[PATCH v3 1/6] iommu/core: split mapping to page sizes as supported by the hardware
From: Roedel, Joerg <hidden>
Date: 2011-09-27 10:05:23
Also in:
kvm, linux-omap, lkml
On Fri, Sep 16, 2011 at 01:51:41PM -0400, Ohad Ben-Cohen wrote:
quoted hunk ↗ jump to hunk
drivers/iommu/iommu.c | 158 +++++++++++++++++++++++++++++++++++++++++--- drivers/iommu/omap-iovmm.c | 12 +--- include/linux/iommu.h | 6 +- virt/kvm/iommu.c | 4 +- 4 files changed, 157 insertions(+), 23 deletions(-)diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index c68ff29..7c01c8c 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 +25,73 @@ #include <linux/slab.h> #include <linux/errno.h> #include <linux/iommu.h> +#include <linux/bitmap.h> static struct iommu_ops *iommu_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) + * + * Note: this is a temporary function, which will be removed once + * all IOMMU drivers are converted. The only reason it exists is to + * allow splitting the pgsizes changes to several patches in order to ease + * the review. + */ +void register_iommu_pgsize(struct iommu_ops *ops, unsigned long *pgsize_bitmap, + unsigned int nr_page_bits)
I think a plain unsigned long value is sufficient to encode the supported page-sizes. No need to use a full bitmap.
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,
+ (unsigned long)size, iommu_min_pagesz);
+ return -EINVAL;
+ }
+
+ pr_debug("map: iova 0x%lx pa 0x%lx size 0x%lx\n", iova,
+ (unsigned long)paddr, (unsigned long)size);
+
+ 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;
+
+ idx = find_next_bit(iommu_pgsize_bitmap,
+ iommu_nr_page_bits, idx + 1);
+
+ /* no more pages to check ? */
+ if (idx >= iommu_nr_page_bits)
+ break;
+
+ try_pgsize = 1 << idx;
- size = 0x1000UL << gfp_order;
+ /* page too big ? addresses not aligned ? */
+ if (size < try_pgsize ||
+ !IS_ALIGNED(addr_merge, try_pgsize))
+ break;
- BUG_ON(!IS_ALIGNED(iova | paddr, size));
+ pgsize = try_pgsize;
+ }With an unsigned long you can use plain and fast bit_ops instead of the full bitmap functions.
- return iommu_ops->map(domain, iova, paddr, gfp_order, prot);
+ 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);-- AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632