[PATCH v2 0/6] soc: ti: Add and use PVU on K3-AM65 for DMA isolation

[PATCH v2 0/6] soc: ti: Add and use PVU on K3-AM65 for DMA isolation

[Jan Kiszka]

Changes in v2:
 - fix dt_bindings_check issues (patch 1)
 - address first review comments (patch 2)
 - extend ti,am65-pci-host bindings for PVU (new patch 3)

Only few of the K3 SoCs have an IOMMU and, thus, can isolate the system
against DMA-based attacks of external PCI devices. The AM65 is without
an IOMMU, but it comes with something close to it: the Peripheral
Virtualization Unit (PVU).

The PVU was originally designed to establish static compartments via a
hypervisor, isolate those DMA-wise against each other and the host and
even allow remapping of guest-physical addresses. But it only provides
a static translation region, not page-granular mappings. Thus, it cannot
be handled transparently like an IOMMU.

Now, to use the PVU for the purpose of isolated PCI devices from the
Linux host, this series takes a different approach. It defines a
restricted-dma-pool for the PCI host, using swiotlb to map all DMA
buffers from a static memory carve-out. And to enforce that the devices
actually follow this, a special PVU soc driver is introduced. The driver
permits access to the GIC ITS and otherwise waits for other drivers that
detect devices with constrained DMA to register pools with the PVU.

For the AM65, the first (and possibly only) driver where this is
introduced is the pci-keystone host controller. Finally, this series
configures the IOT2050 devices (all have MiniPCIe or M.2 extension
slots) to make use of this protection scheme.

Due to the cross-cutting nature of these changes, multiple subsystems
are affected. However, I wanted to present the whole thing in one series
to allow everyone to review with the complete picture in hands. If
preferred, I can also split the series up, of course.

Jan

CC: Bjorn Helgaas <bhelgaas@google.com>
CC: "Krzysztof Wilczyński" <kw@linux.com>
CC: linux-pci@vger.kernel.org
CC: Lorenzo Pieralisi <lpieralisi@kernel.org>

Jan Kiszka (6):
  dt-bindings: soc: ti: Add AM65 peripheral virtualization unit
  soc: ti: Add IOMPU-like PVU driver
  dt-bindings: PCI: ti,am65: Extend for use with PVU
  arm64: dts: ti: k3-am65-main: Add VMAP registers to PCI root complexes
  PCI: keystone: Add supported for PVU-based DMA isolation on AM654
  arm64: dts: ti: iot2050: Enforce DMA isolation for devices behind PCI
    RC

 .../bindings/pci/ti,am65-pci-host.yaml        |  13 +-
 .../bindings/soc/ti/ti,am654-pvu.yaml         |  51 ++
 .../boot/dts/ti/k3-am65-iot2050-common.dtsi   |  32 ++
 arch/arm64/boot/dts/ti/k3-am65-main.dtsi      |  18 +-
 drivers/pci/controller/dwc/pci-keystone.c     | 101 ++++
 drivers/soc/ti/Kconfig                        |   4 +
 drivers/soc/ti/Makefile                       |   1 +
 drivers/soc/ti/ti-pvu.c                       | 487 ++++++++++++++++++
 include/linux/ti-pvu.h                        |  16 +
 9 files changed, 716 insertions(+), 7 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml
 create mode 100644 drivers/soc/ti/ti-pvu.c
 create mode 100644 include/linux/ti-pvu.h

-- 
2.43.0

[PATCH v2 1/6] dt-bindings: soc: ti: Add AM65 peripheral virtualization unit

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

The PVU allows to define a limited set of mappings for incoming DMA
requests to the system memory. It is not a real IOMMU, thus hooked up
under the TI SoC bindings.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 .../bindings/soc/ti/ti,am654-pvu.yaml         | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml

diff --git a/Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml b/Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml
new file mode 100644
index 000000000000..fd0f86fa27b0
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (c) Siemens AG, 2024
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/ti/ti,am654-pvu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI AM654 Peripheral Virtualization Unit
+
+maintainers:
+  - Jan Kiszka <jan.kiszka@siemens.com>
+
+properties:
+  compatible:
+    enum:
+      - ti,am654-pvu
+
+  reg:
+    minItems: 2
+
+  reg-names:
+    items:
+      - const: cfg
+      - const: tlbif
+
+  interrupts:
+    items:
+      - description: fault interrupt
+
+  interrupt-names:
+    items:
+      - const: pvu
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-names
+
+additionalProperties: false
+
+examples:
+  - |
+    ti-pvu@30f80000 {
+        compatible = "ti,am654-pvu";
+        reg = <0x30f80000 0x1000>,
+              <0x36000000 0x100000>;
+        reg-names = "cfg", "tlbif";
+        interrupts-extended = <&intr_main_navss 390>;
+        interrupt-names = "pvu";
+    };
-- 
2.43.0

