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Merge branches 'arm/allwinner', 'arm/mediatek', 'arm/renesas', 'arm/t…
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…egra', 'arm/qcom', 'arm/smmu', 'ppc/pamu', 'x86/amd', 'x86/vt-d' and 'core' into next
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joergroedel committed Oct 7, 2020
11 parents 549738f + 03c7b78 + 3c21356 + d714aaa + 21d3c04 + 7aaf0b0 + 0dd4ce6 + ce433d0 + 54ce12e + c40aaaa + 6278eec commit 7e3c388
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2 changes: 2 additions & 0 deletions Documentation/devicetree/bindings/iommu/mediatek,iommu.txt
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Expand Up @@ -61,6 +61,7 @@ Required properties:
"mediatek,mt6779-m4u" for mt6779 which uses generation two m4u HW.
"mediatek,mt7623-m4u", "mediatek,mt2701-m4u" for mt7623 which uses
generation one m4u HW.
"mediatek,mt8167-m4u" for mt8167 which uses generation two m4u HW.
"mediatek,mt8173-m4u" for mt8173 which uses generation two m4u HW.
"mediatek,mt8183-m4u" for mt8183 which uses generation two m4u HW.
- reg : m4u register base and size.
Expand All @@ -80,6 +81,7 @@ Required properties:
dt-binding/memory/mt2701-larb-port.h for mt2701, mt7623
dt-binding/memory/mt2712-larb-port.h for mt2712,
dt-binding/memory/mt6779-larb-port.h for mt6779,
dt-binding/memory/mt8167-larb-port.h for mt8167,
dt-binding/memory/mt8173-larb-port.h for mt8173, and
dt-binding/memory/mt8183-larb-port.h for mt8183.

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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@ properties:
- items:
- enum:
- renesas,ipmmu-r8a73a4 # R-Mobile APE6
- renesas,ipmmu-r8a7742 # RZ/G1H
- renesas,ipmmu-r8a7743 # RZ/G1M
- renesas,ipmmu-r8a7744 # RZ/G1N
- renesas,ipmmu-r8a7745 # RZ/G1E
Expand All @@ -32,8 +33,8 @@ properties:
- enum:
- renesas,ipmmu-r8a774a1 # RZ/G2M
- renesas,ipmmu-r8a774b1 # RZ/G2N
- renesas,ipmmu-r8a774e1 # RZ/G2H
- renesas,ipmmu-r8a774c0 # RZ/G2E
- renesas,ipmmu-r8a774e1 # RZ/G2H
- renesas,ipmmu-r8a7795 # R-Car H3
- renesas,ipmmu-r8a7796 # R-Car M3-W
- renesas,ipmmu-r8a77961 # R-Car M3-W+
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209 changes: 209 additions & 0 deletions Documentation/userspace-api/iommu.rst
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@@ -0,0 +1,209 @@
.. SPDX-License-Identifier: GPL-2.0
.. iommu:
=====================================
IOMMU Userspace API
=====================================

IOMMU UAPI is used for virtualization cases where communications are
needed between physical and virtual IOMMU drivers. For baremetal
usage, the IOMMU is a system device which does not need to communicate
with userspace directly.

The primary use cases are guest Shared Virtual Address (SVA) and
guest IO virtual address (IOVA), wherein the vIOMMU implementation
relies on the physical IOMMU and for this reason requires interactions
with the host driver.

.. contents:: :local:

Functionalities
===============
Communications of user and kernel involve both directions. The
supported user-kernel APIs are as follows:

1. Bind/Unbind guest PASID (e.g. Intel VT-d)
2. Bind/Unbind guest PASID table (e.g. ARM SMMU)
3. Invalidate IOMMU caches upon guest requests
4. Report errors to the guest and serve page requests

Requirements
============
The IOMMU UAPIs are generic and extensible to meet the following
requirements:

1. Emulated and para-virtualised vIOMMUs
2. Multiple vendors (Intel VT-d, ARM SMMU, etc.)
3. Extensions to the UAPI shall not break existing userspace

Interfaces
==========
Although the data structures defined in IOMMU UAPI are self-contained,
there are no user API functions introduced. Instead, IOMMU UAPI is
designed to work with existing user driver frameworks such as VFIO.

