/*      $NetBSD: bus_dmamem_common.c,v 1.5 2022/11/12 07:48:34 skrll Exp $      */

/*-
* Copyright (c) 1997, 1998, 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <sys/cdefs.h>                  /* RCS ID & Copyright macro defns */

__KERNEL_RCSID(0, "$NetBSD: bus_dmamem_common.c,v 1.5 2022/11/12 07:48:34 skrll Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/bus.h>

#include <uvm/uvm_extern.h>
#include <uvm/uvm_page.h>

#include <dev/bus_dma/bus_dmamem_common.h>

/*
* _bus_dmamem_alloc_range_common --
*      Allocate physical memory from the specified physical address range.
*/
int
_bus_dmamem_alloc_range_common(bus_dma_tag_t t,
                              bus_size_t size,
                              bus_size_t alignment,
                              bus_size_t boundary,
                              bus_dma_segment_t *segs,
                              int nsegs,
                              int *rsegs,
                              int flags,
                              paddr_t low,
                              paddr_t high)
{
       paddr_t curaddr, lastaddr;
       struct vm_page *m;
       struct pglist mlist;
       int curseg, error;

       /* Always round the size. */
       size = round_page(size);

       /* Allocate pages from the VM system. */
       error = uvm_pglistalloc(size, low, high, alignment, boundary,
                               &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0);
       if (__predict_false(error != 0))
               return (error);

       /*
        * Compute the location, size, and number of segments actually
        * returned by the VM system.
        */
       m = TAILQ_FIRST(&mlist);
       curseg = 0;
       lastaddr = segs[curseg].ds_addr = VM_PAGE_TO_PHYS(m);
       segs[curseg].ds_len = PAGE_SIZE;
       m = TAILQ_NEXT(m, pageq.queue);

       for (; m != NULL; m = TAILQ_NEXT(m, pageq.queue)) {
               curaddr = VM_PAGE_TO_PHYS(m);
               KASSERT(curaddr >= low);
               KASSERT(curaddr < high);
               if (curaddr == (lastaddr + PAGE_SIZE))
                       segs[curseg].ds_len += PAGE_SIZE;
               else {
                       curseg++;
                       segs[curseg].ds_addr = curaddr;
                       segs[curseg].ds_len = PAGE_SIZE;
               }
               lastaddr = curaddr;
       }

       *rsegs = curseg + 1;

       return (0);
}

/*
* _bus_dmamem_free_common --
*      Free memory allocated with _bus_dmamem_alloc_range_common()
*      back to the VM system.
*/
void
_bus_dmamem_free_common(bus_dma_tag_t t,
                       bus_dma_segment_t *segs,
                       int nsegs)
{
       struct vm_page *m;
       bus_addr_t addr;
       struct pglist mlist;
       int curseg;

       TAILQ_INIT(&mlist);
       for (curseg = 0; curseg < nsegs; curseg++) {
               for (addr = segs[curseg].ds_addr;
                    addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
                    addr += PAGE_SIZE) {
                       m = PHYS_TO_VM_PAGE(addr);
                       TAILQ_INSERT_TAIL(&mlist, m, pageq.queue);
               }
       }

       uvm_pglistfree(&mlist);
}

/*
* _bus_dmamem_map_common --
*      Map memory allocated with _bus_dmamem_alloc_range_common() into
*      the kernel virtual address space.
*/
int
_bus_dmamem_map_common(bus_dma_tag_t t,
                      bus_dma_segment_t *segs,
                      int nsegs,
                      size_t size,
                      void **kvap,
                      int flags,
                      int pmapflags)
{
       vaddr_t va;
       bus_addr_t addr;
       int curseg;
       const uvm_flag_t kmflags =
           (flags & BUS_DMA_NOWAIT) != 0 ? UVM_KMF_NOWAIT : 0;

       size = round_page(size);

       va = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_VAONLY | kmflags);
       if (__predict_false(va == 0))
               return (ENOMEM);

       *kvap = (void *)va;

       for (curseg = 0; curseg < nsegs; curseg++) {
               for (addr = segs[curseg].ds_addr;
                    addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
                    addr += PAGE_SIZE, va += PAGE_SIZE, size -= PAGE_SIZE) {
                       KASSERT(size != 0);
                       /* XXX pmap_kenter_pa()? */
                       pmap_enter(pmap_kernel(), va, addr,
                           VM_PROT_READ | VM_PROT_WRITE,
                           pmapflags | PMAP_WIRED |
                               VM_PROT_READ | VM_PROT_WRITE);
               }
       }
       pmap_update(pmap_kernel());

       return (0);
}

/*
* _bus_dmamem_unmap_common --
*      Remove a mapping created with _bus_dmamem_map_common().
*/
void
_bus_dmamem_unmap_common(bus_dma_tag_t t,
                        void *kva,
                        size_t size)
{

       KASSERT(((vaddr_t)kva & PAGE_MASK) == 0);

       size = round_page(size);
       /* XXX pmap_kremove()?  See above... */
       pmap_remove(pmap_kernel(), (vaddr_t)kva, (vaddr_t)kva + size);
       pmap_update(pmap_kernel());
       uvm_km_free(kernel_map, (vaddr_t)kva, size, UVM_KMF_VAONLY);
}

/*
* _bus_dmamem_mmap_common --
*      Mmap support for memory allocated with _bus_dmamem_alloc_range_common().
*/
bus_addr_t
_bus_dmamem_mmap_common(bus_dma_tag_t t,
                       bus_dma_segment_t *segs,
                       int nsegs,
                       off_t off,
                       int prot,
                       int flags)
{
       int i;

       for (i = 0; i < nsegs; i++) {
               KASSERT((off & PAGE_MASK) == 0);
               KASSERT((segs[i].ds_addr & PAGE_MASK) == 0);
               KASSERT((segs[i].ds_len & PAGE_MASK) == 0);
               if (off >= segs[i].ds_len) {
                       off -= segs[i].ds_len;
                       continue;
               }

               /* XXX BUS_DMA_COHERENT */

               return (segs[i].ds_addr + off);
       }

       /* Page not found. */
       return ((bus_addr_t)-1);
}

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