Older HW only supports debugging on a single process because the
SPI debug mode setting registers are device global.

The HWS has supplied a single pinned VMID (0xf) for MAP_PROCESS
for debug purposes. To pin the VMID, the KFD will remove the VMID from
the HWS dynamic VMID allocation via SET_RESOUCES so that a debugged
process will never migrate away from its pinned VMID.

The KFD is responsible for reserving and releasing this pinned VMID
accordingly whenever the debugger attaches and detaches respectively.

v2: spot fix ups using new kfd_node references

Signed-off-by: Jonathan Kim <jonathan....@amd.com>
---
 .../drm/amd/amdkfd/kfd_device_queue_manager.c | 93 +++++++++++++++++++
 .../drm/amd/amdkfd/kfd_device_queue_manager.h |  5 +
 .../drm/amd/amdkfd/kfd_packet_manager_v9.c    |  9 ++
 .../gpu/drm/amd/amdkfd/kfd_pm4_headers_ai.h   |  5 +-
 4 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index d1f44feb7084..c8519adc89ac 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -1524,6 +1524,7 @@ static int initialize_cpsch(struct device_queue_manager 
*dqm)
        dqm->gws_queue_count = 0;
        dqm->active_runlist = false;
        INIT_WORK(&dqm->hw_exception_work, kfd_process_hw_exception);
+       dqm->trap_debug_vmid = 0;
 
        init_sdma_bitmaps(dqm);
 
@@ -2500,6 +2501,98 @@ static void kfd_process_hw_exception(struct work_struct 
*work)
        amdgpu_amdkfd_gpu_reset(dqm->dev->adev);
 }
 
+int reserve_debug_trap_vmid(struct device_queue_manager *dqm,
+                               struct qcm_process_device *qpd)
+{
+       int r;
+       int updated_vmid_mask;
+
+       if (dqm->sched_policy == KFD_SCHED_POLICY_NO_HWS) {
+               pr_err("Unsupported on sched_policy: %i\n", dqm->sched_policy);
+               return -EINVAL;
+       }
+
+       dqm_lock(dqm);
+
+       if (dqm->trap_debug_vmid != 0) {
+               pr_err("Trap debug id already reserved\n");
+               r = -EBUSY;
+               goto out_unlock;
+       }
+
+       r = unmap_queues_cpsch(dqm, KFD_UNMAP_QUEUES_FILTER_ALL_QUEUES, 0,
+                       USE_DEFAULT_GRACE_PERIOD, false);
+       if (r)
+               goto out_unlock;
+
+       updated_vmid_mask = dqm->dev->kfd->shared_resources.compute_vmid_bitmap;
+       updated_vmid_mask &= ~(1 << dqm->dev->vm_info.last_vmid_kfd);
+
+       dqm->dev->kfd->shared_resources.compute_vmid_bitmap = updated_vmid_mask;
+       dqm->trap_debug_vmid = dqm->dev->vm_info.last_vmid_kfd;
+       r = set_sched_resources(dqm);
+       if (r)
+               goto out_unlock;
+
+       r = map_queues_cpsch(dqm);
+       if (r)
+               goto out_unlock;
+
+       pr_debug("Reserved VMID for trap debug: %i\n", dqm->trap_debug_vmid);
+
+out_unlock:
+       dqm_unlock(dqm);
+       return r;
+}
+
+/*
+ * Releases vmid for the trap debugger
+ */
+int release_debug_trap_vmid(struct device_queue_manager *dqm,
+                       struct qcm_process_device *qpd)
+{
+       int r;
+       int updated_vmid_mask;
+       uint32_t trap_debug_vmid;
+
+       if (dqm->sched_policy == KFD_SCHED_POLICY_NO_HWS) {
+               pr_err("Unsupported on sched_policy: %i\n", dqm->sched_policy);
+               return -EINVAL;
+       }
+
+       dqm_lock(dqm);
+       trap_debug_vmid = dqm->trap_debug_vmid;
+       if (dqm->trap_debug_vmid == 0) {
+               pr_err("Trap debug id is not reserved\n");
+               r = -EINVAL;
+               goto out_unlock;
+       }
+
+       r = unmap_queues_cpsch(dqm, KFD_UNMAP_QUEUES_FILTER_ALL_QUEUES, 0,
+                       USE_DEFAULT_GRACE_PERIOD, false);
+       if (r)
+               goto out_unlock;
+
+       updated_vmid_mask = dqm->dev->kfd->shared_resources.compute_vmid_bitmap;
+       updated_vmid_mask |= (1 << dqm->dev->vm_info.last_vmid_kfd);
+
+       dqm->dev->kfd->shared_resources.compute_vmid_bitmap = updated_vmid_mask;
+       dqm->trap_debug_vmid = 0;
+       r = set_sched_resources(dqm);
+       if (r)
+               goto out_unlock;
+
+       r = map_queues_cpsch(dqm);
+       if (r)
+               goto out_unlock;
+
+       pr_debug("Released VMID for trap debug: %i\n", trap_debug_vmid);
+
+out_unlock:
+       dqm_unlock(dqm);
+       return r;
+}
+
 #if defined(CONFIG_DEBUG_FS)
 