[PATCH v2 2/6] soc: ti: Add IOMPU-like PVU driver

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

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@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 drivers/soc/ti/Kconfig  |   4 +
 drivers/soc/ti/Makefile |   1 +
 drivers/soc/ti/ti-pvu.c | 487 ++++++++++++++++++++++++++++++++++++++++
 include/linux/ti-pvu.h  |  16 ++
 4 files changed, 508 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..5b71d503051f
--- /dev/null
+++ b/drivers/soc/ti/ti-pvu.c
@@ -0,0 +1,487 @@
+// 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 int pvu_get_free_entry(struct ti_pvu *pvu)
+{
+	unsigned int n;
+	u32 val;
+
+	for (n = 0; n < pvu->num_entries; n++) {
+		val = readl(pvu->tlbif_base + n * 0x20 + 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->tlbif_base + entry * 0x20;
+	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 0.%d: 0x%08llx, psize %d (0x%08llx)\n",
+			 entry, 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; n++) {
+		entry_base = pvu->tlbif_base + n * 0x20;
+		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 0.%d\n", n);
+		}
+	}
+}
+
+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;
+	}
+
+	val = readl(pvu->tlbif_base + PVU_CHAIN);
+	val |= PVU_CHAIN_EN;
+	writel(val, pvu->tlbif_base + PVU_CHAIN);
+
+	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

[PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

Describe also the VMAP registers which are needed in order to make use
of the PVU with this PCI host. Furthermore, permit to specify a
restricted DMA pool by phandle.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 .../devicetree/bindings/pci/ti,am65-pci-host.yaml   | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
index 0a9d10532cc8..72f78f21e1e8 100644
--- a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
+++ b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
@@ -20,7 +20,7 @@ properties:
       - ti,keystone-pcie
 
   reg:
-    maxItems: 4
+    maxItems: 6
 
   reg-names:
     items:
@@ -28,6 +28,8 @@ properties:
       - const: dbics
       - const: config
       - const: atu
+      - const: vmap_lp
+      - const: vmap_hp
 
   interrupts:
     maxItems: 1
@@ -69,6 +71,9 @@ properties:
     items:
       pattern: '^pcie-phy[0-1]$'
 
+  memory-region:
+    description: phandle to restricted DMA pool to be used for all devices behind this controller
+
 required:
   - compatible
   - reg
@@ -104,8 +109,10 @@ examples:
         reg =  <0x5500000 0x1000>,
                <0x5501000 0x1000>,
                <0x10000000 0x2000>,
-               <0x5506000 0x1000>;
-        reg-names = "app", "dbics", "config", "atu";
+               <0x5506000 0x1000>,
+               <0x2900000 0x1000>,
+               <0x2908000 0x1000>;
+        reg-names = "app", "dbics", "config", "atu", "vmap_lp", "vmap_hp";
         power-domains = <&k3_pds 120 TI_SCI_PD_EXCLUSIVE>;
         #address-cells = <3>;
         #size-cells = <2>;
-- 
2.43.0

[PATCH v2 4/6] arm64: dts: ti: k3-am65-main: Add VMAP registers to PCI root complexes

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

Rewrap the long lines at this chance.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 arch/arm64/boot/dts/ti/k3-am65-main.dtsi | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
index a8664b246795..c91969ddcf4d 100644
--- a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
@@ -867,8 +867,13 @@ main_gpio1: gpio@601000 {
 
 	pcie0_rc: pcie@5500000 {
 		compatible = "ti,am654-pcie-rc";
-		reg = <0x0 0x5500000 0x0 0x1000>, <0x0 0x5501000 0x0 0x1000>, <0x0 0x10000000 0x0 0x2000>, <0x0 0x5506000 0x0 0x1000>;
-		reg-names = "app", "dbics", "config", "atu";
+		reg = <0x0 0x5500000 0x0 0x1000>,
+		      <0x0 0x5501000 0x0 0x1000>,
+		      <0x0 0x10000000 0x0 0x2000>,
+		      <0x0 0x5506000 0x0 0x1000>,
+		      <0x0 0x2900000 0x0 0x1000>,
+		      <0x0 0x2908000 0x0 0x1000>;
+		reg-names = "app", "dbics", "config", "atu", "vmap_lp", "vmap_hp";
 		power-domains = <&k3_pds 120 TI_SCI_PD_EXCLUSIVE>;
 		#address-cells = <3>;
 		#size-cells = <2>;
@@ -888,8 +893,13 @@ pcie0_rc: pcie@5500000 {
 
 	pcie1_rc: pcie@5600000 {
 		compatible = "ti,am654-pcie-rc";
-		reg = <0x0 0x5600000 0x0 0x1000>, <0x0 0x5601000 0x0 0x1000>, <0x0 0x18000000 0x0 0x2000>, <0x0 0x5606000 0x0 0x1000>;
-		reg-names = "app", "dbics", "config", "atu";
+		reg = <0x0 0x5600000 0x0 0x1000>,
+		      <0x0 0x5601000 0x0 0x1000>,
+		      <0x0 0x18000000 0x0 0x2000>,
+		      <0x0 0x5606000 0x0 0x1000>,
+		      <0x0 0x2910000 0x0 0x1000>,
+		      <0x0 0x2918000 0x0 0x1000>;
+		reg-names = "app", "dbics", "config", "atu", "vmap_lp", "vmap_hp";
 		power-domains = <&k3_pds 121 TI_SCI_PD_EXCLUSIVE>;
 		#address-cells = <3>;
 		#size-cells = <2>;
-- 
2.43.0

[PATCH v2 5/6] PCI: keystone: Add supported for PVU-based DMA isolation on AM654

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

The AM654 lacks an IOMMU, thus does not support isolating DMA requests
from untrusted PCI devices to selected memory regions this way. Use
static PVU-based protection instead.

