[PATCH kernel v8 24/31] powerpc/powernv/ioda: Define and implement DMA table/window management callbacks

From: Alexey Kardashevskiy
Date: Fri Apr 10 2015 - 02:33:32 EST


This extends iommu_table_group_ops by a set of callbacks to support
dynamic DMA windows management.

query() returns IOMMU capabilities such as default DMA window address and
supported number of DMA windows and TCE table levels.

create_table() creates a TCE table with specific parameters.
it receives iommu_table_group to know nodeid in order to allocate
TCE table memory closer to the PHB. The exact format of allocated
multi-level table might be also specific to the PHB model (not
the case now though).
This callback calculated the DMA window offset on a PCI bus from @num
and stores it in a just created table.

set_window() sets the window at specified TVT index + @num on PHB.

unset_window() unsets the window from specified TVT.

This adds a free() callback to iommu_table_ops to free the memory
(potentially a tree of tables) allocated for the TCE table.

create_table() and free() are supposed to be called once per
VFIO container and set_window()/unset_window() are supposed to be
called for every group in a container.

Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
---
arch/powerpc/include/asm/iommu.h | 21 +++++++
arch/powerpc/platforms/powernv/pci-ioda.c | 87 ++++++++++++++++++++++++-----
arch/powerpc/platforms/powernv/pci-p5ioc2.c | 11 +++-
3 files changed, 102 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 1e0d907..2c08c91 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -64,6 +64,8 @@ struct iommu_table_ops {
long index, long npages);
unsigned long (*get)(struct iommu_table *tbl, long index);
void (*flush)(struct iommu_table *tbl);
+
+ void (*free)(struct iommu_table *tbl);
};

/* These are used by VIO */
@@ -150,12 +152,31 @@ struct iommu_table_group_ops {
*/
void (*set_ownership)(struct iommu_table_group *table_group,
bool enable);
+
+ long (*create_table)(struct iommu_table_group *table_group,
+ int num,
+ __u32 page_shift,
+ __u64 window_size,
+ __u32 levels,
+ struct iommu_table *tbl);
+ long (*set_window)(struct iommu_table_group *table_group,
+ int num,
+ struct iommu_table *tblnew);
+ long (*unset_window)(struct iommu_table_group *table_group,
+ int num);
};

struct iommu_table_group {
#ifdef CONFIG_IOMMU_API
struct iommu_group *group;
#endif
+ /* Some key properties of IOMMU */
+ __u32 tce32_start;
+ __u32 tce32_size;
+ __u64 pgsizes; /* Bitmap of supported page sizes */
+ __u32 max_dynamic_windows_supported;
+ __u32 max_levels;
+
struct iommu_table tables[IOMMU_TABLE_GROUP_MAX_TABLES];
struct iommu_table_group_ops *ops;
};
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 99d1a92..ab0cfb7 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -25,6 +25,7 @@
#include <linux/memblock.h>
#include <linux/iommu.h>
#include <linux/mmzone.h>
+#include <linux/sizes.h>

#include <asm/mmzone.h>
#include <asm/sections.h>
@@ -1236,6 +1237,8 @@ static void pnv_ioda2_tce_free_vm(struct iommu_table *tbl, long index,
pnv_pci_ioda2_tce_invalidate(tbl, index, npages, false);
}

+static void pnv_pci_free_table(struct iommu_table *tbl);
+
static struct iommu_table_ops pnv_ioda2_iommu_ops = {
.set = pnv_ioda2_tce_build_vm,
#ifdef CONFIG_IOMMU_API
@@ -1243,6 +1246,7 @@ static struct iommu_table_ops pnv_ioda2_iommu_ops = {
#endif
.clear = pnv_ioda2_tce_free_vm,
.get = pnv_tce_get,
+ .free = pnv_pci_free_table,
};

static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
@@ -1325,6 +1329,8 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
TCE_PCI_SWINV_PAIR);
}
tbl->it_ops = &pnv_ioda1_iommu_ops;
+ pe->table_group.tce32_start = tbl->it_offset << tbl->it_page_shift;
+ pe->table_group.tce32_size = tbl->it_size << tbl->it_page_shift;
iommu_init_table(tbl, phb->hose->node);
iommu_register_group(&pe->table_group, phb->hose->global_number,
pe->pe_number);
@@ -1409,7 +1415,7 @@ static __be64 *pnv_alloc_tce_table(int nid,
}

static long pnv_pci_ioda2_create_table(struct iommu_table_group *table_group,
- __u32 page_shift, __u64 window_size, __u32 levels,
+ int num, __u32 page_shift, __u64 window_size, __u32 levels,
struct iommu_table *tbl)
{
struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe,
@@ -1422,6 +1428,9 @@ static long pnv_pci_ioda2_create_table(struct iommu_table_group *table_group,
if (!levels || (levels > POWERNV_IOMMU_MAX_LEVELS))
return -EINVAL;

