Commit-ID: 0feae533ddebe02cda6ccce5cac7349b446776a8
Gitweb: http://git.kernel.org/tip/0feae533ddebe02cda6ccce5cac7349b446776a8
Author: Joerg Roedel <joerg.roedel@xxxxxxx>
AuthorDate: Wed, 26 Aug 2009 15:26:30 +0200
Committer: Joerg Roedel <joerg.roedel@xxxxxxx>
CommitDate: Thu, 3 Sep 2009 16:15:42 +0200
x86/amd-iommu: Add passthrough mode initialization functions
When iommu=pt is passed on kernel command line the devices
should run untranslated. This requires the allocation of a
special domain for that purpose. This patch implements the
allocation and initialization path for iommu=pt.
Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/include/asm/amd_iommu.h | 1 +
arch/x86/include/asm/amd_iommu_types.h | 4 ++
arch/x86/kernel/amd_iommu.c | 72 ++++++++++++++++++++++++++++----
3 files changed, 69 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/amd_iommu.h b/arch/x86/include/asm/amd_iommu.h
index bdf96f1..ac95995 100644
--- a/arch/x86/include/asm/amd_iommu.h
+++ b/arch/x86/include/asm/amd_iommu.h
@@ -25,6 +25,7 @@
#ifdef CONFIG_AMD_IOMMU
extern int amd_iommu_init(void);
extern int amd_iommu_init_dma_ops(void);
+extern int amd_iommu_init_passthrough(void);
extern void amd_iommu_detect(void);
extern irqreturn_t amd_iommu_int_handler(int irq, void *data);
extern void amd_iommu_flush_all_domains(void);
diff --git a/arch/x86/include/asm/amd_iommu_types.h b/arch/x86/include/asm/amd_iommu_types.h
index 0c878ca..49f7453 100644
--- a/arch/x86/include/asm/amd_iommu_types.h
+++ b/arch/x86/include/asm/amd_iommu_types.h
@@ -143,6 +143,7 @@
#define EVT_BUFFER_SIZE 8192 /* 512 entries */
#define EVT_LEN_MASK (0x9ULL << 56)
+#define PAGE_MODE_NONE 0x00
#define PAGE_MODE_1_LEVEL 0x01
#define PAGE_MODE_2_LEVEL 0x02
#define PAGE_MODE_3_LEVEL 0x03
@@ -194,6 +195,9 @@
#define PD_DMA_OPS_MASK (1UL << 0) /* domain used for dma_ops */
#define PD_DEFAULT_MASK (1UL << 1) /* domain is a default dma_ops
domain for an IOMMU */
+#define PD_PASSTHROUGH_MASK (1UL << 2) /* domain has no page
+ translation */
+
extern bool amd_iommu_dump;
#define DUMP_printk(format, arg...) \
do { \
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 0934348..7987f20 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -41,6 +41,12 @@ static DEFINE_RWLOCK(amd_iommu_devtable_lock);
static LIST_HEAD(iommu_pd_list);
static DEFINE_SPINLOCK(iommu_pd_list_lock);
+/*
+ * Domain for untranslated devices - only allocated
+ * if iommu=pt passed on kernel cmd line.
+ */
+static struct protection_domain *pt_domain;
+
#ifdef CONFIG_IOMMU_API
static struct iommu_ops amd_iommu_ops;
#endif
@@ -1067,9 +1073,9 @@ static struct protection_domain *domain_for_device(u16 devid)
* If a device is not yet associated with a domain, this function does
* assigns it visible for the hardware
*/
-static void attach_device(struct amd_iommu *iommu,
- struct protection_domain *domain,
- u16 devid)
+static void __attach_device(struct amd_iommu *iommu,
+ struct protection_domain *domain,
+ u16 devid)
{
unsigned long flags;
u64 pte_root = virt_to_phys(domain->pt_root);
@@ -1087,12 +1093,19 @@ static void attach_device(struct amd_iommu *iommu,
amd_iommu_pd_table[devid] = domain;
write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+}
- /*
- * We might boot into a crash-kernel here. The crashed kernel
- * left the caches in the IOMMU dirty. So we have to flush
- * here to evict all dirty stuff.
- */
+static void attach_device(struct amd_iommu *iommu,
+ struct protection_domain *domain,
+ u16 devid)
+{
+ __attach_device(iommu, domain, devid);
+
+ /*
+ * We might boot into a crash-kernel here. The crashed kernel
+ * left the caches in the IOMMU dirty. So we have to flush
+ * here to evict all dirty stuff.
+ */
iommu_queue_inv_dev_entry(iommu, devid);
iommu_flush_tlb_pde(iommu, domain->id);
}
@@ -2219,3 +2232,46 @@ static struct iommu_ops amd_iommu_ops = {
.domain_has_cap = amd_iommu_domain_has_cap,
};
+/*****************************************************************************
+ *
+ * The next functions do a basic initialization of IOMMU for pass through
+ * mode
+ *
+ * In passthrough mode the IOMMU is initialized and enabled but not used for
+ * DMA-API translation.
+ *
+ *****************************************************************************/
+
+int __init amd_iommu_init_passthrough(void)
+{
+ struct pci_dev *dev = NULL;
+ u16 devid, devid2;
+
+ /* allocate passthroug domain */
+ pt_domain = protection_domain_alloc();
+ if (!pt_domain)
+ return -ENOMEM;
+
+ pt_domain->mode |= PAGE_MODE_NONE;
+
+ while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
+ struct amd_iommu *iommu;
+
+ devid = calc_devid(dev->bus->number, dev->devfn);
+ if (devid > amd_iommu_last_bdf)
+ continue;
+
+ devid2 = amd_iommu_alias_table[devid];
+
+ iommu = amd_iommu_rlookup_table[devid2];
+ if (!iommu)
+ continue;
+
+ __attach_device(iommu, pt_domain, devid);
+ __attach_device(iommu, pt_domain, devid2);
+ }
+
+ pr_info("AMD-Vi: Initialized for Passthrough Mode\n");
+
+ return 0;
+}
--
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