powerpc/iommu/ioda2: Add get_table_size() to calculate the size of future table
This adds a way for the IOMMU user to know how much a new table will
use so it can be accounted in the locked_vm limit before allocation
happens.
This stores the allocated table size in pnv_pci_ioda2_get_table_size()
so the locked_vm counter can be updated correctly when a table is
being disposed.
This defines an iommu_table_group_ops callback to let VFIO know
how much memory will be locked if a table is created.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 510bb9c..a7e098d 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -2074,6 +2074,38 @@
}
#ifdef CONFIG_IOMMU_API
+static unsigned long pnv_pci_ioda2_get_table_size(__u32 page_shift,
+ __u64 window_size, __u32 levels)
+{
+ unsigned long bytes = 0;
+ const unsigned window_shift = ilog2(window_size);
+ unsigned entries_shift = window_shift - page_shift;
+ unsigned table_shift = entries_shift + 3;
+ unsigned long tce_table_size = max(0x1000UL, 1UL << table_shift);
+ unsigned long direct_table_size;
+
+ if (!levels || (levels > POWERNV_IOMMU_MAX_LEVELS) ||
+ (window_size > memory_hotplug_max()) ||
+ !is_power_of_2(window_size))
+ return 0;
+
+ /* Calculate a direct table size from window_size and levels */
+ entries_shift = (entries_shift + levels - 1) / levels;
+ table_shift = entries_shift + 3;
+ table_shift = max_t(unsigned, table_shift, PAGE_SHIFT);
+ direct_table_size = 1UL << table_shift;
+
+ for ( ; levels; --levels) {
+ bytes += _ALIGN_UP(tce_table_size, direct_table_size);
+
+ tce_table_size /= direct_table_size;
+ tce_table_size <<= 3;
+ tce_table_size = _ALIGN_UP(tce_table_size, direct_table_size);
+ }
+
+ return bytes;
+}
+
static long pnv_pci_ioda2_unset_window(struct iommu_table_group *table_group,
int num)
{
@@ -2117,6 +2149,7 @@
}
static struct iommu_table_group_ops pnv_pci_ioda2_ops = {
+ .get_table_size = pnv_pci_ioda2_get_table_size,
.create_table = pnv_pci_ioda2_create_table,
.set_window = pnv_pci_ioda2_set_window,
.unset_window = pnv_pci_ioda2_unset_window,
@@ -2228,6 +2261,7 @@
page_shift);
tbl->it_level_size = 1ULL << (level_shift - 3);
tbl->it_indirect_levels = levels - 1;
+ tbl->it_allocated_size = offset;
pr_devel("Created TCE table: ws=%08llx ts=%lx @%08llx\n",
window_size, tce_table_size, bus_offset);