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Subject[PATCH v9 4/8] iommu/msi-iommu: initialization
Date
iommu_get/put_msi_cookie allocates/frees the resource used to store
and ref count the MSI doorbell mappings. iommu_msi_set_aperture
initializes the iova domain used for MSI IOVA allocation and sets the
iommu domain's msi geometry.

The implementation relies on dma-iommu API and iova API.

New msi functions are fully implemented if CONFIG_IOMMU_MSI is set.

Signed-off-by: Eric Auger <eric.auger@linaro.org>

---
v9:
- remove is_aperture_set and use iommu_domain_msi_aperture_valid helper
instead
- set iommu domain's msi geometry

v8:
- new design where msi-iommu relies on dma-iommu
- remove the iommu_domain * from the doorbell_mapping struct
- added is_aperture_set

v7:
- fix locking
- add iova_cache_get/put
- static inline functions when CONFIG_IOMMU_DMA_RESERVED is not set
- introduce struct reserved_iova_domain to encapsulate prot info &
add prot parameter in alloc_reserved_iova_domain

v5 -> v6:
- use spin lock instead of mutex

v3 -> v4:
- formerly in "iommu/arm-smmu: implement alloc/free_reserved_iova_domain" &
"iommu: add alloc/free_reserved_iova_domain"

v2 -> v3:
- remove iommu_alloc_reserved_iova_domain & iommu_free_reserved_iova_domain
static implementation in case CONFIG_IOMMU_API is not set

v1 -> v2:
- moved from vfio API to IOMMU API
---
drivers/iommu/Kconfig | 7 ++++
drivers/iommu/Makefile | 1 +
drivers/iommu/msi-iommu.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/msi-iommu.h | 65 +++++++++++++++++++++++++++++++
4 files changed, 170 insertions(+)
create mode 100644 drivers/iommu/msi-iommu.c
create mode 100644 include/linux/msi-iommu.h

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index dd1dc39..0078b72 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -74,6 +74,11 @@ config IOMMU_DMA
select IOMMU_IOVA
select NEED_SG_DMA_LENGTH

