iommu/amd: Restore GA log/tail pointer on host resume

This will give IOMMU GA log a chance to work after resume
from s3/s4.

Fixes: 8bda0cf ("iommu/amd: Detect and initialize guest vAPIC log")

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20211123161038.48009-2-mlevitsk@redhat.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: Maxim Levitsky

drivers/iommu/amd/init.c

@@ -806,16 +806,27 @@ static int iommu_ga_log_enable(struct amd_iommu *iommu)
 {
 #ifdef CONFIG_IRQ_REMAP
 	u32 status, i;
+	u64 entry;
 
 	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))
+	status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);
+	if (WARN_ON(status & (MMIO_STATUS_GALOG_RUN_MASK)))
 		return 0;
 
+	entry = iommu_virt_to_phys(iommu->ga_log) | GA_LOG_SIZE_512;
+	memcpy_toio(iommu->mmio_base + MMIO_GA_LOG_BASE_OFFSET,
+		    &entry, sizeof(entry));
+	entry = (iommu_virt_to_phys(iommu->ga_log_tail) &
+		 (BIT_ULL(52)-1)) & ~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);
+
+
 	iommu_feature_enable(iommu, CONTROL_GAINT_EN);
 	iommu_feature_enable(iommu, CONTROL_GALOG_EN);
 
@@ -825,7 +836,7 @@ static int iommu_ga_log_enable(struct amd_iommu *iommu)
 			break;
 	}
 
-	if (i >= LOOP_TIMEOUT)
+	if (WARN_ON(i >= LOOP_TIMEOUT))
 		return -EINVAL;
 #endif /* CONFIG_IRQ_REMAP */
 	return 0;
@@ -834,8 +845,6 @@ static int iommu_ga_log_enable(struct amd_iommu *iommu)
 static int iommu_init_ga_log(struct amd_iommu *iommu)
 {
 #ifdef CONFIG_IRQ_REMAP
-	u64 entry;
-
 	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
 		return 0;
 
@@ -849,16 +858,6 @@ static int iommu_init_ga_log(struct amd_iommu *iommu)
 	if (!iommu->ga_log_tail)
 		goto err_out;
 
-	entry = iommu_virt_to_phys(iommu->ga_log) | GA_LOG_SIZE_512;
-	memcpy_toio(iommu->mmio_base + MMIO_GA_LOG_BASE_OFFSET,
-		    &entry, sizeof(entry));
-	entry = (iommu_virt_to_phys(iommu->ga_log_tail) &
-		 (BIT_ULL(52)-1)) & ~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);