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Diffstat (limited to 'arch/x86/xen/p2m.c')
-rw-r--r--arch/x86/xen/p2m.c104
1 files changed, 31 insertions, 73 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 3172692381ae..b456b048eca9 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -163,6 +163,7 @@
#include <linux/hash.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
+#include <linux/bootmem.h>
#include <asm/cache.h>
#include <asm/setup.h>
@@ -173,6 +174,7 @@
#include <xen/balloon.h>
#include <xen/grant_table.h>
+#include "p2m.h"
#include "multicalls.h"
#include "xen-ops.h"
@@ -180,38 +182,27 @@ static void __init m2p_override_init(void);
unsigned long xen_max_p2m_pfn __read_mostly;
-#define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
-#define P2M_MID_PER_PAGE (PAGE_SIZE / sizeof(unsigned long *))
-#define P2M_TOP_PER_PAGE (PAGE_SIZE / sizeof(unsigned long **))
-
-#define MAX_P2M_PFN (P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE)
+static unsigned long *p2m_mid_missing_mfn;
+static unsigned long *p2m_top_mfn;
+static unsigned long **p2m_top_mfn_p;
/* Placeholders for holes in the address space */
static RESERVE_BRK_ARRAY(unsigned long, p2m_missing, P2M_PER_PAGE);
static RESERVE_BRK_ARRAY(unsigned long *, p2m_mid_missing, P2M_MID_PER_PAGE);
-static RESERVE_BRK_ARRAY(unsigned long, p2m_mid_missing_mfn, P2M_MID_PER_PAGE);
static RESERVE_BRK_ARRAY(unsigned long **, p2m_top, P2M_TOP_PER_PAGE);
-static RESERVE_BRK_ARRAY(unsigned long, p2m_top_mfn, P2M_TOP_PER_PAGE);
-static RESERVE_BRK_ARRAY(unsigned long *, p2m_top_mfn_p, P2M_TOP_PER_PAGE);
static RESERVE_BRK_ARRAY(unsigned long, p2m_identity, P2M_PER_PAGE);
static RESERVE_BRK_ARRAY(unsigned long *, p2m_mid_identity, P2M_MID_PER_PAGE);
-static RESERVE_BRK_ARRAY(unsigned long, p2m_mid_identity_mfn, P2M_MID_PER_PAGE);
RESERVE_BRK(p2m_mid, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE)));
-RESERVE_BRK(p2m_mid_mfn, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE)));
-/* We might hit two boundary violations at the start and end, at max each
- * boundary violation will require three middle nodes. */
-RESERVE_BRK(p2m_mid_extra, PAGE_SIZE * 2 * 3);
-
-/* When we populate back during bootup, the amount of pages can vary. The
- * max we have is seen is 395979, but that does not mean it can't be more.
- * Some machines can have 3GB I/O holes even. With early_can_reuse_p2m_middle
- * it can re-use Xen provided mfn_list array, so we only need to allocate at
- * most three P2M top nodes. */
-RESERVE_BRK(p2m_populated, PAGE_SIZE * 3);
+/* For each I/O range remapped we may lose up to two leaf pages for the boundary
+ * violations and three mid pages to cover up to 3GB. With
+ * early_can_reuse_p2m_middle() most of the leaf pages will be reused by the
+ * remapped region.
+ */
+RESERVE_BRK(p2m_identity_remap, PAGE_SIZE * 2 * 3 * MAX_REMAP_RANGES);
static inline unsigned p2m_top_index(unsigned long pfn)
{
@@ -281,11 +272,11 @@ static void p2m_init(unsigned long *p2m)
* Build the parallel p2m_top_mfn and p2m_mid_mfn structures
*
* This is called both at boot time, and after resuming from suspend:
- * - At boot time we're called very early, and must use extend_brk()
+ * - At boot time we're called rather early, and must use alloc_bootmem*()
* to allocate memory.
*
* - After resume we're called from within stop_machine, but the mfn
- * tree should alreay be completely allocated.
+ * tree should already be completely allocated.
