From 49a1a4becb2deaeb5764dfe4022807b147b87b9c Mon Sep 17 00:00:00 2001
From: Mark Kettenis <kettenis@openbsd.org>
Date: Sat, 21 Jan 2023 20:27:53 +0100
Subject: [PATCH] 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>
---
 drivers/iommu/sandbox_iommu.c | 58 +++++++++++++++++++++++++++++++++++++++++++
 test/dm/iommu.c               | 44 +++++++++++++++++++++++++++++++-
 2 files changed, 101 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/sandbox_iommu.c b/drivers/iommu/sandbox_iommu.c
index c8161a4..6ceb7fd 100644
--- a/drivers/iommu/sandbox_iommu.c
+++ b/drivers/iommu/sandbox_iommu.c
@@ -5,6 +5,61 @@
 
 #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" },
@@ -15,4 +70,7 @@ 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,
 };
diff --git a/test/dm/iommu.c b/test/dm/iommu.c
index 94174a7..6f932ef 100644
--- a/test/dm/iommu.c
+++ b/test/dm/iommu.c
@@ -8,12 +8,16 @@
 #include <dm/test.h>
 #include <dm/uclass-internal.h>
 #include <iommu.h>
+#include <malloc.h>
 #include <test/test.h>
 #include <test/ut.h>
+#include <asm/io.h>
 
 static int dm_test_iommu(struct unit_test_state *uts)
 {
 	struct udevice *dev;
+	dma_addr_t dva;
+	void *addr;
 
 	ut_assertok(uclass_find_device(UCLASS_IOMMU, 0, &dev));
 	ut_assert(!(dev_get_flags(dev) & DM_FLAG_ACTIVATED));
@@ -22,7 +26,45 @@ static int dm_test_iommu(struct unit_test_state *uts)
 	ut_assertok(uclass_probe_all(UCLASS_USB));
 	ut_assert(dev_get_flags(dev) & DM_FLAG_ACTIVATED);
 
+	addr = malloc(256);
+	ut_assert(addr);
+
+	ut_assertok(uclass_find_device(UCLASS_USB, 0, &dev));
+	dva = dev_iommu_dma_map(dev, addr, 256);
+	ut_assert(dva >= 0x89abc000 && dva < 0x89ac00000);
+
+	dev_iommu_dma_unmap(dev, dva, 256);
+
+	free(addr);
+
 	return 0;
 }
-
 DM_TEST(dm_test_iommu, UT_TESTF_SCAN_FDT);
+
+static int dm_test_iommu_noiommu(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+	dma_addr_t dva;
+	void *addr;
+
+	ut_assertok(uclass_find_device(UCLASS_IOMMU, 0, &dev));
+	ut_assert(!(dev_get_flags(dev) & DM_FLAG_ACTIVATED));
+
+	/* Probing ethernet should not probe the IOMMU */
+	ut_assertok(uclass_probe_all(UCLASS_ETH));
+	ut_assert(!(dev_get_flags(dev) & DM_FLAG_ACTIVATED));
+
+	addr = malloc(256);
+	ut_assert(addr);
+
+	ut_assertok(uclass_find_device(UCLASS_ETH, 0, &dev));
+	dva = dev_iommu_dma_map(dev, addr, 256);
+	ut_assert(dva == virt_to_phys(addr));
+
+	dev_iommu_dma_unmap(dev, dva, 256);
+
+	free(addr);
+
+	return 0;
+}
+DM_TEST(dm_test_iommu_noiommu, UT_TESTF_SCAN_FDT);
-- 
2.7.4