For this, we use the availability of restricted-dma-pool memory regions
as trigger and register those as valid DMA targets with the PVU. In
addition, we need to enable the mapping of requester IDs to VirtIDs in
the PCI RC. We only use a single VirtID so far, catching all devices.
This may be extended later on.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
CC: Lorenzo Pieralisi <lpieralisi@kernel.org>
CC: "Krzysztof Wilczyński" <kw@linux.com>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: linux-pci@vger.kernel.org
---
 drivers/pci/controller/dwc/pci-keystone.c | 101 ++++++++++++++++++++++
 1 file changed, 101 insertions(+)

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index 2219b1a866fa..96b871656da4 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -19,6 +19,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/msi.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_pci.h>
 #include <linux/phy/phy.h>
@@ -26,6 +27,7 @@
 #include <linux/regmap.h>
 #include <linux/resource.h>
 #include <linux/signal.h>
+#include <linux/ti-pvu.h>
 
 #include "../../pci.h"
 #include "pcie-designware.h"
@@ -111,6 +113,16 @@
 
 #define PCI_DEVICE_ID_TI_AM654X		0xb00c
 
+#define KS_PCI_VIRTID			0
+
+#define PCIE_VMAP_xP_CTRL		0x0
+#define PCIE_VMAP_xP_REQID		0x4
+#define PCIE_VMAP_xP_VIRTID		0x8
+
+#define PCIE_VMAP_xP_CTRL_EN		BIT(0)
+
+#define PCIE_VMAP_xP_VIRTID_VID_MASK	0xfff
+
 struct ks_pcie_of_data {
 	enum dw_pcie_device_mode mode;
 	const struct dw_pcie_host_ops *host_ops;
@@ -1125,6 +1137,89 @@ static const struct of_device_id ks_pcie_of_match[] = {
 	{ },
 };
 
+#ifdef CONFIG_TI_PVU
+static const char *ks_vmap_res[] = {"vmap_lp", "vmap_hp"};
+
+static int ks_init_restricted_dma(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct of_phandle_iterator it;
+	bool init_vmap = false;
+	struct resource phys;
+	struct resource *res;
+	void __iomem *base;
+	unsigned int n;
+	u32 val;
+	int err;
+
+	of_for_each_phandle(&it, err, dev->of_node, "memory-region",
+			    NULL, 0) {
+		if (!of_device_is_compatible(it.node, "restricted-dma-pool"))
+			continue;
+
+		err = of_address_to_resource(it.node, 0, &phys);
+		if (err < 0) {
+			dev_err(dev, "failed to parse memory region %pOF: %d\n",
+				it.node, err);
+			continue;
+		}
+
+		err = ti_pvu_create_region(KS_PCI_VIRTID, &phys);
+		if (err < 0)
+			return err;
+
+		init_vmap = true;
+	}
+
+	if (init_vmap) {
+		for (n = 0; n < ARRAY_SIZE(ks_vmap_res); n++) {
+			res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+							   ks_vmap_res[n]);
+			base = devm_pci_remap_cfg_resource(dev, res);
+			if (IS_ERR(base))
+				return PTR_ERR(base);
+
+			writel(0, base + PCIE_VMAP_xP_REQID);
+
+			val = readl(base + PCIE_VMAP_xP_VIRTID);
+			val &= ~PCIE_VMAP_xP_VIRTID_VID_MASK;
+			val |= KS_PCI_VIRTID;
+			writel(val, base + PCIE_VMAP_xP_VIRTID);
+
+			val = readl(base + PCIE_VMAP_xP_CTRL);
+			val |= PCIE_VMAP_xP_CTRL_EN;
+			writel(val, base + PCIE_VMAP_xP_CTRL);
+		}
+	}
+
+	return 0;
+}
+
+static void ks_release_restricted_dma(struct platform_device *pdev)
+{
+	struct of_phandle_iterator it;
+	struct resource phys;
+	int err;
+
+	of_for_each_phandle(&it, err, pdev->dev.of_node, "memory-region",
+			    NULL, 0) {
+		if (of_device_is_compatible(it.node, "restricted-dma-pool") &&
+		    of_address_to_resource(it.node, 0, &phys) == 0)
+			ti_pvu_remove_region(KS_PCI_VIRTID, &phys);
+
+	}
+}
+#else
+static inline int ks_init_restricted_dma(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static inline void ks_release_restricted_dma(struct platform_device *pdev)
+{
+}
+#endif
+
 static int ks_pcie_probe(struct platform_device *pdev)
 {
 	const struct dw_pcie_host_ops *host_ops;
@@ -1273,6 +1368,10 @@ static int ks_pcie_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto err_get_sync;
 
