[PATCH 07/10] acpi: Do not return struct iommu_ops from acpi_iommu_configure_id()

From: Jason Gunthorpe <jgg@nvidia.com>
To: David Airlie <airlied@gmail.com>,
	Alyssa Rosenzweig <alyssa@rosenzweig.io>,
	Albert Ou <aou@eecs.berkeley.edu>,
	asahi@lists.linux.dev, Catalin Marinas <catalin.marinas@arm.com>,
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	Haiyang Zhang <haiyangz@microsoft.com>,
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Cc: Lu Baolu <baolu.lu@linux.intel.com>,
	Christoph Hellwig <hch@lst.de>,
	Jerry Snitselaar <jsnitsel@redhat.com>,
	Hector Martin <marcan@marcan.st>, Moritz Fischer <mdf@kernel.org>,
	patches@lists.linux.dev,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	Rob Herring <robh@kernel.org>,
	Thierry Reding <thierry.reding@gmail.com>
Subject: [PATCH 07/10] acpi: Do not return struct iommu_ops from acpi_iommu_configure_id()
Date: Tue, 28 Nov 2023 20:48:03 -0400	[thread overview]
Message-ID: <7-v1-720585788a7d+811b-iommu_fwspec_p1_jgg@nvidia.com> (raw)
In-Reply-To: <0-v1-720585788a7d+811b-iommu_fwspec_p1_jgg@nvidia.com>

Nothing needs this pointer. Return a normal error code with the usual
IOMMU semantic that ENODEV means 'there is no IOMMU driver'.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/acpi/scan.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 444a0b3c72f2d8..340ba720c72129 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1562,8 +1562,7 @@ static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
 	return fwspec ? fwspec->ops : NULL;
 }
 
-static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
-						       const u32 *id_in)
+static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
 {
 	int err;
 	const struct iommu_ops *ops;
@@ -1577,7 +1576,7 @@ static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
 	ops = acpi_iommu_fwspec_ops(dev);
 	if (ops) {
 		mutex_unlock(&iommu_probe_device_lock);
-		return ops;
+		return 0;
 	}
 
 	err = iort_iommu_configure_id(dev, id_in);
@@ -1594,12 +1593,14 @@ static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
 
 	/* Ignore all other errors apart from EPROBE_DEFER */
 	if (err == -EPROBE_DEFER) {
-		return ERR_PTR(err);
+		return err;
 	} else if (err) {
 		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
-		return NULL;
+		return -ENODEV;
 	}
-	return acpi_iommu_fwspec_ops(dev);
+	if (!acpi_iommu_fwspec_ops(dev))
+		return -ENODEV;
+	return 0;
 }
 
 #else /* !CONFIG_IOMMU_API */
@@ -1611,10 +1612,9 @@ int acpi_iommu_fwspec_init(struct device *dev, u32 id,
 	return -ENODEV;
 }
 
-static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
-						       const u32 *id_in)
+static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
 {
-	return NULL;
+	return -ENODEV;
 }
 
 #endif /* !CONFIG_IOMMU_API */
@@ -1628,7 +1628,7 @@ static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
 			  const u32 *input_id)
 {
-	const struct iommu_ops *iommu;
+	int ret;
 
 	if (attr == DEV_DMA_NOT_SUPPORTED) {
 		set_dma_ops(dev, &dma_dummy_ops);
@@ -1637,10 +1637,15 @@ int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
 
 	acpi_arch_dma_setup(dev);
 
-	iommu = acpi_iommu_configure_id(dev, input_id);
-	if (PTR_ERR(iommu) == -EPROBE_DEFER)
+	ret = acpi_iommu_configure_id(dev, input_id);
+	if (ret == -EPROBE_DEFER)
 		return -EPROBE_DEFER;
 
+	/*
+	 * Historically this routine doesn't fail driver probing due to errors
+	 * in acpi_iommu_configure_id()
+	 */
+
 	arch_setup_dma_ops(dev, 0, U64_MAX, attr == DEV_DMA_COHERENT);
 
 	return 0;
-- 
2.42.0


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