Re: [PATCH 3/3] iommu/core: split mapping to page sizes as supportedby the hardware

From: Roedel, Joerg
Date: Tue Sep 13 2011 - 06:10:22 EST

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On Wed, Sep 07, 2011 at 02:53:24PM -0400, Ohad Ben-Cohen wrote:

> drivers/iommu/amd_iommu.c | 20 ++++++-
> drivers/iommu/intel-iommu.c | 20 ++++++-
> drivers/iommu/iommu.c | 129 +++++++++++++++++++++++++++++++++++++++----
> drivers/iommu/msm_iommu.c | 8 ++-
> drivers/iommu/omap-iommu.c | 6 ++-
> drivers/iommu/omap-iovmm.c | 12 +---
> include/linux/iommu.h | 7 +-
> virt/kvm/iommu.c | 4 +-
> 8 files changed, 176 insertions(+), 30 deletions(-)

Please split this patch into the core-change and patches for the
individual iommu-drivers and post this as a seperate patch-set.

>
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index a14f8dc..5cdfa91 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -2488,12 +2488,30 @@ static unsigned device_dma_ops_init(void)
> }
>
> /*
> + * This bitmap is used to advertise the page sizes our hardware support
> + * to the IOMMU core, which will then use this information to split
> + * physically contiguous memory regions it is mapping into page sizes
> + * that we support.
> + *
> + * Traditionally the IOMMU core just handed us the mappings directly,
> + * after making sure the size is an order of a 4KB page and that the
> + * mapping has natural alignment.
> + *
> + * To retain this behavior, we currently advertise that we support
> + * all page sizes that are an order of 4KB.
> + *
> + * If at some point we'd like to utilize the IOMMU core's new behavior,
> + * we could change this to advertise the real page sizes we support.
> + */
> +static unsigned long amd_iommu_pgsizes = ~0xFFFUL;
> +
> +/*
> * The function which clues the AMD IOMMU driver into dma_ops.
> */
>
> void __init amd_iommu_init_api(void)
> {
> - register_iommu(&amd_iommu_ops);
> + register_iommu(&amd_iommu_ops, &amd_iommu_pgsizes, BITS_PER_LONG);
> }
>
> int __init amd_iommu_init_dma_ops(void)
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index c621c98..a8c91a6 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -3426,6 +3426,24 @@ static struct notifier_block device_nb = {
> .notifier_call = device_notifier,
> };
>
> +/*
> + * This bitmap is used to advertise the page sizes our hardware support
> + * to the IOMMU core, which will then use this information to split
> + * physically contiguous memory regions it is mapping into page sizes
> + * that we support.
> + *
> + * Traditionally the IOMMU core just handed us the mappings directly,
> + * after making sure the size is an order of a 4KB page and that the
> + * mapping has natural alignment.
> + *
> + * To retain this behavior, we currently advertise that we support
> + * all page sizes that are an order of 4KB.
> + *
> + * If at some point we'd like to utilize the IOMMU core's new behavior,
> + * we could change this to advertise the real page sizes we support.
> + */
> +static unsigned long intel_iommu_pgsizes = ~0xFFFUL;

Intel IOMMU does not support arbitrary page-sizes, afaik.

