summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2011-10-25 09:17:07 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2011-10-25 09:17:07 +0200
commit5eef150c1d7e41baaefd00dd56c153debcd86aee (patch)
tree612723d8b0930ba8c6292cd317231249713c1877
parent315eb8a2a1b7f335d40ceeeb11b9e067475eb881 (diff)
parentf3f436e33b925ead21e3f9b47b1e2aed965511d9 (diff)
Merge branch 'stable/e820-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/e820-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: release all pages within 1-1 p2m mappings xen: allow extra memory to be in multiple regions xen: allow balloon driver to use more than one memory region xen/balloon: simplify test for the end of usable RAM xen/balloon: account for pages released during memory setup
-rw-r--r--arch/x86/xen/setup.c284
-rw-r--r--drivers/xen/balloon.c50
-rw-r--r--include/xen/page.h12
3 files changed, 165 insertions, 181 deletions
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 46d6d21dbdb..38d0af4fefe 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -37,7 +37,10 @@ extern void xen_syscall_target(void);
extern void xen_syscall32_target(void);
/* Amount of extra memory space we add to the e820 ranges */
-phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
+struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
+
+/* Number of pages released from the initial allocation. */
+unsigned long xen_released_pages;
/*
* The maximum amount of extra memory compared to the base size. The
@@ -51,48 +54,47 @@ phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
*/
#define EXTRA_MEM_RATIO (10)
-static void __init xen_add_extra_mem(unsigned long pages)
+static void __init xen_add_extra_mem(u64 start, u64 size)
{
unsigned long pfn;
+ int i;
- u64 size = (u64)pages * PAGE_SIZE;
- u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
-
- if (!pages)
- return;
-
- e820_add_region(extra_start, size, E820_RAM);
- sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
-
- memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA");
+ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+ /* Add new region. */
+ if (xen_extra_mem[i].size == 0) {
+ xen_extra_mem[i].start = start;
+ xen_extra_mem[i].size = size;
+ break;
+ }
+ /* Append to existing region. */
+ if (xen_extra_mem[i].start + xen_extra_mem[i].size == start) {
+ xen_extra_mem[i].size += size;
+ break;
+ }
+ }
+ if (i == XEN_EXTRA_MEM_MAX_REGIONS)
+ printk(KERN_WARNING "Warning: not enough extra memory regions\n");
- xen_extra_mem_size += size;
+ memblock_x86_reserve_range(start, start + size, "XEN EXTRA");
- xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
+ xen_max_p2m_pfn = PFN_DOWN(start + size);
- for (pfn = PFN_DOWN(extra_start); pfn <= xen_max_p2m_pfn; pfn++)
+ for (pfn = PFN_DOWN(start); pfn <= xen_max_p2m_pfn; pfn++)
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
-static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
- phys_addr_t end_addr)
+static unsigned long __init xen_release_chunk(unsigned long start,
+ unsigned long end)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = 0,
.domid = DOMID_SELF
};
- unsigned long start, end;
unsigned long len = 0;
unsigned long pfn;
int ret;
- start = PFN_UP(start_addr);
- end = PFN_DOWN(end_addr);
-
- if (end <= start)
- return 0;
-
for(pfn = start; pfn < end; pfn++) {
unsigned long mfn = pfn_to_mfn(pfn);
@@ -117,72 +119,52 @@ static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
return len;
}
-static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
- const struct e820map *e820)
+static unsigned long __init xen_set_identity_and_release(
+ const struct e820entry *list, size_t map_size, unsigned long nr_pages)
{
- phys_addr_t max_addr = PFN_PHYS(max_pfn);
- phys_addr_t last_end = ISA_END_ADDRESS;
+ phys_addr_t start = 0;
unsigned long released = 0;
- int i;
-
- /* Free any unused memory above the low 1Mbyte. */
- for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
- phys_addr_t end = e820->map[i].addr;
- end = min(max_addr, end);
-
- if (last_end < end)
- released += xen_release_chunk(last_end, end);
- last_end = max(last_end, e820->map[i].addr + e820->map[i].size);
- }
-
- if (last_end < max_addr)
- released += xen_release_chunk(last_end, max_addr);
-
- printk(KERN_INFO "released %lu pages of unused memory\n", released);
- return released;
-}
-
-static unsigned long __init xen_set_identity(const struct e820entry *list,
- ssize_t map_size)
-{
- phys_addr_t last = xen_initial_domain() ? 0 : ISA_END_ADDRESS;
- phys_addr_t start_pci = last;
- const struct e820entry *entry;
unsigned long identity = 0;
+ const struct e820entry *entry;
int i;
+ /*
+ * Combine non-RAM regions and gaps until a RAM region (or the
+ * end of the map) is reached, then set the 1:1 map and
+ * release the pages (if available) in those non-RAM regions.
