On 04/30/2015 02:37 PM, David Gibson wrote:
On Wed, Apr 29, 2015 at 07:44:20PM +1000, Alexey Kardashevskiy wrote:On 04/29/2015 03:30 PM, David Gibson wrote:On Sat, Apr 25, 2015 at 10:14:47PM +1000, Alexey Kardashevskiy wrote:This extends iommu_table_group_ops by a set of callbacks to support dynamic DMA windows management.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.Doesn't the free callback belong with the previous patch introducing multi-level tables?If I did that, you would say "why is it here if nothing calls it" on "multilevel" patch and "I see the allocation but I do not see memory release" ;)Yeah, fair enough ;)I need some rule of thumb here. I think it is a bit cleaner if the same patch adds a callback for memory allocation and its counterpart, no?On further consideration, yes, I think you're right.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. This adds IOMMU capabilities to iommu_table_group such as default 32bit window parameters and others. Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> --- arch/powerpc/include/asm/iommu.h | 19 ++++++++ arch/powerpc/platforms/powernv/pci-ioda.c | 75 ++++++++++++++++++++++++++--- arch/powerpc/platforms/powernv/pci-p5ioc2.c | 12 +++-- 3 files changed, 96 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h index 0f50ee2..7694546 100644 --- a/arch/powerpc/include/asm/iommu.h +++ b/arch/powerpc/include/asm/iommu.h @@ -70,6 +70,7 @@ struct iommu_table_ops { /* get() returns a physical address */ 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 */ @@ -148,6 +149,17 @@ extern struct iommu_table *iommu_init_table(struct iommu_table * tbl, struct iommu_table_group; struct iommu_table_group_ops { + 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); /* * Switches ownership from the kernel itself to an external * user. While onwership is taken, the kernel cannot use IOMMU itself. @@ -160,6 +172,13 @@ 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;With this information, table_group seems even more like a bad name. "iommu_state" maybe?Please, no. We will never come to agreement then :( And "iommu_state" is too general anyway, it won't pass.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 cc1d09c..4828837 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -24,6 +24,7 @@ #include <linux/msi.h> #include <linux/memblock.h> #include <linux/iommu.h> +#include <linux/sizes.h> #include <asm/sections.h> #include <asm/io.h> @@ -1846,6 +1847,7 @@ static struct iommu_table_ops pnv_ioda2_iommu_ops = { #endif .clear = pnv_ioda2_tce_free, .get = pnv_tce_get, + .free = pnv_pci_free_table, }; static void pnv_pci_ioda_setup_opal_tce_kill(struct pnv_phb *phb, @@ -1936,6 +1938,8 @@ 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); if (pe->flags & PNV_IODA_PE_DEV) { @@ -1961,7 +1965,7 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb, } 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); @@ -1972,9 +1976,10 @@ 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 " + pe_info(pe, "Setting up window#%d at %llx..%llx " "pgsize=0x%x tablesize=0x%lx " "levels=%d levelsize=%x\n", + num, start_addr, start_addr + win_size - 1, 1UL << tbl->it_page_shift, tbl->it_size << 3, tbl->it_indirect_levels + 1, tbl->it_level_size << 3); @@ -1987,7 +1992,7 @@ static long pnv_pci_ioda2_set_window(struct iommu_table_group *table_group, */ rc = opal_pci_map_pe_dma_window(phb->opal_id, pe->pe_number, - pe->pe_number << 1, + (pe->pe_number << 1) + num,Heh, yes, well, that makes it rather clear that only 2 tables are possible.tbl->it_indirect_levels + 1, __pa(tbl->it_base), size << 3, @@ -2000,7 +2005,7 @@ static long pnv_pci_ioda2_set_window(struct iommu_table_group *table_group, pnv_pci_ioda2_tvt_invalidate(pe); /* Store fully initialized *tbl (may be external) in PE */ - pe->table_group.tables[0] = *tbl; + pe->table_group.tables[num] = *tbl;I'm a bit confused by this whole set_window thing. Is the idea that with multiple groups in a container you have multiple table_group s each with different copies of the iommu_table structures, but pointing to the same actual TCE entries (it_base)?Yes.It seems to me not terribly obvious when you "create" a table and when you "set" a window.A table is not attached anywhere until its address is programmed (in set_window()) to the hardware, it is just a table in memory. For POWER8/IODA2, I create a table before I attach any group to a container, then I program this table to every attached container, right now it is done in container's attach_group(). So later we can hotplug any host PCI device to a container - it will program same TCE table to every new group in the container.So you "create" once, then "set" it to one or more table_groups? It seems odd that "create" is a table_group callback in that case.
Where else could it be? ppc_md? We are getting rid of these. Some global function? We do not want VFIO to know about this. I run out of ideas here.
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