linux-imx

/* SPDX-License-Identifier: GPL-2.0 */

#include <linux/prefetch.h>

​

/**

 * iommu_fill_pdir - Insert coalesced scatter/gather chunks into the I/O Pdir.

 * @ioc: The I/O Controller.

 * @startsg: The scatter/gather list of coalesced chunks.

 * @nents: The number of entries in the scatter/gather list.

 * @hint: The DMA Hint.

 *

 * This function inserts the coalesced scatter/gather list chunks into the

 * I/O Controller's I/O Pdir.

 */ 

static inline unsigned int

iommu_fill_pdir(struct ioc *ioc, struct scatterlist *startsg, int nents, 

        unsigned long hint,

        void (*iommu_io_pdir_entry)(u64 *, space_t, unsigned long,

                        unsigned long))

{

    struct scatterlist *dma_sg = startsg;   /* pointer to current DMA */

    unsigned int n_mappings = 0;

    unsigned long dma_offset = 0, dma_len = 0;

    u64 *pdirp = NULL;

​

    /* Horrible hack.  For efficiency's sake, dma_sg starts one 

     * entry below the true start (it is immediately incremented

     * in the loop) */

     dma_sg--;

​

    while (nents-- > 0) {

        unsigned long vaddr;

        long size;

​

        DBG_RUN_SG(" %d : %08lx/%05x %p/%05x\n", nents,

               (unsigned long)sg_dma_address(startsg), cnt,

               sg_virt(startsg), startsg->length

        );

​

​

        /*

        ** Look for the start of a new DMA stream

        */

        if (sg_dma_address(startsg) & PIDE_FLAG) {

            u32 pide = sg_dma_address(startsg) & ~PIDE_FLAG;

​

            BUG_ON(pdirp && (dma_len != sg_dma_len(dma_sg)));

​

            dma_sg++;

​

            dma_len = sg_dma_len(startsg);

            sg_dma_len(startsg) = 0;

            dma_offset = (unsigned long) pide & ~IOVP_MASK;

            n_mappings++;

#if defined(ZX1_SUPPORT)

            /* Pluto IOMMU IO Virt Address is not zero based */

            sg_dma_address(dma_sg) = pide | ioc->ibase;

#else

            /* SBA, ccio, and dino are zero based.

             * Trying to save a few CPU cycles for most users.

             */

            sg_dma_address(dma_sg) = pide;

#endif