Merge tag 'erofs-for-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang...

[linux-2.6-microblaze.git] / drivers / hv / hv_balloon.c

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 2f776d7..58af84e 100644 (file)
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -21,6 +21,7 @@
 #include <linux/memory.h>
 #include <linux/notifier.h>
 #include <linux/percpu_counter.h>
+#include <linux/page_reporting.h>
 
 #include <linux/hyperv.h>
 #include <asm/hyperv-tlfs.h>
@@ -563,6 +564,8 @@ struct hv_dynmem_device {
         * The negotiated version agreed by host.
         */
        __u32 version;
+
+       struct page_reporting_dev_info pr_dev_info;
 };
 
 static struct hv_dynmem_device dm_device;
@@ -1568,6 +1571,89 @@ static void balloon_onchannelcallback(void *context)
 
 }
 
+/* Hyper-V only supports reporting 2MB pages or higher */
+#define HV_MIN_PAGE_REPORTING_ORDER    9
+#define HV_MIN_PAGE_REPORTING_LEN (HV_HYP_PAGE_SIZE << HV_MIN_PAGE_REPORTING_ORDER)
+static int hv_free_page_report(struct page_reporting_dev_info *pr_dev_info,
+                   struct scatterlist *sgl, unsigned int nents)
+{
+       unsigned long flags;
+       struct hv_memory_hint *hint;
+       int i;
+       u64 status;
+       struct scatterlist *sg;
+
+       WARN_ON_ONCE(nents > HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES);
+       WARN_ON_ONCE(sgl->length < HV_MIN_PAGE_REPORTING_LEN);
+       local_irq_save(flags);
+       hint = *(struct hv_memory_hint **)this_cpu_ptr(hyperv_pcpu_input_arg);
+       if (!hint) {
+               local_irq_restore(flags);
+               return -ENOSPC;
+       }
+
+       hint->type = HV_EXT_MEMORY_HEAT_HINT_TYPE_COLD_DISCARD;
+       hint->reserved = 0;
+       for_each_sg(sgl, sg, nents, i) {
+               union hv_gpa_page_range *range;
+
+               range = &hint->ranges[i];
+               range->address_space = 0;
+               /* page reporting only reports 2MB pages or higher */
+               range->page.largepage = 1;
+               range->page.additional_pages =
+                       (sg->length / HV_MIN_PAGE_REPORTING_LEN) - 1;
+               range->page_size = HV_GPA_PAGE_RANGE_PAGE_SIZE_2MB;
+               range->base_large_pfn =
+                       page_to_hvpfn(sg_page(sg)) >> HV_MIN_PAGE_REPORTING_ORDER;
+       }
+
+       status = hv_do_rep_hypercall(HV_EXT_CALL_MEMORY_HEAT_HINT, nents, 0,
+                                    hint, NULL);
+       local_irq_restore(flags);
+       if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS) {
+               pr_err("Cold memory discard hypercall failed with status %llx\n",
+                       status);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static void enable_page_reporting(void)
+{
+       int ret;
+
+       /* Essentially, validating 'PAGE_REPORTING_MIN_ORDER' is big enough. */
+       if (pageblock_order < HV_MIN_PAGE_REPORTING_ORDER) {
+               pr_debug("Cold memory discard is only supported on 2MB pages and above\n");
+               return;
+       }
+
+       if (!hv_query_ext_cap(HV_EXT_CAPABILITY_MEMORY_COLD_DISCARD_HINT)) {
+               pr_debug("Cold memory discard hint not supported by Hyper-V\n");
+               return;
+       }
+
+       BUILD_BUG_ON(PAGE_REPORTING_CAPACITY > HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES);
+       dm_device.pr_dev_info.report = hv_free_page_report;
+       ret = page_reporting_register(&dm_device.pr_dev_info);
+       if (ret < 0) {
+               dm_device.pr_dev_info.report = NULL;
+               pr_err("Failed to enable cold memory discard: %d\n", ret);
+       } else {
+               pr_info("Cold memory discard hint enabled\n");
+       }
+}
+
+static void disable_page_reporting(void)
+{
+       if (dm_device.pr_dev_info.report) {
+               page_reporting_unregister(&dm_device.pr_dev_info);
+               dm_device.pr_dev_info.report = NULL;
+       }
+}
+
 static int balloon_connect_vsp(struct hv_device *dev)
 {
        struct dm_version_request version_req;
@@ -1713,6 +1799,7 @@ static int balloon_probe(struct hv_device *dev,
        if (ret != 0)
                return ret;
 
+       enable_page_reporting();
        dm_device.state = DM_INITIALIZED;
 
        dm_device.thread =
@@ -1727,6 +1814,7 @@ static int balloon_probe(struct hv_device *dev,
 probe_error:
        dm_device.state = DM_INIT_ERROR;
        dm_device.thread  = NULL;
+       disable_page_reporting();
        vmbus_close(dev->channel);
 #ifdef CONFIG_MEMORY_HOTPLUG
        unregister_memory_notifier(&hv_memory_nb);
@@ -1749,6 +1837,7 @@ static int balloon_remove(struct hv_device *dev)
        cancel_work_sync(&dm->ha_wrk.wrk);
 
        kthread_stop(dm->thread);
+       disable_page_reporting();
        vmbus_close(dev->channel);
 #ifdef CONFIG_MEMORY_HOTPLUG
        unregister_memory_notifier(&hv_memory_nb);