> +
> int __init intel_iommu_init(void)
> {
> int ret = 0;
> @@ -3486,7 +3504,7 @@ int __init intel_iommu_init(void)
>
> init_iommu_pm_ops();
>
> - register_iommu(&intel_iommu_ops);
> + register_iommu(&intel_iommu_ops, &intel_iommu_pgsizes, BITS_PER_LONG);
>
> bus_register_notifier(&pci_bus_type, &device_nb);
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index c68ff29..e07ea03 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -16,6 +16,8 @@
> * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> */
>
> +#define pr_fmt(fmt) "%s: " fmt, __func__
> +
> #include <linux/kernel.h>
> #include <linux/bug.h>
> #include <linux/types.h>
> @@ -23,15 +25,41 @@
> #include <linux/slab.h>
> #include <linux/errno.h>
> #include <linux/iommu.h>
> +#include <linux/bitmap.h>
>
> static struct iommu_ops *iommu_ops;
>
> -void register_iommu(struct iommu_ops *ops)
> +/* bitmap of supported page sizes */
> +static unsigned long *iommu_pgsize_bitmap;
> +
> +/* number of bits used to represent the supported pages */
> +static unsigned int iommu_nr_page_bits;
> +
> +/* size of the smallest supported page (in bytes) */
> +static unsigned int iommu_min_pagesz;
> +
> +/* bit number of the smallest supported page */
> +static unsigned int iommu_min_page_idx;
> +
> +/**
> + * register_iommu() - register an IOMMU hardware
> + * @ops: iommu handlers
> + * @pgsize_bitmap: bitmap of page sizes supported by the hardware
> + * @nr_page_bits: size of @pgsize_bitmap (in bits)
> + */
> +void register_iommu(struct iommu_ops *ops, unsigned long *pgsize_bitmap,
> + unsigned int nr_page_bits)
> {
> - if (iommu_ops)
> + if (iommu_ops || iommu_pgsize_bitmap || !nr_page_bits)
> BUG();
>
> iommu_ops = ops;
> + iommu_pgsize_bitmap = pgsize_bitmap;
> + iommu_nr_page_bits = nr_page_bits;
> +
> + /* find the minimum page size and its index only once */
> + iommu_min_page_idx = find_first_bit(pgsize_bitmap, nr_page_bits);
> + iommu_min_pagesz = 1 << iommu_min_page_idx;
> }
>
> bool iommu_found(void)
> @@ -109,26 +137,103 @@ int iommu_domain_has_cap(struct iommu_domain *domain,
> EXPORT_SYMBOL_GPL(iommu_domain_has_cap);
>
> int iommu_map(struct iommu_domain *domain, unsigned long iova,
> - phys_addr_t paddr, int gfp_order, int prot)
> + phys_addr_t paddr, size_t size, int prot)
> {
> - size_t size;
> + int ret = 0;
> +
> + /*
> + * both the virtual address and the physical one, as well as
> + * the size of the mapping, must be aligned (at least) to the
> + * size of the smallest page supported by the hardware
> + */
> + if (!IS_ALIGNED(iova | paddr | size, iommu_min_pagesz)) {
> + pr_err("unaligned: iova 0x%lx pa 0x%lx size 0x%lx min_pagesz "
> + "0x%x\n", iova, (unsigned long)paddr, size,
> + iommu_min_pagesz);
> + return -EINVAL;
> + }
> +
> + pr_debug("map: iova 0x%lx pa 0x%lx size 0x%lx\n", iova,
> + (unsigned long)paddr, size);

Please keep the debug-code in a seperate patch in your dev-tree. No need
for it to be merged upstream.