+	ret = ks_init_restricted_dma(pdev);
+	if (ret < 0)
+		goto err_get_sync;
+
 	switch (mode) {
 	case DW_PCIE_RC_TYPE:
 		if (!IS_ENABLED(CONFIG_PCI_KEYSTONE_HOST)) {
@@ -1354,6 +1453,8 @@ static void ks_pcie_remove(struct platform_device *pdev)
 	int num_lanes = ks_pcie->num_lanes;
 	struct device *dev = &pdev->dev;
 
+	ks_release_restricted_dma(pdev);
+
 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);
 	ks_pcie_disable_phy(ks_pcie);
-- 
2.43.0

[PATCH v2 6/6] arm64: dts: ti: iot2050: Enforce DMA isolation for devices behind PCI RC

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

Reserve a 64M memory region below the top of 1G RAM (smallest RAM size
across the series, space left for firmware carve-outs) and ensure that
all PCI devices do their DMA only inside that region. This is configured
via a restricted-dma-pool and enforced with the help of the first PVU.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 .../boot/dts/ti/k3-am65-iot2050-common.dtsi   | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
index e76828ccf21b..cc0f33e3519c 100644
--- a/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
@@ -82,6 +82,11 @@ wdt_reset_memory_region: wdt-memory@a2200000 {
 			reg = <0x00 0xa2200000 0x00 0x1000>;
 			no-map;
 		};
+
+		pci_restricted_dma_region: restricted-dma@ba000000 {
+			compatible = "restricted-dma-pool";
+			reg = <0 0xba000000 0 0x4000000>;
+		};
 	};
 
 	leds {
@@ -571,6 +576,10 @@ seboot-backup@e80000 {
 	};
 };
 
+&pcie0_rc {
+	memory-region = <&pci_restricted_dma_region>;
+};
+
 &pcie1_rc {
 	status = "okay";
 	pinctrl-names = "default";
@@ -580,6 +589,8 @@ &pcie1_rc {
 	phys = <&serdes1 PHY_TYPE_PCIE 0>;
 	phy-names = "pcie-phy0";
 	reset-gpios = <&wkup_gpio0 27 GPIO_ACTIVE_HIGH>;
+
+	memory-region = <&pci_restricted_dma_region>;
 };
 
 &mailbox0_cluster0 {
@@ -640,3 +651,24 @@ &mcu_r5fss0 {
 	/* lock-step mode not supported on iot2050 boards */
 	ti,cluster-mode = <0>;
 };
+
+&main_navss {
+	ti_pvu0: ti-pvu@30f80000 {
+		compatible = "ti,am654-pvu";
+		reg = <0 0x30f80000 0 0x1000>,
+		      <0 0x36000000 0 0x100000>;
+		reg-names = "cfg", "tlbif";
+		interrupts-extended = <&intr_main_navss 390>;
+		interrupt-names = "pvu";
+	};
+
+	ti_pvu1: ti-pvu@30f81000 {
+		compatible = "ti,am654-pvu";
+		reg = <0 0x30f81000 0 0x1000>,
+		      <0 0x36100000 0 0x100000>;
+		reg-names = "cfg", "tlbif";
+		interrupts-extended = <&intr_main_navss 389>;
+		interrupt-names = "pvu";
+		status = "disabled";
+	};
+};
-- 
2.43.0

Re: [PATCH v2 1/6] dt-bindings: soc: ti: Add AM65 peripheral virtualization unit

[Krzysztof Kozlowski]

On Mon, Aug 26, 2024 at 11:50:02PM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
> 
> The PVU allows to define a limited set of mappings for incoming DMA
> requests to the system memory. It is not a real IOMMU, thus hooked up
> under the TI SoC bindings.

You still keep developing it on wrong, old kernel (or not using
get_maintainers.pl, but this one seems too obvious so I assumed wrong
kernel).

> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  .../bindings/soc/ti/ti,am654-pvu.yaml         | 51 +++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml
> 
> diff --git a/Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml b/Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml
> new file mode 100644
> index 000000000000..fd0f86fa27b0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml
> @@ -0,0 +1,51 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (c) Siemens AG, 2024
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/soc/ti/ti,am654-pvu.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TI AM654 Peripheral Virtualization Unit
> +
> +maintainers:
> +  - Jan Kiszka <jan.kiszka@siemens.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - ti,am654-pvu
> +
> +  reg:
> +    minItems: 2

maxItems instead.

> +
> +  reg-names:
> +    items:
> +      - const: cfg
> +      - const: tlbif
> +
> +  interrupts:
> +    items:
> +      - description: fault interrupt
> +
> +  interrupt-names:
> +    items:
> +      - const: pvu
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - interrupt-names
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    ti-pvu@30f80000 {

Node names should be generic. See also an explanation and list of
examples (not exhaustive) in DT specification:
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

for sure "ti" is not generic. pvu is the device name.

