From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
Add root device handling to the IPMMU driver by allowing certain
DT compat strings to enable has_cache_leaf_nodes that in turn will
support both root devices with interrupts and leaf devices that
face the actual IPMMU consumer devices.
Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
---
Changes since V4: (Many thanks to Robin for feedback)
- Put the root pointer under struct ipmmu_vmsa_device
- Drop is_leaf flag
- Use driver_for_each_device instead of local list of devices
- Return -EPROBE_DEFER to hook up root device first
Changes since V3:
- Reworked root finding code to make it easier to follow, thanks Geert!
Changes since V2:
- Fixed a bug in ipmmu_find_root() when only leaf devices are present
- Broke out __ipmmu_find_root() to allow ->xlate() check for root devices
Changes since V1:
- Moved patch to earlier in the series
- Updated code to work with recent changes in:
[PATCH v3 00/06] iommu/ipmmu-vmsa: IPMMU multi-arch update V3
drivers/iommu/ipmmu-vmsa.c | 90 +++++++++++++++++++++++++++++++++++---------
1 file changed, 73 insertions(+), 17 deletions(-)
--- 0009/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c 2017-10-16 19:43:27.020607110 +0900
@@ -36,12 +36,14 @@
struct ipmmu_features {
bool use_ns_alias_offset;
+ bool has_cache_leaf_nodes;
};
struct ipmmu_vmsa_device {
struct device *dev;
void __iomem *base;
struct iommu_device iommu;
+ struct ipmmu_vmsa_device *root;
const struct ipmmu_features *features;
unsigned int num_utlbs;
spinlock_t lock; /* Protects ctx and domains[] */
@@ -199,6 +201,36 @@ static struct ipmmu_vmsa_iommu_priv *to_
#define IMUASID_ASID0_SHIFT 0
/* -----------------------------------------------------------------------------
+ * Root device handling
+ */
+
+static struct platform_driver ipmmu_driver;
+
+static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
+{
+ return mmu->root == mmu;
+}
+
+static int __ipmmu_check_device(struct device *dev, void *data)
+{
+ struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
+ struct ipmmu_vmsa_device **rootp = data;
+
+ if (ipmmu_is_root(mmu))
+ *rootp = mmu;
+
+ return 0;
+}
+
+static struct ipmmu_vmsa_device *ipmmu_find_root(void)
+{
+ struct ipmmu_vmsa_device *root = NULL;
+
+ return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
+ __ipmmu_check_device) == 0 ? root : NULL;
+}
+
+/* -----------------------------------------------------------------------------
* Read/Write Access
*/
@@ -215,13 +247,15 @@ static void ipmmu_write(struct ipmmu_vms
static u32 ipmmu_ctx_read(struct ipmmu_vmsa_domain *domain, unsigned int reg)
{
- return ipmmu_read(domain->mmu, domain->context_id * IM_CTX_SIZE + reg);
+ return ipmmu_read(domain->mmu->root,
+ domain->context_id * IM_CTX_SIZE + reg);
}
static void ipmmu_ctx_write(struct ipmmu_vmsa_domain *domain, unsigned int reg,
u32 data)
{
- ipmmu_write(domain->mmu, domain->context_id * IM_CTX_SIZE + reg, data);
+ ipmmu_write(domain->mmu->root,
+ domain->context_id * IM_CTX_SIZE + reg, data);
}
/* -----------------------------------------------------------------------------
@@ -369,12 +403,12 @@ static int ipmmu_domain_init_context(str
* TODO: Add support for coherent walk through CCI with DVM and remove
* cache handling. For now, delegate it to the io-pgtable code.
*/
- domain->cfg.iommu_dev = domain->mmu->dev;
+ domain->cfg.iommu_dev = domain->mmu->root->dev;
/*
* Find an unused context.
*/
- ret = ipmmu_domain_allocate_context(domain->mmu, domain);
+ ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
if (ret == IPMMU_CTX_MAX)
return -EBUSY;
@@ -383,7 +417,8 @@ static int ipmmu_domain_init_context(str
domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
domain);
if (!domain->iop) {
- ipmmu_domain_free_context(domain->mmu, domain->context_id);
+ ipmmu_domain_free_context(domain->mmu->root,
+ domain->context_id);
return -EINVAL;
}
@@ -437,7 +472,7 @@ static void ipmmu_domain_destroy_context
*/
ipmmu_ctx_write(domain, IMCTR, IMCTR_FLUSH);
ipmmu_tlb_sync(domain);
- ipmmu_domain_free_context(domain->mmu, domain->context_id);
+ ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
}
/* -----------------------------------------------------------------------------
@@ -917,6 +952,7 @@ static void ipmmu_device_reset(struct ip
static const struct ipmmu_features ipmmu_features_default = {
.use_ns_alias_offset = true,
+ .has_cache_leaf_nodes = false,
};
static const struct of_device_id ipmmu_of_ids[] = {
@@ -971,19 +1007,39 @@ static int ipmmu_probe(struct platform_d
mmu->base += IM_NS_ALIAS_OFFSET;
irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "no IRQ found\n");
- return irq;
- }
- ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
- dev_name(&pdev->dev), mmu);
- if (ret < 0) {
- dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
- return ret;
- }
+ /*
+ * Determine if this IPMMU instance is a root device by checking for
+ * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
+ */
+ if (!mmu->features->has_cache_leaf_nodes ||
+ !of_find_property(pdev->dev.of_node, "renesas,ipmmu-main", NULL))
+ mmu->root = mmu;
+ else
+ mmu->root = ipmmu_find_root();
+
+ /*
+ * Wait until the root device has been registered for sure.
+ */
+ if (!mmu->root)
+ return -EPROBE_DEFER;
+
+ /* Root devices have mandatory IRQs */
+ if (ipmmu_is_root(mmu)) {
+ if (irq < 0) {
+ dev_err(&pdev->dev, "no IRQ found\n");
+ return irq;
+ }
- ipmmu_device_reset(mmu);
+ ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
+ dev_name(&pdev->dev), mmu);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
+ return ret;
+ }
+
+ ipmmu_device_reset(mmu);
+ }
ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
dev_name(&pdev->dev));