+ *
+ * The combined non-RAM regions are rounded to a whole number
+ * of pages so any partial pages are accessible via the 1:1
+ * mapping. This is needed for some BIOSes that put (for
+ * example) the DMI tables in a reserved region that begins on
+ * a non-page boundary.
+ */
for (i = 0, entry = list; i < map_size; i++, entry++) {
- phys_addr_t start = entry->addr;
- phys_addr_t end = start + entry->size;
+ phys_addr_t end = entry->addr + entry->size;
- if (start < last)
- start = last;
+ if (entry->type == E820_RAM || i == map_size - 1) {
+ unsigned long start_pfn = PFN_DOWN(start);
+ unsigned long end_pfn = PFN_UP(end);
- if (end <= start)
- continue;
+ if (entry->type == E820_RAM)
+ end_pfn = PFN_UP(entry->addr);
- /* Skip over the 1MB region. */
- if (last > end)
- continue;
+ if (start_pfn < end_pfn) {
+ if (start_pfn < nr_pages)
+ released += xen_release_chunk(
+ start_pfn, min(end_pfn, nr_pages));
- if ((entry->type == E820_RAM) || (entry->type == E820_UNUSABLE)) {
- if (start > start_pci)
identity += set_phys_range_identity(
- PFN_UP(start_pci), PFN_DOWN(start));
-
- /* Without saving 'last' we would gooble RAM too
- * at the end of the loop. */
- last = end;
- start_pci = end;
- continue;
+ start_pfn, end_pfn);
+ }
+ start = end;
}
- start_pci = min(start, start_pci);
- last = end;
}
- if (last > start_pci)
- identity += set_phys_range_identity(
- PFN_UP(start_pci), PFN_DOWN(last));
- return identity;
+
+ printk(KERN_INFO "Released %lu pages of unused memory\n", released);
+ printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
+
+ return released;
}
static unsigned long __init xen_get_max_pages(void)
@@ -197,21 +179,32 @@ static unsigned long __init xen_get_max_pages(void)
return min(max_pages, MAX_DOMAIN_PAGES);
}
+static void xen_align_and_add_e820_region(u64 start, u64 size, int type)
+{
+ u64 end = start + size;
+
+ /* Align RAM regions to page boundaries. */
+ if (type == E820_RAM) {
+ start = PAGE_ALIGN(start);
+ end &= ~((u64)PAGE_SIZE - 1);
+ }
+
+ e820_add_region(start, end - start, type);
+}
+
/**
* machine_specific_memory_setup - Hook for machine specific memory setup.
**/
char * __init xen_memory_setup(void)
{
static struct e820entry map[E820MAX] __initdata;
- static struct e820entry map_raw[E820MAX] __initdata;
unsigned long max_pfn = xen_start_info->nr_pages;
unsigned long long mem_end;
int rc;
struct xen_memory_map memmap;
+ unsigned long max_pages;
unsigned long extra_pages = 0;
- unsigned long extra_limit;
- unsigned long identity_pages = 0;
int i;
int op;
@@ -237,58 +230,65 @@ char * __init xen_memory_setup(void)
}
BUG_ON(rc);
- memcpy(map_raw, map, sizeof(map));
- e820.nr_map = 0;
- xen_extra_mem_start = mem_end;
- for (i = 0; i < memmap.nr_entries; i++) {
- unsigned long long end;
-
- /* Guard against non-page aligned E820 entries. */
- if (map[i].type == E820_RAM)
- map[i].size -= (map[i].size + map[i].addr) % PAGE_SIZE;
-
- end = map[i].addr + map[i].size;
- if (map[i].type == E820_RAM && end > mem_end) {
- /* RAM off the end - may be partially included */
- u64 delta = min(map[i].size, end - mem_end);
-
- map[i].size -= delta;
- end -= delta;
-
- extra_pages += PFN_DOWN(delta);
- /*
- * Set RAM below 4GB that is not for us to be unusable.
