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author | David Vrabel <david.vrabel@citrix.com> | 2015-06-24 15:58:42 +0100 |
---|---|---|
committer | David Vrabel <david.vrabel@citrix.com> | 2015-10-23 14:20:03 +0100 |
commit | 55b3da98a40dbb3776f7454daf0d95dde25c33d2 (patch) | |
tree | 8785a1fb0ea443d60e345d87b7b5d5d474da539a /drivers/xen/balloon.c | |
parent | f5775e0b6116b7e2425ccf535243b21768566d87 (diff) | |
download | op-kernel-dev-55b3da98a40dbb3776f7454daf0d95dde25c33d2.zip op-kernel-dev-55b3da98a40dbb3776f7454daf0d95dde25c33d2.tar.gz |
xen/balloon: find non-conflicting regions to place hotplugged memory
Instead of placing hotplugged memory at the end of RAM (which may
conflict with PCI devices or reserved regions) use allocate_resource()
to get a new, suitably aligned resource that does not conflict.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
v3:
- Remove stale comment.
Diffstat (limited to 'drivers/xen/balloon.c')
-rw-r--r-- | drivers/xen/balloon.c | 73 |
1 files changed, 53 insertions, 20 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index c79329f..095bb67 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -54,6 +54,7 @@ #include <linux/memory.h> #include <linux/memory_hotplug.h> #include <linux/percpu-defs.h> +#include <linux/slab.h> #include <asm/page.h> #include <asm/pgalloc.h> @@ -208,26 +209,56 @@ static bool balloon_is_inflated(void) return false; } -/* - * reserve_additional_memory() adds memory region of size >= credit above - * max_pfn. New region is section aligned and size is modified to be multiple - * of section size. Those features allow optimal use of address space and - * establish proper alignment when this function is called first time after - * boot (last section not fully populated at boot time contains unused memory - * pages with PG_reserved bit not set; online_pages_range() does not allow page - * onlining in whole range if first onlined page does not have PG_reserved - * bit set). Real size of added memory is established at page onlining stage. - */ +static struct resource *additional_memory_resource(phys_addr_t size) +{ + struct resource *res; + int ret; + + res = kzalloc(sizeof(*res), GFP_KERNEL); + if (!res) + return NULL; + + res->name = "System RAM"; + res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; + + ret = allocate_resource(&iomem_resource, res, + size, 0, -1, + PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL); + if (ret < 0) { + pr_err("Cannot allocate new System RAM resource\n"); + kfree(res); + return NULL; + } + + return res; +} + +static void release_memory_resource(struct resource *resource) +{ + if (!resource) + return; + + /* + * No need to reset region to identity mapped since we now + * know that no I/O can be in this region + */ + release_resource(resource); + kfree(resource); +} static enum bp_state reserve_additional_memory(long credit) { + struct resource *resource; int nid, rc; - u64 hotplug_start_paddr; - unsigned long balloon_hotplug = credit; + unsigned long balloon_hotplug; + + balloon_hotplug = round_up(credit, PAGES_PER_SECTION); + + resource = additional_memory_resource(balloon_hotplug * PAGE_SIZE); + if (!resource) + goto err; - hotplug_start_paddr = PFN_PHYS(SECTION_ALIGN_UP(max_pfn)); - balloon_hotplug = round_up(balloon_hotplug, PAGES_PER_SECTION); - nid = memory_add_physaddr_to_nid(hotplug_start_paddr); + nid = memory_add_physaddr_to_nid(resource->start); #ifdef CONFIG_XEN_HAVE_PVMMU /* @@ -242,21 +273,20 @@ static enum bp_state reserve_additional_memory(long credit) if (!xen_feature(XENFEAT_auto_translated_physmap)) { unsigned long pfn, i; - pfn = PFN_DOWN(hotplug_start_paddr); + pfn = PFN_DOWN(resource->start); for (i = 0; i < balloon_hotplug; i++) { if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) { pr_warn("set_phys_to_machine() failed, no memory added\n"); - return BP_ECANCELED; + goto err; } } } #endif - rc = add_memory(nid, hotplug_start_paddr, balloon_hotplug << PAGE_SHIFT); - + rc = add_memory_resource(nid, resource); if (rc) { pr_warn("Cannot add additional memory (%i)\n", rc); - return BP_ECANCELED; + goto err; } balloon_hotplug -= credit; @@ -265,6 +295,9 @@ static enum bp_state reserve_additional_memory(long credit) balloon_stats.balloon_hotplug = balloon_hotplug; return BP_DONE; + err: + release_memory_resource(resource); + return BP_ECANCELED; } static void xen_online_page(struct page *page) |