From: Lu Baolu <baolu.lu@linux.intel.com>
To: Jean-Philippe Brucker <jean-philippe@linaro.org>,
iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org
Cc: fenghua.yu@intel.com, catalin.marinas@arm.com,
robin.murphy@arm.com, hch@infradead.org, zhengxiang9@huawei.com,
zhangfei.gao@linaro.org, will@kernel.org
Subject: Re: [PATCH v8 03/12] iommu/sva: Add PASID helpers
Date: Fri, 19 Jun 2020 15:37:30 +0800 [thread overview]
Message-ID: <e2363732-e891-8263-16f1-c60b70d46ebc@linux.intel.com> (raw)
In-Reply-To: <20200618155125.1548969-4-jean-philippe@linaro.org>
Hi Jean,
On 2020/6/18 23:51, Jean-Philippe Brucker wrote:
> Let IOMMU drivers allocate a single PASID per mm. Store the mm in the
> IOASID set to allow refcounting and searching mm by PASID, when handling
> an I/O page fault.
>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Best regards,
baolu
> ---
> v7->v8: rename to IOMMU_SVA_LIB (Lu Baolu)
> ---
> drivers/iommu/Kconfig | 5 +++
> drivers/iommu/Makefile | 1 +
> drivers/iommu/iommu-sva-lib.h | 15 +++++++
> drivers/iommu/iommu-sva-lib.c | 85 +++++++++++++++++++++++++++++++++++
> 4 files changed, 106 insertions(+)
> create mode 100644 drivers/iommu/iommu-sva-lib.h
> create mode 100644 drivers/iommu/iommu-sva-lib.c
>
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index b510f67dfa499..74a10e7a8d082 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -102,6 +102,11 @@ config IOMMU_DMA
> select IRQ_MSI_IOMMU
> select NEED_SG_DMA_LENGTH
>
> +# Shared Virtual Addressing library
> +config IOMMU_SVA_LIB
> + bool
> + select IOASID
> +
> config FSL_PAMU
> bool "Freescale IOMMU support"
> depends on PCI
> diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
> index 342190196dfb0..0fe5a7f9bc69c 100644
> --- a/drivers/iommu/Makefile
> +++ b/drivers/iommu/Makefile
> @@ -38,3 +38,4 @@ obj-$(CONFIG_S390_IOMMU) += s390-iommu.o
> obj-$(CONFIG_QCOM_IOMMU) += qcom_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
> diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
> new file mode 100644
> index 0000000000000..b40990aef3fde
> --- /dev/null
> +++ b/drivers/iommu/iommu-sva-lib.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * SVA library for IOMMU drivers
> + */
> +#ifndef _IOMMU_SVA_LIB_H
> +#define _IOMMU_SVA_LIB_H
> +
> +#include <linux/ioasid.h>
> +#include <linux/mm_types.h>
> +
> +int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);
> +void iommu_sva_free_pasid(struct mm_struct *mm);
> +struct mm_struct *iommu_sva_find(ioasid_t pasid);
> +
> +#endif /* _IOMMU_SVA_LIB_H */
> diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
> new file mode 100644
> index 0000000000000..db7e6c104d6b0
> --- /dev/null
> +++ b/drivers/iommu/iommu-sva-lib.c
> @@ -0,0 +1,85 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Helpers for IOMMU drivers implementing SVA
> + */
> +#include <linux/mutex.h>
> +#include <linux/sched/mm.h>
> +
> +#include "iommu-sva-lib.h"
> +
> +static DEFINE_MUTEX(iommu_sva_lock);
> +static DECLARE_IOASID_SET(iommu_sva_pasid);
> +
> +/**
> + * iommu_sva_alloc_pasid - Allocate a PASID for the mm
> + * @mm: the mm
> + * @min: minimum PASID value (inclusive)
> + * @max: maximum PASID value (inclusive)
> + *
> + * Try to allocate a PASID for this mm, or take a reference to the existing one
> + * provided it fits within the [min, max] range. On success the PASID is
> + * available in mm->pasid, and must be released with iommu_sva_free_pasid().
> + *
> + * Returns 0 on success and < 0 on error.
