Re: [Intel-gfx] [PATCH 20/20] drm/i915/gsc: allocate extended operational memory in LMEM

From: Matthew Auld
Date: Fri Apr 08 2022 - 06:55:35 EST


On Thu, 7 Apr 2022 at 14:00, Alexander Usyskin
<alexander.usyskin@xxxxxxxxx> wrote:
>
> From: Tomas Winkler <tomas.winkler@xxxxxxxxx>
>
> 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.
>
> Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
> Cc: Alan Previn <alan.previn.teres.alexis@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/intel_gsc.c | 92 ++++++++++++++++++++++++++---
> drivers/gpu/drm/i915/gt/intel_gsc.h | 3 +
> 2 files changed, 88 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gsc.c b/drivers/gpu/drm/i915/gt/intel_gsc.c
> index bfc307e49bf9..4d87519d5773 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gsc.c
> +++ b/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 +37,68 @@ 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;
> + void *vaddr;
> + int err;
> +
> + obj = i915_gem_object_create_lmem(gt->i915, size, I915_BO_ALLOC_CONTIGUOUS);
> + 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;
> + }
> +
> + vaddr = i915_gem_object_pin_map_unlocked(obj, i915_coherent_map_type(gt->i915, obj, true));
> + if (IS_ERR(vaddr)) {
> + err = PTR_ERR(vaddr);
> + drm_err(&gt->i915->drm, "Failed to map gsc memory\n");
> + goto out_unpin;
> + }
> +
> + memset(vaddr, 0, obj->base.size);

We should be able to pass I915_BO_ALLOC_CPU_CLEAR to create_lmem,
which should do something like this for us, when later calling
pin_pages or similar.

> +
> + i915_gem_object_unpin_map(obj);
> +
> + intf->gem_obj = obj;
> +
> + return 0;
> +
> +out_unpin:
> + i915_gem_object_unpin_pages(obj);
> +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_fw;
> + size_t lmem_size;
> };
>
> /* gsc resources and definitions (HECI1 and HECI2) */
> @@ -74,6 +131,7 @@ 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 +148,33 @@ 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,
> - unsigned int intf_id)
> + 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 +206,7 @@ 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 +220,19 @@ static void gsc_init_one(struct drm_i915_private *i915,
> if (!adev)
> goto fail;
>
> + if (def->lmem_size) {
> + dev_dbg(&pdev->dev, "setting up GSC lmem\n");
> +
> + if (gsc_ext_om_alloc(gsc, intf, def->lmem_size)) {
> + dev_err(&pdev->dev, "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 +266,7 @@ 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 +307,7 @@ 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 +319,5 @@ 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);
> }
> diff --git a/drivers/gpu/drm/i915/gt/intel_gsc.h b/drivers/gpu/drm/i915/gt/intel_gsc.h
> index 68582f912b21..fcac1775e9c3 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gsc.h
> +++ b/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];
> --
> 2.32.0
>