Gh0st
/
linux
mirror of https://github.com/torvalds/linux.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

iommupt: Use the incoherent start/stop functions for PT_FEAT_DMA_INCOHERENT 

This is the first step to supporting an incoherent walker, start and stop
the incoherence around the allocation and frees of the page table memory.

The iommu_pages API maps this to dma_map/unmap_single(), or arch cache
flushing calls.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Jason Gunthorpe 2025-10-23 15:22:31 -03:00 committed by Joerg Roedel
parent bcc64b57b4
commit aefd967dab
5 changed files with 88 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

89
drivers/iommu/generic_pt/iommu_pt.h
View File

@ -24,6 +24,10 @@ static void gather_range_pages(struct iommu_iotlb_gather *iotlb_gather,
{
struct pt_common *common = common_from_iommu(iommu_table);
if (pt_feature(common, PT_FEAT_DMA_INCOHERENT))
iommu_pages_stop_incoherent_list(free_list,
iommu_table->iommu_device);
if (pt_feature(common, PT_FEAT_FLUSH_RANGE_NO_GAPS) &&
iommu_iotlb_gather_is_disjoint(iotlb_gather, iova, len)) {
iommu_iotlb_sync(&iommu_table->domain, iotlb_gather);
@ -329,35 +333,55 @@ static int __collect_tables(struct pt_range *range, void *arg,
return 0;
}
static inline struct pt_table_p *table_alloc_top(struct pt_common *common,
uintptr_t top_of_table,
gfp_t gfp)
enum alloc_mode {ALLOC_NORMAL, ALLOC_DEFER_COHERENT_FLUSH};
/* Allocate a table, the empty table will be ready to be installed. */
static inline struct pt_table_p *_table_alloc(struct pt_common *common,
size_t lg2sz, gfp_t gfp,
enum alloc_mode mode)
{
struct pt_iommu *iommu_table = iommu_from_common(common);
struct pt_table_p *table_mem;
table_mem = iommu_alloc_pages_node_sz(iommu_table->nid, gfp,
log2_to_int(lg2sz));
if (pt_feature(common, PT_FEAT_DMA_INCOHERENT) &&
mode == ALLOC_NORMAL) {
int ret = iommu_pages_start_incoherent(
table_mem, iommu_table->iommu_device);
if (ret) {
iommu_free_pages(table_mem);
return ERR_PTR(ret);
}
}
return table_mem;
}
static inline struct pt_table_p *table_alloc_top(struct pt_common *common,
uintptr_t top_of_table,
gfp_t gfp,
enum alloc_mode mode)
{
/*
* Top doesn't need the free list or otherwise, so it technically
* doesn't need to use iommu pages. Use the API anyhow as the top is
* usually not smaller than PAGE_SIZE to keep things simple.
*/
return iommu_alloc_pages_node_sz(
iommu_table->nid, gfp,
log2_to_int(pt_top_memsize_lg2(common, top_of_table)));
return _table_alloc(common, pt_top_memsize_lg2(common, top_of_table),
gfp, mode);
}
/* Allocate an interior table */
static inline struct pt_table_p *table_alloc(const struct pt_state *parent_pts,
gfp_t gfp)
gfp_t gfp, enum alloc_mode mode)
{
struct pt_iommu *iommu_table =
iommu_from_common(parent_pts->range->common);
struct pt_state child_pts =
pt_init(parent_pts->range, parent_pts->level - 1, NULL);
return iommu_alloc_pages_node_sz(
iommu_table->nid, gfp,
log2_to_int(pt_num_items_lg2(&child_pts) +
ilog2(PT_ITEM_WORD_SIZE)));
return _table_alloc(parent_pts->range->common,
pt_num_items_lg2(&child_pts) +
ilog2(PT_ITEM_WORD_SIZE),
gfp, mode);
}
static inline int pt_iommu_new_table(struct pt_state *pts,
@ -370,13 +394,15 @@ static inline int pt_iommu_new_table(struct pt_state *pts,
if (PT_WARN_ON(!pt_can_have_table(pts)))
return -ENXIO;
table_mem = table_alloc(pts, attrs->gfp);
table_mem = table_alloc(pts, attrs->gfp, ALLOC_NORMAL);
if (IS_ERR(table_mem))
return PTR_ERR(table_mem);
phys = virt_to_phys(table_mem);
if (!pt_install_table(pts, phys, attrs)) {
iommu_free_pages(table_mem);
iommu_pages_free_incoherent(
table_mem,
iommu_from_common(pts->range->common)->iommu_device);
return -EAGAIN;
}
@ -389,7 +415,9 @@ static inline int pt_iommu_new_table(struct pt_state *pts,
pt_load_single_entry(pts);
if (PT_WARN_ON(pt_table_pa(pts) != phys)) {
pt_clear_entries(pts, ilog2(1));
iommu_free_pages(table_mem);
iommu_pages_free_incoherent(
table_mem, iommu_from_common(pts->range->common)
->iommu_device);
return -EINVAL;
}
}
@ -615,8 +643,9 @@ static int increase_top(struct pt_iommu *iommu_table, struct pt_range *range,
}
new_level = pts.level;
table_mem = table_alloc_top(
common, _pt_top_set(NULL, pts.level), map->attrs.gfp);
table_mem =
table_alloc_top(common, _pt_top_set(NULL, pts.level),
map->attrs.gfp, ALLOC_DEFER_COHERENT_FLUSH);
if (IS_ERR(table_mem))
return PTR_ERR(table_mem);
iommu_pages_list_add(&free_list, table_mem);
@ -633,6 +662,16 @@ static int increase_top(struct pt_iommu *iommu_table, struct pt_range *range,
new_top_of_table = _pt_top_set(pts.table, pts.level);
}
/*
* Avoid double flushing, flush it once after all pt_install_table()
*/
if (pt_feature(common, PT_FEAT_DMA_INCOHERENT)) {
ret = iommu_pages_start_incoherent_list(
&free_list, iommu_table->iommu_device);
if (ret)
goto err_free;
}
/*
* top_of_table is write locked by the spinlock, but readers can use
* READ_ONCE() to get the value. Since we encode both the level and the
@ -665,6 +704,9 @@ static int increase_top(struct pt_iommu *iommu_table, struct pt_range *range,
return 0;
err_free:
if (pt_feature(common, PT_FEAT_DMA_INCOHERENT))
iommu_pages_stop_incoherent_list(&free_list,
iommu_table->iommu_device);
iommu_put_pages_list(&free_list);
return ret;
}
@ -988,6 +1030,9 @@ static void NS(deinit)(struct pt_iommu *iommu_table)
* The driver has to already have fenced the HW access to the page table
* and invalidated any caching referring to this memory.
*/
if (pt_feature(common, PT_FEAT_DMA_INCOHERENT))
iommu_pages_stop_incoherent_list(&collect.free_list,
iommu_table->iommu_device);
iommu_put_pages_list(&collect.free_list);
}
@ -1078,6 +1123,7 @@ static void pt_iommu_zero(struct pt_iommu_table *fmt_table)
memset_after(fmt_table, 0, iommu.domain);
/* The caller can initialize some of these values */
iommu_table->iommu_device = cfg.iommu_device;
iommu_table->driver_ops = cfg.driver_ops;
iommu_table->nid = cfg.nid;
}
@ -1123,11 +1169,16 @@ int pt_iommu_init(struct pt_iommu_table *fmt_table,
pt_feature(common, PT_FEAT_DYNAMIC_TOP)))
return -EINVAL;
if (pt_feature(common, PT_FEAT_DMA_INCOHERENT) &&
WARN_ON(!iommu_table->iommu_device))
return -EINVAL;
ret = pt_iommu_init_domain(iommu_table, &iommu_table->domain);
if (ret)
return ret;
table_mem = table_alloc_top(common, common->top_of_table, gfp);
table_mem = table_alloc_top(common, common->top_of_table, gfp,
ALLOC_NORMAL);
if (IS_ERR(table_mem))
return PTR_ERR(table_mem);
pt_top_set(common, table_mem, pt_top_get_level(common));

