[xen staging] xen/arm: Enhance IPMMU-VMSA driver robustness and debug output

[patchbot@xxxxxxx]

commit 2e73633a175a7c3ba8b534416de9f6af262a8a9b
Author:     Jahan Murudi <jahan.murudi.zg@xxxxxxxxxxx>
AuthorDate: Fri Jun 20 16:01:23 2025 +0530
Commit:     Julien Grall <julien@xxxxxxx>
CommitDate: Sat Jul 12 11:32:35 2025 +0100

    xen/arm: Enhance IPMMU-VMSA driver robustness and debug output
    
    - Fix typo in source comment ("you can found" -> "which can be found").
    - Add dsb(sy) after IMCTR write to ensure flush is complete before polling.
    - Add dev_info() log in ipmmu_device_reset() to indicate the number of 
disabled contexts.
    
    These changes improve memory operation ordering, code readability, and 
runtime traceability
    for IPMMU on R-Car Gen3/Gen4 SoCs
    
    Signed-off-by: Jahan Murudi <jahan.murudi.zg@xxxxxxxxxxx>
    Acked-by: Michal Orzel <michal.orzel@xxxxxxx>
---
 xen/drivers/passthrough/arm/ipmmu-vmsa.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/xen/drivers/passthrough/arm/ipmmu-vmsa.c 
b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
index d828d9cf6a..dac0dd6d46 100644
--- a/xen/drivers/passthrough/arm/ipmmu-vmsa.c
+++ b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
@@ -13,7 +13,7 @@
  *
  * Based on Linux's IPMMU-VMSA driver from Renesas BSP:
  *    drivers/iommu/ipmmu-vmsa.c
- * you can found at:
+ * which can be found at:
  *    url: git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas-bsp.git
  *    branch: v4.14.75-ltsi/rcar-3.9.6
  *    commit: e206eb5b81a60e64c35fbc3a999b1a0db2b98044
@@ -433,6 +433,8 @@ static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain 
*domain)
     data |= IMCTR_FLUSH;
     ipmmu_ctx_write_all(domain, IMCTR, data);
 
+    /* Force IMCTR write to complete before polling to avoid false completion 
check. */
+    dsb(sy);
     ipmmu_tlb_sync(domain);
 }
 
@@ -780,6 +782,8 @@ static void ipmmu_device_reset(struct ipmmu_vmsa_device 
*mmu)
     /* Disable all contexts. */
     for ( i = 0; i < mmu->num_ctx; ++i )
         ipmmu_ctx_write(mmu, i, IMCTR, 0);
+
+    dev_info(mmu->dev, "Reset completed, disabled %u contexts\n", 
mmu->num_ctx);
 }
 
 /* R-Car Gen3/Gen4 SoCs product and cut information. */
--
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