[PATCH v3 04/14] iommu/ioasid: Support setting system-wide capacity
From: Jacob Pan <hidden>
Date: 2020-09-28 21:36:52
Also in:
linux-iommu, lkml
Subsystem:
intel iommu (vt-d), iommu subsystem, the rest · Maintainers:
David Woodhouse, Lu Baolu, Joerg Roedel, Will Deacon, Linus Torvalds
IOASID is a system-wide resource that could vary on different systems. The default capacity is 20 bits as defined in the PCI-E specifications. This patch adds a function to allow adjusting system IOASID capacity. For VT-d this is set during boot as part of the Intel IOMMU initialization. Signed-off-by: Jacob Pan <redacted> --- drivers/iommu/intel/iommu.c | 5 +++++ drivers/iommu/ioasid.c | 20 ++++++++++++++++++++ include/linux/ioasid.h | 11 +++++++++++ 3 files changed, 36 insertions(+)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 18ed3b3c70d7..e7bcb299e51e 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c@@ -42,6 +42,7 @@ #include <linux/crash_dump.h> #include <linux/numa.h> #include <linux/swiotlb.h> +#include <linux/ioasid.h> #include <asm/irq_remapping.h> #include <asm/cacheflush.h> #include <asm/iommu.h>
@@ -3331,6 +3332,10 @@ static int __init init_dmars(void) if (ret) goto free_iommu; + /* PASID is needed for scalable mode irrespective to SVM */ + if (intel_iommu_sm) + ioasid_install_capacity(intel_pasid_max_id); + /* * for each drhd * enable fault log
diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
index 6cfbdfb492e0..4277cb17e15b 100644
--- a/drivers/iommu/ioasid.c
+++ b/drivers/iommu/ioasid.c@@ -10,6 +10,10 @@ #include <linux/spinlock.h> #include <linux/xarray.h> +/* Default to PCIe standard 20 bit PASID */ +#define PCI_PASID_MAX 0x100000 +static ioasid_t ioasid_capacity = PCI_PASID_MAX; +static ioasid_t ioasid_capacity_avail = PCI_PASID_MAX; struct ioasid_data { ioasid_t id; struct ioasid_set *set;
@@ -17,6 +21,22 @@ struct ioasid_data { struct rcu_head rcu; }; +void ioasid_install_capacity(ioasid_t total) +{ + if (ioasid_capacity && ioasid_capacity != PCI_PASID_MAX) { + pr_warn("IOASID capacity is already set.\n"); + return; + } + ioasid_capacity = ioasid_capacity_avail = total; +} +EXPORT_SYMBOL_GPL(ioasid_install_capacity); + +ioasid_t ioasid_get_capacity(void) +{ + return ioasid_capacity; +} +EXPORT_SYMBOL_GPL(ioasid_get_capacity); + /* * struct ioasid_allocator_data - Internal data structure to hold information * about an allocator. There are two types of allocators:
diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
index c7f649fa970a..7fc320656be2 100644
--- a/include/linux/ioasid.h
+++ b/include/linux/ioasid.h@@ -32,6 +32,8 @@ struct ioasid_allocator_ops { #define DECLARE_IOASID_SET(name) struct ioasid_set name = { 0 } #if IS_ENABLED(CONFIG_IOASID) +void ioasid_install_capacity(ioasid_t total); +ioasid_t ioasid_get_capacity(void); ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, void *private); void ioasid_free(ioasid_t ioasid);
@@ -42,6 +44,15 @@ void ioasid_unregister_allocator(struct ioasid_allocator_ops *allocator); int ioasid_attach_data(ioasid_t ioasid, void *data); void ioasid_detach_data(ioasid_t ioasid); #else /* !CONFIG_IOASID */ +static inline void ioasid_install_capacity(ioasid_t total) +{ +} + +static inline ioasid_t ioasid_get_capacity(void) +{ + return 0; +} + static inline ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, void *private) {
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2.7.4