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Message-Id: <1431337974-545-8-git-send-email-zhen-hual@hp.com>
Date: Mon, 11 May 2015 17:52:51 +0800
From: "Li, Zhen-Hua" <zhen-hual@...com>
To: <dwmw2@...radead.org>, <indou.takao@...fujitsu.com>,
<bhe@...hat.com>, <joro@...tes.org>, <vgoyal@...hat.com>,
<dyoung@...hat.com>
Cc: <iommu@...ts.linux-foundation.org>, <linux-kernel@...r.kernel.org>,
<linux-pci@...r.kernel.org>, <kexec@...ts.infradead.org>,
<alex.williamson@...hat.com>, <ddutile@...hat.com>,
<ishii.hironobu@...fujitsu.com>, <bhelgaas@...gle.com>,
<doug.hatch@...com>, <jerry.hoemann@...com>, <tom.vaden@...com>,
<li.zhang6@...com>, <lisa.mitchell@...com>,
<billsumnerlinux@...il.com>, <zhen-hual@...com>, <rwright@...com>
Subject: [PATCH v11 07/10] iommu/vt-d: enable kdump support in iommu module
Modify the operation of the following functions when called during crash dump:
iommu_context_addr
free_context_table
get_domain_for_dev
init_dmars
intel_iommu_init
Bill Sumner:
Original version.
Zhenhua:
The name of new calling functions.
Do not disable and re-enable TE in kdump kernel.
Use the did and gaw from old context entry;
Signed-off-by: Bill Sumner <billsumnerlinux@...il.com>
Signed-off-by: Li, Zhen-Hua <zhen-hual@...com>
---
drivers/iommu/intel-iommu.c | 95 +++++++++++++++++++++++++++++++++++++++------
1 file changed, 83 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 28c3c64..91545bf 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -397,6 +397,7 @@ static int copy_root_entry_table(struct intel_iommu *iommu);
static int intel_iommu_load_translation_tables(struct intel_iommu *iommu);
static void iommu_check_pre_te_status(struct intel_iommu *iommu);
+static u8 g_translation_pre_enabled;
/*
* This domain is a statically identity mapping domain.
@@ -794,6 +795,9 @@ static inline struct context_entry *iommu_context_addr(struct intel_iommu *iommu
phy_addr = virt_to_phys((void *)context);
*entry = phy_addr | 1;
__iommu_flush_cache(iommu, entry, sizeof(*entry));
+
+ if (iommu->pre_enabled_trans)
+ __iommu_update_old_root_entry(iommu, bus);
}
return &context[devfn];
}
@@ -887,13 +891,15 @@ static void clear_context_table(struct intel_iommu *iommu, u8 bus, u8 devfn)
static void free_context_table(struct intel_iommu *iommu)
{
+ struct root_entry *root = NULL;
int i;
unsigned long flags;
struct context_entry *context;
spin_lock_irqsave(&iommu->lock, flags);
if (!iommu->root_entry) {
- goto out;
+ spin_unlock_irqrestore(&iommu->lock, flags);
+ return;
}
for (i = 0; i < ROOT_ENTRY_NR; i++) {
context = iommu_context_addr(iommu, i, 0, 0);
@@ -908,10 +914,23 @@ static void free_context_table(struct intel_iommu *iommu)
free_pgtable_page(context);
}
+
+ if (iommu->pre_enabled_trans) {
+ iommu->root_entry_old_phys = 0;
+ root = iommu->root_entry_old_virt;
+ iommu->root_entry_old_virt = NULL;
+ }
+
free_pgtable_page(iommu->root_entry);
iommu->root_entry = NULL;
-out:
+
spin_unlock_irqrestore(&iommu->lock, flags);
+
+ /* We put this out of spin_unlock is because iounmap() may
+ * cause error if surrounded by spin_lock and unlock;
+ */
+ if (iommu->pre_enabled_trans)
+ iounmap(root);
}
static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
@@ -2333,6 +2352,7 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw)
unsigned long flags;
u8 bus, devfn;
int did = -1; /* Default to "no domain_id supplied" */
+ struct context_entry *ce = NULL;
domain = find_domain(dev);
if (domain)
@@ -2366,6 +2386,20 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw)
domain = alloc_domain(0);
if (!domain)
return NULL;
+
+ if (iommu->pre_enabled_trans) {
+ /*
+ * if this device had a did in the old kernel
+ * use its values instead of generating new ones
+ */
+ ce = device_to_existing_context_entry(iommu, bus, devfn);
+
+ if (ce) {
+ did = context_domain_id(ce);
+ gaw = agaw_to_width(context_address_width(ce));
+ }
+ }
+
domain->id = iommu_attach_domain_with_id(domain, iommu, did);
if (domain->id < 0) {
free_domain_mem(domain);
@@ -2897,6 +2931,7 @@ static int __init init_dmars(void)
goto free_g_iommus;
}
+ g_translation_pre_enabled = 0; /* To know whether to skip RMRR */
for_each_active_iommu(iommu, drhd) {
g_iommus[iommu->seq_id] = iommu;
@@ -2904,14 +2939,30 @@ static int __init init_dmars(void)
if (ret)
goto free_iommu;
- /*
- * TBD:
- * we could share the same root & context tables
- * among all IOMMU's. Need to Split it later.