- * This prevents "System RAM" address space from being
- * used as potential resource for I/O address (happens
- * when 'allocate_resource' is called).
- */
- if (delta &&
- (xen_initial_domain() && end < 0x100000000ULL))
- e820_add_region(end, delta, E820_UNUSABLE);
+ /* Make sure the Xen-supplied memory map is well-ordered. */
+ sanitize_e820_map(map, memmap.nr_entries, &memmap.nr_entries);
+
+ max_pages = xen_get_max_pages();
+ if (max_pages > max_pfn)
+ extra_pages += max_pages - max_pfn;
+
+ /*
+ * Set P2M for all non-RAM pages and E820 gaps to be identity
+ * type PFNs. Any RAM pages that would be made inaccesible by
+ * this are first released.
+ */
+ xen_released_pages = xen_set_identity_and_release(
+ map, memmap.nr_entries, max_pfn);
+ extra_pages += xen_released_pages;
+
+ /*
+ * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
+ * factor the base size. On non-highmem systems, the base
+ * size is the full initial memory allocation; on highmem it
+ * is limited to the max size of lowmem, so that it doesn't
+ * get completely filled.
+ *
+ * In principle there could be a problem in lowmem systems if
+ * the initial memory is also very large with respect to
+ * lowmem, but we won't try to deal with that here.
+ */
+ extra_pages = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
+ extra_pages);
+
+ i = 0;
+ while (i < memmap.nr_entries) {
+ u64 addr = map[i].addr;
+ u64 size = map[i].size;
+ u32 type = map[i].type;
+
+ if (type == E820_RAM) {
+ if (addr < mem_end) {
+ size = min(size, mem_end - addr);
+ } else if (extra_pages) {
+ size = min(size, (u64)extra_pages * PAGE_SIZE);
+ extra_pages -= size / PAGE_SIZE;
+ xen_add_extra_mem(addr, size);
+ } else
+ type = E820_UNUSABLE;
}
- if (map[i].size > 0 && end > xen_extra_mem_start)
- xen_extra_mem_start = end;
+ xen_align_and_add_e820_region(addr, size, type);
- /* Add region if any remains */
- if (map[i].size > 0)
- e820_add_region(map[i].addr, map[i].size, map[i].type);
+ map[i].addr += size;
+ map[i].size -= size;
+ if (map[i].size == 0)
+ i++;
}
- /* Align the balloon area so that max_low_pfn does not get set
- * to be at the _end_ of the PCI gap at the far end (fee01000).
- * Note that xen_extra_mem_start gets set in the loop above to be
- * past the last E820 region. */
- if (xen_initial_domain() && (xen_extra_mem_start < (1ULL<<32)))
- xen_extra_mem_start = (1ULL<<32);
/*
* In domU, the ISA region is normal, usable memory, but we
* reserve ISA memory anyway because too many things poke
* about in there.
- *
- * In Dom0, the host E820 information can leave gaps in the
- * ISA range, which would cause us to release those pages. To
- * avoid this, we unconditionally reserve them here.
*/
e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
E820_RESERVED);
@@ -305,44 +305,6 @@ char * __init xen_memory_setup(void)
sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
- extra_limit = xen_get_max_pages();
- if (max_pfn + extra_pages > extra_limit) {
- if (extra_limit > max_pfn)
- extra_pages = extra_limit - max_pfn;
- else
- extra_pages = 0;
- }
-
- extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
-
- /*
- * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
- * factor the base size. On non-highmem systems, the base
- * size is the full initial memory allocation; on highmem it
- * is limited to the max size of lowmem, so that it doesn't
- * get completely filled.
