[Intel-gfx] [PATCH] drm/i915: Use per device iommu check

Tvrtko Ursulin
2021-11-09T12:18:13Z

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

On igfx + dgfx setups, it appears that intel_iommu=igfx_off option only
disables the igfx iommu. Stop relying on global intel_iommu_gfx_mapped
and probe presence of iommu domain per device to accurately reflect its
status.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
---
Baolu, is my understanding here correct? Maybe I am confused by both
intel_iommu_gfx_mapped and dmar_map_gfx being globals in the intel_iommu
driver. But it certainly appears the setup can assign some iommu ops (and
assign the discrete i915 to iommu group) when those two are set to off.
---
drivers/gpu/drm/i915/display/intel_bw.c | 2 +-
drivers/gpu/drm/i915/display/intel_display.c | 2 +-
drivers/gpu/drm/i915/display/intel_fbc.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gemfs.c | 2 +-
drivers/gpu/drm/i915/gt/intel_ggtt.c | 4 ++--
drivers/gpu/drm/i915/i915_debugfs.c | 1 +
drivers/gpu/drm/i915/i915_drv.c | 7 +++++++
drivers/gpu/drm/i915/i915_drv.h | 13 +++++++------
drivers/gpu/drm/i915/i915_gpu_error.c | 5 +----
drivers/gpu/drm/i915/intel_device_info.c | 14 +-------------
drivers/gpu/drm/i915/intel_pm.c | 2 +-
12 files changed, 25 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index 8d9d888e9316..a4d8088e4f71 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -490,7 +490,7 @@ static unsigned int intel_bw_data_rate(struct drm_i915_private *dev_priv,
for_each_pipe(dev_priv, pipe)
data_rate += bw_state->data_rate[pipe];

- if (DISPLAY_VER(dev_priv) >= 13 && intel_vtd_active())
+ if (DISPLAY_VER(dev_priv) >= 13 && intel_vtd_active(dev_priv))
data_rate = data_rate * 105 / 100;

return data_rate;
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 29392dfc46c8..80d206f3e9da 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -1315,7 +1315,7 @@ static bool needs_async_flip_vtd_wa(const struct intel_crtc_state *crtc_state)
{
struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);

- return crtc_state->uapi.async_flip && intel_vtd_active() &&
+ return crtc_state->uapi.async_flip && intel_vtd_active(i915) &&
(DISPLAY_VER(i915) == 9 || IS_BROADWELL(i915) || IS_HASWELL(i915));
}

diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
index 834eb4cc7c10..0ccbfc9e4101 100644
--- a/drivers/gpu/drm/i915/display/intel_fbc.c
+++ b/drivers/gpu/drm/i915/display/intel_fbc.c
@@ -1539,7 +1539,7 @@ static int intel_sanitize_fbc_option(struct drm_i915_private *dev_priv)
static bool need_fbc_vtd_wa(struct drm_i915_private *dev_priv)
{
/* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */
- if (intel_vtd_active() &&
+ if (intel_vtd_active(dev_priv) &&
(IS_SKYLAKE(dev_priv) || IS_BROXTON(dev_priv))) {
drm_info(&dev_priv->drm,
"Disabling framebuffer compression (FBC) to prevent screen flicker with VT-d enabled\n");
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
index ddd37ccb1362..cf100c0ea3b7 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
@@ -399,7 +399,7 @@ static int i915_gem_init_stolen(struct intel_memory_region *mem)
return 0;
}

- if (intel_vtd_active() && GRAPHICS_VER(i915) < 8) {
+ if (intel_vtd_active(i915) && GRAPHICS_VER(i915) < 8) {
drm_notice(&i915->drm,
"%s, disabling use of stolen memory\n",
"DMAR active");
diff --git a/drivers/gpu/drm/i915/gem/i915_gemfs.c b/drivers/gpu/drm/i915/gem/i915_gemfs.c
index dbdbdc344d87..11cd66d183e6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gemfs.c
+++ b/drivers/gpu/drm/i915/gem/i915_gemfs.c
@@ -31,7 +31,7 @@ int i915_gemfs_init(struct drm_i915_private *i915)
*/

opts = NULL;
- if (intel_vtd_active()) {
+ if (intel_vtd_active(i915)) {
if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
static char huge_opt[] = "huge=within_size"; /* r/w */

diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index 1fb4a03d7ac3..ddb4a9d039d4 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -104,7 +104,7 @@ static bool needs_idle_maps(struct drm_i915_private *i915)
* Query intel_iommu to see if we need the workaround. Presumably that
* was loaded first.
*/
- if (!intel_vtd_active())
+ if (!intel_vtd_active(i915))
return false;

if (GRAPHICS_VER(i915) == 5 && IS_MOBILE(i915))
@@ -1231,7 +1231,7 @@ int i915_ggtt_probe_hw(struct drm_i915_private *i915)
if (ret)
return ret;

- if (intel_vtd_active())
+ if (intel_vtd_active(i915))
drm_info(&i915->drm, "VT-d active for gfx access\n");

return 0;
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index fe638b5da7c0..390d541f64ea 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -65,6 +65,7 @@ static int i915_capabilities(struct seq_file *m, void *data)

intel_device_info_print_static(INTEL_INFO(i915), &p);
intel_device_info_print_runtime(RUNTIME_INFO(i915), &p);
+ i915_print_iommu_status(i915, &p);
intel_gt_info_print(&i915->gt.info, &p);
intel_driver_caps_print(&i915->caps, &p);

