[PATCH v6 10/12] iommu/vt-d: Add first level page table interface

Lu Baolu
2018-12-10T01:59:04Z

This adds an interface to setup the PASID entries for first
level page table translation.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
---
drivers/iommu/intel-pasid.c | 80 +++++++++++++++++++++++++++++++++++++
drivers/iommu/intel-pasid.h | 11 +++++
include/linux/intel-iommu.h | 1 +
3 files changed, 92 insertions(+)

diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c
index 6d2b2e87e6fc..c3dcf4dc2496 100644
--- a/drivers/iommu/intel-pasid.c
+++ b/drivers/iommu/intel-pasid.c
@@ -10,6 +10,7 @@
#define pr_fmt(fmt) "DMAR: " fmt

#include <linux/bitops.h>
+#include <linux/cpufeature.h>
#include <linux/dmar.h>
#include <linux/intel-iommu.h>
#include <linux/iommu.h>
@@ -389,6 +390,26 @@ static inline void pasid_set_page_snoop(struct pasid_entry *pe, bool value)
pasid_set_bits(&pe->val[1], 1 << 23, value);
}

+/*
+ * Setup the First Level Page table Pointer field (Bit 140~191)
+ * of a scalable mode PASID entry.
+ */
+static inline void
+pasid_set_flptr(struct pasid_entry *pe, u64 value)
+{
+ pasid_set_bits(&pe->val[2], VTD_PAGE_MASK, value);
+}
+
+/*
+ * Setup the First Level Paging Mode field (Bit 130~131) of a
+ * scalable mode PASID entry.
+ */
+static inline void
+pasid_set_flpm(struct pasid_entry *pe, u64 value)
+{
+ pasid_set_bits(&pe->val[2], GENMASK_ULL(3, 2), value << 2);
+}
+
static void
pasid_cache_invalidation_with_pasid(struct intel_iommu *iommu,
u16 did, int pasid)
@@ -459,6 +480,65 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu,
devtlb_invalidation_with_pasid(iommu, dev, pasid);
}

+/*
+ * Set up the scalable mode pasid table entry for first only
+ * translation type.
+ */
+int intel_pasid_setup_first_level(struct intel_iommu *iommu,
+ struct device *dev, pgd_t *pgd,
+ int pasid, u16 did, int flags)
+{
+ struct pasid_entry *pte;
+
+ if (!ecap_flts(iommu->ecap)) {
+ pr_err("No first level translation support on %s\n",
+ iommu->name);
+ return -EINVAL;
+ }
+
+ pte = intel_pasid_get_entry(dev, pasid);
+ if (WARN_ON(!pte))
+ return -EINVAL;
+
+ pasid_clear_entry(pte);
+
+ /* Setup the first level page table pointer: */
+ pasid_set_flptr(pte, (u64)__pa(pgd));
+ if (flags & PASID_FLAG_SUPERVISOR_MODE) {
+ if (!ecap_srs(iommu->ecap)) {
+ pr_err("No supervisor request support on %s\n",
+ iommu->name);
+ return -EINVAL;
+ }
+ pasid_set_sre(pte);
+ }
+
+#ifdef CONFIG_X86
+ if (cpu_feature_enabled(X86_FEATURE_LA57))
+ pasid_set_flpm(pte, 1);
+#endif /* CONFIG_X86 */
+
+ pasid_set_domain_id(pte, did);
+ pasid_set_address_width(pte, iommu->agaw);
+ pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
+
+ /* Setup Present and PASID Granular Transfer Type: */
+ pasid_set_translation_type(pte, 1);
+ pasid_set_present(pte);
+
+ if (!ecap_coherent(iommu->ecap))
+ clflush_cache_range(pte, sizeof(*pte));
+
+ if (cap_caching_mode(iommu->cap)) {
+ pasid_cache_invalidation_with_pasid(iommu, did, pasid);
+ iotlb_invalidation_with_pasid(iommu, did, pasid);
+ } else {
+ iommu_flush_write_buffer(iommu);
+ }
+
+ return 0;
+}
+
/*
* Set up the scalable mode pasid entry for second only translation type.
*/
diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h
index 55bb8715329d..512c63ec8a22 100644
--- a/drivers/iommu/intel-pasid.h
+++ b/drivers/iommu/intel-pasid.h
@@ -25,6 +25,14 @@
*/
#define FLPT_DEFAULT_DID 1

+/*
+ * The SUPERVISOR_MODE flag indicates a first level translation which
+ * can be used for access to kernel addresses. It is valid only for
+ * access to the kernel's static 1:1 mapping of physical memory — not
+ * to vmalloc or even module mappings.
+ */
+#define PASID_FLAG_SUPERVISOR_MODE BIT(0)
+
struct pasid_dir_entry {
u64 val;
};
@@ -51,6 +59,9 @@ struct pasid_table *intel_pasid_get_table(struct device *dev);
int intel_pasid_get_dev_max_id(struct device *dev);
struct pasid_entry *intel_pasid_get_entry(struct device *dev, int pasid);
void intel_pasid_clear_entry(struct device *dev, int pasid);
+int intel_pasid_setup_first_level(struct intel_iommu *iommu,
+ struct device *dev, pgd_t *pgd,
+ int pasid, u16 did, int flags);
int intel_pasid_setup_second_level(struct intel_iommu *iommu,
struct dmar_domain *domain,
struct device *dev, int pasid);
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 5fdd33ed2cce..4ad62396e81e 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -178,6 +178,7 @@
*/

#define ecap_smpwc(e) (((e) >> 48) & 0x1)
+#define ecap_flts(e) (((e) >> 47) & 0x1)
#define ecap_slts(e) (((e) >> 46) & 0x1)
#define ecap_smts(e) (((e) >> 43) & 0x1)
#define ecap_dit(e) ((e >> 41) & 0x1)
--
2.17.1