Mailing List Archive

From: Paul Durrant <pdurrant@amazon.com>

The VT-d and AMD IOMMU both use the general x86 IOMMU page table allocator
and ARM always shares page tables with CPU. Hence there is no need to retain
the free_page_table() method or the tasklet which invokes it.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Jan Beulich <jbeulich@suse.com>

v2:
- New in v2 (split from "add common page-table allocator")
---
xen/drivers/passthrough/iommu.c | 25 -------------------------
xen/include/xen/iommu.h | 2 --
2 files changed, 27 deletions(-)

diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 2b1db8022c..660dc5deb2 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -49,10 +49,6 @@ bool_t __read_mostly amd_iommu_perdev_intremap = 1;

DEFINE_PER_CPU(bool_t, iommu_dont_flush_iotlb);

-DEFINE_SPINLOCK(iommu_pt_cleanup_lock);
-PAGE_LIST_HEAD(iommu_pt_cleanup_list);
-static struct tasklet iommu_pt_cleanup_tasklet;
-
static int __init parse_iommu_param(const char *s)
{
const char *ss;
@@ -226,9 +222,6 @@ static void iommu_teardown(struct domain *d)
struct domain_iommu *hd = dom_iommu(d);

iommu_vcall(hd->platform_ops, teardown, d);
-
- if ( hd->platform_ops->free_page_table )
- tasklet_schedule(&iommu_pt_cleanup_tasklet);
}

void iommu_domain_destroy(struct domain *d)
@@ -368,23 +361,6 @@ int iommu_lookup_page(struct domain *d, dfn_t dfn, mfn_t *mfn,
return iommu_call(hd->platform_ops, lookup_page, d, dfn, mfn, flags);
}

-static void iommu_free_pagetables(void *unused)
-{
- do {
- struct page_info *pg;
-
- spin_lock(&iommu_pt_cleanup_lock);
- pg = page_list_remove_head(&iommu_pt_cleanup_list);
- spin_unlock(&iommu_pt_cleanup_lock);
- if ( !pg )
- return;
- iommu_vcall(iommu_get_ops(), free_page_table, pg);
- } while ( !softirq_pending(smp_processor_id()) );
-
- tasklet_schedule_on_cpu(&iommu_pt_cleanup_tasklet,
- cpumask_cycle(smp_processor_id(), &cpu_online_map));
-}
-
int iommu_iotlb_flush(struct domain *d, dfn_t dfn, unsigned int page_count,
unsigned int flush_flags)
{
@@ -508,7 +484,6 @@ int __init iommu_setup(void)
#ifndef iommu_intremap
printk("Interrupt remapping %sabled\n", iommu_intremap ? "en" : "dis");
#endif
- tasklet_init(&iommu_pt_cleanup_tasklet, iommu_free_pagetables, NULL);
}

return rc;
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 3272874958..1831dc66b0 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -263,8 +263,6 @@ struct iommu_ops {
int __must_check (*lookup_page)(struct domain *d, dfn_t dfn, mfn_t *mfn,
unsigned int *flags);

- void (*free_page_table)(struct page_info *);
-
#ifdef CONFIG_X86
int (*enable_x2apic)(void);
void (*disable_x2apic)(void);
--
2.20.1