[PATCH v2 2/2] iommu: add Unisoc iommu basic driver

From: Chunyan Zhang
Date: Tue Feb 02 2021 - 02:35:43 EST


From: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>

This iommu module can be used by Unisoc's multimedia devices, such as
display, Image codec(jpeg) and a few signal processors, including
VSP(video), GSP(graphic), ISP(image), and CPP(camera pixel processor), etc.

Signed-off-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
---
drivers/iommu/Kconfig | 12 +
drivers/iommu/Makefile | 1 +
drivers/iommu/sprd-iommu.c | 581 +++++++++++++++++++++++++++++++++++++
3 files changed, 594 insertions(+)
create mode 100644 drivers/iommu/sprd-iommu.c

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 192ef8f61310..79af62c519ae 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -408,4 +408,16 @@ config VIRTIO_IOMMU

Say Y here if you intend to run this kernel as a guest.

+config SPRD_IOMMU
+ tristate "Unisoc IOMMU Support"
+ depends on ARCH_SPRD || COMPILE_TEST
+ select IOMMU_API
+ help
+ Support for IOMMU on Unisoc's SoCs on which multi-media subsystems
+ need IOMMU, such as DPU, Image codec(jpeg) processor, and a few
+ signal processors, including VSP(video), GSP(graphic), ISP(image), and
+ CPP, etc.
+
+ Say Y here if you want multi-media functions.
+
endif # IOMMU_SUPPORT
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 61bd30cd8369..5925b6af2123 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -28,3 +28,4 @@ obj-$(CONFIG_S390_IOMMU) += s390-iommu.o
obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o
obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
obj-$(CONFIG_IOMMU_SVA_LIB) += iommu-sva-lib.o
+obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o
diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c
new file mode 100644
index 000000000000..0e638d56b309
--- /dev/null
+++ b/drivers/iommu/sprd-iommu.c
@@ -0,0 +1,581 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Unisoc IOMMU driver
+ *
+ * Copyright (C) 2020 Unisoc, Inc.
+ * Author: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/dma-iommu.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/iommu.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/* SPRD IOMMU page is 4K size alignment */
+#define SPRD_IOMMU_PAGE_SHIFT 12
+#define SPRD_IOMMU_PAGE_SIZE SZ_4K
+
+#define SPRD_EX_CFG 0x0
+#define SPRD_IOMMU_VAOR_BYPASS BIT(4)
+#define SPRD_IOMMU_GATE_EN BIT(1)
+#define SPRD_IOMMU_EN BIT(0)
+#define SPRD_EX_UPDATE 0x4
+#define SPRD_EX_FIRST_VPN 0x8
+#define SPRD_EX_VPN_RANGE 0xc
+#define SPRD_EX_FIRST_PPN 0x10
+#define SPRD_EX_DEFAULT_PPN 0x14
+
+#define SPRD_IOMMU_VERSION 0x0
+#define SPRD_VERSION_MASK GENMASK(15, 8)
+#define SPRD_VERSION_SHIFT 0x8
+#define SPRD_VAU_CFG 0x4
+#define SPRD_VAU_UPDATE 0x8
+#define SPRD_VAU_AUTH_CFG 0xc
