[Intel-xe] [RFC v2 2/6] drm/xe/xe2: Determine bios enablement for flat ccs on igfx.

[Ghimiray, Himal Prasad]

On 24-11-2023 16:35, Thomas Hellström wrote:
> On Tue, 2023-11-21 at 15:39 +0530, Himal Prasad Ghimiray wrote:
>> If bios disables flat ccs on igfx  make has_flat_ccs as 0 and notify
> double space above                 ^^
Will address in next patch.
>> via drm_info.
>>
>> Bspec:59255
>>
>> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
>> Signed-off-by: Himal Prasad Ghimiray
>> <himal.prasad.ghimiray at intel.com>
>> ---
>>   drivers/gpu/drm/xe/regs/xe_gt_regs.h |  3 +++
>>   drivers/gpu/drm/xe/xe_device.c       | 30
>> ++++++++++++++++++++++++++++
>>   2 files changed, 33 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> index cc27fe8fc363..b642301947f5 100644
>> --- a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> +++ b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> @@ -142,6 +142,9 @@
>>   #define XEHP_SLICE_COMMON_ECO_CHICKEN1         XE_REG_MCR(0x731c,
>> XE_REG_OPTION_MASKED)
>>   #define   MSC_MSAA_REODER_BUF_BYPASS_DISABLE   REG_BIT(14)
>>   
>> +#define XE2_FLAT_CCS_BASE_RANGE_LOWER          XE_REG_MCR(0x8800)
>> +#define   XE2_FLAT_CCS_ENABLE                  REG_BIT(0)
>> +
>>   #define VF_PREEMPTION                          XE_REG(0x83a4,
>> XE_REG_OPTION_MASKED)
>>   #define   PREEMPTION_VERTEX_COUNT              REG_GENMASK(15, 0)
>>   
>> diff --git a/drivers/gpu/drm/xe/xe_device.c
>> b/drivers/gpu/drm/xe/xe_device.c
>> index 8be765adf702..07a3e4cf48d1 100644
>> --- a/drivers/gpu/drm/xe/xe_device.c
>> +++ b/drivers/gpu/drm/xe/xe_device.c
>> @@ -16,6 +16,7 @@
>>   #include <drm/xe_drm.h>
>>   
>>   #include "regs/xe_regs.h"
>> +#include "regs/xe_gt_regs.h"
>>   #include "xe_bo.h"
>>   #include "xe_debugfs.h"
>>   #include "xe_display.h"
>> @@ -25,6 +26,7 @@
>>   #include "xe_exec_queue.h"
>>   #include "xe_exec.h"
>>   #include "xe_gt.h"
>> +#include "xe_gt_mcr.h"
>>   #include "xe_irq.h"
>>   #include "xe_mmio.h"
>>   #include "xe_module.h"
>> @@ -342,6 +344,29 @@ static void xe_device_sanitize(struct drm_device
>> *drm, void *arg)
>>                  xe_gt_sanitize(gt);
>>   }
>>   
>> +static int xe_device_set_has_flat_ccs(struct  xe_device *xe)
>> +{
>> +       u32 reg;
>> +       int err;
>> +
>> +       if (IS_DGFX(xe) || GRAPHICS_VER(xe) < 20 || !xe-
>>> info.has_flat_ccs)
>> +               return 0;
> Depending on the outcome of the iommu discussion we might need to check
> for iommu present here as well?
Sure. That makes sense.
>
>> +
>> +       struct xe_gt *gt = xe_root_mmio_gt(xe);
>> +
>> +       err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
>> +       if (err)
>> +               return err;
>> +
>> +       reg = xe_gt_mcr_unicast_read_any(gt,
>> XE2_FLAT_CCS_BASE_RANGE_LOWER);
>> +       xe->info.has_flat_ccs = (reg & XE2_FLAT_CCS_ENABLE);
>> +
>> +       if (!xe->info.has_flat_ccs)
>> +               drm_info(&xe->drm,
>> +                        "Flat CCS has been disabled in bios, May
>> lead to performance impact");
>> +       return 0;
>> +}
>> +
>>   int xe_device_probe(struct xe_device *xe)
>>   {
>>          struct xe_tile *tile;
>> @@ -352,6 +377,7 @@ int xe_device_probe(struct xe_device *xe)
>>          xe_pat_init_early(xe);
>>   
>>          xe->info.mem_region_mask = 1;
>> +
> Unrelated change.
>
>>          err = xe_display_init_nommio(xe);
>>          if (err)
>>                  return err;
>> @@ -390,6 +416,10 @@ int xe_device_probe(struct xe_device *xe)
>>                          goto err_irq_shutdown;
>>          }
>>   
>> +       err = xe_device_set_has_flat_ccs(xe);
>> +       if (err)
>> +               return err;
>> +
>>          err = xe_mmio_probe_vram(xe);
>>          if (err)
>>                  goto err_irq_shutdown;