u-boot/drivers/iommu/sandbox_iommu.c
Mark Kettenis 49a1a4becb test: Add test for IOMMU uclass map/unmap ops
Test that the map and unmap operations work for devices that
have DMA translated by an IOMMU and devices that don't have
DMA translated by an IOMMU.

Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
2023-01-27 14:47:58 -05:00

76 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
*/
#include <common.h>
#include <dm.h>
#include <iommu.h>
#include <lmb.h>
#include <asm/io.h>
#include <linux/sizes.h>
#define IOMMU_PAGE_SIZE SZ_4K
struct sandbox_iommu_priv {
struct lmb lmb;
};
static dma_addr_t sandbox_iommu_map(struct udevice *dev, void *addr,
size_t size)
{
struct sandbox_iommu_priv *priv = dev_get_priv(dev);
phys_addr_t paddr, dva;
phys_size_t psize, off;
paddr = ALIGN_DOWN(virt_to_phys(addr), IOMMU_PAGE_SIZE);
off = virt_to_phys(addr) - paddr;
psize = ALIGN(size + off, IOMMU_PAGE_SIZE);
dva = lmb_alloc(&priv->lmb, psize, IOMMU_PAGE_SIZE);
return dva + off;
}
static void sandbox_iommu_unmap(struct udevice *dev, dma_addr_t addr,
size_t size)
{
struct sandbox_iommu_priv *priv = dev_get_priv(dev);
phys_addr_t dva;
phys_size_t psize;
dva = ALIGN_DOWN(addr, IOMMU_PAGE_SIZE);
psize = size + (addr - dva);
psize = ALIGN(psize, IOMMU_PAGE_SIZE);
lmb_free(&priv->lmb, dva, psize);
}
static struct iommu_ops sandbox_iommu_ops = {
.map = sandbox_iommu_map,
.unmap = sandbox_iommu_unmap,
};
static int sandbox_iommu_probe(struct udevice *dev)
{
struct sandbox_iommu_priv *priv = dev_get_priv(dev);
lmb_init(&priv->lmb);
lmb_add(&priv->lmb, 0x89abc000, SZ_16K);
return 0;
}
static const struct udevice_id sandbox_iommu_ids[] = {
{ .compatible = "sandbox,iommu" },
{ /* sentinel */ }
};
U_BOOT_DRIVER(sandbox_iommu) = {
.name = "sandbox_iommu",
.id = UCLASS_IOMMU,
.of_match = sandbox_iommu_ids,
.priv_auto = sizeof(struct sandbox_iommu_priv),
.ops = &sandbox_iommu_ops,
.probe = sandbox_iommu_probe,
};