+#define SPRD_VAU_FIRST_PPN 0x10
+#define SPRD_VAU_DEFAULT_PPN_RD 0x14
+#define SPRD_VAU_DEFAULT_PPN_WR 0x18
+#define SPRD_VAU_FIRST_VPN 0x1c
+#define SPRD_VAU_VPN_RANGE 0x20
+
+enum sprd_iommu_version {
+ SPRD_IOMMU_EX,
+ SPRD_IOMMU_VAU,
+};
+
+/*
+ * struct sprd_iommu_device - high-level sprd iommu device representation,
+ * including hardware information and configuration, also driver data, etc
+ *
+ * @mdata: hardware configuration and information
+ * @ver: sprd iommu device version
+ * @prot_page: protect page base address, data would be written to here
+ * while translation fault
+ * @base: mapped base address for accessing registers
+ * @dev: pointer to basic device structure
+ * @iommu: IOMMU core representation
+ * @group: IOMMU group
+ */
+struct sprd_iommu_device {
+ enum sprd_iommu_version ver;
+ u32 *prot_page_va;
+ dma_addr_t prot_page_pa;
+ struct regmap *base;
+ unsigned int reg_offset;
+ struct device *dev;
+ struct iommu_device iommu;
+ struct iommu_group *group;
+ struct clk *eb;
+};
+
+struct sprd_iommu_domain {
+ spinlock_t pgtlock; /* lock for page table */
+ struct iommu_domain domain;
+ u32 *pgt_va; /* page table virtual address base */
+ dma_addr_t pgt_pa; /* page table physical address base */
+ struct sprd_iommu_device *sdev;
+};
+
+static const struct iommu_ops sprd_iommu_ops;
+
+static struct sprd_iommu_domain *to_sprd_domain(struct iommu_domain *dom)
+{
+ return container_of(dom, struct sprd_iommu_domain, domain);
+}
+
+static inline void
+sprd_iommu_writel(struct sprd_iommu_device *sdev, unsigned int reg, u32 val)
+{
+ regmap_write(sdev->base, sdev->reg_offset + reg, val);
+}
+
+static inline u32
+sprd_iommu_readl(struct sprd_iommu_device *sdev, unsigned int reg)
+{
+ u32 val;
+
+ regmap_read(sdev->base, sdev->reg_offset + reg, &val);
+ return val;
+}
+
+static inline void
+sprd_iommu_update_bits(struct sprd_iommu_device *sdev, unsigned int reg,
+ u32 mask, u32 shift, u32 val)
+{
+ u32 t = sprd_iommu_readl(sdev, reg);
+
+ t = (t & (~(mask << shift))) | ((val & mask) << shift);
+ sprd_iommu_writel(sdev, reg, t);
+}
+
+static inline int
+sprd_iommu_get_version(struct sprd_iommu_device *sdev)
+{
+ int ver = (sprd_iommu_readl(sdev, SPRD_IOMMU_VERSION) &
+ SPRD_VERSION_MASK) >> SPRD_VERSION_SHIFT;
+
+ switch (ver) {
+ case SPRD_IOMMU_EX:
+ case SPRD_IOMMU_VAU:
+ return ver;
+ default:
+ return -EINVAL;
+ }
+}
+
+static size_t
+sprd_iommu_pgt_size(struct iommu_domain *domain)
+{
+ return ((domain->geometry.aperture_end -
+ domain->geometry.aperture_start + 1) >>
+ SPRD_IOMMU_PAGE_SHIFT) * sizeof(u32);
+}
+
+static struct iommu_domain *sprd_iommu_domain_alloc(unsigned int domain_type)
+{
+ struct sprd_iommu_domain *dom;
+
+ if (domain_type != IOMMU_DOMAIN_DMA && domain_type != IOMMU_DOMAIN_UNMANAGED)
