On Tue, Nov 25, 2025 at 03:43:46PM +0530, Nareshkumar Gollakoti wrote: Big subject, no message... Please: https://www.kernel.org/doc/html/latest/process/submitting-patches.html
> v2: > - function xe_device_is_vf_enabled has been refactored to > xe_sriov_pf_has_vfs_enabled and moved to xe_sriov_pf_helper.h. > - The code now distinctly checks for SR-IOV VF mode and > SR-IOV PF with VFs enabled. > - Log messages have been updated to explicitly state the current mode. > - The function xe_multi_ccs_mode_enabled is moved to xe_device.h > > v3: Described missed arg documentation for xe_sriov_pf_has_vfs_enabled > > v4: > - sysfs interface for CCS mode is not initialized > when operating in SRIOV VF Mode. > - xe_sriov_pf_has_vfs_enabled() check is sufficient while CCS mode > enablement. > - remove unnecessary comments as flow is self explanatory. > > v5:(review comments from Michal) > - Add xe device level CCS mode block with mutex lock and CCS mode state > - necessesary functions to manage ccs mode state to provide strict mutual > exclusive support b/w CCS mode & SRIOV VF enabling > > v6: > - Re modeled implementation based on lockdown the PF using custom guard > supported functions by Michal > > Signed-off-by: Nareshkumar Gollakoti <[email protected]> > --- > drivers/gpu/drm/xe/xe_gt_ccs_mode.c | 47 ++++++++++++++++++++++++----- > 1 file changed, 39 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/xe/xe_gt_ccs_mode.c > b/drivers/gpu/drm/xe/xe_gt_ccs_mode.c > index 50fffc9ebf62..495bf517a6d3 100644 > --- a/drivers/gpu/drm/xe/xe_gt_ccs_mode.c > +++ b/drivers/gpu/drm/xe/xe_gt_ccs_mode.c > @@ -13,6 +13,7 @@ > #include "xe_gt_sysfs.h" > #include "xe_mmio.h" > #include "xe_sriov.h" > +#include "xe_sriov_pf_helpers.h" > > static void __xe_gt_apply_ccs_mode(struct xe_gt *gt, u32 num_engines) > { > @@ -108,6 +109,30 @@ ccs_mode_show(struct device *kdev, > return sysfs_emit(buf, "%u\n", gt->ccs_mode); > } > > +static int xe_gt_prepare_ccs_mode_enabling(struct xe_device *xe, > + struct xe_gt *gt) > +{ > + /* > + * The arm guard is only activated during CCS mode enabling, > + * and this shuould happen when CCS mode is in default mode. > + * lockdown arm guard ensures there is no VFS enabling > + * as CCS mode enabling in progress/enabled. > + */ > + if (!(gt->ccs_mode > 1)) > + return xe_sriov_pf_arm_guard(xe, > &xe->sriov.pf.guard_vfs_enabling, > + true, NULL); > + return 0; > +} > + > +static void xe_gt_finish_ccs_mode_enabling(struct xe_device *xe, > + struct xe_gt *gt) > +{ > + /* disarm the guard, if CCS mode is reverted to default */ > + if (!(gt->ccs_mode > 1)) > + xe_sriov_pf_disarm_guard(xe, &xe->sriov.pf.guard_vfs_enabling, > + true, NULL); > +} > + > static ssize_t > ccs_mode_store(struct device *kdev, struct device_attribute *attr, > const char *buff, size_t count) > @@ -117,15 +142,13 @@ ccs_mode_store(struct device *kdev, struct > device_attribute *attr, > u32 num_engines, num_slices; > int ret; > > - if (IS_SRIOV(xe)) { > - xe_gt_dbg(gt, "Can't change compute mode when running as %s\n", > - xe_sriov_mode_to_string(xe_device_sriov_mode(xe))); > - return -EOPNOTSUPP; > - } > + ret = xe_gt_prepare_ccs_mode_enabling(xe, gt); > + if (ret) > + return ret; > > ret = kstrtou32(buff, 0, &num_engines); > if (ret) > - return ret; > + goto err; > > /* > * Ensure number of engines specified is valid and there is an > @@ -135,7 +158,8 @@ ccs_mode_store(struct device *kdev, struct > device_attribute *attr, > if (!num_engines || num_engines > num_slices || num_slices % > num_engines) { > xe_gt_dbg(gt, "Invalid compute config, %d engines %d slices\n", > num_engines, num_slices); > - return -EINVAL; > + ret = -EINVAL; > + goto err; > } > > /* CCS mode can only be updated when there are no drm clients */ > @@ -143,7 +167,8 @@ ccs_mode_store(struct device *kdev, struct > device_attribute *attr, > if (!list_empty(&xe->drm.filelist)) { > mutex_unlock(&xe->drm.filelist_mutex); > xe_gt_dbg(gt, "Rejecting compute mode change as there are > active drm clients\n"); > - return -EBUSY; > + ret = -EBUSY; > + goto err; > } > > if (gt->ccs_mode != num_engines) { > @@ -155,7 +180,13 @@ ccs_mode_store(struct device *kdev, struct > device_attribute *attr, > > mutex_unlock(&xe->drm.filelist_mutex); > > + xe_gt_finish_ccs_mode_enabling(xe, gt); > + > return count; > +err: > + xe_gt_finish_ccs_mode_enabling(xe, gt); > + > + return ret; > } > > static DEVICE_ATTR_RW(ccs_mode); > -- > 2.43.0 >
