HLOS can create s1 pagetable and request firmware to share the same
pgtable to different entity(vmid).
Use arm-smmu vendor implementation call to define custom
alloc/free pgtable callback, And use these callbacks to share
pgtable to different entity while creating pgtable.
Signed-off-by: Gaurav Kohli <quic_gkohli@xxxxxxxxxxx>
---
drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 81 ++++++++++++++++++++++
drivers/iommu/arm/arm-smmu/arm-smmu.h | 8 +++
2 files changed, 89 insertions(+)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index c71afda79d64..e04079988787 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -4,6 +4,7 @@
*/
#include <linux/acpi.h>
+#include <linux/dev_printk.h>
#include <linux/adreno-smmu-priv.h>
#include <linux/delay.h>
#include <linux/of_device.h>
@@ -258,11 +259,91 @@ static const struct of_device_id qcom_smmu_client_of_match[] __maybe_unused = {
{ }
};
+static void *qcom_alloc_pages(void *cookie, size_t size, gfp_t gfp)
+{
+ struct page *p;
+ struct qcom_scm_vmperm perms[2];
+ u64 src = BIT(QCOM_SCM_VMID_HLOS);
+ int ret;
+
+ struct arm_smmu_domain *domain = (void *)cookie;
+ /*
+ * qcom_scm_assign_mem call during atomic allocation can sleep, Using GFP flags
+ * to detect allocation path and return failure for atomic allocations.
+ */
+ if (!gfpflags_allow_blocking(gfp)) {
+ dev_err(domain->smmu->dev,
+ "qcom_scm_assign_mem call are not allowed during atomic allocations\n");
+ return NULL;
+ }
+ p = alloc_page(gfp);
+ if (!p)
+ return NULL;
+
+ perms[0].vmid = QCOM_SCM_VMID_HLOS;
+ perms[0].perm = QCOM_SCM_PERM_RW;
+ perms[1].vmid = domain->secure_vmid;
+ perms[1].perm = QCOM_SCM_PERM_READ;
+ ret = qcom_scm_assign_mem(page_to_phys(p), PAGE_SIZE,
+ &src, perms, 2);
+ if (ret < 0) {
+ dev_err(domain->smmu->dev,
+ "assign memory failed for vmid=%x ret=%d\n",
+ domain->secure_vmid, ret);
+ __free_page(p);
+ return NULL;
+ }
+
+ return page_address(p);
+}
+
+static void qcom_free_pages(void *cookie, void *pages, size_t size)
+{
+ struct qcom_scm_vmperm perms;
+ struct page *p;
+ u64 src;
+ int ret;
+
+ struct arm_smmu_domain *domain = (void *)cookie;
+
+ p = virt_to_page(pages);
+
+ perms.vmid = QCOM_SCM_VMID_HLOS;
+ perms.perm = QCOM_SCM_PERM_RWX;
+ src = BIT(domain->secure_vmid) | BIT(QCOM_SCM_VMID_HLOS);
+ ret = qcom_scm_assign_mem(page_to_phys(p), PAGE_SIZE,
+ &src, &perms, 1);
+ /*
+ * For assign failure scenario, it is not safe to use these pages by HLOS.
+ * So returning from here instead of freeing the page.
+ */
+ if (ret < 0) {
+ dev_err(domain->smmu->dev,
+ "assign memory failed to HLOS for vmid=%x ret=%d\n",
+ domain->secure_vmid, ret);
+ return;
+ }
+
+ __free_page(p);
+}
+
static int qcom_smmu_init_context(struct arm_smmu_domain *smmu_domain,
struct io_pgtable_cfg *pgtbl_cfg, struct device *dev)
{
+ u32 val;
+
smmu_domain->cfg.flush_walk_prefer_tlbiasid = true;
+ /*
+ * For those client where qcom,iommu-vmid is not defined, default arm-smmu pgtable
+ * alloc/free handler will be used.
+ */
+ if (of_property_read_u32(dev->of_node, "qcom,iommu-vmid", &val) == 0) {
+ smmu_domain->secure_vmid = val;
+ pgtbl_cfg->alloc = qcom_alloc_pages;
+ pgtbl_cfg->free = qcom_free_pages;
+ }
+
return 0;
}
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h
index 703fd5817ec1..98e1c5369e58 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.h
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h
@@ -374,6 +374,14 @@ struct arm_smmu_domain {
struct mutex init_mutex; /* Protects smmu pointer */
spinlock_t cb_lock; /* Serialises ATS1* ops and TLB syncs */
struct iommu_domain domain;
+ /*
+ * Use to store parse vmid value for those clients which want HLOS
+ * to share pgtable to different entity(VMID).
+ * Fix Me: Ideally this should be implemented on arm-smmu vendor implementation
+ * driver, but as per current design of arm_smmu_domain_alloc there is no way
+ * to call implementation callbacks.
+ */
+ u32 secure_vmid;
};
struct arm_smmu_master_cfg {
--
2.17.1
