From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> The TI Peripheral Virtualization Unit (PVU) permits to define a limited set of mappings for DMA requests on the system memory. Unlike with an IOMMU, there is no fallback to a memory-backed page table, only a fixed set of register-backed TLBs. Emulating an IOMMU behavior appears to be the more fragile the more fragmentation of pending requests occur. Therefore, this driver does not expose the PVU as an IOMMU. It rather introduces a simple, static interface to devices that are under restricted-dma-pool constraints. They can register their pools with the PVUs, enabling only those pools to work for DMA. As also MSI is issued as DMA, the PVU already register the related translator region of the AM654 as valid DMA target. This driver is the essential building block for limiting DMA from untrusted devices to clearly defined memory regions in the absence of a real IOMMU (SMMU). Co-developed-by: Diogo Ivo <diogo.ivo@xxxxxxxxxxx> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> --- drivers/soc/ti/Kconfig | 4 + drivers/soc/ti/Makefile | 1 + drivers/soc/ti/ti-pvu.c | 500 ++++++++++++++++++++++++++++++++++++++++ include/linux/ti-pvu.h | 16 ++ 4 files changed, 521 insertions(+) create mode 100644 drivers/soc/ti/ti-pvu.c create mode 100644 include/linux/ti-pvu.h diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig index 1a93001c9e36..af7173ad84de 100644 --- a/drivers/soc/ti/Kconfig +++ b/drivers/soc/ti/Kconfig @@ -82,6 +82,10 @@ config TI_PRUSS processors on various TI SoCs. It's safe to say N here if you're not interested in the PRU or if you are unsure. +config TI_PVU + bool "TI Peripheral Virtualization Unit driver" + depends on ARCH_K3 && DMA_RESTRICTED_POOL + endif # SOC_TI config TI_SCI_INTA_MSI_DOMAIN diff --git a/drivers/soc/ti/Makefile b/drivers/soc/ti/Makefile index cb800a745e66..ecff3fd8c433 100644 --- a/drivers/soc/ti/Makefile +++ b/drivers/soc/ti/Makefile @@ -12,3 +12,4 @@ obj-$(CONFIG_TI_K3_RINGACC) += k3-ringacc.o obj-$(CONFIG_TI_K3_SOCINFO) += k3-socinfo.o obj-$(CONFIG_TI_PRUSS) += pruss.o obj-$(CONFIG_POWER_AVS_OMAP) += smartreflex.o +obj-$(CONFIG_TI_PVU) += ti-pvu.o diff --git a/drivers/soc/ti/ti-pvu.c b/drivers/soc/ti/ti-pvu.c new file mode 100644 index 000000000000..8bce3845d5b6 --- /dev/null +++ b/drivers/soc/ti/ti-pvu.c @@ -0,0 +1,500 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * TI Peripheral Virtualization Unit driver for static DMA isolation + * + * Copyright (c) 2024, Siemens AG + */ + +#include <linux/io.h> +#include <linux/interrupt.