[PATCH 16/37] iommu: Add generic PASID table library
Jacob Pan
jacob.jun.pan at linux.intel.com
Tue Feb 27 10:51:21 PST 2018
On Mon, 12 Feb 2018 18:33:31 +0000
Jean-Philippe Brucker <jean-philippe.brucker at arm.com> wrote:
> Add a small API within the IOMMU subsystem to handle different
> formats of PASID tables. It uses the same principle as io-pgtable:
>
> * The IOMMU driver registers a PASID table with some invalidation
> callbacks.
> * The pasid-table lib allocates a set of tables of the right format,
> and returns an iommu_pasid_table_ops structure.
> * The IOMMU driver allocates entries and writes them using the
> provided ops.
> * The pasid-table lib calls the IOMMU driver back for invalidation
> when necessary.
> * The IOMMU driver unregisters the ops which frees the tables when
> finished.
>
> An example user will be Arm SMMU in a subsequent patch.
>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker at arm.com>
> ---
> drivers/iommu/Kconfig | 8 +++
> drivers/iommu/Makefile | 1 +
> drivers/iommu/iommu-pasid.c | 53 +++++++++++++++++
> drivers/iommu/iommu-pasid.h | 142
> ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 204
> insertions(+) create mode 100644 drivers/iommu/iommu-pasid.c
> create mode 100644 drivers/iommu/iommu-pasid.h
>
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index e751bb9958ba..8add90ba9b75 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -60,6 +60,14 @@ config IOMMU_IO_PGTABLE_ARMV7S_SELFTEST
>
> endmenu
>
> +menu "Generic PASID table support"
> +
> +# Selected by the actual PASID table implementations
> +config IOMMU_PASID_TABLE
> + bool
> +
> +endmenu
> +
> config IOMMU_IOVA
> tristate
>
> diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
> index f4324e29035e..338e59c93131 100644
> --- a/drivers/iommu/Makefile
> +++ b/drivers/iommu/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_IOMMU_FAULT) += io-pgfault.o
> obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o
> obj-$(CONFIG_IOMMU_IO_PGTABLE_ARMV7S) += io-pgtable-arm-v7s.o
> obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o
> +obj-$(CONFIG_IOMMU_PASID_TABLE) += iommu-pasid.o
> obj-$(CONFIG_IOMMU_IOVA) += iova.o
> obj-$(CONFIG_OF_IOMMU) += of_iommu.o
> obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o
> diff --git a/drivers/iommu/iommu-pasid.c b/drivers/iommu/iommu-pasid.c
> new file mode 100644
> index 000000000000..6b21d369d514
> --- /dev/null
> +++ b/drivers/iommu/iommu-pasid.c
> @@ -0,0 +1,53 @@
> +/*
> + * PASID table management for the IOMMU
> + *
> + * Copyright (C) 2018 ARM Ltd.
> + * Author: Jean-Philippe Brucker <jean-philippe.brucker at arm.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#include <linux/kernel.h>
> +
> +#include "iommu-pasid.h"
> +
> +static const struct iommu_pasid_init_fns *
> +pasid_table_init_fns[PASID_TABLE_NUM_FMTS] = {
> +};
> +
> +struct iommu_pasid_table_ops *
> +iommu_alloc_pasid_ops(enum iommu_pasid_table_fmt fmt,
> + struct iommu_pasid_table_cfg *cfg, void
> *cookie) +{
I guess you don't need to pass in cookie here.
> + struct iommu_pasid_table *table;
> + const struct iommu_pasid_init_fns *fns;
> +
> + if (fmt >= PASID_TABLE_NUM_FMTS)
> + return NULL;
> +
> + fns = pasid_table_init_fns[fmt];
> + if (!fns)
> + return NULL;
> +
> + table = fns->alloc(cfg, cookie);
> + if (!table)
> + return NULL;
> +
> + table->fmt = fmt;
> + table->cookie = cookie;
> + table->cfg = *cfg;
> +
the ops is already IOMMU model specific, why do you need to pass cfg
back?
> + return &table->ops;
If there is no common code that uses these ops, I don't see the benefit
of having these APIs. Or the plan is to consolidate even further such
that referene to pasid table can be attached at per iommu_domain etc,
but that would be model specific choice.
Jacob
> +}
> +
> +void iommu_free_pasid_ops(struct iommu_pasid_table_ops *ops)
> +{
> + struct iommu_pasid_table *table;
> +
> + if (!ops)
> + return;
> +
> + table = container_of(ops, struct iommu_pasid_table, ops);
> + iommu_pasid_flush_all(table);
> + pasid_table_init_fns[table->fmt]->free(table);
> +}
> diff --git a/drivers/iommu/iommu-pasid.h b/drivers/iommu/iommu-pasid.h
> new file mode 100644
> index 000000000000..40a27d35c1e0
> --- /dev/null
> +++ b/drivers/iommu/iommu-pasid.h
> @@ -0,0 +1,142 @@
> +/*
> + * PASID table management for the IOMMU
> + *
> + * Copyright (C) 2017 ARM Ltd.