Extension Rules & Precautions
-----------------------------
When IOMMU UAPI gets extended, the data structures can *only* be
modified in two ways:

1. Adding new fields by re-purposing the padding[] field. No size change.
2. Adding new union members at the end. May increase the structure sizes.

No new fields can be added *after* the variable sized union in that it
will break backward compatibility when offset moves. A new flag must
be introduced whenever a change affects the structure using either
method. The IOMMU driver processes the data based on flags which
ensures backward compatibility.

Version field is only reserved for the unlikely event of UAPI upgrade
at its entirety.

It's *always* the caller's responsibility to indicate the size of the
structure passed by setting argsz appropriately.
Though at the same time, argsz is user provided data which is not
trusted. The argsz field allows the user app to indicate how much data
it is providing; it's still the kernel's responsibility to validate
whether it's correct and sufficient for the requested operation.

Compatibility Checking
----------------------
When IOMMU UAPI extension results in some structure size increase,
IOMMU UAPI code shall handle the following cases:

1. User and kernel has exact size match
2. An older user with older kernel header (smaller UAPI size) running on a
newer kernel (larger UAPI size)
3. A newer user with newer kernel header (larger UAPI size) running
on an older kernel.
4. A malicious/misbehaving user passing illegal/invalid size but within
range. The data may contain garbage.

Feature Checking
----------------
While launching a guest with vIOMMU, it is strongly advised to check
the compatibility upfront, as some subsequent errors happening during
vIOMMU operation, such as cache invalidation failures cannot be nicely
escalated to the guest due to IOMMU specifications. This can lead to
catastrophic failures for the users.

User applications such as QEMU are expected to import kernel UAPI
headers. Backward compatibility is supported per feature flags.
For example, an older QEMU (with older kernel header) can run on newer
kernel. Newer QEMU (with new kernel header) may refuse to initialize
on an older kernel if new feature flags are not supported by older
kernel. Simply recompiling existing code with newer kernel header should
not be an issue in that only existing flags are used.

IOMMU vendor driver should report the below features to IOMMU UAPI
consumers (e.g. via VFIO).

1. IOMMU_NESTING_FEAT_SYSWIDE_PASID
2. IOMMU_NESTING_FEAT_BIND_PGTBL
3. IOMMU_NESTING_FEAT_BIND_PASID_TABLE
4. IOMMU_NESTING_FEAT_CACHE_INVLD
5. IOMMU_NESTING_FEAT_PAGE_REQUEST

Take VFIO as example, upon request from VFIO userspace (e.g. QEMU),
VFIO kernel code shall query IOMMU vendor driver for the support of
the above features. Query result can then be reported back to the
userspace caller. Details can be found in
Documentation/driver-api/vfio.rst.


Data Passing Example with VFIO
------------------------------
As the ubiquitous userspace driver framework, VFIO is already IOMMU
aware and shares many key concepts such as device model, group, and
protection domain. Other user driver frameworks can also be extended
to support IOMMU UAPI but it is outside the scope of this document.

In this tight-knit VFIO-IOMMU interface, the ultimate consumer of the
IOMMU UAPI data is the host IOMMU driver. VFIO facilitates user-kernel
transport, capability checking, security, and life cycle management of
process address space ID (PASID).

VFIO layer conveys the data structures down to the IOMMU driver. It
follows the pattern below::

struct {
__u32 argsz;
__u32 flags;
__u8 data[];
};

Here data[] contains the IOMMU UAPI data structures. VFIO has the
freedom to bundle the data as well as parse data size based on its own flags.

In order to determine the size and feature set of the user data, argsz
and flags (or the equivalent) are also embedded in the IOMMU UAPI data
structures.

A "__u32 argsz" field is *always* at the beginning of each structure.

