# HG changeset patch
# User Jimi Xenidis <[EMAIL PROTECTED]>
# Node ID f18ec562c11cabed94d448a12754660c63497fac
# Parent 2765c83b576d5af048d381c481e33f597c2be258
[LINUX][XEN][POWERPC] More accurate Grant Table Ops
This patch add the following:
- More DBG() points of interest
- If we run out of Bolted PTEs simply report it and let the "natural"
page fault occur
- Use the page counters to track PTE redundancies
- BUG() if GNTTABOP_transfer is ever used
- Add GNTTABOP_copy
The use of page counters may have SMP ramifications since the Linear
map inits the refcount to 1 and there is no atomic methods to inc/dec
and see if counter == 1.
Signed-off-by: Jimi Xenidis <[EMAIL PROTECTED]>
---
arch/powerpc/platforms/xen/gnttab.c | 109 +++++++++++++++++++++++++++---------
1 files changed, 82 insertions(+), 27 deletions(-)
diff -r 2765c83b576d -r f18ec562c11c arch/powerpc/platforms/xen/gnttab.c
--- a/arch/powerpc/platforms/xen/gnttab.c Mon Oct 09 19:57:42 2006 -0400
+++ b/arch/powerpc/platforms/xen/gnttab.c Tue Oct 10 09:48:33 2006 -0400
@@ -39,6 +39,8 @@ static long map_to_linear(ulong paddr)
mode = _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX;
vaddr = (ulong)__va(paddr);
+ DBG("%s: 0x%lx: 0x%x\n",
+ __func__, paddr, page_count(virt_to_page(vaddr)));
{
unsigned long vpn, hash, hpteg;
unsigned long vsid = get_kernel_vsid(vaddr);
@@ -57,25 +59,13 @@ static long map_to_linear(ulong paddr)
BUG_ON(!ppc_md.hpte_insert);
slot = ppc_md.hpte_insert(hpteg, va, paddr,
tmp_mode, HPTE_V_BOLTED, psize);
- BUG_ON(slot < 0);
+ if (slot < 0)
+ printk(KERN_EMERG
+ "%s: no more bolted entries "
+ "HTAB[0x%lx]: 0x%lx\n",
+ __func__, hpteg, paddr);
}
return slot;
-}
-
-static void gnttab_post_map_grant_ref(
- struct gnttab_map_grant_ref *map, int count)
-{
- int i;
- long slot;
-
- for (i = 0 ; i < count; i++) {
- ulong pa = map[i].dev_bus_addr;
- BUG_ON(pa < foreign_map_base || pa >= foreign_map_end);
-
- slot = map_to_linear(pa);
- /* store the slot somewhere */
- map[i].host_addr = (ulong)__va(pa);
- }
}
static unsigned long get_hpte_vsid(ulong slot)
@@ -128,29 +118,89 @@ static long find_hpte_slot(unsigned long
return -1;
}
+static long find_map_slot(ulong ea)
+{
+ int psize = MMU_PAGE_4K;
+ ulong vsid;
+ ulong va;
+
+ vsid = get_kernel_vsid(ea);
+ va = (vsid << 28) | (ea & 0x0fffffff);
+
+ return find_hpte_slot(va, psize);
+}
+
+
static void gnttab_pre_unmap_grant_ref(
struct gnttab_unmap_grant_ref *unmap, int count)
{
long slot;
- ulong vsid;
- ulong va;
- int psize = MMU_PAGE_4K;
int i;
ulong ea;
unsigned long dummy1, dummy2;
for (i = 0 ; i < count; i++) {
+ struct page *page;
+
ea = unmap[i].host_addr;
- vsid = get_kernel_vsid(ea);
- va = (vsid << 28) | (ea & 0x0fffffff);
-
- slot = find_hpte_slot(va, psize);
- BUG_ON(slot < 0);
-
+ page = virt_to_page(ea);
+
+ /* Unfortunately, there is no put_page_testone() like
+ * put_page_testzero(). The Linear Map starts all
+ * pages with a count of 1, so there may be SMP issues
+ * here. */
+
+ put_page(page);
+ if (page_count(page) > 1) {
+ DBG("%s: skip: 0x%lx\n", __func__, ea);
+ continue;
+ }
+ slot = find_map_slot(ea);
+ if (slot < 0) {
+ printk(KERN_EMERG "%s: PTE not found: 0x%lx\n",
+ __func__, ea);
+ continue;
+ }
+
+ DBG("%s: 0x%lx: 0x%x\n",
+ __func__, ea, page_count(virt_to_page(ea)));
plpar_pte_remove(0, slot, 0, &dummy1, &dummy2);
DBG("%s: remove_pages(0x%lx, 0x%lx)\n",
__func__, unmap[i].host_addr, unmap[i].dev_bus_addr);
+ }
+}
+
+static void gnttab_post_map_grant_ref(
+ struct gnttab_map_grant_ref *map, int count)
+{
+ int i;
+ long slot;
+
+ for (i = 0 ; i < count; i++) {
+ ulong pa = map[i].dev_bus_addr;
+ struct page *page;
+
+ BUG_ON(pa < foreign_map_base || pa >= foreign_map_end);
+
+ /* ??? store the slot somewhere ??? */
+ map[i].host_addr = (ulong)__va(pa);
+ page = virt_to_page(map[i].host_addr);
+
+ if (page_count(page) == 1) {
+#ifdef DEBUG
+ /* we need to get smarted than this */
+ slot = find_map_slot((ulong)__va(pa));
+ if (slot >= 0) {
+ DBG("%s: redundant 0x%lx\n", __func__, pa);
+ continue;
+ }
+#endif
+ slot = map_to_linear(pa);
+ } else {
+ DBG("%s: skip 0x%lx\n", __func__, pa);
+ }
+ get_page(page);
}
}
@@ -175,7 +225,8 @@ int HYPERVISOR_grant_table_op(unsigned i
memcpy(&setup, op, sizeof(setup));
argsize = sizeof(setup);
- frame_list =
xencomm_create_inline(xen_guest_handle(setup.frame_list));
+ frame_list = xencomm_create_inline(
+ xen_guest_handle(setup.frame_list));
set_xen_guest_handle(setup.frame_list, frame_list);
memcpy(op, &setup, sizeof(setup));
@@ -185,6 +236,10 @@ int HYPERVISOR_grant_table_op(unsigned i
argsize = sizeof(struct gnttab_dump_table);
break;
case GNTTABOP_transfer:
+ BUG();
+ argsize = sizeof(struct gnttab_transfer);
+ break;
+ case GNTTABOP_copy:
argsize = sizeof(struct gnttab_transfer);
break;
default:
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