[PATCH 06/10] iommu/ipmmu-vmsa: Add optional root device feature
From: Magnus Damm
Date: Thu Mar 17 2016 - 12:26:51 EST
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>
---
drivers/iommu/ipmmu-vmsa.c | 92 ++++++++++++++++++++++++++++++++++----------
1 file changed, 73 insertions(+), 19 deletions(-)
--- 0019/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c 2016-03-18 00:30:22.270513000 +0900
@@ -35,6 +35,7 @@
struct ipmmu_features {
bool use_ns_alias_offset;
+ bool has_cache_leaf_nodes;
};
struct ipmmu_vmsa_device {
@@ -50,10 +51,12 @@ struct ipmmu_vmsa_device {
struct dma_iommu_mapping *mapping;
#endif
const struct ipmmu_features *features;
+ bool is_leaf;
};
struct ipmmu_vmsa_domain {
struct ipmmu_vmsa_device *mmu;
+ struct ipmmu_vmsa_device *root;
struct iommu_domain io_domain;
struct io_pgtable_cfg cfg;
@@ -198,6 +201,36 @@ static struct ipmmu_vmsa_domain *to_vmsa
#define IMUASID_ASID0_SHIFT 0
/* -----------------------------------------------------------------------------
+ * Root device handling
+ */
+
+static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
+{
+ if (mmu->features->has_cache_leaf_nodes)
+ return mmu->is_leaf ? false : true;
+ else
+ return true; /* older IPMMU hardware treated as single root */
+}
+
+static struct ipmmu_vmsa_device *ipmmu_find_root(struct ipmmu_vmsa_device *leaf)
+{
+ struct ipmmu_vmsa_device *mmu = NULL;
+
+ if (ipmmu_is_root(leaf))
+ return leaf;
+
+ spin_lock(&ipmmu_devices_lock);
+
+ list_for_each_entry(mmu, &ipmmu_devices, list) {
+ if (ipmmu_is_root(mmu))
+ break;
+ }
+
+ spin_unlock(&ipmmu_devices_lock);
+ return mmu;
+}
+
+/* -----------------------------------------------------------------------------
* Read/Write Access
*/
@@ -214,13 +247,13 @@ 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->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->root, domain->context_id * IM_CTX_SIZE + reg, data);
}
/* -----------------------------------------------------------------------------
@@ -334,7 +367,7 @@ 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->root->dev;
domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
domain);
@@ -344,15 +377,15 @@ static int ipmmu_domain_init_context(str
/*
* Find an unused context.
*/
- ret = find_first_zero_bit(domain->mmu->ctx, IPMMU_CTX_MAX);
+ ret = find_first_zero_bit(domain->root->ctx, IPMMU_CTX_MAX);
if (ret == IPMMU_CTX_MAX) {
free_io_pgtable_ops(domain->iop);
return -EBUSY;
}
domain->context_id = ret;
- domain->mmu->domains[ret] = domain;
- set_bit(ret, domain->mmu->ctx);
+ domain->root->domains[ret] = domain;
+ set_bit(ret, domain->root->ctx);
/* TTBR0 */
ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
@@ -396,7 +429,7 @@ static int ipmmu_domain_init_context(str
static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
{
- clear_bit(domain->context_id, domain->mmu->ctx);
+ clear_bit(domain->context_id, domain->root->ctx);
/*
* Disable the context. Flush the TLB as required when modifying the
@@ -524,7 +557,7 @@ static int ipmmu_attach_device(struct io
struct device *dev)
{
struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
- struct ipmmu_vmsa_device *mmu = archdata->mmu;
+ struct ipmmu_vmsa_device *root, *mmu = archdata->mmu;
struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
unsigned long flags;
unsigned int i;
@@ -535,15 +568,23 @@ static int ipmmu_attach_device(struct io
return -ENXIO;
}
+ root = ipmmu_find_root(archdata->mmu);
+ if (!root) {
+ dev_err(dev, "Unable to locate root IPMMU\n");
+ return -EAGAIN;
+ }
+
spin_lock_irqsave(&domain->lock, flags);
if (!domain->mmu) {
/* The domain hasn't been used yet, initialize it. */
domain->mmu = mmu;
+ domain->root = root;
ret = ipmmu_domain_init_context(domain);
if (ret < 0) {
dev_err(dev, "Unable to initialize IPMMU context\n");
domain->mmu = NULL;
+ domain->root = NULL;
} else {
dev_info(dev, "Using IPMMU context %u\n",
domain->context_id);
@@ -939,6 +980,7 @@ 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[] = {
@@ -998,19 +1040,31 @@ 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 leaf device by checking
+ * if the renesas,ipmmu-main property exists or not.
+ */
+ if (mmu->features->has_cache_leaf_nodes &&
+ of_find_property(pdev->dev.of_node, "renesas,ipmmu-main", NULL))
+ mmu->is_leaf = true;
+
+ /* Root devices have mandatory IRQs */
+ if (ipmmu_is_root(mmu)) {
+ 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;
+ }
- ipmmu_device_reset(mmu);
+ ipmmu_device_reset(mmu);
+ }
/*
* We can't create the ARM mapping here as it requires the bus to have