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Message-ID: <2c64bcfc-e93b-703a-0326-54b6eef73766@arm.com>
Date: Wed, 17 May 2017 15:29:43 +0100
From: Robin Murphy <robin.murphy@....com>
To: Magnus Damm <magnus.damm@...il.com>, joro@...tes.org
Cc: laurent.pinchart+renesas@...asonboard.com, geert+renesas@...der.be,
sricharan@...eaurora.org, will.deacon@....com,
linux-kernel@...r.kernel.org, linux-renesas-soc@...r.kernel.org,
iommu@...ts.linux-foundation.org, horms+renesas@...ge.net.au,
m.szyprowski@...sung.com
Subject: Re: [PATCH v8 06/08] iommu/ipmmu-vmsa: Use fwspec iommu_priv on ARM64
Hi Magnus,
On 17/05/17 11:07, Magnus Damm wrote:
> From: Magnus Damm <damm+renesas@...nsource.se>
>
> Convert from archdata to iommu_priv via iommu_fwspec on ARM64 but
> let 32-bit ARM keep on using archdata for now.
>
> Once the 32-bit ARM code and the IPMMU driver is able to move over
> to CONFIG_IOMMU_DMA=y then coverting to fwspec via ->of_xlate() will
> be easy.
>
> For now fwspec ids and num_ids are not used to allow code sharing between
> 32-bit and 64-bit ARM code inside the driver.
That's not what I meant at all - this just looks like a crazy
unmaintainable mess that's making things that much harder to unpick in
future.
Leaving the existing code fossilised and building up half of a second
separate driver around it wrapped in ifdefs is not only hideous, it's
more work in the end than simply pulling things into the right shape to
begin with. What I meant was to start with the below (compile-tested
only), and add the of_xlate support on top. AFAICS the arm/arm64
differences overall should only come down to a bit of special-casing in
add_device(), and (optionally) whether you outright reject
IOMMU_DOMAIN_DMA or not.
Sorry, but I just can't agree with the two-drivers-in-one approach.
Robin.
----->8-----
From: Robin Murphy <robin.murphy@....com>
Subject: [PATCH] iommu/ipmmu-vmsa: Convert to iommu_fwspec
The parent IPMMU pointer and set of uTLB IDs are, as intended, a perfect
fit for the generic iommu_fwspec. Get rid of the architecture-specific
archdata handling in favour of the common solution.
Signed-off-by: Robin Murphy <robin.murphy@....com>
---
drivers/iommu/ipmmu-vmsa.c | 68
++++++++++++++++++++--------------------------
1 file changed, 29 insertions(+), 39 deletions(-)
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index b7e14ee863f9..96479690269f 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -47,12 +47,6 @@ struct ipmmu_vmsa_domain {
spinlock_t lock; /* Protects mappings */
};
-struct ipmmu_vmsa_archdata {
- struct ipmmu_vmsa_device *mmu;
- unsigned int *utlbs;
- unsigned int num_utlbs;
-};
-
static DEFINE_SPINLOCK(ipmmu_devices_lock);
static LIST_HEAD(ipmmu_devices);
@@ -455,6 +449,8 @@ static irqreturn_t ipmmu_irq(int irq, void *dev)
* IOMMU Operations
*/
+static const struct iommu_ops ipmmu_ops;
+
static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
{
struct ipmmu_vmsa_domain *domain;
@@ -487,18 +483,20 @@ static void ipmmu_domain_free(struct iommu_domain
*io_domain)
static int ipmmu_attach_device(struct iommu_domain *io_domain,
struct device *dev)
{
- struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
- struct ipmmu_vmsa_device *mmu = archdata->mmu;
+ struct iommu_fwspec *fwspec = dev->iommu_fwspec;
+ struct ipmmu_vmsa_device *mmu;
struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
unsigned long flags;