> +
> + while (size) {
> + unsigned long pgsize = iommu_min_pagesz;
> + unsigned long idx = iommu_min_page_idx;
> + unsigned long addr_merge = iova | paddr;
> + int order;
> +
> + /* find the max page size with which iova, paddr are aligned */
> + for (;;) {
> + unsigned long try_pgsize;
>
> - size = 0x1000UL << gfp_order;
> + idx = find_next_bit(iommu_pgsize_bitmap,
> + iommu_nr_page_bits, idx + 1);
>
> - BUG_ON(!IS_ALIGNED(iova | paddr, size));
> + /* no more pages to check ? */
> + if (idx >= iommu_nr_page_bits)
> + break;
>
> - return iommu_ops->map(domain, iova, paddr, gfp_order, prot);
> + try_pgsize = 1 << idx;
> +
> + /* page too big ? addresses not aligned ? */
> + if (size < try_pgsize ||
> + !IS_ALIGNED(addr_merge, try_pgsize))
> + break;
> +
> + pgsize = try_pgsize;
> + }
> +
> + order = get_order(pgsize);
> +
> + pr_debug("mapping: iova 0x%lx pa 0x%lx order %d\n", iova,
> + (unsigned long)paddr, order);
> +
> + ret = iommu_ops->map(domain, iova, paddr, order, prot);
> + if (ret)
> + break;
> +
> + size -= pgsize;
> + iova += pgsize;
> + paddr += pgsize;
> + }
> +
> + return ret;
> }
> EXPORT_SYMBOL_GPL(iommu_map);
>
> -int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order)
> +int iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
> {
> - size_t size;
> + int order, unmapped_size, unmapped_order, total_unmapped = 0;
> +
> + /*
> + * The virtual address, as well as the size of the mapping, must be
> + * aligned (at least) to the size of the smallest page supported
> + * by the hardware
> + */
> + if (!IS_ALIGNED(iova | size, iommu_min_pagesz)) {
> + pr_err("unaligned: iova 0x%lx size 0x%lx min_pagesz 0x%x\n",
> + iova, size, iommu_min_pagesz);
> + return -EINVAL;
> + }
> +
> + pr_debug("unmap this: iova 0x%lx size 0x%lx\n", iova, size);
> +
> + while (size > total_unmapped) {
> + order = get_order(size - total_unmapped);
> +
> + unmapped_order = iommu_ops->unmap(domain, iova, order);
> + if (unmapped_order < 0)
> + return unmapped_order;
> +
> + pr_debug("unmapped: iova 0x%lx order %d\n", iova,
> + unmapped_order);
>
> - size = 0x1000UL << gfp_order;
> + unmapped_size = 0x1000UL << unmapped_order;
>
> - BUG_ON(!IS_ALIGNED(iova, size));
> + iova += unmapped_size;
> + total_unmapped += unmapped_size;
> + }
>
> - return iommu_ops->unmap(domain, iova, gfp_order);
> + return get_order(total_unmapped);
> }
> EXPORT_SYMBOL_GPL(iommu_unmap);
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index d1733f6..e59ced9 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -676,6 +676,9 @@ fail:
> return 0;
> }
>
> +/* bitmap of the page sizes currently supported */
> +static unsigned long msm_iommu_pgsizes = SZ_4K | SZ_64K | SZ_1M | SZ_16M;
> +
> static struct iommu_ops msm_iommu_ops = {
> .domain_init = msm_iommu_domain_init,
> .domain_destroy = msm_iommu_domain_destroy,
> @@ -728,7 +731,10 @@ static void __init setup_iommu_tex_classes(void)
> static int __init msm_iommu_init(void)
> {
> setup_iommu_tex_classes();
> - register_iommu(&msm_iommu_ops);
> +
> + /* we're only using the first 25 bits of the pgsizes bitmap */
> + register_iommu(&msm_iommu_ops, &msm_iommu_pgsizes, 25);
> +
> return 0;
> }
>
> diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
> index ef70a08..3e8b815 100644
> --- a/drivers/iommu/omap-iommu.c
> +++ b/drivers/iommu/omap-iommu.c
> @@ -1202,6 +1202,9 @@ static int omap_iommu_domain_has_cap(struct iommu_domain *domain,
> return 0;
> }
>
> +/* bitmap of the page sizes supported by the OMAP IOMMU hardware */
> +static unsigned long omap_iommu_pgsizes = SZ_4K | SZ_64K | SZ_1M | SZ_16M;
> +
> static struct iommu_ops omap_iommu_ops = {
> .domain_init = omap_iommu_domain_init,
> .domain_destroy = omap_iommu_domain_destroy,
> @@ -1225,7 +1228,8 @@ static int __init omap_iommu_init(void)
> return -ENOMEM;
> iopte_cachep = p;
>
> - register_iommu(&omap_iommu_ops);
> + /* we're only using the first 25 bits of the pgsizes bitmap */
> + register_iommu(&omap_iommu_ops, &omap_iommu_pgsizes, 25);
>
> return platform_driver_register(&omap_iommu_driver);