+ return NULL;
+
+ dom = kzalloc(sizeof(*dom), GFP_KERNEL);
+ if (!dom)
+ return NULL;
+
+ if (iommu_get_dma_cookie(&dom->domain)) {
+ kfree(dom);
+ return NULL;
+ }
+
+ spin_lock_init(&dom->pgtlock);
+
+ dom->domain.geometry.aperture_start = 0;
+ dom->domain.geometry.aperture_end = SZ_256M - 1;
+
+ return &dom->domain;
+}
+
+static void sprd_iommu_domain_free(struct iommu_domain *domain)
+{
+ struct sprd_iommu_domain *dom = to_sprd_domain(domain);
+
+ iommu_put_dma_cookie(domain);
+ kfree(dom);
+}
+
+static void sprd_iommu_first_vpn(struct sprd_iommu_domain *dom)
+{
+ struct sprd_iommu_device *sdev = dom->sdev;
+ u32 val;
+ unsigned int reg;
+
+ if (sdev->ver == SPRD_IOMMU_EX)
+ reg = SPRD_EX_FIRST_VPN;
+ else
+ reg = SPRD_VAU_FIRST_VPN;
+
+ val = dom->domain.geometry.aperture_start >> SPRD_IOMMU_PAGE_SHIFT;
+ sprd_iommu_writel(sdev, reg, val);
+}
+
+static void sprd_iommu_vpn_range(struct sprd_iommu_domain *dom)
+{
+ struct sprd_iommu_device *sdev = dom->sdev;
+ u32 val;
+ unsigned int reg;
+
+ if (sdev->ver == SPRD_IOMMU_EX)
+ reg = SPRD_EX_VPN_RANGE;
+ else
+ reg = SPRD_VAU_VPN_RANGE;
+
+ val = (dom->domain.geometry.aperture_end -
+ dom->domain.geometry.aperture_start) >> SPRD_IOMMU_PAGE_SHIFT;
+ sprd_iommu_writel(sdev, reg, val);
+}
+
+static void sprd_iommu_first_ppn(struct sprd_iommu_domain *dom)
+{
+ u32 val = dom->pgt_pa >> SPRD_IOMMU_PAGE_SHIFT;
+ struct sprd_iommu_device *sdev = dom->sdev;
+ unsigned int reg;
+
+ if (sdev->ver == SPRD_IOMMU_EX)
+ reg = SPRD_EX_FIRST_PPN;
+ else
+ reg = SPRD_VAU_FIRST_PPN;
+
+ sprd_iommu_writel(sdev, reg, val);
+}
+
+static void sprd_iommu_default_ppn(struct sprd_iommu_device *sdev)
+{
+ u32 val = sdev->prot_page_pa >> SPRD_IOMMU_PAGE_SHIFT;
+
+ if (sdev->ver == SPRD_IOMMU_EX) {
+ sprd_iommu_writel(sdev, SPRD_EX_DEFAULT_PPN, val);
+ } else if (sdev->ver == SPRD_IOMMU_VAU) {
+ sprd_iommu_writel(sdev, SPRD_VAU_DEFAULT_PPN_RD, val);
+ sprd_iommu_writel(sdev, SPRD_VAU_DEFAULT_PPN_WR, val);
+ }
+}
+
+static void sprd_iommu_hw_en(struct sprd_iommu_device *sdev, bool en)
+{
+ unsigned int reg_cfg;
+ u32 mask, val;
+
+ if (sdev->ver == SPRD_IOMMU_EX)
+ reg_cfg = SPRD_EX_CFG;
+ else
+ reg_cfg = SPRD_VAU_CFG;
+
+ /* enable mmu, clk gate */
+ mask = SPRD_IOMMU_EN | SPRD_IOMMU_GATE_EN;
+ val = en ? mask : 0;
+ sprd_iommu_update_bits(sdev, reg_cfg, mask, 0, val);
+}
+
+static int sprd_iommu_attach_device(struct iommu_domain *domain,
+ struct device *dev)
+{
+ struct sprd_iommu_device *sdev = dev_iommu_priv_get(dev);
+ struct sprd_iommu_domain *dom = to_sprd_domain(domain);
+ size_t pgt_size = sprd_iommu_pgt_size(domain);
+
+ if (dom->sdev) {
+ pr_err("There's already a device attached to this domain.\n");
+ return -EINVAL;
+ }
+
+ dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL);