> + * Author: Jean-Philippe Brucker <jean-philippe.brucker at arm.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +#ifndef __IOMMU_PASID_H
> +#define __IOMMU_PASID_H
> +
> +#include <linux/types.h>
> +#include "io-pgtable.h"
> +
> +struct mm_struct;
> +
> +enum iommu_pasid_table_fmt {
> + PASID_TABLE_NUM_FMTS,
> +};
> +
> +/**
> + * iommu_pasid_entry - Entry of a PASID table
> + *
> + * @token: architecture-specific data needed to uniquely
> identify the
> + * entry. Most notably used for TLB invalidation
> + */
> +struct iommu_pasid_entry {
> + u64 tag;
> +};
> +
> +/**
> + * iommu_pasid_table_ops - Operations on a PASID table
> + *
> + * @alloc_shared_entry: allocate an entry for sharing an mm
> (SVA)
> + * Returns the pointer to a new entry or an
> error
> + * @alloc_priv_entry: allocate an entry for map/unmap
> operations
> + * Returns the pointer to a new entry or an
> error
> + * @free_entry: free an entry obtained with
> alloc_entry
> + * @set_entry: write PASID table entry
> + * @clear_entry: clear PASID table entry
> + */
> +struct iommu_pasid_table_ops {
> + struct iommu_pasid_entry *
> + (*alloc_shared_entry)(struct iommu_pasid_table_ops *ops,
> + struct mm_struct *mm);
> + struct iommu_pasid_entry *
> + (*alloc_priv_entry)(struct iommu_pasid_table_ops *ops,
> + enum io_pgtable_fmt fmt,
> + struct io_pgtable_cfg *cfg);
> + void (*free_entry)(struct iommu_pasid_table_ops *ops,
> + struct iommu_pasid_entry *entry);
> + int (*set_entry)(struct iommu_pasid_table_ops *ops, int
> pasid,
> + struct iommu_pasid_entry *entry);
> + void (*clear_entry)(struct iommu_pasid_table_ops *ops, int
> pasid,
> + struct iommu_pasid_entry *entry);
> +};
> +
> +/**
> + * iommu_pasid_sync_ops - Callbacks into the IOMMU driver
> + *
> + * @cfg_flush: flush cached configuration for one
> entry. For a
> + * multi-level PASID table, 'leaf' tells
> whether to only
> + * flush cached leaf entries or intermediate
> levels as
> + * well.
> + * @cfg_flush_all: flush cached configuration for all entries
> of the PASID
> + * table
> + * @tlb_flush: flush TLB entries for one entry
> + */
> +struct iommu_pasid_sync_ops {
> + void (*cfg_flush)(void *cookie, int pasid, bool leaf);
> + void (*cfg_flush_all)(void *cookie);
> + void (*tlb_flush)(void *cookie, int pasid,
> + struct iommu_pasid_entry *entry);
> +};
> +
> +/**
> + * struct iommu_pasid_table_cfg - Configuration data for a set of
> PASID tables.
> + *
> + * @iommu_dev device performing the DMA table walks
> + * @order: number of PASID bits, set by IOMMU driver
> + * @flush: TLB management callbacks for this set of tables.
> + *
> + * @base: DMA address of the allocated table, set by the
> allocator.
> + */
> +struct iommu_pasid_table_cfg {
> + struct device *iommu_dev;
> + size_t order;
> + const struct iommu_pasid_sync_ops *sync;
> +
> + dma_addr_t base;
> +};
> +
> +struct iommu_pasid_table_ops *
> +iommu_alloc_pasid_ops(enum iommu_pasid_table_fmt fmt,
> + struct iommu_pasid_table_cfg *cfg,
> + void *cookie);
> +void iommu_free_pasid_ops(struct iommu_pasid_table_ops *ops);
> +
> +/**
> + * struct iommu_pasid_table - describes a set of PASID tables
> + *
> + * @fmt: The PASID table format.
> + * @cookie: An opaque token provided by the IOMMU driver and
> passed back to
> + * any callback routine.
> + * @cfg: A copy of the PASID table configuration.
> + * @ops: The PASID table operations in use for this set of
> page tables.
> + */
> +struct iommu_pasid_table {
> + enum iommu_pasid_table_fmt fmt;
> + void *cookie;
> + struct iommu_pasid_table_cfg cfg;
> + struct iommu_pasid_table_ops ops;
> +};
> +
> +#define iommu_pasid_table_ops_to_table(ops) \
> + container_of((ops), struct iommu_pasid_table, ops)
> +
> +struct iommu_pasid_init_fns {
> + struct iommu_pasid_table *(*alloc)(struct
> iommu_pasid_table_cfg *cfg,
> + void *cookie);
> + void (*free)(struct iommu_pasid_table *table);
> +};
> +
> +static inline void iommu_pasid_flush_all(struct iommu_pasid_table
> *table) +{
> + table->cfg.sync->cfg_flush_all(table->cookie);
> +}
> +
> +static inline void iommu_pasid_flush(struct iommu_pasid_table *table,
> + int pasid, bool leaf)
> +{
> + table->cfg.sync->cfg_flush(table->cookie, pasid, leaf);
> +}
> +
> +static inline void iommu_pasid_flush_tlbs(struct iommu_pasid_table
> *table,
> + int pasid,
> + struct iommu_pasid_entry
> *entry) +{
> + table->cfg.sync->tlb_flush(table->cookie, pasid, entry);
> +}
> +
> +#endif /* __IOMMU_PASID_H */
[Jacob Pan]
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