+ if (!(table_group->pgsizes & (1ULL << page_shift)))
+ return -EINVAL;
+
if ((window_size > memory_hotplug_max()) || !is_power_of_2(window_size))
return -EINVAL;

@@ -1432,8 +1441,8 @@ static long pnv_pci_ioda2_create_table(struct iommu_table_group *table_group,
shift = ROUND_UP(ilog2(window_size) - page_shift, levels) / levels;
shift += 3;
shift = max_t(unsigned, shift, IOMMU_PAGE_SHIFT_4K);
- pr_info("Creating TCE table %08llx, %d levels, TCE table size = %lx\n",
- window_size, levels, 1UL << shift);
+ pr_info("Creating TCE table #%d %08llx, %d levels, TCE table size = %lx\n",
+ num, window_size, levels, 1UL << shift);

tbl->it_level_size = 1ULL << (shift - 3);
left = tce_table_size;
@@ -1444,8 +1453,8 @@ static long pnv_pci_ioda2_create_table(struct iommu_table_group *table_group,
tbl->it_indirect_levels = levels - 1;

/* Setup linux iommu table */
- pnv_pci_setup_iommu_table(tbl, addr, tce_table_size, 0,
- page_shift);
+ pnv_pci_setup_iommu_table(tbl, addr, tce_table_size,
+ num ? pe->tce_bypass_base : 0, page_shift);

tbl->it_ops = &pnv_ioda2_iommu_ops;

@@ -1464,8 +1473,21 @@ static void pnv_pci_free_table(struct iommu_table *tbl)
iommu_reset_table(tbl, "ioda2");
}

+static inline void pnv_pci_ioda2_tvt_invalidate(unsigned int pe_number,
+ unsigned long it_index)
+{
+ __be64 __iomem *invalidate = (__be64 __iomem *)it_index;
+ /* 01xb - invalidate TCEs that match the specified PE# */
+ unsigned long addr = (0x4ull << 60) | (pe_number & 0xFF);
+
+ if (!it_index)
+ return;
+
+ __raw_writeq(cpu_to_be64(addr), invalidate);
+}
+
static long pnv_pci_ioda2_set_window(struct iommu_table_group *table_group,
- struct iommu_table *tbl)
+ int num, struct iommu_table *tbl)
{
struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe,
table_group);
@@ -1477,13 +1499,13 @@ static long pnv_pci_ioda2_set_window(struct iommu_table_group *table_group,
const __u64 start_addr = tbl->it_offset << tbl->it_page_shift;
const __u64 win_size = tbl->it_size << tbl->it_page_shift;

- pe_info(pe, "Setting up window at %llx..%llx pagesize=0x%x tablesize=0x%lx levels=%d levelsize=%x\n",
- start_addr, start_addr + win_size - 1,
+ pe_info(pe, "Setting up window #%d (%p) at %llx..%llx pagesize=0x%x tablesize=0x%lx levels=%d levelsize=%x\n",
+ num, tbl, start_addr, start_addr + win_size - 1,
1UL << tbl->it_page_shift, tbl->it_size,
tbl->it_indirect_levels + 1, tbl->it_level_size);

- pe->table_group.tables[0] = *tbl;
- tbl = &pe->table_group.tables[0];
+ pe->table_group.tables[num] = *tbl;
+ tbl = &pe->table_group.tables[num];
tbl->it_group = &pe->table_group;

/*
@@ -1491,7 +1513,8 @@ static long pnv_pci_ioda2_set_window(struct iommu_table_group *table_group,
* shifted by 1 bit for 32-bits DMA space.
*/
rc = opal_pci_map_pe_dma_window(phb->opal_id, pe->pe_number,
- pe->pe_number << 1, tbl->it_indirect_levels + 1,
+ (pe->pe_number << 1) + num,
+ tbl->it_indirect_levels + 1,
__pa(tbl->it_base),
size << 3, 1ULL << tbl->it_page_shift);
if (rc) {
@@ -1513,6 +1536,8 @@ static long pnv_pci_ioda2_set_window(struct iommu_table_group *table_group,
tbl->it_type |= (TCE_PCI_SWINV_CREATE | TCE_PCI_SWINV_FREE);
}

+ pnv_pci_ioda2_tvt_invalidate(pe->pe_number, tbl->it_index);
+
return 0;
fail:
if (pe->tce32_seg >= 0)
@@ -1572,6 +1597,30 @@ static void pnv_pci_ioda2_setup_bypass_pe(struct pnv_phb *phb,
}