 static void seq_reg_dump(struct seq_file *m,
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h 
b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h
index d4dd3b4acbf0..bf7aa3f84182 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h
@@ -250,6 +250,7 @@ struct device_queue_manager {
        struct kfd_mem_obj      *fence_mem;
        bool                    active_runlist;
        int                     sched_policy;
+       uint32_t                trap_debug_vmid;
 
        /* hw exception  */
        bool                    is_hws_hang;
@@ -285,6 +286,10 @@ unsigned int get_queues_per_pipe(struct 
device_queue_manager *dqm);
 unsigned int get_pipes_per_mec(struct device_queue_manager *dqm);
 unsigned int get_num_sdma_queues(struct device_queue_manager *dqm);
 unsigned int get_num_xgmi_sdma_queues(struct device_queue_manager *dqm);
+int reserve_debug_trap_vmid(struct device_queue_manager *dqm,
+                       struct qcm_process_device *qpd);
+int release_debug_trap_vmid(struct device_queue_manager *dqm,
+                       struct qcm_process_device *qpd);
 
 static inline unsigned int get_sh_mem_bases_32(struct kfd_process_device *pdd)
 {
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
index 1fda6dcf84b1..0fe73dbd28af 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
@@ -34,6 +34,9 @@ static int pm_map_process_v9(struct packet_manager *pm,
 {
        struct pm4_mes_map_process *packet;
        uint64_t vm_page_table_base_addr = qpd->page_table_base;
+       struct kfd_node *kfd = pm->dqm->dev;
+       struct kfd_process_device *pdd =
+                       container_of(qpd, struct kfd_process_device, qpd);
 
        packet = (struct pm4_mes_map_process *)buffer;
        memset(buffer, 0, sizeof(struct pm4_mes_map_process));
@@ -49,6 +52,12 @@ static int pm_map_process_v9(struct packet_manager *pm,
        packet->bitfields14.sdma_enable = 1;
        packet->bitfields14.num_queues = (qpd->is_debug) ? 0 : qpd->queue_count;
 
+       if (kfd->dqm->trap_debug_vmid && pdd->process->debug_trap_enabled &&
+                       pdd->process->runtime_info.runtime_state == 
DEBUG_RUNTIME_STATE_ENABLED) {
+               packet->bitfields2.debug_vmid = kfd->dqm->trap_debug_vmid;
+               packet->bitfields2.new_debug = 1;
+       }
+
        packet->sh_mem_config = qpd->sh_mem_config;
        packet->sh_mem_bases = qpd->sh_mem_bases;
        if (qpd->tba_addr) {
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_pm4_headers_ai.h 
b/drivers/gpu/drm/amd/amdkfd/kfd_pm4_headers_ai.h
index 206f1960857f..8b6b2bd5c148 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_pm4_headers_ai.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_pm4_headers_ai.h
@@ -146,7 +146,10 @@ struct pm4_mes_map_process {
        union {
                struct {
                        uint32_t pasid:16;
-                       uint32_t reserved1:8;
+                       uint32_t reserved1:2;
+                       uint32_t debug_vmid:4;
+                       uint32_t new_debug:1;
+                       uint32_t reserved2:1;
                        uint32_t diq_enable:1;
                        uint32_t process_quantum:7;
                } bitfields2;
-- 
2.25.1

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