Patch "iommu/amd: Restore GA log/tail pointer on host resume" has been added to the 5.16-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

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

to the 5.16-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     iommu-amd-restore-ga-log-tail-pointer-on-host-resume.patch
and it can be found in the queue-5.16 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6ea4ddbca2a06bd1cbce9730446ae68bfffe1b67
Author: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Date:   Tue Nov 23 18:10:34 2021 +0200

    iommu/amd: Restore GA log/tail pointer on host resume
    
    [ Upstream commit a8d4a37d1bb93608501d0d0545f902061152669a ]
    
    This will give IOMMU GA log a chance to work after resume
    from s3/s4.
    
    Fixes: 8bda0cfbdc1a6 ("iommu/amd: Detect and initialize guest vAPIC log")
    
    Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20211123161038.48009-2-mlevitsk@xxxxxxxxxx
    Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 1eacd43cb4368..8dae85fcfc2eb 100644
--- a/drivers/iommu/amd/init.c
+++ b/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);