On Tue, Dec 02, 2025 at 04:48:02PM -0800, Umesh Nerlige Ramappa wrote:

SoC remapper is used to map different HW functions in the SoC to their
respective drivers. Initialize SoC remapper during driver load.

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
---
v2: (Ashutosh/Lucas)
- s/remapper/soc_remapper/
- return status from init during probe
- reorder patches 1 and 2 from earlier series
- fix copyright year

v3: (Michal, Badal)
- Kernel doc fixes
- Alphabetical order for headers/objects
- Add has_soc_remapper
- Drop unnecessary headers
---
drivers/gpu/drm/xe/Makefile          |  1 +
drivers/gpu/drm/xe/xe_device.c       |  5 +++++
drivers/gpu/drm/xe/xe_device_types.h |  8 ++++++++
drivers/gpu/drm/xe/xe_pci.c          |  2 ++
drivers/gpu/drm/xe/xe_pci_types.h    |  2 ++
drivers/gpu/drm/xe/xe_soc_remapper.c | 24 ++++++++++++++++++++++++
drivers/gpu/drm/xe/xe_soc_remapper.h | 13 +++++++++++++
7 files changed, 55 insertions(+)
create mode 100644 drivers/gpu/drm/xe/xe_soc_remapper.c
create mode 100644 drivers/gpu/drm/xe/xe_soc_remapper.h

diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index 0eadfeda67d9..06c3987afd4c 100644
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -115,6 +115,7 @@ xe-y += xe_bb.o \
    xe_sa.o \
    xe_sched_job.o \
    xe_shrinker.o \
+    xe_soc_remapper.o \
    xe_step.o \
    xe_survivability_mode.o \
    xe_sync.o \
diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
index 92f883dd8877..b54fc5852fef 100644
--- a/drivers/gpu/drm/xe/xe_device.c
+++ b/drivers/gpu/drm/xe/xe_device.c
@@ -61,6 +61,7 @@
#include "xe_pxp.h"
#include "xe_query.h"
#include "xe_shrinker.h"
+#include "xe_soc_remapper.h"
#include "xe_survivability_mode.h"
#include "xe_sriov.h"
#include "xe_tile.h"
@@ -906,6 +907,10 @@ int xe_device_probe(struct xe_device *xe)

    xe_nvm_init(xe);

+    err = xe_soc_remapper_init(xe);
+    if (err)
+        return err;
+
    err = xe_heci_gsc_init(xe);
    if (err)
        return err;
diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index 9a9a8eb84a78..450fe703a3b9 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -315,6 +315,8 @@ struct xe_device {
        u8 has_pxp:1;
        /** @info.has_range_tlb_inval: Has range based TLB invalidations */
        u8 has_range_tlb_inval:1;
+        /** @info.has_soc_remapper: Has SoC remapper support */
+        u8 has_soc_remapper:1;
        /** @info.has_sriov: Supports SR-IOV */
        u8 has_sriov:1;
        /** @info.has_usm: Device has unified shared memory support */
@@ -555,6 +557,12 @@ struct xe_device {
        struct mutex lock;
    } pmt;

+    /** @soc_remapper: SoC remapper object */
+    struct {
+        /** @soc_remapper.lock: Serialize access to SoC Remapper's index registers */
+        spinlock_t lock;
+    } soc_remapper;
+
    /**
     * @pm_callback_task: Track the active task that is running in either
     * the runtime_suspend or runtime_resume callbacks.
diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
index 75e3588242c7..ec0fed691fa0 100644
--- a/drivers/gpu/drm/xe/xe_pci.c
+++ b/drivers/gpu/drm/xe/xe_pci.c
@@ -413,6 +413,7 @@ static const struct xe_device_desc cri_desc = {
    .has_flat_ccs = false,
    .has_mbx_power_limits = true,
    .has_mert = true,
+    .has_soc_remapper = true,

Needs to be enabled for BMG also, hence the BAT failure. 

We should use has_soc_remapper not just for protecting spinlock initialization, but also for guarding soc remapper accesses.

Since there are two soc remappers—SC and Telemetry—we could update has_soc_remapper to use 2 bits (u8 has_soc_remapper:2), and set only the relevant bits in the platform descriptor. For example:

static const struct xe_device_desc bmg_desc = {
    .has_soc_remapper = SOC_REMAP_TELEM 
    
static const struct xe_device_desc cri_desc = {
    .has_soc_remapper = SOC_REMAP_TELEM | SOC_REMAP_SC 

If we prefer a true/false approach, we should use two separate flags: has_soc_telem_remapper and has_soc_sc_remapper.

Thanks,
Badal

Umesh