- */
- ret = iommu_alloc_root_entry(iommu);
- if (ret)
- goto free_iommu;
+ iommu_check_pre_te_status(iommu);
+ if (iommu->pre_enabled_trans) {
+ pr_info("IOMMU Copying translate tables from panicked kernel\n");
+ ret = intel_iommu_load_translation_tables(iommu);
+ if (ret) {
+ pr_err("IOMMU: Copy translate tables failed\n");
+
+ /* Best to stop trying */
+ goto free_iommu;
+ }
+ pr_info("IOMMU: root_cache:0x%12.12llx phys:0x%12.12llx\n",
+ (u64)iommu->root_entry,
+ (u64)iommu->root_entry_old_phys);
+ } else {
+ /*
+ * TBD:
+ * we could share the same root & context tables
+ * among all IOMMU's. Need to Split it later.
+ */
+ ret = iommu_alloc_root_entry(iommu);
+ if (ret)
+ goto free_iommu;
+ }
+
if (!ecap_pass_through(iommu->ecap))
hw_pass_through = 0;
}
@@ -2929,6 +2980,14 @@ static int __init init_dmars(void)
check_tylersburg_isoch();
/*
+ * In the second kernel: Skip setting-up new domains for
+ * si, rmrr, and the isa bus on the expectation that these
+ * translations were copied from the old kernel.
+ */
+ if (g_translation_pre_enabled)
+ goto skip_new_domains_for_si_rmrr_isa;
+
+ /*
* If pass through is not set or not enabled, setup context entries for
* identity mappings for rmrr, gfx, and isa and may fall back to static
* identity mapping if iommu_identity_mapping is set.
@@ -2968,6 +3027,8 @@ static int __init init_dmars(void)
iommu_prepare_isa();
+skip_new_domains_for_si_rmrr_isa:;
+
/*
* for each drhd
* enable fault log
@@ -2996,7 +3057,13 @@ static int __init init_dmars(void)
iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
- iommu_enable_translation(iommu);
+
+ if (iommu->pre_enabled_trans) {
+ if (!(iommu->gcmd & DMA_GCMD_TE))
+ iommu_enable_translation(iommu);
+ } else
+ iommu_enable_translation(iommu);
+
iommu_disable_protect_mem_regions(iommu);
}
@@ -4282,11 +4349,14 @@ int __init intel_iommu_init(void)
}
/*
- * Disable translation if already enabled prior to OS handover.
+ * We do not need to disable translation if already enabled prior
+ * to OS handover. Because we will try to copy old tables;
*/
+ /*
for_each_active_iommu(iommu, drhd)
if (iommu->gcmd & DMA_GCMD_TE)
iommu_disable_translation(iommu);
+ */
if (dmar_dev_scope_init() < 0) {
if (force_on)
@@ -5106,5 +5176,6 @@ static void iommu_check_pre_te_status(struct intel_iommu *iommu)
if (sts & DMA_GSTS_TES) {
pr_info("Translation is enabled prior to OS.\n");
iommu->pre_enabled_trans = 1;
+ g_translation_pre_enabled = 1;
}
}
--
2.0.0-rc0
--
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