Re: Fwd: [PATCH v4 06/18] cxl: Isolate a few bare-metal-specific calls

Subject: [PATCH v4 06/18] cxl: Isolate a few bare-metal-specific calls
Date: Tue, 16 Feb 2016 22:38:59 +0100
From: Frederic Barrat <redacted>
To: imunsie@au1.ibm.com, michael.neuling@au1.ibm.com,
mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org

A few functions are mostly common between bare-metal and guest and
just need minor tuning. To avoid crowding the backend API, introduce a
few 'if' based on the CPU being in HV mode.

Co-authored-by: Christophe Lombard [off-list ref]
Signed-off-by: Frederic Barrat <redacted>
Signed-off-by: Christophe Lombard <redacted>
Acked-by: Ian Munsie <redacted>
---
  drivers/misc/cxl/context.c |  3 ++-
  drivers/misc/cxl/cxl.h     |  7 +++++--
  drivers/misc/cxl/debugfs.c |  4 ++++
  drivers/misc/cxl/fault.c   | 19 +++++++++++--------
  4 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index aa65262..46f9844 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c

@@ -95,7 +95,8 @@ int cxl_context_init(struct cxl_context *ctx, struct

cxl_afu *afu, bool master,
          return i;

      ctx->pe = i;
-    ctx->elem = &ctx->afu->spa[i];
+    if (cpu_has_feature(CPU_FTR_HVMODE))
+        ctx->elem = &ctx->afu->spa[i];
      ctx->pe_inserted = false;

      /*

diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index 02065b4..40f6783 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h

@@ -560,8 +560,11 @@ static inline bool cxl_adapter_link_ok(struct cxl

*cxl)
  {
      struct pci_dev *pdev;

-    pdev = to_pci_dev(cxl->dev.parent);
-    return !pci_channel_offline(pdev);
+    if (cpu_has_feature(CPU_FTR_HVMODE)) {
+        pdev = to_pci_dev(cxl->dev.parent);
+        return !pci_channel_offline(pdev);
+    }
+    return true;
  }

  static inline void __iomem *_cxl_p1_addr(struct cxl *cxl, cxl_p1_reg_t
reg)

diff --git a/drivers/misc/cxl/debugfs.c b/drivers/misc/cxl/debugfs.c
index 18df6f4..5751899 100644
--- a/drivers/misc/cxl/debugfs.c
+++ b/drivers/misc/cxl/debugfs.c

@@ -118,6 +118,10 @@ void cxl_debugfs_afu_remove(struct cxl_afu *afu)
  int __init cxl_debugfs_init(void)
  {
      struct dentry *ent;
+
+    if (!cpu_has_feature(CPU_FTR_HVMODE))
+        return 0;
+
      ent = debugfs_create_dir("cxl", NULL);
      if (IS_ERR(ent))
          return PTR_ERR(ent);

diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c
index ab740a1..9a8650b 100644
--- a/drivers/misc/cxl/fault.c
+++ b/drivers/misc/cxl/fault.c

@@ -254,14 +254,17 @@ void cxl_handle_fault(struct work_struct *fault_work)
      u64 dar = ctx->dar;
      struct mm_struct *mm = NULL;

-    if (cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An) != dsisr ||
-        cxl_p2n_read(ctx->afu, CXL_PSL_DAR_An) != dar ||
-        cxl_p2n_read(ctx->afu, CXL_PSL_PEHandle_An) != ctx->pe) {
-        /* Most likely explanation is harmless - a dedicated process
-         * has detached and these were cleared by the PSL purge, but
-         * warn about it just in case */
-        dev_notice(&ctx->afu->dev, "cxl_handle_fault: Translation fault

regs changed\n");
-        return;
+    if (cpu_has_feature(CPU_FTR_HVMODE)) {
+        if (cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An) != dsisr ||
+            cxl_p2n_read(ctx->afu, CXL_PSL_DAR_An) != dar ||
+            cxl_p2n_read(ctx->afu, CXL_PSL_PEHandle_An) != ctx->pe) {
+            /* Most likely explanation is harmless - a dedicated
+             * process has detached and these were cleared by the
+             * PSL purge, but warn about it just in case
+             */
+            dev_notice(&ctx->afu->dev, "cxl_handle_fault: Translation
fault regs changed\n");
+            return;
+        }
      }

      /* Early return if the context is being / has been detached */