Commit 00547193 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman
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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: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent c035e37b

arch/powerpc/include/asm/iommu.h

+5 −0
Original line number Diff line number Diff line
@@ -99,6 +99,7 @@ struct iommu_table { 
	unsigned long  it_size;      /* Size of iommu table in entries */

	unsigned long  it_indirect_levels;

	unsigned long  it_level_size;

	unsigned long  it_allocated_size;

	unsigned long  it_offset;    /* Offset into global table */

	unsigned long  it_base;      /* mapped address of tce table */

	unsigned long  it_index;     /* which iommu table this is */
@@ -147,6 +148,10 @@ extern struct iommu_table *iommu_init_table(struct iommu_table * tbl, 
struct iommu_table_group;



struct iommu_table_group_ops {

	unsigned long (*get_table_size)(

			__u32 page_shift,

			__u64 window_size,

			__u32 levels);

	long (*create_table)(struct iommu_table_group *table_group,

			int num,

			__u32 page_shift,

arch/powerpc/platforms/powernv/pci-ioda.c

+34 −0
Original line number Diff line number Diff line
@@ -2074,6 +2074,38 @@ static long pnv_pci_ioda2_create_table(struct iommu_table_group *table_group, 
}



#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 void pnv_ioda2_release_ownership(struct iommu_table_group *table_group) 
}



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 @@ static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset, 
			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);

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