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index f184b44d05f2..8efd0ad5bef0 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -733,6 +733,12 @@ static void i915_driver_unregister(struct drm_i915_private *dev_priv)
i915_gem_driver_unregister(dev_priv);
}

+void
+i915_print_iommu_status(struct drm_i915_private *i915, struct drm_printer *p)
+{
+ drm_printf(p, "iommu: %s\n", enableddisabled(intel_vtd_active(i915)));
+}
+
static void i915_welcome_messages(struct drm_i915_private *dev_priv)
{
if (drm_debug_enabled(DRM_UT_DRIVER)) {
@@ -748,6 +754,7 @@ static void i915_welcome_messages(struct drm_i915_private *dev_priv)

intel_device_info_print_static(INTEL_INFO(dev_priv), &p);
intel_device_info_print_runtime(RUNTIME_INFO(dev_priv), &p);
+ i915_print_iommu_status(dev_priv, &p);
intel_gt_info_print(&dev_priv->gt.info, &p);
}

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e967cd08f23e..9fb38a54f1fe 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1763,26 +1763,27 @@ static inline bool run_as_guest(void)
#define HAS_D12_PLANE_MINIMIZATION(dev_priv) (IS_ROCKETLAKE(dev_priv) || \
IS_ALDERLAKE_S(dev_priv))

-static inline bool intel_vtd_active(void)
+static inline bool intel_vtd_active(struct drm_i915_private *i915)
{
-#ifdef CONFIG_INTEL_IOMMU
- if (intel_iommu_gfx_mapped)
+ if (iommu_get_domain_for_dev(i915->drm.dev))
return true;
-#endif

/* Running as a guest, we assume the host is enforcing VT'd */
return run_as_guest();
}

+void
+i915_print_iommu_status(struct drm_i915_private *i915, struct drm_printer *p);
+
static inline bool intel_scanout_needs_vtd_wa(struct drm_i915_private *dev_priv)
{
- return GRAPHICS_VER(dev_priv) >= 6 && intel_vtd_active();
+ return GRAPHICS_VER(dev_priv) >= 6 && intel_vtd_active(dev_priv);
}

static inline bool
intel_ggtt_update_needs_vtd_wa(struct drm_i915_private *i915)
{
- return IS_BROXTON(i915) && intel_vtd_active();
+ return IS_BROXTON(i915) && intel_vtd_active(i915);
}

static inline bool
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index aa2b3aad9643..7672927ed10b 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1750,10 +1750,7 @@ static void capture_gen(struct i915_gpu_coredump *error)
error->wakelock = atomic_read(&i915->runtime_pm.wakeref_count);
error->suspended = i915->runtime_pm.suspended;

- error->iommu = -1;
-#ifdef CONFIG_INTEL_IOMMU
- error->iommu = intel_iommu_gfx_mapped;
-#endif
+ error->iommu = intel_vtd_active(i915);
error->reset_count = i915_reset_count(&i915->gpu_error);
error->suspend_count = i915->suspend_count;

diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
index 6e6b317bc33c..e6605b5181a5 100644
--- a/drivers/gpu/drm/i915/intel_device_info.c
+++ b/drivers/gpu/drm/i915/intel_device_info.c
@@ -83,17 +83,6 @@ const char *intel_platform_name(enum intel_platform platform)
return platform_names[platform];
}

-static const char *iommu_name(void)
-{
- const char *msg = "n/a";
-
-#ifdef CONFIG_INTEL_IOMMU
- msg = enableddisabled(intel_iommu_gfx_mapped);
-#endif
-
- return msg;
-}
-
void intel_device_info_print_static(const struct intel_device_info *info,
struct drm_printer *p)
{
@@ -114,7 +103,6 @@ void intel_device_info_print_static(const struct intel_device_info *info,
drm_printf(p, "display version: %u\n", info->display.ver);

drm_printf(p, "gt: %d\n", info->gt);
- drm_printf(p, "iommu: %s\n", iommu_name());
drm_printf(p, "memory-regions: %x\n", info->memory_regions);
drm_printf(p, "page-sizes: %x\n", info->page_sizes);
drm_printf(p, "platform: %s\n", intel_platform_name(info->platform));
@@ -374,7 +362,7 @@ void intel_device_info_runtime_init(struct drm_i915_private *dev_priv)
info->display.has_dsc = 0;
}

- if (GRAPHICS_VER(dev_priv) == 6 && intel_vtd_active()) {
+ if (GRAPHICS_VER(dev_priv) == 6 && intel_vtd_active(dev_priv)) {
drm_info(&dev_priv->drm,
"Disabling ppGTT for VT-d support\n");
info->ppgtt_type = INTEL_PPGTT_NONE;
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 59adf0ce6719..f5b567f87c24 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -98,7 +98,7 @@ static void gen9_init_clock_gating(struct drm_i915_private *dev_priv)
* "Plane N strech max must be programmed to 11b (x1)
* when Async flips are enabled on that plane."
*/
- if (!IS_GEMINILAKE(dev_priv) && intel_vtd_active())
+ if (!IS_GEMINILAKE(dev_priv) && intel_vtd_active(dev_priv))
intel_uncore_rmw(&dev_priv->uncore, CHICKEN_PIPESL_1(pipe),
SKL_PLANE1_STRETCH_MAX_MASK, SKL_PLANE1_STRETCH_MAX_X1);
}
--
2.30.2