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/ti-pvu.h> + +#define PVU_CONFIG 0x4 +#define PVU_ENABLE 0x10 +#define PVU_VIRTID_MAP1 0x14 +#define PVU_VIRTID_MAP2 0x18 +#define PVU_EXCEPTION_LOGGING_CONTROL 0x120 +#define PVU_EXCEPTION_LOGGING_HEADER0 0x124 +#define PVU_EXCEPTION_LOGGING_HEADER1 0x128 +#define PVU_EXCEPTION_LOGGING_DATA0 0x12c +#define PVU_EXCEPTION_LOGGING_DATA1 0x130 +#define PVU_EXCEPTION_LOGGING_DATA2 0x134 +#define PVU_EXCEPTION_LOGGING_DATA2_SECURE BIT(0) +#define PVU_EXCEPTION_LOGGING_DATA2_PRIV BIT(1) +#define PVU_EXCEPTION_LOGGING_DATA2_CACHEABLE BIT(2) +#define PVU_EXCEPTION_LOGGING_DATA2_DEBUG BIT(3) +#define PVU_EXCEPTION_LOGGING_DATA2_READ BIT(4) +#define PVU_EXCEPTION_LOGGING_DATA2_WRITE BIT(5) +#define PVU_EXCEPTION_LOGGING_DATA3 0x138 +#define PVU_EXCEPTION_ENABLE_SET 0x148 +#define PVU_EOI_REG 0x150 + +#define PVU_CHAIN 0x0 +#define PVU_CHAIN_EN BIT(31) +#define PVU_CHAIN_LOG_DIS BIT(30) +#define PVU_CHAIN_FAULT BIT(29) +#define PVU_CHAIN_MASK 0xfff +#define PVU_ENTRY0 0x20 +#define PVU_ENTRY1 0x24 +#define PVU_ENTRY1_RESERVED_MASK 0xffff0000 +#define PVU_ENTRY1_VBASE_H_MASK 0xffff +#define PVU_ENTRY2 0x28 +#define PVU_ENTRY2_RESERVED_MASK 0x1fd00080 +#define PVU_ENTRY2_INVALID (0U << 30) +#define PVU_ENTRY2_VALID (2U << 30) +#define PVU_ENTRY2_MODE_MASK 0xc0000000 +#define PVU_ENTRY2_PSIZE_SHIFT 16 +#define PVU_ENTRY2_PSIZE_MASK 0xf +#define PVU_ENTRY2_PERM_SX BIT(15) +#define PVU_ENTRY2_PERM_SW BIT(14) +#define PVU_ENTRY2_PERM_SR BIT(13) +#define PVU_ENTRY2_PERM_UX BIT(12) +#define PVU_ENTRY2_PERM_UW BIT(11) +#define PVU_ENTRY2_PERM_UR BIT(10) +#define PVU_ENTRY2_MEM_WRITETHROUGH (2 << 8) +#define PVU_ENTRY2_OUTER_SHARABLE BIT(4) +#define PVU_ENTRY2_IS_NOALLOC (0 << 2) +#define PVU_ENTRY2_OS_NOALLOC (0 << 0) +#define PVU_ENTRY4 0x30 +#define PVU_ENTRY5 0x34 +#define PVU_ENTRY5_RESERVED_MASK 0xffff0000 +#define PVU_ENTRY5_PBASE_H_MASK 0xffff +#define PVU_ENTRY6 0x38 +#define PVU_ENTRY6_RESERVED_MASK 0xffffffe0 + +#define NUM_VIRTIDS 1 + +static const struct regmap_config pvu_cfg_regmap_cfg = { + .name = "pvu-cfg", + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .max_register = PVU_EOI_REG, +}; + +enum pvu_cfg_regfields { + PVU_TLBS, + PVU_TLB_ENTRIES, + PVU_ENABLED, + PVU_DMA_CNT, + PVU_DMA_CL0, + PVU_DMA_CL1, + PVU_DMA_CL2, + PVU_DMA_CL3, + PVU_MAX_VIRTID, + PVU_EXC_SRC_ID, + PVU_EXC_CODE, + PVU_EXC_ADDR_L, + PVU_EXC_ADDR_H, + PVU_EXC_PRIV_ID, + PVU_EXC_PROPS, + PVU_EXC_ROUTE_ID, + PVU_EXC_BYTE_CNT, + PVU_EXC_ENABLE, + PVU_EOI, + PVU_MAX_CFG_FIELDS, +}; + +static const struct reg_field pvu_cfg_reg_fields[] = { + [PVU_TLBS] = REG_FIELD(PVU_CONFIG, 0, 15), + [PVU_TLB_ENTRIES] = REG_FIELD(PVU_CONFIG, 16, 23), + [PVU_ENABLED] = REG_FIELD(PVU_ENABLE, 0, 0), + [PVU_DMA_CNT] = REG_FIELD(PVU_VIRTID_MAP1, 0, 11), + [PVU_DMA_CL0] = REG_FIELD(PVU_VIRTID_MAP1, 16, 17), + [PVU_DMA_CL1] = REG_FIELD(PVU_VIRTID_MAP1, 18, 19), + [PVU_DMA_CL2] = REG_FIELD(PVU_VIRTID_MAP1, 20, 21), + [PVU_DMA_CL3] = REG_FIELD(PVU_VIRTID_MAP1, 22, 