From: Lu Baolu <baolu.lu@linux.intel.com>
To: David Woodhouse <dwmw2@infradead.org>, Joerg Roedel <joro@8bytes.org>
Cc: iommu <iommu@lists.linux-foundation.org>
Subject: Re: [PATCH] iommu/vt-d: gracefully handle DMAR units with no supported address widths
Date: Fri, 25 Sep 2020 09:52:31 +0800 [thread overview]
Message-ID: <6872be84-2df5-e4a5-d656-64249dab88dd@linux.intel.com> (raw)
In-Reply-To: <549928db2de6532117f36c9c810373c14cf76f51.camel@infradead.org>
On 9/24/20 10:08 PM, David Woodhouse wrote:
> From: David Woodhouse <dwmw@amazon.co.uk>
>
> Instead of bailing out completely, such a unit can still be used for
> interrupt remapping.
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Best regards,
baolu
>
> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
> ---
> drivers/iommu/intel/dmar.c | 46 +++++++++++++++++++++++++-------------
> 1 file changed, 31 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
> index 93e6345f3414..4420a759f095 100644
> --- a/drivers/iommu/intel/dmar.c
> +++ b/drivers/iommu/intel/dmar.c
> @@ -1024,8 +1024,8 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
> {
> struct intel_iommu *iommu;
> u32 ver, sts;
> - int agaw = 0;
> - int msagaw = 0;
> + int agaw = -1;
> + int msagaw = -1;
> int err;
>
> if (!drhd->reg_base_addr) {
> @@ -1050,17 +1050,28 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
> }
>
> err = -EINVAL;
> - agaw = iommu_calculate_agaw(iommu);
> - if (agaw < 0) {
> - pr_err("Cannot get a valid agaw for iommu (seq_id = %d)\n",
> - iommu->seq_id);
> - goto err_unmap;
> - }
> - msagaw = iommu_calculate_max_sagaw(iommu);
> - if (msagaw < 0) {
> - pr_err("Cannot get a valid max agaw for iommu (seq_id = %d)\n",
> - iommu->seq_id);
> - goto err_unmap;
> + if (cap_sagaw(iommu->cap) == 0) {
> + pr_info("%s: No supported address widths. Not attempting DMA translation.\n",
> + iommu->name);
> + drhd->ignored = 1;
> + }
> +
> + if (!drhd->ignored) {
> + agaw = iommu_calculate_agaw(iommu);
> + if (agaw < 0) {
> + pr_err("Cannot get a valid agaw for iommu (seq_id = %d)\n",
> + iommu->seq_id);
> + drhd->ignored = 1;
> + }
> + }
> + if (!drhd->ignored) {
> + msagaw = iommu_calculate_max_sagaw(iommu);
> + if (msagaw < 0) {
> + pr_err("Cannot get a valid max agaw for iommu (seq_id = %d)\n",
> + iommu->seq_id);
> + drhd->ignored = 1;
> + agaw = -1;
> + }
> }
> iommu->agaw = agaw;
> iommu->msagaw = msagaw;
> @@ -1087,7 +1098,12 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
>
> raw_spin_lock_init(&iommu->register_lock);
>
> - if (intel_iommu_enabled) {
> + /*
> + * This is only for hotplug; at boot time intel_iommu_enabled won't
> + * be set yet. When intel_iommu_init() runs, it registers the units
> + * present at boot time, then sets intel_iommu_enabled.
> + */
> + if (intel_iommu_enabled && !drhd->ignored) {
> err = iommu_device_sysfs_add(&iommu->iommu, NULL,
> intel_iommu_groups,
> "%s", iommu->name);
> @@ -1117,7 +1133,7 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
>
> static void free_iommu(struct intel_iommu *iommu)
> {
> - if (intel_iommu_enabled) {
> + if (intel_iommu_enabled && iommu->iommu.ops) {
> iommu_device_unregister(&iommu->iommu);
> iommu_device_sysfs_remove(&iommu->iommu);
> }
>
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next prev parent reply other threads:[~2020-09-25 1:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-24 14:08 [PATCH] iommu/vt-d: gracefully handle DMAR units with no supported address widths David Woodhouse
2020-09-25 1:52 ` Lu Baolu [this message]
2020-10-07 9:52 ` Joerg Roedel
2021-01-20 9:42 ` David Woodhouse
2021-01-20 9:42 ` David Woodhouse
2021-01-20 12:06 ` Greg KH
2021-01-20 12:06 ` Greg KH
2021-01-20 15:55 ` David Woodhouse
2021-01-20 15:55 ` David Woodhouse
2021-01-20 17:04 ` Greg KH
2021-01-20 17:04 ` Greg KH
2021-01-20 20:06 ` David Woodhouse
2021-01-20 20:06 ` David Woodhouse
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