+# IOMMU MSI mapping
+config IOMMU_MSI
+ bool
+ select IOMMU_DMA
+
config FSL_PAMU
bool "Freescale IOMMU support"
depends on PPC32
@@ -307,6 +312,7 @@ config SPAPR_TCE_IOMMU
config ARM_SMMU
bool "ARM Ltd. System MMU (SMMU) Support"
depends on (ARM64 || ARM) && MMU
+ select IOMMU_MSI
select IOMMU_API
select IOMMU_IO_PGTABLE_LPAE
select ARM_DMA_USE_IOMMU if ARM
@@ -320,6 +326,7 @@ config ARM_SMMU
config ARM_SMMU_V3
bool "ARM Ltd. System MMU Version 3 (SMMUv3) Support"
depends on ARM64 && PCI
+ select IOMMU_MSI
select IOMMU_API
select IOMMU_IO_PGTABLE_LPAE
select GENERIC_MSI_IRQ_DOMAIN
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index c6edb31..a381e66 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -2,6 +2,7 @@ obj-$(CONFIG_IOMMU_API) += iommu.o
obj-$(CONFIG_IOMMU_API) += iommu-traces.o
obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o
obj-$(CONFIG_IOMMU_DMA) += dma-iommu.o
+obj-$(CONFIG_IOMMU_MSI) += msi-iommu.o
obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o
obj-$(CONFIG_IOMMU_IO_PGTABLE_ARMV7S) += io-pgtable-arm-v7s.o
obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o
diff --git a/drivers/iommu/msi-iommu.c b/drivers/iommu/msi-iommu.c
new file mode 100644
index 0000000..4292957
--- /dev/null
+++ b/drivers/iommu/msi-iommu.c
@@ -0,0 +1,97 @@
+/*
+ * Reserved IOVA Management
+ *
+ * Copyright (c) 2015 Linaro Ltd.
+ * www.linaro.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/iommu.h>
+#include <linux/dma-iommu.h>
+#include <linux/msi-iommu.h>
+#include <linux/spinlock.h>
+#include <linux/iova.h>
+
+struct doorbell_mapping {
+ struct kref kref;
+ struct list_head next;
+ phys_addr_t addr;
+ dma_addr_t iova;
+ size_t size;
+};
+
+struct doorbell_mapping_info {
+ struct list_head list; /* list of doorbell mapping entries */
+ spinlock_t lock;
+};
+
+int iommu_get_msi_cookie(struct iommu_domain *domain)
+{
+ struct doorbell_mapping_info *dmi;
+ int ret;
+
+ if (domain->msi_cookie || domain->iova_cookie)
+ return -EINVAL;
+
+ ret = iommu_get_dma_cookie(domain);
+ if (ret)
+ return ret;
+
+ dmi = kzalloc(sizeof(*dmi), GFP_KERNEL);
+
+ INIT_LIST_HEAD(&dmi->list);
+ spin_lock_init(&dmi->lock);
+ iova_cache_get();
+
+ domain->msi_cookie = dmi;
+
+ return dmi ? 0 : -ENOMEM;
+}
+EXPORT_SYMBOL(iommu_get_msi_cookie);
+
+void iommu_put_msi_cookie(struct iommu_domain *domain)
+{
+ struct doorbell_mapping_info *dmi = domain->msi_cookie;
+
+ if (!dmi)
+ return;
+
+ domain->msi_cookie = NULL;
+
+ WARN_ON(!list_empty(&dmi->list));
+
+ kfree(dmi);
+ iommu_put_dma_cookie(domain);
+ iova_cache_put();
+}
+EXPORT_SYMBOL(iommu_put_msi_cookie);
+
+int iommu_msi_set_aperture(struct iommu_domain *domain,
+ dma_addr_t start, dma_addr_t end)
+{
+ struct doorbell_mapping_info *dmi = domain->msi_cookie;
+ int ret;
+
+ if (!dmi || iommu_domain_msi_aperture_valid(domain))
+ return -ENODEV;
+
+ ret = iommu_dma_init_domain(domain, start, end - start + 1);
+
+ if (!ret) {
+ domain->msi_geometry.aperture_start = start;
+ domain->msi_geometry.aperture_end = end;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_msi_set_aperture);
+
diff --git a/include/linux/msi-iommu.h b/include/linux/msi-iommu.h
new file mode 100644
index 0000000..392aa6f
--- /dev/null
+++ b/include/linux/msi-iommu.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2015 Linaro Ltd.
+ * www.linaro.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+#ifndef __MSI_IOMMU_H
+#define __MSI_IOMMU_H
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+
+struct iommu_domain;
+
+#ifdef CONFIG_IOMMU_MSI
+
+/**
+ * iommu_get_msi_cookie - Acquire MSI mapping resources for a domain
+ * @domain: IOMMU domain to prepare for MSI mapping
+ *
+ * IOMMU drivers which require MSI mapping should normally call this
+ * from their domain_alloc callback when domain->type ==
+ * IOMMU_DOMAIN_UNMANAGED.
+ */
+int iommu_get_msi_cookie(struct iommu_domain *domain);
+
+/**
+ * iommu_put_msi_cookie - Release a domain's MSI mapping resources
+ * @domain: IOMMU domain previously prepared by iommu_get_msi_cookie()
+ *
+ * IOMMU drivers requesting MSI mapping should normally call this from
+ * their domain_free callback.
+ */
+void iommu_put_msi_cookie(struct iommu_domain *domain);
+
+/**
+ * iommu_msi_set_aperture: allocate the msi iova domain
+ * according to the specified start/end IOVAs
+ *
+ * @domain: iommu domain handle
+ * @start: MSI iova start address
+ * @end: MSI iova end address
+ */
+int iommu_msi_set_aperture(struct iommu_domain *domain,
+ dma_addr_t start, dma_addr_t end);
+
+#else
+
+static inline int
+iommu_msi_set_aperture(struct iommu_domain *domain,
+ dma_addr_t start, dma_addr_t end)
+{
+ return -ENOENT;
+}
+
+#endif /* CONFIG_IOMMU_MSI */
+#endif /* __MSI_IOMMU_H */
--
1.9.1
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