23), + [PVU_MAX_VIRTID] = REG_FIELD(PVU_VIRTID_MAP2, 0, 11), + [PVU_EXC_SRC_ID] = REG_FIELD(PVU_EXCEPTION_LOGGING_HEADER0, 8, 23), + [PVU_EXC_CODE] = REG_FIELD(PVU_EXCEPTION_LOGGING_HEADER1, 16, 23), + [PVU_EXC_ADDR_L] = REG_FIELD(PVU_EXCEPTION_LOGGING_DATA0, 0, 31), + [PVU_EXC_ADDR_H] = REG_FIELD(PVU_EXCEPTION_LOGGING_DATA1, 0, 15), + [PVU_EXC_PRIV_ID] = REG_FIELD(PVU_EXCEPTION_LOGGING_DATA2, 0, 7), + [PVU_EXC_PROPS] = REG_FIELD(PVU_EXCEPTION_LOGGING_DATA2, 8, 13), + [PVU_EXC_ROUTE_ID] = REG_FIELD(PVU_EXCEPTION_LOGGING_DATA2, 16, 27), + [PVU_EXC_BYTE_CNT] = REG_FIELD(PVU_EXCEPTION_LOGGING_DATA3, 0, 9), + [PVU_EXC_ENABLE] = REG_FIELD(PVU_EXCEPTION_ENABLE_SET, 0, 0), + [PVU_EOI] = REG_FIELD(PVU_EOI_REG, 0, 15), +}; + +struct ti_pvu { + struct list_head entry; + struct platform_device *pdev; + struct regmap *cfg; + struct regmap_field *cfg_fields[PVU_MAX_CFG_FIELDS]; + void __iomem *tlbif_base; + unsigned int num_tlbs; + unsigned int num_entries; +}; + +static const char *pvu_excp_code_string[] = { + "PVU miss", + "maximum VirtID violation", + "<reserved>", + "read permission violation", + "write permission violation", + "execute permission violation", + "prefetch permission violation", + "<unknown>", +}; + +static const u64 pvu_page_size[] = { + 4 * 1024ULL, + 16 * 1024ULL, + 64 * 1024ULL, + 2 * 1024 * 1024ULL, + 32 * 1024 * 1024ULL, + 512 * 1024 * 1024ULL, + 1 * 1024 * 1024 * 1024ULL, + 16 * 1024 * 1024 * 1024ULL +}; + +static DEFINE_MUTEX(ti_pvu_lock); +static LIST_HEAD(ti_pvu_list); + +static unsigned int pvu_field_read(struct ti_pvu *pvu, enum pvu_cfg_regfields f) +{ + int ret; + unsigned int val; + + ret = regmap_field_read(pvu->cfg_fields[f], &val); + if (ret) + dev_err(&pvu->pdev->dev, "failed to read field\n"); + + return val; +} + +static void pvu_field_write(struct ti_pvu *pvu, enum pvu_cfg_regfields f, + unsigned int val) +{ + int ret; + + ret = regmap_field_write(pvu->cfg_fields[f], val); + if (ret) + dev_err(&pvu->pdev->dev, "failed to write field\n"); +} + +static irqreturn_t pvu_fault_isr(int irq, void *dev_id) +{ + u32 code, bytes, route_id, priv_id, props; + struct ti_pvu *pvu = dev_id; + const char *code_str; + u64 address; + + code = pvu_field_read(pvu, PVU_EXC_CODE); + code_str = pvu_excp_code_string[ + min(code, (u32)ARRAY_SIZE(pvu_excp_code_string) - 1)]; + + dev_err(&pvu->pdev->dev, "fault detected, code %d (%s)\n", + code, code_str); + + address = pvu_field_read(pvu, PVU_EXC_ADDR_L); + address |= (u64)pvu_field_read(pvu, PVU_EXC_ADDR_H) << 32; + + bytes = pvu_field_read(pvu, PVU_EXC_BYTE_CNT); + + route_id = pvu_field_read(pvu, PVU_EXC_ROUTE_ID); + priv_id = pvu_field_read(pvu, PVU_EXC_PRIV_ID); + props = pvu_field_read(pvu, PVU_EXC_PROPS); + + dev_err(&pvu->pdev->dev, + " address 0x%016llx size %d route-ID %d priv-ID %d flags %c%c%c%c%c%c\n", + address, bytes, route_id, priv_id, + (props & PVU_EXCEPTION_LOGGING_DATA2_WRITE) ? 