Best regards,
Krzysztof

Re: [PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Krzysztof Kozlowski]

On Mon, Aug 26, 2024 at 11:50:04PM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
> 
> Describe also the VMAP registers which are needed in order to make use
> of the PVU with this PCI host. Furthermore, permit to specify a
> restricted DMA pool by phandle.

That's an ABI break without explanation why it is necessary.

> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  .../devicetree/bindings/pci/ti,am65-pci-host.yaml   | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
> index 0a9d10532cc8..72f78f21e1e8 100644
> --- a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
> +++ b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
> @@ -20,7 +20,7 @@ properties:
>        - ti,keystone-pcie
>  
>    reg:
> -    maxItems: 4
> +    maxItems: 6
>  
>    reg-names:
>      items:
> @@ -28,6 +28,8 @@ properties:
>        - const: dbics
>        - const: config
>        - const: atu
> +      - const: vmap_lp
> +      - const: vmap_hp
>  
>    interrupts:
>      maxItems: 1
> @@ -69,6 +71,9 @@ properties:
>      items:
>        pattern: '^pcie-phy[0-1]$'
>  
> +  memory-region:
> +    description: phandle to restricted DMA pool to be used for all devices behind this controller

missing constraints, maxItems

Best regards,
Krzysztof

Re: [PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Jan Kiszka]

On 27.08.24 08:37, Krzysztof Kozlowski wrote:
> On Mon, Aug 26, 2024 at 11:50:04PM +0200, Jan Kiszka wrote:
>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>
>> Describe also the VMAP registers which are needed in order to make use
>> of the PVU with this PCI host. Furthermore, permit to specify a
>> restricted DMA pool by phandle.
> 
> That's an ABI break without explanation why it is necessary.
> 

It is needed in order to support the PVU, as written above.

Previous versions of this binding likely didn't consider this use case
and therefore didn't describe all registers associated with the hardware.

BTW, if you see a way to add the required registers without breaking
more than needed, I'm all ears. At least the kernel driver will continue
to work with older DTs when you disable PVU support or do not add a DMA
pool to the DT.

Jan

>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>> ---
>>  .../devicetree/bindings/pci/ti,am65-pci-host.yaml   | 13 ++++++++++---
>>  1 file changed, 10 insertions(+), 3 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> index 0a9d10532cc8..72f78f21e1e8 100644
>> --- a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> +++ b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> @@ -20,7 +20,7 @@ properties:
>>        - ti,keystone-pcie
>>  
>>    reg:
>> -    maxItems: 4
>> +    maxItems: 6
>>  
>>    reg-names:
>>      items:
>> @@ -28,6 +28,8 @@ properties:
>>        - const: dbics
>>        - const: config
>>        - const: atu
>> +      - const: vmap_lp
>> +      - const: vmap_hp
>>  
>>    interrupts:
>>      maxItems: 1
>> @@ -69,6 +71,9 @@ properties:
>>      items:
>>        pattern: '^pcie-phy[0-1]$'
>>  
>> +  memory-region:
>> +    description: phandle to restricted DMA pool to be used for all devices behind this controller
> 
> missing constraints, maxItems
> 
> Best regards,
> Krzysztof
> 

-- 
Siemens AG, Technology
Linux Expert Center

Re: [PATCH v2 1/6] dt-bindings: soc: ti: Add AM65 peripheral virtualization unit

[Jan Kiszka]

On 27.08.24 08:36, Krzysztof Kozlowski wrote:
> On Mon, Aug 26, 2024 at 11:50:02PM +0200, Jan Kiszka wrote:
>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>
>> The PVU allows to define a limited set of mappings for incoming DMA
>> requests to the system memory. It is not a real IOMMU, thus hooked up
>> under the TI SoC bindings.
> 
> You still keep developing it on wrong, old kernel (or not using
> get_maintainers.pl, but this one seems too obvious so I assumed wrong
> kernel).

Explained elsewhere, will update the two subtly changed addresses in the
next round.

> 
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>> ---
>>  .../bindings/soc/ti/ti,am654-pvu.yaml         | 51 +++++++++++++++++++
>>  1 file changed, 51 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml b/Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml
>> new file mode 100644
>> index 000000000000..fd0f86fa27b0
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/soc/ti/ti,am654-pvu.yaml
>> @@ -0,0 +1,51 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +# Copyright (c) Siemens AG, 2024
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/soc/ti/ti,am654-pvu.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: TI AM654 Peripheral Virtualization Unit
>> +
>> +maintainers:
>> +  - Jan Kiszka <jan.kiszka@siemens.com>
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - ti,am654-pvu
>> +
>> +  reg:
>> +    minItems: 2
> 
> maxItems instead.

Can change, but maybe use the chance to explain to me why "maxItems" and
why also "instead".

> 
>> +
>> +  reg-names:
>> +    items:
>> +      - const: cfg
>> +      - const: tlbif
>> +
>> +  interrupts:
>> +    items:
>> +      - description: fault interrupt
>> +
>> +  interrupt-names:
>> +    items:
>> +      - const: pvu
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - interrupts
>> +  - interrupt-names
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    ti-pvu@30f80000 {
> 
> Node names should be generic. See also an explanation and list of
> examples (not exhaustive) in DT specification:
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
> 
> for sure "ti" is not generic. pvu is the device name.