> + */
> +int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
> +{
> + int ret = 0;
> + ioasid_t pasid;
> +
> + if (min == INVALID_IOASID || max == INVALID_IOASID ||
> + min == 0 || max < min)
> + return -EINVAL;
> +
> + mutex_lock(&iommu_sva_lock);
> + if (mm->pasid) {
> + if (mm->pasid >= min && mm->pasid <= max)
> + ioasid_get(mm->pasid);
> + else
> + ret = -EOVERFLOW;
> + } else {
> + pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm);
> + if (pasid == INVALID_IOASID)
> + ret = -ENOMEM;
> + else
> + mm->pasid = pasid;
> + }
> + mutex_unlock(&iommu_sva_lock);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);
> +
> +/**
> + * iommu_sva_free_pasid - Release the mm's PASID
> + * @mm: the mm.
> + *
> + * Drop one reference to a PASID allocated with iommu_sva_alloc_pasid()
> + */
> +void iommu_sva_free_pasid(struct mm_struct *mm)
> +{
> + mutex_lock(&iommu_sva_lock);
> + if (ioasid_put(mm->pasid))
> + mm->pasid = 0;
> + mutex_unlock(&iommu_sva_lock);
> +}
> +EXPORT_SYMBOL_GPL(iommu_sva_free_pasid);
> +
> +/* ioasid wants a void * argument */
> +static bool __mmget_not_zero(void *mm)
> +{
> + return mmget_not_zero(mm);
> +}
> +
> +/**
> + * iommu_sva_find() - Find mm associated to the given PASID
> + * @pasid: Process Address Space ID assigned to the mm
> + *
> + * On success a reference to the mm is taken, and must be released with mmput().
> + *
> + * Returns the mm corresponding to this PASID, or an error if not found.
> + */
> +struct mm_struct *iommu_sva_find(ioasid_t pasid)
> +{
> + return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
> +}
> +EXPORT_SYMBOL_GPL(iommu_sva_find);
>
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-06-19 7:37 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-18 15:51 [PATCH v8 00/12] iommu: Shared Virtual Addressing for SMMUv3 (PT sharing part) Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 01/12] mm: Define pasid in mm Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 02/12] iommu/ioasid: Add ioasid references Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 03/12] iommu/sva: Add PASID helpers Jean-Philippe Brucker
2020-06-19 7:37 ` Lu Baolu [this message]
2020-06-18 15:51 ` [PATCH v8 04/12] arm64: mm: Pin down ASIDs for sharing mm with devices Jean-Philippe Brucker
2020-07-13 15:46 ` Will Deacon
2020-07-16 15:44 ` Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 05/12] iommu/io-pgtable-arm: Move some definitions to a header Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 06/12] arm64: cpufeature: Export symbol read_sanitised_ftr_reg() Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 07/12] iommu/arm-smmu-v3: Share process page tables Jean-Philippe Brucker
2020-07-13 20:22 ` Will Deacon
2020-07-16 15:45 ` Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 08/12] iommu/arm-smmu-v3: Seize private ASID Jean-Philippe Brucker
2020-07-06 12:40 ` Xiang Zheng
2020-07-06 16:07 ` Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 09/12] iommu/arm-smmu-v3: Check for SVA features Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 10/12] iommu/arm-smmu-v3: Add SVA device feature Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 11/12] iommu/arm-smmu-v3: Implement iommu_sva_bind/unbind() Jean-Philippe Brucker
2020-06-18 15:51 ` [PATCH v8 12/12] iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops Jean-Philippe Brucker
2020-07-09 9:39 ` [PATCH v8 00/12] iommu: Shared Virtual Addressing for SMMUv3 (PT sharing part) Jean-Philippe Brucker
2020-07-20 11:11 ` Will Deacon
2020-07-20 15:39 ` Jean-Philippe Brucker
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=e2363732-e891-8263-16f1-c60b70d46ebc@linux.intel.com \
--to=baolu.lu@linux.intel.com \
--cc=catalin.marinas@arm.com \
--cc=fenghua.yu@intel.com \
--cc=hch@infradead.org \
--cc=iommu@lists.linux-foundation.org \
--cc=jean-philippe@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-mm@kvack.org \
--cc=robin.murphy@arm.com \
--cc=will@kernel.org \
--cc=zhangfei.gao@linaro.org \
--cc=zhengxiang9@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).