'W' : '-', + (props & PVU_EXCEPTION_LOGGING_DATA2_READ) ? 'R' : '-', + (props & PVU_EXCEPTION_LOGGING_DATA2_DEBUG) ? 'D' : '-', + (props & PVU_EXCEPTION_LOGGING_DATA2_CACHEABLE) ? 'C' : '-', + (props & PVU_EXCEPTION_LOGGING_DATA2_PRIV) ? 'P' : '-', + (props & PVU_EXCEPTION_LOGGING_DATA2_SECURE) ? 'S' : '-'); + + pvu_field_write(pvu, PVU_EOI, 0); + + return IRQ_HANDLED; +} + +static void __iomem *pvu_get_entry_base(struct ti_pvu *pvu, unsigned int entry) +{ + return pvu->tlbif_base + (entry / pvu->num_entries) * 0x1000 + + (entry % pvu->num_entries) * 0x20; +} + +static int pvu_get_free_entry(struct ti_pvu *pvu) +{ + unsigned int n; + u32 val; + + /* We use up to 2 TLBs via chainging */ + for (n = 0; n < pvu->num_entries * 2; n++) { + val = readl(pvu_get_entry_base(pvu, n) + PVU_ENTRY2); + if ((val & PVU_ENTRY2_MODE_MASK) == PVU_ENTRY2_INVALID) + return n; + } + return -ENOSPC; +} + +static void pvu_write_entry(struct ti_pvu *pvu, unsigned int entry, + u64 addr, u32 psize) +{ + void __iomem *entry_base = pvu_get_entry_base(pvu, entry); + u32 val; + + writel((u32)addr, entry_base + PVU_ENTRY0); + + val = readl(entry_base + PVU_ENTRY1); + val &= PVU_ENTRY1_RESERVED_MASK; + val |= (addr >> 32) & PVU_ENTRY1_VBASE_H_MASK; + writel(val, entry_base + PVU_ENTRY1); + + writel((u32)addr, entry_base + PVU_ENTRY4); + + val = readl(entry_base + PVU_ENTRY5); + val &= PVU_ENTRY5_RESERVED_MASK; + val |= (addr >> 32) & PVU_ENTRY5_PBASE_H_MASK; + writel(val, entry_base + PVU_ENTRY5); + + val = readl(entry_base + PVU_ENTRY6); + val &= PVU_ENTRY6_RESERVED_MASK; + writel(val, entry_base + PVU_ENTRY6); + + val = readl(entry_base + PVU_ENTRY2); + val &= PVU_ENTRY2_RESERVED_MASK; + val |= psize << PVU_ENTRY2_PSIZE_SHIFT; + val |= PVU_ENTRY2_VALID | + PVU_ENTRY2_PERM_UR | PVU_ENTRY2_PERM_SR | + PVU_ENTRY2_PERM_UW | PVU_ENTRY2_PERM_SW | + PVU_ENTRY2_PERM_UX | PVU_ENTRY2_PERM_SX | + PVU_ENTRY2_MEM_WRITETHROUGH | PVU_ENTRY2_OUTER_SHARABLE | + PVU_ENTRY2_IS_NOALLOC | PVU_ENTRY2_OS_NOALLOC; + writel(val, entry_base + PVU_ENTRY2); +} + +static int pvu_create_region(struct ti_pvu *pvu, u64 addr, u64 size) +{ + u64 page_size; + int psize; + int entry; + + while (size > 0) { + entry = pvu_get_free_entry(pvu); + if (entry < 0) { + dev_err(&pvu->pdev->dev, "ran out of TLB entries\n"); + return -ENOSPC; + } + + for (psize = ARRAY_SIZE(pvu_page_size) - 1; psize >= 0; psize--) { + page_size = pvu_page_size[psize]; + if (size >= page_size && (addr & (page_size - 1)) == 0) + break; + } + if (psize < 0) { + dev_err(&pvu->pdev->dev, "unaligned region provided\n"); + return -EINVAL; + } + + pvu_write_entry(pvu, entry, addr, psize); + dev_info(&pvu->pdev->dev, + "created TLB entry %d.