*/
void __ref xen_build_mfn_list_list(void)
{
@@ -296,20 +287,17 @@ void __ref xen_build_mfn_list_list(void)
/* Pre-initialize p2m_top_mfn to be completely missing */
if (p2m_top_mfn == NULL) {
- p2m_mid_missing_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE);
+ p2m_mid_missing_mfn = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
- p2m_mid_identity_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE);
- p2m_mid_mfn_init(p2m_mid_identity_mfn, p2m_identity);
- p2m_top_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
+ p2m_top_mfn_p = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
p2m_top_mfn_p_init(p2m_top_mfn_p);
- p2m_top_mfn = extend_brk(PAGE_SIZE, PAGE_SIZE);
+ p2m_top_mfn = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
p2m_top_mfn_init(p2m_top_mfn);
} else {
/* Reinitialise, mfn's all change after migration */
p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
- p2m_mid_mfn_init(p2m_mid_identity_mfn, p2m_identity);
}
for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += P2M_PER_PAGE) {
@@ -337,10 +325,9 @@ void __ref xen_build_mfn_list_list(void)
/*
* XXX boot-time only! We should never find
* missing parts of the mfn tree after
- * runtime. extend_brk() will BUG if we call
- * it too late.
+ * runtime.
*/
- mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
+ mid_mfn_p = alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
p2m_mid_mfn_init(mid_mfn_p, p2m_missing);
p2m_top_mfn_p[topidx] = mid_mfn_p;
@@ -424,7 +411,6 @@ void __init xen_build_dynamic_phys_to_machine(void)
m2p_override_init();
}
#ifdef CONFIG_X86_64
-#include <linux/bootmem.h>
unsigned long __init xen_revector_p2m_tree(void)
{
unsigned long va_start;
@@ -486,7 +472,6 @@ unsigned long __init xen_revector_p2m_tree(void)
copy_page(new, mid_p);
p2m_top[topidx][mididx] = &mfn_list[pfn_free];
- p2m_top_mfn_p[topidx][mididx] = virt_to_mfn(&mfn_list[pfn_free]);
pfn_free += P2M_PER_PAGE;
@@ -547,12 +532,13 @@ static bool alloc_p2m(unsigned long pfn)
unsigned topidx, mididx;
unsigned long ***top_p, **mid;
unsigned long *top_mfn_p, *mid_mfn;
+ unsigned long *p2m_orig;
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
top_p = &p2m_top[topidx];
- mid = *top_p;
+ mid = ACCESS_ONCE(*top_p);
if (mid == p2m_mid_missing) {
/* Mid level is missing, allocate a new one */
@@ -567,7 +553,7 @@ static bool alloc_p2m(unsigned long pfn)
}
top_mfn_p = &p2m_top_mfn[topidx];
- mid_mfn = p2m_top_mfn_p[topidx];
+ mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]);
BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p);
@@ -575,6 +561,7 @@ static bool alloc_p2m(unsigned long pfn)
/* Separately check the mid mfn level */
unsigned long missing_mfn;
unsigned long mid_mfn_mfn;
+ unsigned long old_mfn;
mid_mfn = alloc_p2m_page();
if (!mid_mfn)
@@ -584,17 +571,19 @@ static bool alloc_p2m(unsigned long pfn)
missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);
mid_mfn_mfn = virt_to_mfn(mid_mfn);
- if (cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn) != missing_mfn)
+ old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn);
+ if (old_mfn != missing_mfn) {
free_p2m_page(mid_mfn);
- else
+ mid_mfn = mfn_to_virt(old_mfn);
+ } else {
p2m_top_mfn_p[topidx] = mid_mfn;
+ }
}
- if (p2m_top[topidx][mididx] == p2m_identity ||
- p2m_top[topidx][mididx] == p2m_missing) {
