drm/i915/gsc: allocate extended operational memory in LMEM

GSC requires more operational memory than available on chip.
Reserve 4M of LMEM for GSC operation. The memory is provided to the
GSC as struct resource to the auxiliary data of the child device.

Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220907215113.1596567-16-tomas.winkler@intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/gt/intel_gsc.c

@@ -7,6 +7,7 @@
 #include <linux/mei_aux.h>
 #include "i915_drv.h"
 #include "i915_reg.h"
+#include "gem/i915_gem_region.h"
 #include "gt/intel_gsc.h"
 #include "gt/intel_gt.h"
 
@@ -36,12 +37,56 @@ static int gsc_irq_init(int irq)
 	return irq_set_chip_data(irq, NULL);
 }
 
+static int
+gsc_ext_om_alloc(struct intel_gsc *gsc, struct intel_gsc_intf *intf, size_t size)
+{
+	struct intel_gt *gt = gsc_to_gt(gsc);
+	struct drm_i915_gem_object *obj;
+	int err;
+
+	obj = i915_gem_object_create_lmem(gt->i915, size,
+					  I915_BO_ALLOC_CONTIGUOUS |
+					  I915_BO_ALLOC_CPU_CLEAR);
+	if (IS_ERR(obj)) {
+		drm_err(&gt->i915->drm, "Failed to allocate gsc memory\n");
+		return PTR_ERR(obj);
+	}
+
+	err = i915_gem_object_pin_pages_unlocked(obj);
+	if (err) {
+		drm_err(&gt->i915->drm, "Failed to pin pages for gsc memory\n");
+		goto out_put;
+	}
+
+	intf->gem_obj = obj;
+
+	return 0;
+
+out_put:
+	i915_gem_object_put(obj);
+	return err;
+}
+
+static void gsc_ext_om_destroy(struct intel_gsc_intf *intf)
+{
+	struct drm_i915_gem_object *obj = fetch_and_zero(&intf->gem_obj);
+
+	if (!obj)
+		return;
+
+	if (i915_gem_object_has_pinned_pages(obj))
+		i915_gem_object_unpin_pages(obj);
+
+	i915_gem_object_put(obj);
+}
+
 struct gsc_def {
 	const char *name;
 	unsigned long bar;
 	size_t bar_size;
 	bool use_polling;
 	bool slow_firmware;
+	size_t lmem_size;
 };
 
 /* gsc resources and definitions (HECI1 and HECI2) */
@@ -74,6 +119,7 @@ static const struct gsc_def gsc_def_dg2[] = {
 		.name = "mei-gsc",
 		.bar = DG2_GSC_HECI1_BASE,
 		.bar_size = GSC_BAR_LENGTH,
+		.lmem_size = SZ_4M,
 	},
 	{
 		.name = "mei-gscfi",
@@ -90,26 +136,32 @@ static void gsc_release_dev(struct device *dev)
 	kfree(adev);
 }
 
-static void gsc_destroy_one(struct intel_gsc_intf *intf)
+static void gsc_destroy_one(struct drm_i915_private *i915,
+			    struct intel_gsc *gsc, unsigned int intf_id)
 {
+	struct intel_gsc_intf *intf = &gsc->intf[intf_id];
+
 	if (intf->adev) {
 		auxiliary_device_delete(&intf->adev->aux_dev);
 		auxiliary_device_uninit(&intf->adev->aux_dev);
 		intf->adev = NULL;
 	}
+
 	if (intf->irq >= 0)
 		irq_free_desc(intf->irq);
 	intf->irq = -1;
+
+	gsc_ext_om_destroy(intf);
 }
 
-static void gsc_init_one(struct drm_i915_private *i915,
-			 struct intel_gsc_intf *intf,
+static void gsc_init_one(struct drm_i915_private *i915, struct intel_gsc *gsc,
 			 unsigned int intf_id)
 {
 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
 	struct mei_aux_device *adev;
 	struct auxiliary_device *aux_dev;
 	const struct gsc_def *def;
+	struct intel_gsc_intf *intf = &gsc->intf[intf_id];
 	int ret;
 
 	intf->irq = -1;
@@ -141,7 +193,7 @@ static void gsc_init_one(struct drm_i915_private *i915,
 	intf->irq = irq_alloc_desc(0);
 	if (intf->irq < 0) {
 		drm_err(&i915->drm, "gsc irq error %d\n", intf->irq);
-		return;
+		goto fail;
 	}
 
 	ret = gsc_irq_init(intf->irq);
@@ -155,6 +207,19 @@ static void gsc_init_one(struct drm_i915_private *i915,
 	if (!adev)
 		goto fail;
 
+	if (def->lmem_size) {
+		drm_dbg(&i915->drm, "setting up GSC lmem\n");
+
+		if (gsc_ext_om_alloc(gsc, intf, def->lmem_size)) {
+			drm_err(&i915->drm, "setting up gsc extended operational memory failed\n");
+			kfree(adev);
+			goto fail;
+		}
+
+		adev->ext_op_mem.start = i915_gem_object_get_dma_address(intf->gem_obj, 0);
+		adev->ext_op_mem.end = adev->ext_op_mem.start + def->lmem_size;
+	}
+
 	adev->irq = intf->irq;
 	adev->bar.parent = &pdev->resource[0];
 	adev->bar.start = def->bar + pdev->resource[0].start;
@@ -188,7 +253,7 @@ static void gsc_init_one(struct drm_i915_private *i915,
 
 	return;
 fail:
-	gsc_destroy_one(intf);
+	gsc_destroy_one(i915, gsc, intf->id);
 }
 
 static void gsc_irq_handler(struct intel_gt *gt, unsigned int intf_id)
@@ -229,7 +294,7 @@ void intel_gsc_init(struct intel_gsc *gsc, struct drm_i915_private *i915)
 		return;
 
 	for (i = 0; i < INTEL_GSC_NUM_INTERFACES; i++)
-		gsc_init_one(i915, &gsc->intf[i], i);
+		gsc_init_one(i915, gsc, i);
 }
 
 void intel_gsc_fini(struct intel_gsc *gsc)
@@ -241,5 +306,5 @@ void intel_gsc_fini(struct intel_gsc *gsc)
 		return;
 
 	for (i = 0; i < INTEL_GSC_NUM_INTERFACES; i++)
-		gsc_destroy_one(&gsc->intf[i]);
+		gsc_destroy_one(gt->i915, gsc, i);
 }

drivers/gpu/drm/i915/gt/intel_gsc.h

@@ -20,11 +20,14 @@ struct mei_aux_device;
 
 /**
  * struct intel_gsc - graphics security controller
+ *
+ * @gem_obj: scratch memory GSC operations
  * @intf : gsc interface
  */
 struct intel_gsc {
 	struct intel_gsc_intf {
 		struct mei_aux_device *adev;
+		struct drm_i915_gem_object *gem_obj;
 		int irq;
 		unsigned int id;
 	} intf[INTEL_GSC_NUM_INTERFACES];