For example:
::

struct iommu_cache_invalidate_info {
__u32 argsz;
#define IOMMU_CACHE_INVALIDATE_INFO_VERSION_1 1
__u32 version;
/* IOMMU paging structure cache */
#define IOMMU_CACHE_INV_TYPE_IOTLB (1 << 0) /* IOMMU IOTLB */
#define IOMMU_CACHE_INV_TYPE_DEV_IOTLB (1 << 1) /* Device IOTLB */
#define IOMMU_CACHE_INV_TYPE_PASID (1 << 2) /* PASID cache */
#define IOMMU_CACHE_INV_TYPE_NR (3)
__u8 cache;
__u8 granularity;
__u8 padding[6];
union {
struct iommu_inv_pasid_info pasid_info;
struct iommu_inv_addr_info addr_info;
} granu;
};

VFIO is responsible for checking its own argsz and flags. It then
invokes appropriate IOMMU UAPI functions. The user pointers are passed
to the IOMMU layer for further processing. The responsibilities are
divided as follows:

- Generic IOMMU layer checks argsz range based on UAPI data in the
current kernel version.

- Generic IOMMU layer checks content of the UAPI data for non-zero
reserved bits in flags, padding fields, and unsupported version.
This is to ensure not breaking userspace in the future when these
fields or flags are used.

- Vendor IOMMU driver checks argsz based on vendor flags. UAPI data
is consumed based on flags. Vendor driver has access to
unadulterated argsz value in case of vendor specific future
extensions. Currently, it does not perform the copy_from_user()
itself. A __user pointer can be provided in some future scenarios
where there's vendor data outside of the structure definition.

IOMMU code treats UAPI data in two categories:

- structure contains vendor data
(Example: iommu_uapi_cache_invalidate())

- structure contains only generic data
(Example: iommu_uapi_sva_bind_gpasid())



Sharing UAPI with in-kernel users
---------------------------------
For UAPIs that are shared with in-kernel users, a wrapper function is
provided to distinguish the callers. For example,

Userspace caller ::

int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain,
struct device *dev,
void __user *udata)

In-kernel caller ::

int iommu_sva_unbind_gpasid(struct iommu_domain *domain,
struct device *dev, ioasid_t ioasid);
4 changes: 2 additions & 2 deletions MAINTAINERS
Original file line number Diff line number Diff line change
Expand Up @@ -1506,8 +1506,7 @@ L: [email protected] (moderated for non-subscribers)
S: Maintained
F: Documentation/devicetree/bindings/iommu/arm,smmu*
F: drivers/iommu/arm/
F: drivers/iommu/io-pgtable-arm-v7s.c
F: drivers/iommu/io-pgtable-arm.c
F: drivers/iommu/io-pgtable-arm*

ARM SUB-ARCHITECTURES
L: [email protected] (moderated for non-subscribers)
Expand Down Expand Up @@ -9120,6 +9119,7 @@ L: [email protected]
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git
F: Documentation/devicetree/bindings/iommu/
F: Documentation/userspace-api/iommu.rst
F: drivers/iommu/
F: include/linux/iommu.h
F: include/linux/iova.h
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48 changes: 48 additions & 0 deletions arch/arm/boot/dts/r8a7742.dtsi
Original file line number Diff line number Diff line change
Expand Up @@ -386,6 +386,54 @@
#thermal-sensor-cells = <0>;
};

ipmmu_sy0: iommu@e6280000 {
compatible = "renesas,ipmmu-r8a7742",
"renesas,ipmmu-vmsa";
reg = <0 0xe6280000 0 0x1000>;
interrupts = <GIC_SPI 223 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 224 IRQ_TYPE_LEVEL_HIGH>;
#iommu-cells = <1>;
status = "disabled";
};

ipmmu_sy1: iommu@e6290000 {
compatible = "renesas,ipmmu-r8a7742",
"renesas,ipmmu-vmsa";
reg = <0 0xe6290000 0 0x1000>;
interrupts = <GIC_SPI 225 IRQ_TYPE_LEVEL_HIGH>;
#iommu-cells = <1>;
status = "disabled";
};

