between the beginning of the heap and the beginning
- * of our text */
- free_xenheap(heap_start, (ulong)_start);
- setup_xenheap(mod, mcount);
+ /* Create initial xen heap. */
+ do {
+ pos = boot_of_mem_avail(pos, &start, &end);
+ if (end == ~0UL)
+ end = xenheap_phys_end;
+
+ /* Problem: the bitmap itself is not reserved. */
+ if ((start >= bitmap_start) && (start < bitmap_end)) {
+ /* Start is inside bitmap. */
+ start = bitmap_end;
+ }
+ if ((end > bitmap_start) && (end <= bitmap_end)) {
+ /* End is inside bitmap. */
+ end = bitmap_start;
+ }
+ if ((start < bitmap_start) && (end > bitmap_end)) {
+ /* Range encompasses bitmap. First free low part, then
high. */
+ xenheap_size += bitmap_start - start;
+ DBG("xenheap: %016lx - %016lx\n", start, bitmap_start);
+ init_xenheap_pages(start, bitmap_start);
+ start = bitmap_end;
+ }
+
+ xenheap_size += end - start;
+ DBG("xenheap: %016lx - %016lx\n", start, end);
+ init_xenheap_pages(start, end);
+ } while (pos > 0);
+
printk("Xen Heap: %luMiB (%luKiB)\n",
xenheap_size >> 20, xenheap_size >> 10);
diff -r dbc74db14a4b -r d98b2fbc100c xen/include/asm-powerpc/mm.h
--- a/xen/include/asm-powerpc/mm.h Tue Dec 12 14:35:07 2006 -0600
+++ b/xen/include/asm-powerpc/mm.h Thu Jan 11 15:18:40 2007 -0600
@@ -35,6 +35,7 @@
#define memguard_unguard_range(_p,_l) ((void)0)
extern unsigned long xenheap_phys_end;
+extern int boot_of_mem_avail(int pos, ulong *start, ulong *end);
/*
* Per-page-frame information.
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