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From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
To: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org
Cc: joro@8bytes.org, Jon.Grimm@amd.com, wei.huang2@amd.com,
	Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Subject: [PATCH 1/3] iommu/amd: Introduce helper function to check feature bit on all IOMMUs
Date: Fri, 20 Aug 2021 15:29:55 -0500	[thread overview]
Message-ID: <20210820202957.187572-2-suravee.suthikulpanit@amd.com> (raw)
In-Reply-To: <20210820202957.187572-1-suravee.suthikulpanit@amd.com>

IOMMU advertises feature via Extended Features Register (EFR).
The helper function checks if the specified feature bit is set
across all IOMMUs.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/init.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 46280e6e1535..c97961451ac5 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -298,6 +298,19 @@ int amd_iommu_get_num_iommus(void)
 	return amd_iommus_present;
 }
 
+static bool check_feature_on_all_iommus(u64 mask)
+{
+	bool ret = false;
+	struct amd_iommu *iommu;
+
+	for_each_iommu(iommu) {
+		ret = iommu_feature(iommu, mask);
+		if (!ret)
+			return false;
+	}
+
+	return true;
+}
 /*
  * For IVHD type 0x11/0x40, EFR is also available via IVHD.
  * Default to IVHD EFR since it is available sooner
-- 
2.17.1


  reply	other threads:[~2021-08-20 20:08 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-20 20:29 [PATCH 0/3] iommu/amd: Fix unable to handle page fault due to AVIC Suravee Suthikulpanit
2021-08-20 20:29 ` Suravee Suthikulpanit [this message]
2021-08-20 20:29 ` [PATCH 2/3] iommu/amd: Relocate GAMSup check to early_enable_iommus Suravee Suthikulpanit
2021-08-20 20:29 ` [PATCH 3/3] iommu/amd: Remove iommu_init_ga() Suravee Suthikulpanit
2021-08-31 17:10 ` [PATCH 0/3] iommu/amd: Fix unable to handle page fault due to AVIC Suthikulpanit, Suravee
2021-09-02  7:38   ` Joerg Roedel
2021-09-02 16:13     ` Suthikulpanit, Suravee
2021-09-09  9:36       ` Joerg Roedel
2021-09-09 11:17       ` Joerg Roedel
2021-09-10 18:01         ` Wei Huang

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