Hi Will,
Please see below for another small comment.
On Thursday 27 November 2014 11:51:15 Will Deacon wrote:
> This patch introduces a generic framework for allocating page tables for
> an IOMMU. There are a number of reasons we want to do this:
>
> - It avoids duplication of complex table management code in IOMMU
> drivers that use the same page table format
>
> - It removes any coupling with the CPU table format (and even the
> architecture!)
>
> - It defines an API for IOMMU TLB maintenance
>
> Signed-off-by: Will Deacon <will.dea...@arm.com>
> ---
> drivers/iommu/Kconfig | 8 ++++++
> drivers/iommu/Makefile | 1 +
> drivers/iommu/io-pgtable.c | 71 +++++++++++++++++++++++++++++++++++++++++++
> drivers/iommu/io-pgtable.h | 65 ++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 145 insertions(+)
> create mode 100644 drivers/iommu/io-pgtable.c
> create mode 100644 drivers/iommu/io-pgtable.h
[snip]
> diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h
> new file mode 100644
> index 000000000000..5ae75d9cae50
> --- /dev/null
> +++ b/drivers/iommu/io-pgtable.h
> @@ -0,0 +1,65 @@
> +#ifndef __IO_PGTABLE_H
> +#define __IO_PGTABLE_H
> +
> +struct io_pgtable_ops {
> + int (*map)(struct io_pgtable_ops *ops, unsigned long iova,
> + phys_addr_t paddr, size_t size, int prot);
> + int (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,
> + size_t size);
> + phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
> + unsigned long iova);
> +};
> +
> +struct iommu_gather_ops {
> + /* Synchronously invalidate the entire TLB context */
> + void (*tlb_flush_all)(void *cookie);
> +
> + /* Queue up a TLB invalidation for a virtual address range */
> + void (*tlb_add_flush)(unsigned long iova, size_t size, bool leaf,
> + void *cookie);
> + /* Ensure any queued TLB invalidation has taken effect */
> + void (*tlb_sync)(void *cookie);
> +
> + /* Ensure page tables updates are visible to the IOMMU */
> + void (*flush_pgtable)(void *ptr, size_t size, void *cookie);
> +};
> +
> +struct io_pgtable_cfg {
> + int quirks; /* IO_PGTABLE_QUIRK_* */
> + unsigned long pgsize_bitmap;
> + unsigned int ias;
> + unsigned int oas;
> + struct iommu_gather_ops *tlb;
Could you make this pointer const ?
> + /* Low-level data specific to the table format */
> + union {
> + };
> +};
> +
> +enum io_pgtable_fmt {
> + IO_PGTABLE_NUM_FMTS,
> +};
> +
> +struct io_pgtable {
> + enum io_pgtable_fmt fmt;
> + void *cookie;
> + struct io_pgtable_cfg cfg;
> + struct io_pgtable_ops ops;
> +};
> +
> +struct io_pgtable_init_fns {
> + struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
> + void (*free)(struct io_pgtable *iop);
> +};
> +
> +struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
> + struct io_pgtable_cfg *cfg,
> + void *cookie);
> +
> +/*
> + * Free an io_pgtable_ops structure. The caller *must* ensure that the
> + * page table is no longer live, but the TLB can be dirty.
> + */
> +void free_io_pgtable_ops(struct io_pgtable_ops *ops);
> +
> +#endif /* __IO_PGTABLE_H */
--
Regards,
Laurent Pinchart
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