iommu/amd: Detect and initialize guest vAPIC log

This patch adds support to detect and initialize IOMMU Guest vAPIC log
(GALOG). By default, it also enable GALog interrupt to notify IOMMU driver
when GA Log entry is created.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index c17febb..156ab4b 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -84,6 +84,7 @@
 #define ACPI_DEVFLAG_LINT1              0x80
 #define ACPI_DEVFLAG_ATSDIS             0x10000000
 
+#define LOOP_TIMEOUT	100000
 /*
  * ACPI table definitions
  *
@@ -388,6 +389,10 @@
 	iommu_feature_disable(iommu, CONTROL_EVT_INT_EN);
 	iommu_feature_disable(iommu, CONTROL_EVT_LOG_EN);
 
+	/* Disable IOMMU GA_LOG */
+	iommu_feature_disable(iommu, CONTROL_GALOG_EN);
+	iommu_feature_disable(iommu, CONTROL_GAINT_EN);
+
 	/* Disable IOMMU hardware itself */
 	iommu_feature_disable(iommu, CONTROL_IOMMU_EN);
 }
@@ -673,6 +678,99 @@
 	free_pages((unsigned long)iommu->ppr_log, get_order(PPR_LOG_SIZE));
 }
 
+static void free_ga_log(struct amd_iommu *iommu)
+{
+#ifdef CONFIG_IRQ_REMAP
+	if (iommu->ga_log)
+		free_pages((unsigned long)iommu->ga_log,
+			    get_order(GA_LOG_SIZE));
+	if (iommu->ga_log_tail)
+		free_pages((unsigned long)iommu->ga_log_tail,
+			    get_order(8));
+#endif
+}
+
+static int iommu_ga_log_enable(struct amd_iommu *iommu)
+{
+#ifdef CONFIG_IRQ_REMAP
+	u32 status, i;
+
+	if (!iommu->ga_log)
+		return -EINVAL;
+
+	status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);
+
+	/* Check if already running */
+	if (status & (MMIO_STATUS_GALOG_RUN_MASK))
+		return 0;
+
+	iommu_feature_enable(iommu, CONTROL_GAINT_EN);
+	iommu_feature_enable(iommu, CONTROL_GALOG_EN);
+
+	for (i = 0; i < LOOP_TIMEOUT; ++i) {
+		status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);
+		if (status & (MMIO_STATUS_GALOG_RUN_MASK))
+			break;
+	}
+
+	if (i >= LOOP_TIMEOUT)
+		return -EINVAL;
+#endif /* CONFIG_IRQ_REMAP */
+	return 0;
+}
+
+#ifdef CONFIG_IRQ_REMAP
+static int iommu_init_ga_log(struct amd_iommu *iommu)
+{
+	u64 entry;
+
+	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
+		return 0;
+
+	iommu->ga_log = (u8 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+					get_order(GA_LOG_SIZE));
+	if (!iommu->ga_log)
+		goto err_out;
+
+	iommu->ga_log_tail = (u8 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+					get_order(8));
+	if (!iommu->ga_log_tail)
+		goto err_out;
+
+	entry = (u64)virt_to_phys(iommu->ga_log) | GA_LOG_SIZE_512;
+	memcpy_toio(iommu->mmio_base + MMIO_GA_LOG_BASE_OFFSET,
+		    &entry, sizeof(entry));
+	entry = ((u64)virt_to_phys(iommu->ga_log) & 0xFFFFFFFFFFFFFULL) & ~7ULL;
+	memcpy_toio(iommu->mmio_base + MMIO_GA_LOG_TAIL_OFFSET,
+		    &entry, sizeof(entry));
+	writel(0x00, iommu->mmio_base + MMIO_GA_HEAD_OFFSET);
+	writel(0x00, iommu->mmio_base + MMIO_GA_TAIL_OFFSET);
+
+	return 0;
+err_out:
+	free_ga_log(iommu);
+	return -EINVAL;
+}
+#endif /* CONFIG_IRQ_REMAP */
+
+static int iommu_init_ga(struct amd_iommu *iommu)
+{
+	int ret = 0;
+
+#ifdef CONFIG_IRQ_REMAP
+	/* Note: We have already checked GASup from IVRS table.
+	 *       Now, we need to make sure that GAMSup is set.
+	 */
+	if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) &&
+	    !iommu_feature(iommu, FEATURE_GAM_VAPIC))
+		amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY_GA;
+
+	ret = iommu_init_ga_log(iommu);
+#endif /* CONFIG_IRQ_REMAP */
+
+	return ret;
+}
+
 static void iommu_enable_gt(struct amd_iommu *iommu)
 {
 	if (!iommu_feature(iommu, FEATURE_GT))
@@ -1146,6 +1244,7 @@
 	free_command_buffer(iommu);
 	free_event_buffer(iommu);
 	free_ppr_log(iommu);
+	free_ga_log(iommu);
 	iommu_unmap_mmio_space(iommu);
 }
 
@@ -1438,6 +1537,7 @@
 {
 	int cap_ptr = iommu->cap_ptr;
 	u32 range, misc, low, high;
+	int ret;
 
 	iommu->dev = pci_get_bus_and_slot(PCI_BUS_NUM(iommu->devid),
 					  iommu->devid & 0xff);
@@ -1494,13 +1594,9 @@
 	if (iommu_feature(iommu, FEATURE_PPR) && alloc_ppr_log(iommu))
 		return -ENOMEM;
 
-	/* Note: We have already checked GASup from IVRS table.
-	 *       Now, we need to make sure that GAMSup is set.
-	 */
-	if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) &&
-	    !iommu_feature(iommu, FEATURE_GAM_VAPIC))
-		amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY_GA;
-
+	ret = iommu_init_ga(iommu);
+	if (ret)
+		return ret;
 
 	if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE))
 		amd_iommu_np_cache = true;
@@ -1667,6 +1763,8 @@
 	if (iommu->ppr_log != NULL)
 		iommu_feature_enable(iommu, CONTROL_PPFINT_EN);
 
+	iommu_ga_log_enable(iommu);
+
 	return 0;
 }