#ifdef CONFIG_IOMMU_API
+static long pnv_pci_ioda2_unset_window(struct iommu_table_group *table_group,
+ int num)
+{
+ struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe,
+ table_group);
+ struct pnv_phb *phb = pe->phb;
+ struct iommu_table *tbl = &pe->table_group.tables[num];
+ long ret;
+
+ pe_info(pe, "Removing DMA window #%d\n", num);
+
+ ret = opal_pci_map_pe_dma_window(phb->opal_id, pe->pe_number,
+ (pe->pe_number << 1) + num,
+ 0/* levels */, 0/* table address */,
+ 0/* table size */, 0/* page size */);
+ if (ret)
+ pe_warn(pe, "Unmapping failed, ret = %ld\n", ret);
+
+ pnv_pci_ioda2_tvt_invalidate(pe->pe_number, tbl->it_index);
+ memset(tbl, 0, sizeof(*tbl));
+
+ return ret;
+}
+
static void pnv_ioda2_set_ownership(struct iommu_table_group *table_group,
bool enable)
{
@@ -1587,6 +1636,9 @@ static void pnv_ioda2_set_ownership(struct iommu_table_group *table_group,

static struct iommu_table_group_ops pnv_pci_ioda2_ops = {
.set_ownership = pnv_ioda2_set_ownership,
+ .create_table = pnv_pci_ioda2_create_table,
+ .set_window = pnv_pci_ioda2_set_window,
+ .unset_window = pnv_pci_ioda2_unset_window,
};
#endif

@@ -1607,8 +1659,15 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
pe_info(pe, "Setting up 32-bit TCE table at 0..%08x\n",
end);

- rc = pnv_pci_ioda2_create_table(&pe->table_group, IOMMU_PAGE_SHIFT_4K,
- phb->ioda.m32_pci_base,
+ pe->table_group.tce32_start = 0;
+ pe->table_group.tce32_size = phb->ioda.m32_pci_base;
+ pe->table_group.max_dynamic_windows_supported =
+ IOMMU_TABLE_GROUP_MAX_TABLES;
+ pe->table_group.max_levels = POWERNV_IOMMU_MAX_LEVELS;
+ pe->table_group.pgsizes = SZ_4K | SZ_64K | SZ_16M;
+
+ rc = pnv_pci_ioda2_create_table(&pe->table_group, 0,
+ IOMMU_PAGE_SHIFT_4K, phb->ioda.m32_pci_base,
POWERNV_IOMMU_DEFAULT_LEVELS, tbl);
if (rc) {
pe_err(pe, "Failed to create 32-bit TCE table, err %ld", rc);
@@ -1622,7 +1681,7 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
pe->table_group.ops = &pnv_pci_ioda2_ops;
#endif

- rc = pnv_pci_ioda2_set_window(&pe->table_group, tbl);
+ rc = pnv_pci_ioda2_set_window(&pe->table_group, 0, tbl);
if (rc) {
pe_err(pe, "Failed to configure 32-bit TCE table,"
" err %ld\n", rc);
diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
index d2d9092..99cb858 100644
--- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c
+++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
@@ -116,6 +116,8 @@ static void __init pnv_pci_init_p5ioc2_phb(struct device_node *np, u64 hub_id,
u64 phb_id;
int64_t rc;
static int primary = 1;
+ struct iommu_table_group *table_group;
+ struct iommu_table *tbl;

pr_info(" Initializing p5ioc2 PHB %s\n", np->full_name);

@@ -180,13 +182,16 @@ static void __init pnv_pci_init_p5ioc2_phb(struct device_node *np, u64 hub_id,
pnv_pci_init_p5ioc2_msis(phb);

/* Setup iommu */
- phb->p5ioc2.table_group.tables[0].it_group = &phb->p5ioc2.table_group;
+ table_group = &phb->p5ioc2.table_group;
+ tbl = &phb->p5ioc2.table_group.tables[0];
+ tbl->it_group = table_group;

/* Setup TCEs */
phb->dma_dev_setup = pnv_pci_p5ioc2_dma_dev_setup;
- pnv_pci_setup_iommu_table(&phb->p5ioc2.table_group.tables[0],
- tce_mem, tce_size, 0,
+ pnv_pci_setup_iommu_table(tbl, tce_mem, tce_size, 0,
IOMMU_PAGE_SHIFT_4K);
+ table_group->tce32_start = tbl->it_offset << tbl->it_page_shift;
+ table_group->tce32_size = tbl->it_size << tbl->it_page_shift;
}

void __init pnv_pci_init_p5ioc2_hub(struct device_node *np)
--
2.0.0

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