> }
> diff --git a/drivers/iommu/omap-iovmm.c b/drivers/iommu/omap-iovmm.c
> index e8fdb88..f4dea5a 100644
> --- a/drivers/iommu/omap-iovmm.c
> +++ b/drivers/iommu/omap-iovmm.c
> @@ -409,7 +409,6 @@ static int map_iovm_area(struct iommu_domain *domain, struct iovm_struct *new,
> unsigned int i, j;
> struct scatterlist *sg;
> u32 da = new->da_start;
> - int order;
>
> if (!domain || !sgt)
> return -EINVAL;
> @@ -428,12 +427,10 @@ static int map_iovm_area(struct iommu_domain *domain, struct iovm_struct *new,
> if (bytes_to_iopgsz(bytes) < 0)
> goto err_out;
>
> - order = get_order(bytes);
> -
> pr_debug("%s: [%d] %08x %08x(%x)\n", __func__,
> i, da, pa, bytes);
>
> - err = iommu_map(domain, da, pa, order, flags);
> + err = iommu_map(domain, da, pa, bytes, flags);
> if (err)
> goto err_out;
>
> @@ -448,10 +445,9 @@ err_out:
> size_t bytes;
>
> bytes = sg->length + sg->offset;
> - order = get_order(bytes);
>
> /* ignore failures.. we're already handling one */
> - iommu_unmap(domain, da, order);
> + iommu_unmap(domain, da, bytes);
>
> da += bytes;
> }
> @@ -474,12 +470,10 @@ static void unmap_iovm_area(struct iommu_domain *domain, struct omap_iommu *obj,
> start = area->da_start;
> for_each_sg(sgt->sgl, sg, sgt->nents, i) {
> size_t bytes;
> - int order;
>
> bytes = sg->length + sg->offset;
> - order = get_order(bytes);
>
> - err = iommu_unmap(domain, start, order);
> + err = iommu_unmap(domain, start, bytes);
> if (err < 0)
> break;
>
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index d67bf8c..074acbd 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -73,7 +73,8 @@ struct iommu_ops {
>
> #ifdef CONFIG_IOMMU_API
>
> -extern void register_iommu(struct iommu_ops *ops);
> +extern void register_iommu(struct iommu_ops *ops, unsigned long *pgsize_bitmap,
> + unsigned int nr_page_bits);
> extern bool iommu_found(void);
> extern struct iommu_domain *iommu_domain_alloc(void);
> extern void iommu_domain_free(struct iommu_domain *domain);
> @@ -82,9 +83,9 @@ extern int iommu_attach_device(struct iommu_domain *domain,
> extern void iommu_detach_device(struct iommu_domain *domain,
> struct device *dev);
> extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
> - phys_addr_t paddr, int gfp_order, int prot);
> + phys_addr_t paddr, size_t size, int prot);
> extern int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
> - int gfp_order);
> + size_t size);
> extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
> unsigned long iova);
> extern int iommu_domain_has_cap(struct iommu_domain *domain,
> diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
> index 78c80f6..ea142d3 100644
> --- a/virt/kvm/iommu.c
> +++ b/virt/kvm/iommu.c
> @@ -111,7 +111,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
>
> /* Map into IO address space */
> r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn),
> - get_order(page_size), flags);
> + page_size, flags);
> if (r) {
> printk(KERN_ERR "kvm_iommu_map_address:"
> "iommu failed to map pfn=%llx\n", pfn);
> @@ -293,7 +293,7 @@ static void kvm_iommu_put_pages(struct kvm *kvm,
> pfn = phys >> PAGE_SHIFT;
>
> /* Unmap address from IO address space */
> - order = iommu_unmap(domain, gfn_to_gpa(gfn), 0);
> + order = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE);
> unmap_pages = 1ULL << order;
>
> /* Unpin all pages we just unmapped to not leak any memory */
> --
> 1.7.4.1
>
> _______________________________________________
> iommu mailing list
> iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
> https://lists.linux-foundation.org/mailman/listinfo/iommu

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Next message: Russell King - ARM Linux: "Fwd: [PATCH] Fix build errors with gpio-generic.c"
Previous message: KAMEZAWA Hiroyuki: "Re: [patch 02/11] mm: vmscan: distinguish global reclaim fromglobal LRU scanning"
Next in thread: Ohad Ben-Cohen: "Re: [PATCH 3/3] iommu/core: split mapping to page sizes as supportedby the hardware"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]