- *
- * In principle there could be a problem in lowmem systems if
- * the initial memory is also very large with respect to
- * lowmem, but we won't try to deal with that here.
- */
- extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
- max_pfn + extra_pages);
-
- if (extra_limit >= max_pfn)
- extra_pages = extra_limit - max_pfn;
- else
- extra_pages = 0;
-
- xen_add_extra_mem(extra_pages);
-
- /*
- * Set P2M for all non-RAM pages and E820 gaps to be identity
- * type PFNs. We supply it with the non-sanitized version
- * of the E820.
- */
- identity_pages = xen_set_identity(map_raw, memmap.nr_entries);
- printk(KERN_INFO "Set %ld page(s) to 1-1 mapping.\n", identity_pages);
return "Xen";
}
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 5dfd8f8ff07..fc43b53651d 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -555,17 +555,40 @@ void free_xenballooned_pages(int nr_pages, struct page** pages)
}
EXPORT_SYMBOL(free_xenballooned_pages);
-static int __init balloon_init(void)
+static void __init balloon_add_region(unsigned long start_pfn,
+ unsigned long pages)
{
unsigned long pfn, extra_pfn_end;
struct page *page;
+ /*
+ * If the amount of usable memory has been limited (e.g., with
+ * the 'mem' command line parameter), don't add pages beyond
+ * this limit.
+ */
+ extra_pfn_end = min(max_pfn, start_pfn + pages);
+
+ for (pfn = start_pfn; pfn < extra_pfn_end; pfn++) {
+ page = pfn_to_page(pfn);
+ /* totalram_pages and totalhigh_pages do not
+ include the boot-time balloon extension, so
+ don't subtract from it. */
+ __balloon_append(page);
+ }
+}
+
+static int __init balloon_init(void)
+{
+ int i;
+
if (!xen_domain())
return -ENODEV;
pr_info("xen/balloon: Initialising balloon driver.\n");
- balloon_stats.current_pages = xen_pv_domain() ? min(xen_start_info->nr_pages, max_pfn) : max_pfn;
+ balloon_stats.current_pages = xen_pv_domain()
+ ? min(xen_start_info->nr_pages - xen_released_pages, max_pfn)
+ : max_pfn;
balloon_stats.target_pages = balloon_stats.current_pages;
balloon_stats.balloon_low = 0;
balloon_stats.balloon_high = 0;
@@ -584,24 +607,13 @@ static int __init balloon_init(void)
#endif
/*
- * Initialise the balloon with excess memory space. We need
- * to make sure we don't add memory which doesn't exist or
- * logically exist. The E820 map can be trimmed to be smaller
- * than the amount of physical memory due to the mem= command
- * line parameter. And if this is a 32-bit non-HIGHMEM kernel
- * on a system with memory which requires highmem to access,
- * don't try to use it.
+ * Initialize the balloon with pages from the extra memory
+ * regions (see arch/x86/xen/setup.c).
*/
- extra_pfn_end = min(min(max_pfn, e820_end_of_ram_pfn()),
- (unsigned long)PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size));
- for (pfn = PFN_UP(xen_extra_mem_start);
- pfn < extra_pfn_end;
- pfn++) {
- page = pfn_to_page(pfn);
- /* totalram_pages and totalhigh_pages do not include the boot-time
- balloon extension, so don't subtract from it. */
- __balloon_append(page);
- }
+ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++)
+ if (xen_extra_mem[i].size)
+ balloon_add_region(PFN_UP(xen_extra_mem[i].start),
+ PFN_DOWN(xen_extra_mem[i].size));
return 0;
}
diff --git a/include/xen/page.h b/include/xen/page.h
index 0be36b976f4..12765b6f951 100644
--- a/include/xen/page.h
+++ b/include/xen/page.h
@@ -3,6 +3,16 @@
#include <asm/xen/page.h>
-extern phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
+struct xen_memory_region {
+ phys_addr_t start;
+ phys_addr_t size;
+};
+
+#define XEN_EXTRA_MEM_MAX_REGIONS 128 /* == E820MAX */
+
+extern __initdata
+struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS];
+
+extern unsigned long xen_released_pages;
#endif /* _XEN_PAGE_H */