1
drivers/iommu/generic_pt/kunit_iommu.h
View File

@ -139,6 +139,7 @@ static int pt_kunit_priv_init(struct kunit *test, struct kunit_iommu_priv *priv)
priv->fmt_table.iommu.nid = NUMA_NO_NODE;
priv->fmt_table.iommu.driver_ops = &pt_kunit_driver_ops;
priv->fmt_table.iommu.iommu_device = priv->dummy_dev;
priv->domain.ops = &kunit_pt_ops;
ret = pt_iommu_init(&priv->fmt_table, &priv->cfg, GFP_KERNEL);
if (ret) {

5
drivers/iommu/generic_pt/pt_defs.h
View File

@ -48,13 +48,16 @@ enum {
/*
* When in debug mode we compile all formats with all features. This allows the
* kunit to test the full matrix. SIGN_EXTEND can't co-exist with DYNAMIC_TOP or
* FULL_VA.
* FULL_VA. DMA_INCOHERENT requires a SW bit that not all formats have
*/
#if IS_ENABLED(CONFIG_DEBUG_GENERIC_PT)
enum {
PT_ORIG_SUPPORTED_FEATURES = PT_SUPPORTED_FEATURES,
PT_DEBUG_SUPPORTED_FEATURES =
UINT_MAX &
~((PT_ORIG_SUPPORTED_FEATURES & BIT(PT_FEAT_DMA_INCOHERENT) ?
0 :
BIT(PT_FEAT_DMA_INCOHERENT))) &
~((PT_ORIG_SUPPORTED_FEATURES & BIT(PT_FEAT_SIGN_EXTEND)) ?
BIT(PT_FEAT_DYNAMIC_TOP) | BIT(PT_FEAT_FULL_VA) :
BIT(PT_FEAT_SIGN_EXTEND)),

6
include/linux/generic_pt/common.h
View File

@ -85,6 +85,12 @@ enum {
* position.
*/
enum pt_features {
/**
* @PT_FEAT_DMA_INCOHERENT: Cache flush page table memory before
* assuming the HW can read it. Otherwise a SMP release is sufficient
* for HW to read it.
*/
PT_FEAT_DMA_INCOHERENT,
/**
* @PT_FEAT_FULL_VA: The table can span the full VA range from 0 to
* PT_VADDR_MAX.

7
include/linux/generic_pt/iommu.h
View File

@ -57,6 +57,13 @@ struct pt_iommu {
* table walkers.
*/
int nid;
/**
* @iommu_device: Device pointer used for any DMA cache flushing when
* PT_FEAT_DMA_INCOHERENT. This is the iommu device that created the
* page table which must have dma ops that perform cache flushing.
*/
struct device *iommu_device;
};
/**