unsigned int i;
int ret = 0;
- if (!mmu) {
+ if (!fwspec || fwspec->ops != &ipmmu_ops) {
dev_err(dev, "Cannot attach to IPMMU\n");
return -ENXIO;
}
+ mmu = fwspec->iommu_priv;
+
spin_lock_irqsave(&domain->lock, flags);
if (!domain->mmu) {
@@ -520,8 +518,8 @@ static int ipmmu_attach_device(struct iommu_domain
*io_domain,
if (ret < 0)
return ret;
- for (i = 0; i < archdata->num_utlbs; ++i)
- ipmmu_utlb_enable(domain, archdata->utlbs[i]);
+ for (i = 0; i < fwspec->num_ids; ++i)
+ ipmmu_utlb_enable(domain, fwspec->ids[i]);
return 0;
}
@@ -529,12 +527,15 @@ static int ipmmu_attach_device(struct iommu_domain
*io_domain,
static void ipmmu_detach_device(struct iommu_domain *io_domain,
struct device *dev)
{
- struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
+ struct iommu_fwspec *fwspec = dev->iommu_fwspec;
struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
unsigned int i;
- for (i = 0; i < archdata->num_utlbs; ++i)
- ipmmu_utlb_disable(domain, archdata->utlbs[i]);
+ if (!fwspec || fwspec->ops != &ipmmu_ops)
+ return;
+
+ for (i = 0; i < fwspec->num_ids; ++i)
+ ipmmu_utlb_disable(domain, fwspec->ids[i]);
/*
* TODO: Optimize by disabling the context when no device is attached.
@@ -597,7 +598,6 @@ static int ipmmu_find_utlbs(struct ipmmu_vmsa_device
*mmu, struct device *dev,
static int ipmmu_add_device(struct device *dev)
{
- struct ipmmu_vmsa_archdata *archdata;
struct ipmmu_vmsa_device *mmu;
struct iommu_group *group = NULL;
unsigned int *utlbs;
@@ -605,7 +605,7 @@ static int ipmmu_add_device(struct device *dev)
int num_utlbs;
int ret = -ENODEV;
- if (dev->archdata.iommu) {
+ if (dev->iommu_fwspec) {
dev_warn(dev, "IOMMU driver already assigned to device %s\n",
dev_name(dev));
return -EINVAL;
@@ -638,13 +638,20 @@ static int ipmmu_add_device(struct device *dev)
spin_unlock(&ipmmu_devices_lock);
if (ret < 0)
- goto error;
+ return ret;
+
+ ret = iommu_fwspec_init(dev, mmu->dev->fwnode, &ipmmu_ops);
+ if (ret)
+ return ret;
+
+ dev->iommu_fwspec->iommu_priv = mmu;
for (i = 0; i < num_utlbs; ++i) {
if (utlbs[i] >= mmu->num_utlbs) {
ret = -EINVAL;
goto error;
}
+ iommu_fwspec_add_ids(dev, &utlbs[i], 1);
}
/* Create a device group and add the device to it. */
@@ -664,17 +671,6 @@ static int ipmmu_add_device(struct device *dev)
goto error;
}
- archdata = kzalloc(sizeof(*archdata), GFP_KERNEL);
- if (!archdata) {
- ret = -ENOMEM;
- goto error;
- }
-
- archdata->mmu = mmu;
- archdata->utlbs = utlbs;
- archdata->num_utlbs = num_utlbs;
- dev->archdata.iommu = archdata;
-
/*
* Create the ARM mapping, used by the ARM DMA mapping core to allocate
* VAs. This will allocate a corresponding IOMMU domain.
@@ -710,28 +706,22 @@ static int ipmmu_add_device(struct device *dev)
error:
arm_iommu_release_mapping(mmu->mapping);
- kfree(dev->archdata.iommu);
- kfree(utlbs);
-
- dev->archdata.iommu = NULL;
-
if (!IS_ERR_OR_NULL(group))
iommu_group_remove_device(dev);
+ iommu_fwspec_free(dev);
+
return ret;
}
static void ipmmu_remove_device(struct device *dev)
{
- struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
+ if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &ipmmu_ops)
+ return;
arm_iommu_detach_device(dev);
iommu_group_remove_device(dev);
-
- kfree(archdata->utlbs);
- kfree(archdata);
-
- dev->archdata.iommu = NULL;
+ iommu_fwspec_free(dev);
}
static const struct iommu_ops ipmmu_ops = {
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