No problem - which one do you propose for this type of device?

Thanks,
Jan

-- 
Siemens AG, Technology
Linux Expert Center

Re: [PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Krzysztof Kozlowski]

On 27/08/2024 11:22, Jan Kiszka wrote:
> On 27.08.24 08:37, Krzysztof Kozlowski wrote:
>> On Mon, Aug 26, 2024 at 11:50:04PM +0200, Jan Kiszka wrote:
>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>
>>> Describe also the VMAP registers which are needed in order to make use
>>> of the PVU with this PCI host. Furthermore, permit to specify a
>>> restricted DMA pool by phandle.
>>
>> That's an ABI break without explanation why it is necessary.
>>
> 
> It is needed in order to support the PVU, as written above.

Above say only that you want a new feature and that's not really
suitable explanation for ABI break, because answer to this is: add new
feature without breaking existing users. But maybe there is a bug or
something does not work or never work or there are no users, don't know.

> 
> Previous versions of this binding likely didn't consider this use case
> and therefore didn't describe all registers associated with the hardware.
> 
> BTW, if you see a way to add the required registers without breaking
> more than needed, I'm all ears. At least the kernel driver will continue
> to work with older DTs when you disable PVU support or do not add a DMA
> pool to the DT.

If there is no ABI break, because driver still handles correctly old
DTB, then mention it in the commit msg.

Best regards,
Krzysztof

Re: [PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Jan Kiszka]

On 27.08.24 11:29, Krzysztof Kozlowski wrote:
> On 27/08/2024 11:22, Jan Kiszka wrote:
>> On 27.08.24 08:37, Krzysztof Kozlowski wrote:
>>> On Mon, Aug 26, 2024 at 11:50:04PM +0200, Jan Kiszka wrote:
>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>
>>>> Describe also the VMAP registers which are needed in order to make use
>>>> of the PVU with this PCI host. Furthermore, permit to specify a
>>>> restricted DMA pool by phandle.
>>>
>>> That's an ABI break without explanation why it is necessary.
>>>
>>
>> It is needed in order to support the PVU, as written above.
> 
> Above say only that you want a new feature and that's not really
> suitable explanation for ABI break, because answer to this is: add new
> feature without breaking existing users. But maybe there is a bug or
> something does not work or never work or there are no users, don't know.
> 
>>
>> Previous versions of this binding likely didn't consider this use case
>> and therefore didn't describe all registers associated with the hardware.
>>
>> BTW, if you see a way to add the required registers without breaking
>> more than needed, I'm all ears. At least the kernel driver will continue
>> to work with older DTs when you disable PVU support or do not add a DMA
>> pool to the DT.
> 
> If there is no ABI break, because driver still handles correctly old
> DTB, then mention it in the commit msg.

Well, this is strictly spoken not a topic for this commit because this
one should have no clue about what drivers do with DTs according to this
binding. But I can put a hint and go into details in the driver patch.

Jan

-- 
Siemens AG, Technology
Linux Expert Center

Re: [PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Siddharth Vadapalli]

On Tue, Aug 27, 2024 at 11:32:02AM +0200, Jan Kiszka wrote:
> On 27.08.24 11:29, Krzysztof Kozlowski wrote:
> > On 27/08/2024 11:22, Jan Kiszka wrote:
> >> On 27.08.24 08:37, Krzysztof Kozlowski wrote:
> >>> On Mon, Aug 26, 2024 at 11:50:04PM +0200, Jan Kiszka wrote:
> >>>> From: Jan Kiszka <jan.kiszka@siemens.com>
> >>>>
> >>>> Describe also the VMAP registers which are needed in order to make use
> >>>> of the PVU with this PCI host. Furthermore, permit to specify a
> >>>> restricted DMA pool by phandle.
> >>>
> >>> That's an ABI break without explanation why it is necessary.
> >>>
> >>
> >> It is needed in order to support the PVU, as written above.
> > 
> > Above say only that you want a new feature and that's not really
> > suitable explanation for ABI break, because answer to this is: add new
> > feature without breaking existing users. But maybe there is a bug or
> > something does not work or never work or there are no users, don't know.
> > 
> >>
> >> Previous versions of this binding likely didn't consider this use case
> >> and therefore didn't describe all registers associated with the hardware.
> >>
> >> BTW, if you see a way to add the required registers without breaking
> >> more than needed, I'm all ears. At least the kernel driver will continue
> >> to work with older DTs when you disable PVU support or do not add a DMA
> >> pool to the DT.
> > 
> > If there is no ABI break, because driver still handles correctly old
> > DTB, then mention it in the commit msg.
> 
> Well, this is strictly spoken not a topic for this commit because this
> one should have no clue about what drivers do with DTs according to this
> binding. But I can put a hint and go into details in the driver patch.

