[PATCH 3/5] x86/amd-iommu: Flush device IOTLB if ATS is enabled

From: Joerg Roedel
Date: Fri Apr 08 2011 - 04:18:12 EST


This patch implements a function to flush the IOTLB on
devices supporting ATS and makes sure that this TLB is also
flushed if necessary.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/include/asm/amd_iommu_types.h | 3 +-
arch/x86/kernel/amd_iommu.c | 74 +++++++++++++++++++++++++++++++-
2 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/amd_iommu_types.h b/arch/x86/include/asm/amd_iommu_types.h
index 878ae00..f5d184e 100644
--- a/arch/x86/include/asm/amd_iommu_types.h
+++ b/arch/x86/include/asm/amd_iommu_types.h
@@ -113,7 +113,8 @@
/* command specific defines */
#define CMD_COMPL_WAIT 0x01
#define CMD_INV_DEV_ENTRY 0x02
-#define CMD_INV_IOMMU_PAGES 0x03
+#define CMD_INV_IOMMU_PAGES 0x03
+#define CMD_INV_IOTLB_PAGES 0x04

#define CMD_COMPL_WAIT_STORE_MASK 0x01
#define CMD_COMPL_WAIT_INT_MASK 0x02
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index bcf58ea..f3ce433 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -18,6 +18,7 @@
*/

#include <linux/pci.h>
+#include <linux/pci-ats.h>
#include <linux/bitmap.h>
#include <linux/slab.h>
#include <linux/debugfs.h>
@@ -463,6 +464,37 @@ static void build_inv_iommu_pages(struct iommu_cmd *cmd, u64 address,
cmd->data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK;
}

+static void build_inv_iotlb_pages(struct iommu_cmd *cmd, u16 devid, int qdep,
+ u64 address, size_t size)
+{
+ u64 pages;
+ int s;
+
+ pages = iommu_num_pages(address, size, PAGE_SIZE);
+ s = 0;
+
+ if (pages > 1) {
+ /*
+ * If we have to flush more than one page, flush all
+ * TLB entries for this domain
+ */
+ address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS;
+ s = 1;
+ }
+
+ address &= PAGE_MASK;
+
+ memset(cmd, 0, sizeof(*cmd));
+ cmd->data[0] = devid;
+ cmd->data[0] |= (qdep & 0xff) << 24;
+ cmd->data[1] = devid;
+ cmd->data[2] = lower_32_bits(address);
+ cmd->data[3] = upper_32_bits(address);
+ CMD_SET_TYPE(cmd, CMD_INV_IOTLB_PAGES);
+ if (s)
+ cmd->data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK;
+}
+
/*
* Writes the command to the IOMMUs command buffer and informs the
* hardware about the new command.
@@ -574,17 +606,47 @@ void iommu_flush_all_caches(struct amd_iommu *iommu)
}

/*
+ * Command send function for flushing on-device TLB
+ */
+static int device_flush_iotlb(struct device *dev, u64 address, size_t size)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct amd_iommu *iommu;
+ struct iommu_cmd cmd;
+ u16 devid;
+ int qdep;
+
+ qdep = pci_ats_queue_depth(pdev);
+ devid = get_device_id(dev);
+ iommu = amd_iommu_rlookup_table[devid];
+
+ build_inv_iotlb_pages(&cmd, devid, qdep, address, size);
+
+ return iommu_queue_command(iommu, &cmd);
+}
+
+/*
* Command send function for invalidating a device table entry
*/
static int device_flush_dte(struct device *dev)
{
struct amd_iommu *iommu;
+ struct pci_dev *pdev;
u16 devid;
+ int ret;

+ pdev = to_pci_dev(dev);
devid = get_device_id(dev);
iommu = amd_iommu_rlookup_table[devid];

- return iommu_flush_dte(iommu, devid);
+ ret = iommu_flush_dte(iommu, devid);
+ if (ret)
+ return ret;
+
+ if (pci_ats_enabled(pdev))
+ ret = device_flush_iotlb(dev, 0, ~0UL);
+
+ return ret;
}

/*
@@ -595,6 +657,7 @@ static int device_flush_dte(struct device *dev)
static void __domain_flush_pages(struct protection_domain *domain,
u64 address, size_t size, int pde)
{
+ struct iommu_dev_data *dev_data;
struct iommu_cmd cmd;
int ret = 0, i;

@@ -611,6 +674,15 @@ static void __domain_flush_pages(struct protection_domain *domain,
ret |= iommu_queue_command(amd_iommus[i], &cmd);
}

+ list_for_each_entry(dev_data, &domain->dev_list, list) {
+ struct pci_dev *pdev = to_pci_dev(dev_data->dev);
+
+ if (!pci_ats_enabled(pdev))
+ continue;
+
+ ret |= device_flush_iotlb(dev_data->dev, address, size);
+ }
+
WARN_ON(ret);
}

--
1.7.1


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