%d: 0x%08llx, psize %d (0x%08llx)\n", + entry / pvu->num_entries, entry % pvu->num_entries, + addr, psize, page_size); + + size -= page_size; + addr += page_size; + } + + return 0; +} + +static void pvu_remove_region(struct ti_pvu *pvu, u64 addr, u64 size) +{ + void __iomem *entry_base; + unsigned int n, psize; + u64 entry_addr; + u32 entry2; + + for (n = 0; n < pvu->num_entries * 2; n++) { + entry_base = pvu_get_entry_base(pvu, n); + entry2 = readl(entry_base + PVU_ENTRY2); + if ((entry2 & PVU_ENTRY2_MODE_MASK) != PVU_ENTRY2_VALID) + continue; + + entry_addr = readl(entry_base + PVU_ENTRY0); + entry_addr |= (u64)(readl(entry_base + PVU_ENTRY1) & + PVU_ENTRY1_VBASE_H_MASK) << 32; + + psize = (entry2 >> PVU_ENTRY2_PSIZE_SHIFT) & + PVU_ENTRY2_PSIZE_MASK; + if (psize >= ARRAY_SIZE(pvu_page_size)) + continue; + + if (entry_addr >= addr && + (entry_addr + pvu_page_size[psize]) <= (addr + size)) { + entry2 &= ~PVU_ENTRY2_MODE_MASK; + entry2 |= PVU_ENTRY2_INVALID; + writel(entry2, entry_base + PVU_ENTRY2); + + dev_info(&pvu->pdev->dev, "removed TLB entry %d.%d\n", + n / pvu->num_entries, n % pvu->num_entries); + } + } +} + +int ti_pvu_create_region(unsigned int virt_id, const struct resource *region) +{ + struct ti_pvu *pvu; + int err = 0; + + if (virt_id >= NUM_VIRTIDS) + return -EINVAL; + + mutex_lock(&ti_pvu_lock); + + list_for_each_entry(pvu, &ti_pvu_list, entry) { + err = pvu_create_region(pvu, region->start, + region->end + 1 - region->start); + if (err) + break; + } + + mutex_unlock(&ti_pvu_lock); + + return err; +} + +int ti_pvu_remove_region(unsigned int virt_id, const struct resource *region) +{ + struct ti_pvu *pvu; + + if (virt_id >= NUM_VIRTIDS) + return -EINVAL; + + mutex_lock(&ti_pvu_lock); + + list_for_each_entry(pvu, &ti_pvu_list, entry) { + pvu_remove_region(pvu, region->start, + region->end + 1 - region->start); + } + + mutex_unlock(&ti_pvu_lock); + + return 0; +} + +static int ti_pvu_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *its_node; + void __iomem *base; + struct ti_pvu *pvu; + u32 val; + int ret; + + pvu = devm_kzalloc(dev, sizeof(*pvu), GFP_KERNEL); + if (!pvu) + return -ENOMEM; + + pvu->pdev = pdev; + + base = devm_platform_ioremap_resource_byname(pdev, "cfg"); + if (IS_ERR(base)) + return PTR_ERR(base); + + pvu->cfg = devm_regmap_init_mmio(dev, base, &pvu_cfg_regmap_cfg); + if (IS_ERR(pvu->cfg)) + return dev_err_probe(dev, PTR_ERR(pvu->cfg), "failed to init cfg regmap"); + + ret = devm_regmap_field_bulk_alloc(dev, pvu->cfg, pvu->cfg_fields, + pvu_cfg_reg_fields, PVU_MAX_CFG_FIELDS); + if (ret) + return dev_err_probe(dev, ret, "failed to alloc cfg regmap fields"); + + pvu->num_tlbs = pvu_field_read(pvu, PVU_TLBS); + pvu->num_entries = pvu_field_read(pvu, PVU_TLB_ENTRIES); + dev_info(dev, "TLBs: %d, entries per TLB: %d\n", pvu->num_tlbs, + pvu->num_entries); + + pvu->tlbif_base = devm_platform_ioremap_resource_byname(pdev, "tlbif"); + if (IS_ERR(pvu->tlbif_base)) + return PTR_ERR(pvu->tlbif_base); + + its_node = of_find_compatible_node(0, 0, "arm,gic-v3-its"); + if (its_node) { + u32 pre_its_window[2]; + + ret = of_property_read_u32_array(its_node, + "socionext,synquacer-pre-its", + pre_its_window, + ARRAY_SIZE(pre_its_window)); + if (ret) { + dev_err(dev, "failed to read pre-its property\n"); + return ret; + } + + ret = pvu_create_region(pvu, pre_its_window[0], + pre_its_window[1]); + if (ret) + return ret; + } + + /* Enable the first two TLBs, chaining from 0 to 1 */ + val = readl(pvu->tlbif_base + PVU_CHAIN); + val |= PVU_CHAIN_EN | 1; + writel(val, pvu->tlbif_base + PVU_CHAIN); + + val = readl(pvu->tlbif_base + PVU_CHAIN + 0x1000); + val |= PVU_CHAIN_EN; + writel(val, pvu->tlbif_base + PVU_CHAIN + 0x1000); + + pvu_field_write(pvu, PVU_DMA_CNT, 0); + pvu_field_write(pvu, PVU_DMA_CL0, 0); + pvu_field_write(pvu, PVU_DMA_CL1, 0); + pvu_field_write(pvu, PVU_DMA_CL2, 0); + pvu_field_write(pvu, PVU_DMA_CL3, 0); + pvu_field_write(pvu, PVU_MAX_VIRTID, NUM_VIRTIDS); + + ret = platform_get_irq(pdev, 0); + if (ret < 0) + return dev_err_probe(dev, ret, "failed to get irq\n"); + + ret = devm_request_irq(dev, ret, pvu_fault_isr, 0, dev_name(dev), pvu); + if (ret) + return dev_err_probe(dev, ret, "failed to request irq\n"); + + pvu_field_write(pvu, PVU_EXC_ENABLE, 1); + pvu_field_write(pvu, PVU_ENABLED, 1); + + dev_set_drvdata(dev, pvu); + + mutex_lock(&ti_pvu_lock); + list_add(&pvu->entry, &ti_pvu_list); + mutex_unlock(&ti_pvu_lock); + + return 0; +} + +static void ti_pvu_remove(struct platform_device *pdev) +{ + struct ti_pvu *pvu = dev_get_drvdata(&pdev->dev); + + mutex_lock(&ti_pvu_lock); + list_del(&pvu->entry); + mutex_unlock(&ti_pvu_lock); +} + +static const struct of_device_id ti_pvu_of_match[] = { + { .compatible = "ti,am654-pvu", }, + {}, +}; +MODULE_DEVICE_TABLE(of, ti_pvu_of_match); + +static struct platform_driver ti_pvu_driver = { + .driver = { + .name = "ti-pvu", + .of_match_table = ti_pvu_of_match, + }, + .probe = ti_pvu_probe, + .remove_new = ti_pvu_remove, +}; +module_platform_driver(ti_pvu_driver); diff --git a/include/linux/ti-pvu.h b/include/linux/ti-pvu.h new file mode 100644 index 000000000000..acd4d9e0dc86 --- /dev/null +++ b/include/linux/ti-pvu.h @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * TI Peripheral Virtualization Unit driver for static DMA isolation + * + * Copyright (c) 2024, Siemens AG + */ + +#ifndef _LINUX_TI_PVU_H +#define _LINUX_TI_PVU_H + +#include <linux/ioport.h> + +int ti_pvu_create_region(unsigned int virt_id, const struct resource *region); +int ti_pvu_remove_region(unsigned int virt_id, const struct resource *region); + +#endif /* _LINUX_TI_PVU_H */ -- 2.43.0