Based on the Techincal Reference Manual for AM654 and the driver
implementation in patch 5/6, I think that the following might be one way
of hinting that ABI won't break:

The PVU on the AM65 SoC is capable of restricting DMA from PCIe devices to
specific regions of host memory. Add the optional property "memory-regions"
to point to such regions of memory when PVU is used. Since the PVU deals
with system physical addresses, utilizing the PVU with PCIe devices also
requires setting up the VMAP registers to map the Requester ID of the
PCIe device to the CBA Virtual ID, which in turn is mapped to the system
physical address. Hence, describe the VMAP registers which are optionally
configured whenever PVU is used for PCIe.

Regards,
Siddharth.

Re: [PATCH v2 1/6] dt-bindings: soc: ti: Add AM65 peripheral virtualization unit

[Krzysztof Kozlowski]

On 27/08/2024 11:29, Jan Kiszka wrote:
>>> +  reg:
>>> +    minItems: 2
>>
>> maxItems instead.
> 
> Can change, but maybe use the chance to explain to me why "maxItems" and
> why also "instead".

because minItems is not constrained. maxItem is and, in case of lack of
minItems, it implies minItems.

> 
>>
>>> +
>>> +  reg-names:
>>> +    items:
>>> +      - const: cfg
>>> +      - const: tlbif
>>> +
>>> +  interrupts:
>>> +    items:
>>> +      - description: fault interrupt
>>> +
>>> +  interrupt-names:
>>> +    items:
>>> +      - const: pvu
>>> +
>>> +required:
>>> +  - compatible
>>> +  - reg
>>> +  - interrupts
>>> +  - interrupt-names
>>> +
>>> +additionalProperties: false
>>> +
>>> +examples:
>>> +  - |
>>> +    ti-pvu@30f80000 {
>>
>> Node names should be generic. See also an explanation and list of
>> examples (not exhaustive) in DT specification:
>> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
>>
>> for sure "ti" is not generic. pvu is the device name.
> 
> No problem - which one do you propose for this type of device?

iommu, but if this is not suitable, at pvu could stay. Just the first
'ti-' does not sound right in that case.

Best regards,
Krzysztof

Re: [PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Jan Kiszka]

On 27.08.24 08:37, Krzysztof Kozlowski wrote:
> On Mon, Aug 26, 2024 at 11:50:04PM +0200, Jan Kiszka wrote:
>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>
>> Describe also the VMAP registers which are needed in order to make use
>> of the PVU with this PCI host. Furthermore, permit to specify a
>> restricted DMA pool by phandle.
> 
> That's an ABI break without explanation why it is necessary.
> 
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>> ---
>>  .../devicetree/bindings/pci/ti,am65-pci-host.yaml   | 13 ++++++++++---
>>  1 file changed, 10 insertions(+), 3 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> index 0a9d10532cc8..72f78f21e1e8 100644
>> --- a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> +++ b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> @@ -20,7 +20,7 @@ properties:
>>        - ti,keystone-pcie
>>  
>>    reg:
>> -    maxItems: 4
>> +    maxItems: 6
>>  
>>    reg-names:
>>      items:
>> @@ -28,6 +28,8 @@ properties:
>>        - const: dbics
>>        - const: config
>>        - const: atu
>> +      - const: vmap_lp
>> +      - const: vmap_hp
>>  
>>    interrupts:
>>      maxItems: 1
>> @@ -69,6 +71,9 @@ properties:
>>      items:
>>        pattern: '^pcie-phy[0-1]$'
>>  
>> +  memory-region:
>> +    description: phandle to restricted DMA pool to be used for all devices behind this controller
> 
> missing constraints, maxItems
> 

In fact, that was intentional: There could also be multiple region
specified here. The driver already handles this.

Jan

-- 
Siemens AG, Technology
Linux Expert Center

Re: [PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Jan Kiszka]

On 27.08.24 12:06, Siddharth Vadapalli wrote:
> On Tue, Aug 27, 2024 at 11:32:02AM +0200, Jan Kiszka wrote:
>> On 27.08.24 11:29, Krzysztof Kozlowski wrote:
>>> On 27/08/2024 11:22, Jan Kiszka wrote:
>>>> On 27.08.24 08:37, Krzysztof Kozlowski wrote:
>>>>> On Mon, Aug 26, 2024 at 11:50:04PM +0200, Jan Kiszka wrote:
>>>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>>>
>>>>>> Describe also the VMAP registers which are needed in order to make use
>>>>>> of the PVU with this PCI host. Furthermore, permit to specify a
>>>>>> restricted DMA pool by phandle.
>>>>>
>>>>> That's an ABI break without explanation why it is necessary.
>>>>>
>>>>
>>>> It is needed in order to support the PVU, as written above.
>>>
>>> Above say only that you want a new feature and that's not really
>>> suitable explanation for ABI break, because answer to this is: add new
>>> feature without breaking existing users. But maybe there is a bug or
>>> something does not work or never work or there are no users, don't know.
>>>
>>>>
>>>> Previous versions of this binding likely didn't consider this use case
>>>> and therefore didn't describe all registers associated with the hardware.
>>>>
>>>> BTW, if you see a way to add the required registers without breaking
>>>> more than needed, I'm all ears. At least the kernel driver will continue
>>>> to work with older DTs when you disable PVU support or do not add a DMA
>>>> pool to the DT.
>>>
>>> If there is no ABI break, because driver still handles correctly old
>>> DTB, then mention it in the commit msg.
>>
>> Well, this is strictly spoken not a topic for this commit because this
>> one should have no clue about what drivers do with DTs according to this
>> binding. But I can put a hint and go into details in the driver patch.
> 
> Based on the Techincal Reference Manual for AM654 and the driver
> implementation in patch 5/6, I think that the following might be one way
> of hinting that ABI won't break:
> 
> The PVU on the AM65 SoC is capable of restricting DMA from PCIe devices to
> specific regions of host memory. Add the optional property "memory-regions"
> to point to such regions of memory when PVU is used. Since the PVU deals
> with system physical addresses, utilizing the PVU with PCIe devices also
> requires setting up the VMAP registers to map the Requester ID of the
> PCIe device to the CBA Virtual ID, which in turn is mapped to the system
> physical address. Hence, describe the VMAP registers which are optionally
> configured whenever PVU is used for PCIe.

