amd-iommu: consolidate hardware initialization to one function

This patch restructures the AMD IOMMU initialization code to initialize
all hardware registers with one single function call.
This is helpful for suspend/resume support.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 32 insertions, 18 deletions

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 675a4b642f70..74f4f1fea930 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -252,13 +252,6 @@ static void __init iommu_enable(struct amd_iommu *iommu)
         iommu_feature_enable(iommu, CONTROL_IOMMU_EN);
 }
 
-/* Function to enable IOMMU event logging and event interrupts */
-static void __init iommu_enable_event_logging(struct amd_iommu *iommu)
-{
-        iommu_feature_enable(iommu, CONTROL_EVT_LOG_EN);
-        iommu_feature_enable(iommu, CONTROL_EVT_INT_EN);
-}
-
 /*
  * mapping and unmapping functions for the IOMMU MMIO space. Each AMD IOMMU in
  * the system has one.
@@ -413,25 +406,36 @@ static u8 * __init alloc_command_buffer(struct amd_iommu *iommu)
 {
         u8 *cmd_buf = (u8 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
                         get_order(CMD_BUFFER_SIZE));
-        u64 entry;
 
         if (cmd_buf == NULL)
                 return NULL;
 
         iommu->cmd_buf_size = CMD_BUFFER_SIZE;
 
-        entry = (u64)virt_to_phys(cmd_buf);
+        return cmd_buf;
+}
+
+/*
+ * This function writes the command buffer address to the hardware and
+ * enables it.
+ */
+static void iommu_enable_command_buffer(struct amd_iommu *iommu)
+{
+        u64 entry;
+
+        BUG_ON(iommu->cmd_buf == NULL);
+
+        entry = (u64)virt_to_phys(iommu->cmd_buf);
         entry |= MMIO_CMD_SIZE_512;
+
         memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET,
-                        &entry, sizeof(entry));
+                    &entry, sizeof(entry));
 
         /* set head and tail to zero manually */
         writel(0x00, iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
         writel(0x00, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
 
         iommu_feature_enable(iommu, CONTROL_CMDBUF_EN);
-
-        return cmd_buf;
 }
 
 static void __init free_command_buffer(struct amd_iommu *iommu)
@@ -443,20 +447,27 @@ static void __init free_command_buffer(struct amd_iommu *iommu)
 /* allocates the memory where the IOMMU will log its events to */
 static u8 * __init alloc_event_buffer(struct amd_iommu *iommu)
 {
-        u64 entry;
         iommu->evt_buf = (u8 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
                                                 get_order(EVT_BUFFER_SIZE));
 
         if (iommu->evt_buf == NULL)
                 return NULL;
 
+        return iommu->evt_buf;
+}
+
+static void iommu_enable_event_buffer(struct amd_iommu *iommu)
+{
+        u64 entry;
+
+        BUG_ON(iommu->evt_buf == NULL);
+
         entry = (u64)virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;
+
         memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET,
                     &entry, sizeof(entry));
 
-        iommu->evt_buf_size = EVT_BUFFER_SIZE;
-
-        return iommu->evt_buf;
+        iommu_feature_enable(iommu, CONTROL_EVT_LOG_EN);
 }
 
 static void __init free_event_buffer(struct amd_iommu *iommu)
@@ -710,7 +721,6 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
         if (!iommu->mmio_base)
                 return -ENOMEM;
 
-        iommu_set_device_table(iommu);
         iommu->cmd_buf = alloc_command_buffer(iommu);
         if (!iommu->cmd_buf)
                 return -ENOMEM;
@@ -837,6 +847,8 @@ static int __init iommu_setup_msi(struct amd_iommu *iommu)
                 return 1;
         }
 
+        iommu_feature_enable(iommu, CONTROL_EVT_INT_EN);
+
         return 0;
 }
 
@@ -972,9 +984,11 @@ static void __init enable_iommus(void)
         struct amd_iommu *iommu;
 
         for_each_iommu(iommu) {
+                iommu_set_device_table(iommu);
+                iommu_enable_command_buffer(iommu);
+                iommu_enable_event_buffer(iommu);
                 iommu_set_exclusion_range(iommu);
                 iommu_init_msi(iommu);
-                iommu_enable_event_logging(iommu);
                 iommu_enable(iommu);
         }
 }