[PATCH 03/10] iommu/ipmmu-vmsa: Add helper functions for "uTLB" registers

[Oleksandr Tyshchenko <olekstysh@xxxxxxxxx>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

This is a non-verbatim port of corresponding Linux upsteam commit:
3667c9978b2911dc1ded77f5971df477885409c4

Original commit message:
 commit 3667c9978b2911dc1ded77f5971df477885409c4
 Author: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
 Date:   Wed Nov 6 11:35:49 2019 +0900

  iommu/ipmmu-vmsa: Add helper functions for "uTLB" registers

  Since we will have changed memory mapping of the IPMMU in the future,
  This patch adds helper functions ipmmu_utlb_reg() and
  ipmmu_imu{asid,ctr}_write() for "uTLB" registers. No behavior change.

  Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
  Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
  Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
  Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>

**********

This is a prereq work needed to add support for S4 series easily
in the future.

Besides changes done in the original commit, we also need to introduce
ipmmu_imuctr_read() since Xen driver contains an additional logic in
ipmmu_utlb_enable() to prevent the use cases where devices which use
the same micro-TLB are assigned to different Xen domains.

No change in behavior.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
---
 xen/drivers/passthrough/arm/ipmmu-vmsa.c | 33 +++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/xen/drivers/passthrough/arm/ipmmu-vmsa.c 
b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
index ce5c3bc..1b94af2 100644
--- a/xen/drivers/passthrough/arm/ipmmu-vmsa.c
+++ b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
@@ -366,6 +366,29 @@ static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain 
*domain,
     ipmmu_ctx_write_root(domain, reg, data);
 }
 
+static uint32_t ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, uint32_t reg)
+{
+    return reg;
+}
+
+static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
+                                unsigned int utlb, uint32_t data)
+{
+    ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUASID(utlb)), data);
+}
+
+static void ipmmu_imuctr_write(struct ipmmu_vmsa_device *mmu,
+                               unsigned int utlb, uint32_t data)
+{
+    ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)), data);
+}
+
+static uint32_t ipmmu_imuctr_read(struct ipmmu_vmsa_device *mmu,
+                                  unsigned int utlb)
+{
+    return ipmmu_read(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)));
+}
+
 /* TLB and micro-TLB Management */
 
 /* Wait for any pending TLB invalidations to complete. */
@@ -413,7 +436,7 @@ static int ipmmu_utlb_enable(struct ipmmu_vmsa_domain 
*domain,
      * context_id for already enabled micro-TLB and prevent different context
      * bank from being set.
      */
-    imuctr = ipmmu_read(mmu, IMUCTR(utlb));
+    imuctr = ipmmu_imuctr_read(mmu, utlb);
     if ( imuctr & IMUCTR_MMUEN )
     {
         unsigned int context_id;
@@ -431,9 +454,9 @@ static int ipmmu_utlb_enable(struct ipmmu_vmsa_domain 
*domain,
      * TODO: Reference-count the micro-TLB as several bus masters can be
      * connected to the same micro-TLB.
      */
-    ipmmu_write(mmu, IMUASID(utlb), 0);
-    ipmmu_write(mmu, IMUCTR(utlb), imuctr |
-                IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_MMUEN);
+    ipmmu_imuasid_write(mmu, utlb, 0);
+    ipmmu_imuctr_write(mmu, utlb, imuctr |
+                       IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_MMUEN);
 
     return 0;
 }
@@ -444,7 +467,7 @@ static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain 
*domain,
 {
     struct ipmmu_vmsa_device *mmu = domain->mmu;
 
-    ipmmu_write(mmu, IMUCTR(utlb), 0);
+    ipmmu_imuctr_write(mmu, utlb, 0);
 }
 
 /* Domain/Context Management */
-- 
2.7.4