gpu: nvgpu: assume 1:1 IPA to PA mapping for syncpt

Currently, hyp_read_ipa_pa_info() only translates IPA for RAM
mappings. It fails for MMIO mappings. In particular, it will
fail when attempting to translate addresses in the syncpoint
shim aperture. As a workaround, assume 1:1 IPA to PA mapping
when hyp_read_ipa_pa_info fails, and address is in syncpt
shim aperture.

Bug 2096877

Change-Id: I5267f0a8febf065157910ad3408374cacd398731
Signed-off-by: Thomas Fleury <tfleury@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1687796
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Richard Zhao <rizhao@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/soc.c b/drivers/gpu/nvgpu/common/linux/soc.c
index 22645381..305d8bd9 100644
--- a/drivers/gpu/nvgpu/common/linux/soc.c
+++ b/drivers/gpu/nvgpu/common/linux/soc.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2017-2018, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -67,8 +67,21 @@ static u64 nvgpu_tegra_hv_ipa_pa(struct gk20a *g, u64 ipa)
 
         err = hyp_read_ipa_pa_info(&info, platform->vmid, ipa);
         if (err < 0) {
-                nvgpu_err(g, "ipa=%llx translation failed vmid=%u err=%d",
+                /* WAR for bug 2096877
+                 * hyp_read_ipa_pa_info only looks up RAM mappings.
+                 * assume one to one IPA:PA mapping for syncpt aperture
+                 */
+                u64 start = g->syncpt_unit_base;
+                u64 end = g->syncpt_unit_base + g->syncpt_unit_size;
+                if ((ipa >= start) && (ipa < end)) {
+                        pa = ipa;
+                        nvgpu_log(g, gpu_dbg_map_v,
+                                "ipa=%llx vmid=%d -> pa=%llx (SYNCPT)\n",
+                                ipa, platform->vmid, pa);
+                } else {
+                        nvgpu_err(g, "ipa=%llx translation failed vmid=%u err=%d",
                                 ipa, platform->vmid, err);
+                }
         } else {
                 pa = info.base + info.offset;
                 nvgpu_log(g, gpu_dbg_map_v,