ipmmu_ds: iommu@e6740000 {
compatible = "renesas,ipmmu-r8a7742",
"renesas,ipmmu-vmsa";
reg = <0 0xe6740000 0 0x1000>;
interrupts = <GIC_SPI 198 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 199 IRQ_TYPE_LEVEL_HIGH>;
#iommu-cells = <1>;
status = "disabled";
};

ipmmu_mp: iommu@ec680000 {
compatible = "renesas,ipmmu-r8a7742",
"renesas,ipmmu-vmsa";
reg = <0 0xec680000 0 0x1000>;
interrupts = <GIC_SPI 226 IRQ_TYPE_LEVEL_HIGH>;
#iommu-cells = <1>;
status = "disabled";
};

ipmmu_mx: iommu@fe951000 {
compatible = "renesas,ipmmu-r8a7742",
"renesas,ipmmu-vmsa";
reg = <0 0xfe951000 0 0x1000>;
interrupts = <GIC_SPI 222 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 221 IRQ_TYPE_LEVEL_HIGH>;
#iommu-cells = <1>;
status = "disabled";
};

icram0: sram@e63a0000 {
compatible = "mmio-sram";
reg = <0 0xe63a0000 0 0x12000>;
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1 change: 1 addition & 0 deletions arch/arm64/include/asm/barrier.h
Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,7 @@
#define rmb() dsb(ld)
#define wmb() dsb(st)

#define dma_mb() dmb(osh)
#define dma_rmb() dmb(oshld)
#define dma_wmb() dmb(oshst)

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1 change: 1 addition & 0 deletions arch/arm64/include/asm/io.h
Original file line number Diff line number Diff line change
Expand Up @@ -110,6 +110,7 @@ static inline u64 __raw_readq(const volatile void __iomem *addr)

#define __io_par(v) __iormb(v)
#define __iowmb() dma_wmb()
#define __iomb() dma_mb()

/*
* Relaxed I/O memory access primitives. These follow the Device memory
Expand Down
3 changes: 3 additions & 0 deletions arch/arm64/include/asm/mmu.h
Original file line number Diff line number Diff line change
Expand Up @@ -17,11 +17,14 @@

#ifndef __ASSEMBLY__

#include <linux/refcount.h>

typedef struct {
atomic64_t id;
#ifdef CONFIG_COMPAT
void *sigpage;
#endif
refcount_t pinned;
void *vdso;
unsigned long flags;
} mm_context_t;
Expand Down
11 changes: 10 additions & 1 deletion arch/arm64/include/asm/mmu_context.h
Original file line number Diff line number Diff line change
Expand Up @@ -177,7 +177,13 @@ static inline void cpu_replace_ttbr1(pgd_t *pgdp)
#define destroy_context(mm) do { } while(0)
void check_and_switch_context(struct mm_struct *mm);

#define init_new_context(tsk,mm) ({ atomic64_set(&(mm)->context.id, 0); 0; })
static inline int
init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
atomic64_set(&mm->context.id, 0);
refcount_set(&mm->context.pinned, 0);
return 0;
}

#ifdef CONFIG_ARM64_SW_TTBR0_PAN
static inline void update_saved_ttbr0(struct task_struct *tsk,
Expand Down Expand Up @@ -248,6 +254,9 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next,
void verify_cpu_asid_bits(void);
void post_ttbr_update_workaround(void);

unsigned long arm64_mm_context_get(struct mm_struct *mm);
void arm64_mm_context_put(struct mm_struct *mm);

#endif /* !__ASSEMBLY__ */

#endif /* !__ASM_MMU_CONTEXT_H */
1 change: 1 addition & 0 deletions arch/arm64/kernel/cpufeature.c
Original file line number Diff line number Diff line change
Expand Up @@ -1111,6 +1111,7 @@ u64 read_sanitised_ftr_reg(u32 id)
return 0;
return regp->sys_val;
}
EXPORT_SYMBOL_GPL(read_sanitised_ftr_reg);

#define read_sysreg_case(r) \
case r: return read_sysreg_s(r)
Expand Down
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