+ if (!dom->pgt_va)
+ return -ENOMEM;
+
+ dom->sdev = sdev;
+
+ sprd_iommu_first_ppn(dom);
+ sprd_iommu_first_vpn(dom);
+ sprd_iommu_vpn_range(dom);
+ sprd_iommu_default_ppn(sdev);
+ sprd_iommu_hw_en(sdev, true);
+
+ return 0;
+}
+
+static void sprd_iommu_detach_device(struct iommu_domain *domain,
+ struct device *dev)
+{
+ struct sprd_iommu_domain *dom = to_sprd_domain(domain);
+ struct sprd_iommu_device *sdev = dom->sdev;
+ size_t pgt_size = sprd_iommu_pgt_size(domain);
+
+ if (!sdev)
+ return;
+
+ dma_free_coherent(sdev->dev, pgt_size, dom->pgt_va, dom->pgt_pa);
+ sprd_iommu_hw_en(sdev, false);
+ dom->sdev = NULL;
+}
+
+static int sprd_iommu_map(struct iommu_domain *domain, unsigned long iova,
+ phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+{
+ struct sprd_iommu_domain *dom = to_sprd_domain(domain);
+ unsigned int page_num = size >> SPRD_IOMMU_PAGE_SHIFT;
+ unsigned long flags;
+ unsigned int i;
+ u32 *pgt_base_iova;
+ u32 pabase = (u32)paddr;
+ unsigned long start = domain->geometry.aperture_start;
+ unsigned long end = domain->geometry.aperture_end;
+
+ if (!dom->sdev) {
+ pr_err("No sprd_iommu_device attached to the domain\n");
+ return -EINVAL;
+ }
+
+ if (iova < start || (iova + size) > (end + 1)) {
+ dev_err(dom->sdev->dev, "(iova(0x%lx) + sixe(%zx)) are not in the range!\n",
+ iova, size);
+ return -EINVAL;
+ }
+
+ pgt_base_iova = dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT);
+
+ spin_lock_irqsave(&dom->pgtlock, flags);
+ for (i = 0; i < page_num; i++) {
+ pgt_base_iova[i] = pabase >> SPRD_IOMMU_PAGE_SHIFT;
+ pabase += SPRD_IOMMU_PAGE_SIZE;
+ }
+ spin_unlock_irqrestore(&dom->pgtlock, flags);
+
+ return 0;
+}
+
+static size_t sprd_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
+ size_t size, struct iommu_iotlb_gather *iotlb_gather)
+{
+ struct sprd_iommu_domain *dom = to_sprd_domain(domain);
+ unsigned long flags;
+ u32 *pgt_base_iova;
+ unsigned int page_num = size >> SPRD_IOMMU_PAGE_SHIFT;
+ unsigned long start = domain->geometry.aperture_start;
+ unsigned long end = domain->geometry.aperture_end;
+
+ if (iova < start || (iova + size) > (end + 1))
+ return -EINVAL;
+
+ pgt_base_iova = dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT);
+
+ spin_lock_irqsave(&dom->pgtlock, flags);
+ memset(pgt_base_iova, 0, page_num * sizeof(u32));
+ spin_unlock_irqrestore(&dom->pgtlock, flags);
+
+ return 0;
+}
+
+static void sprd_iommu_sync_map(struct iommu_domain *domain)
+{
+ struct sprd_iommu_domain *dom = to_sprd_domain(domain);
+ unsigned int reg;
+
+ if (dom->sdev->ver == SPRD_IOMMU_EX)
+ reg = SPRD_EX_UPDATE;
+ else
+ reg = SPRD_VAU_UPDATE;
+
+ /* clear iommu TLB buffer after page table updated */
+ sprd_iommu_writel(dom->sdev, reg, 0xffffffff);
+}
+