Thanks, will reuse this!

Additionally, we should then likely do

  reg:
    minItems: 4
    maxItems: 6

to underline that the old form is still fine. Do I need to do anything
to reg-names then as well?

Jan

-- 
Siemens AG, Technology
Linux Expert Center

Re: [PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Krzysztof Kozlowski]

On 27/08/2024 12:46, Jan Kiszka wrote:
> On 27.08.24 12:06, Siddharth Vadapalli wrote:
>> On Tue, Aug 27, 2024 at 11:32:02AM +0200, Jan Kiszka wrote:
>>> On 27.08.24 11:29, Krzysztof Kozlowski wrote:
>>>> On 27/08/2024 11:22, Jan Kiszka wrote:
>>>>> On 27.08.24 08:37, Krzysztof Kozlowski wrote:
>>>>>> On Mon, Aug 26, 2024 at 11:50:04PM +0200, Jan Kiszka wrote:
>>>>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>>>>
>>>>>>> Describe also the VMAP registers which are needed in order to make use
>>>>>>> of the PVU with this PCI host. Furthermore, permit to specify a
>>>>>>> restricted DMA pool by phandle.
>>>>>>
>>>>>> That's an ABI break without explanation why it is necessary.
>>>>>>
>>>>>
>>>>> It is needed in order to support the PVU, as written above.
>>>>
>>>> Above say only that you want a new feature and that's not really
>>>> suitable explanation for ABI break, because answer to this is: add new
>>>> feature without breaking existing users. But maybe there is a bug or
>>>> something does not work or never work or there are no users, don't know.
>>>>
>>>>>
>>>>> Previous versions of this binding likely didn't consider this use case
>>>>> and therefore didn't describe all registers associated with the hardware.
>>>>>
>>>>> BTW, if you see a way to add the required registers without breaking
>>>>> more than needed, I'm all ears. At least the kernel driver will continue
>>>>> to work with older DTs when you disable PVU support or do not add a DMA
>>>>> pool to the DT.
>>>>
>>>> If there is no ABI break, because driver still handles correctly old
>>>> DTB, then mention it in the commit msg.
>>>
>>> Well, this is strictly spoken not a topic for this commit because this
>>> one should have no clue about what drivers do with DTs according to this
>>> binding. But I can put a hint and go into details in the driver patch.
>>
>> Based on the Techincal Reference Manual for AM654 and the driver
>> implementation in patch 5/6, I think that the following might be one way
>> of hinting that ABI won't break:
>>
>> The PVU on the AM65 SoC is capable of restricting DMA from PCIe devices to
>> specific regions of host memory. Add the optional property "memory-regions"
>> to point to such regions of memory when PVU is used. Since the PVU deals
>> with system physical addresses, utilizing the PVU with PCIe devices also
>> requires setting up the VMAP registers to map the Requester ID of the
>> PCIe device to the CBA Virtual ID, which in turn is mapped to the system
>> physical address. Hence, describe the VMAP registers which are optionally
>> configured whenever PVU is used for PCIe.
> 
> Thanks, will reuse this!
> 
> Additionally, we should then likely do
> 
>   reg:
>     minItems: 4
>     maxItems: 6
> 
> to underline that the old form is still fine. Do I need to do anything
> to reg-names then as well?

They need "minItems: 4".

Best regards,
Krzysztof

Re: [PATCH v2 3/6] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Krzysztof Kozlowski]

On 27/08/2024 12:44, Jan Kiszka wrote:
>>>      maxItems: 1
>>> @@ -69,6 +71,9 @@ properties:
>>>      items:
>>>        pattern: '^pcie-phy[0-1]$'
>>>  
>>> +  memory-region:
>>> +    description: phandle to restricted DMA pool to be used for all devices behind this controller
>>
>> missing constraints, maxItems
>>
> 
> In fact, that was intentional: There could also be multiple region
> specified here. The driver already handles this.

Then list the items with description and minItems: 1.


Best regards,
Krzysztof