+ p2m_orig = ACCESS_ONCE(p2m_top[topidx][mididx]);
+ if (p2m_orig == p2m_identity || p2m_orig == p2m_missing) {
/* p2m leaf page is missing */
unsigned long *p2m;
- unsigned long *p2m_orig = p2m_top[topidx][mididx];
p2m = alloc_p2m_page();
if (!p2m)
@@ -615,7 +604,6 @@ static bool __init early_alloc_p2m(unsigned long pfn, bool check_boundary)
{
unsigned topidx, mididx, idx;
unsigned long *p2m;
- unsigned long *mid_mfn_p;
topidx = p2m_top_index(pfn);
mididx = p2m_mid_index(pfn);
@@ -642,43 +630,21 @@ static bool __init early_alloc_p2m(unsigned long pfn, bool check_boundary)
p2m_top[topidx][mididx] = p2m;
- /* For save/restore we need to MFN of the P2M saved */
-
- mid_mfn_p = p2m_top_mfn_p[topidx];
- WARN(mid_mfn_p[mididx] != virt_to_mfn(p2m_missing),
- "P2M_TOP_P[%d][%d] != MFN of p2m_missing!\n",
- topidx, mididx);
- mid_mfn_p[mididx] = virt_to_mfn(p2m);
-
return true;
}
static bool __init early_alloc_p2m_middle(unsigned long pfn)
{
unsigned topidx = p2m_top_index(pfn);
- unsigned long *mid_mfn_p;
unsigned long **mid;
mid = p2m_top[topidx];
- mid_mfn_p = p2m_top_mfn_p[topidx];
if (mid == p2m_mid_missing) {
mid = extend_brk(PAGE_SIZE, PAGE_SIZE);
p2m_mid_init(mid, p2m_missing);
p2m_top[topidx] = mid;
-
- BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
- }
- /* And the save/restore P2M tables.. */
- if (mid_mfn_p == p2m_mid_missing_mfn) {
- mid_mfn_p = extend_brk(PAGE_SIZE, PAGE_SIZE);
- p2m_mid_mfn_init(mid_mfn_p, p2m_missing);
-
- p2m_top_mfn_p[topidx] = mid_mfn_p;
- p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
- /* Note: we don't set mid_mfn_p[midix] here,
- * look in early_alloc_p2m() */
}
return true;
}
@@ -689,14 +655,13 @@ static bool __init early_alloc_p2m_middle(unsigned long pfn)
* replace the P2M leaf with a p2m_missing or p2m_identity.
* Stick the old page in the new P2M tree location.
*/
-bool __init early_can_reuse_p2m_middle(unsigned long set_pfn, unsigned long set_mfn)
+static bool __init early_can_reuse_p2m_middle(unsigned long set_pfn)
{
unsigned topidx;
unsigned mididx;
unsigned ident_pfns;
unsigned inv_pfns;
unsigned long *p2m;
- unsigned long *mid_mfn_p;
unsigned idx;
unsigned long pfn;
@@ -742,11 +707,6 @@ bool __init early_can_reuse_p2m_middle(unsigned long set_pfn, unsigned long set_
found:
/* Found one, replace old with p2m_identity or p2m_missing */
p2m_top[topidx][mididx] = (ident_pfns ? p2m_identity : p2m_missing);
- /* And the other for save/restore.. */
- mid_mfn_p = p2m_top_mfn_p[topidx];
- /* NOTE: Even if it is a p2m_identity it should still be point to
- * a page filled with INVALID_P2M_ENTRY entries. */
- mid_mfn_p[mididx] = virt_to_mfn(p2m_missing);
/* Reset where we want to stick the old page in. */
topidx = p2m_top_index(set_pfn);
@@ -761,8 +721,6 @@ found:
p2m_init(p2m);
p2m_top[topidx][mididx] = p2m;
- mid_mfn_p = p2m_top_mfn_p[topidx];
- mid_mfn_p[mididx] = virt_to_mfn(p2m);
return true;
}
@@ -772,7 +730,7 @@ bool __init early_set_phys_to_machine(unsigned long pfn, unsigned long mfn)
if (!early_alloc_p2m_middle(pfn))
return false;
- if (early_can_reuse_p2m_middle(pfn, mfn))
+ if (early_can_reuse_p2m_middle(pfn))
return __set_phys_to_machine(pfn, mfn);
if (!early_alloc_p2m(pfn, false /* boundary crossover OK!*/))
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-01 07:30:38 +0300