+static void sprd_iommu_sync(struct iommu_domain *domain,
+ struct iommu_iotlb_gather *iotlb_gather)
+{
+ sprd_iommu_sync_map(domain);
+}
+
+static phys_addr_t sprd_iommu_iova_to_phys(struct iommu_domain *domain,
+ dma_addr_t iova)
+{
+ struct sprd_iommu_domain *dom = to_sprd_domain(domain);
+ unsigned long flags;
+ phys_addr_t pa;
+ unsigned long start = domain->geometry.aperture_start;
+ unsigned long end = domain->geometry.aperture_end;
+
+ if (iova < start || iova > end)
+ pr_err("iova (0x%llx) exceed the vpn range[0x%lx-0x%lx]!\n",
+ iova, start, end);
+
+ spin_lock_irqsave(&dom->pgtlock, flags);
+ pa = *(dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT));
+ pa = (pa << SPRD_IOMMU_PAGE_SHIFT) + ((iova - start) & (SPRD_IOMMU_PAGE_SIZE - 1));
+ spin_unlock_irqrestore(&dom->pgtlock, flags);
+
+ return pa;
+}
+
+static struct iommu_device *sprd_iommu_probe_device(struct device *dev)
+{
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+ struct sprd_iommu_device *sdev;
+
+ if (!fwspec || fwspec->ops != &sprd_iommu_ops)
+ return ERR_PTR(-ENODEV);
+
+ sdev = dev_iommu_priv_get(dev);
+
+ return &sdev->iommu;
+}
+
+static void sprd_iommu_release_device(struct device *dev)
+{
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+ if (!fwspec || fwspec->ops != &sprd_iommu_ops)
+ return;
+
+ iommu_fwspec_free(dev);
+}
+
+static struct iommu_group *sprd_iommu_device_group(struct device *dev)
+{
+ struct sprd_iommu_device *sdev = dev_iommu_priv_get(dev);
+
+ return iommu_group_ref_get(sdev->group);
+}
+
+static int sprd_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
+{
+ struct platform_device *pdev;
+
+ if (!dev_iommu_priv_get(dev)) {
+ pdev = of_find_device_by_node(args->np);
+ dev_iommu_priv_set(dev, platform_get_drvdata(pdev));
+ platform_device_put(pdev);
+ }
+
+ return 0;
+}
+
+
+static const struct iommu_ops sprd_iommu_ops = {
+ .domain_alloc = sprd_iommu_domain_alloc,
+ .domain_free = sprd_iommu_domain_free,
+ .attach_dev = sprd_iommu_attach_device,
+ .detach_dev = sprd_iommu_detach_device,
+ .map = sprd_iommu_map,
+ .unmap = sprd_iommu_unmap,
+ .iotlb_sync_map = sprd_iommu_sync_map,
+ .iotlb_sync = sprd_iommu_sync,
+ .iova_to_phys = sprd_iommu_iova_to_phys,
+ .probe_device = sprd_iommu_probe_device,
+ .release_device = sprd_iommu_release_device,
+ .device_group = sprd_iommu_device_group,
+ .of_xlate = sprd_iommu_of_xlate,
+ .pgsize_bitmap = ~0UL << SPRD_IOMMU_PAGE_SHIFT,
+};
+
+static const struct of_device_id sprd_iommu_of_match[] = {
+ { .compatible = "sprd,iommu-v1" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, sprd_iommu_of_match);
+
+/*
+ * Clock is optional, access to some of IOMMUs are controlled by gate
+ * clk, enabled clocks for that kind of IOMMUs before accessing.
+ * Return 0 for success or no clocks found.
+ */
+static int sprd_iommu_clk_enable(struct sprd_iommu_device *sdev)
+{
+ struct clk *eb;
+
+ eb = clk_get_optional(sdev->dev, 0);
+ if (!eb)
+ return 0;
+
+ if (IS_ERR(eb))
+ return PTR_ERR(eb);
+
+ sdev->eb = eb;
+ return clk_prepare_enable(eb);
+}
+
+static void sprd_iommu_clk_disable(struct sprd_iommu_device *sdev)
+{
+ if (sdev->eb)
+ clk_disable_unprepare(sdev->eb);
+}
+
+static int sprd_iommu_probe(struct platform_device *pdev)
+{
+ struct sprd_iommu_device *sdev;
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ sdev = devm_kzalloc(dev, sizeof(*sdev), GFP_KERNEL);
+ if (!sdev)
+ return -ENOMEM;
+
+ sdev->base = syscon_regmap_lookup_by_phandle_args(dev->of_node,
+ "sprd,iommu-regs", 1, &sdev->reg_offset);
+ if (IS_ERR(sdev->base)) {
+ dev_err(dev, "Failed to get registers syscon.\n");
+ return PTR_ERR(sdev->base);
+ }
+
+ sdev->prot_page_va = dma_alloc_coherent(dev, SPRD_IOMMU_PAGE_SIZE,
+ &sdev->prot_page_pa, GFP_KERNEL);
+ if (!sdev->prot_page_va)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, sdev);
+ sdev->dev = dev;
+
+ /* All the client devices are in the same iommu-group */
+ sdev->group = iommu_group_alloc();
+ if (IS_ERR(sdev->group)) {
+ ret = PTR_ERR(sdev->group);
+ goto free_page;
+ }
+
+ ret = iommu_device_sysfs_add(&sdev->iommu, dev, NULL, dev_name(dev));
+ if (ret)
+ goto put_group;
+
+ iommu_device_set_ops(&sdev->iommu, &sprd_iommu_ops);
+ iommu_device_set_fwnode(&sdev->iommu, &dev->of_node->fwnode);
+
+ ret = iommu_device_register(&sdev->iommu);
+ if (ret)
+ goto remove_sysfs;
+
+ if (!iommu_present(&platform_bus_type))
+ bus_set_iommu(&platform_bus_type, &sprd_iommu_ops);
+
+ ret = sprd_iommu_clk_enable(sdev);
+ if (ret)
+ goto unregister_iommu;
+
+ ret = sprd_iommu_get_version(sdev);
+ if (ret < 0) {
+ dev_err(dev, "iommu version(%d) is invalid.\n", ret);
+ goto disable_clk;
+ }
+ sdev->ver = ret;
+
+ return 0;
+
+disable_clk:
+ sprd_iommu_clk_disable(sdev);
+unregister_iommu:
+ iommu_device_unregister(&sdev->iommu);
+remove_sysfs:
+ iommu_device_sysfs_remove(&sdev->iommu);
+put_group:
+ iommu_group_put(sdev->group);
+free_page:
+ dma_free_coherent(sdev->dev, SPRD_IOMMU_PAGE_SIZE, sdev->prot_page_va, sdev->prot_page_pa);
+ return ret;
+}
+
+static int sprd_iommu_remove(struct platform_device *pdev)
+{
+ struct sprd_iommu_device *sdev = platform_get_drvdata(pdev);
+
+ dma_free_coherent(sdev->dev, SPRD_IOMMU_PAGE_SIZE, sdev->prot_page_va, sdev->prot_page_pa);
+
+ iommu_group_put(sdev->group);
+ sdev->group = NULL;
+
+ bus_set_iommu(&platform_bus_type, NULL);
+
+ platform_set_drvdata(pdev, NULL);
+ iommu_device_sysfs_remove(&sdev->iommu);
+ iommu_device_unregister(&sdev->iommu);
+
+ return 0;
+}
+
+static struct platform_driver sprd_iommu_driver = {
+ .driver = {
+ .name = "sprd-iommu",
+ .of_match_table = sprd_iommu_of_match,
+ .suppress_bind_attrs = true,
+ },
+ .probe = sprd_iommu_probe,
+ .remove = sprd_iommu_remove,
+};
+module_platform_driver(sprd_iommu_driver);
+
+MODULE_DESCRIPTION("IOMMU driver for Unisoc SoCs");
+MODULE_ALIAS("platform:sprd-iommu");
+MODULE_LICENSE("GPL v2");
--
2.25.1