Re: [PATCH 2/2] drm/xe/lnl: Enable GuC Wa_14019882105

["Nilawar, Badal" <badal.nilawar@intel.com>]

On 19-03-2024 03:36, John Harrison wrote:
> On 3/15/2024 04:21, Badal Nilawar wrote:
>> Enable GuC Wa_14019882105 to block interrupts during C6 flow
>> when the memory path has been blocked
>>
>> Cc: John Harrison <john.harrison@intel.com>
>> Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
>> ---
>>   drivers/gpu/drm/xe/abi/guc_klvs_abi.h |  7 +++++
>>   drivers/gpu/drm/xe/xe_guc_ads.c       | 41 +++++++++++++++++++++------
>>   drivers/gpu/drm/xe/xe_wa_oob.rules    |  1 +
>>   3 files changed, 40 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/abi/guc_klvs_abi.h 
>> b/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
>> index 0400bc0fccdc..5dd45e06f0b6 100644
>> --- a/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
>> +++ b/drivers/gpu/drm/xe/abi/guc_klvs_abi.h
>> @@ -319,4 +319,11 @@ enum  {
>>   #define GUC_KLV_VF_CFG_BEGIN_CONTEXT_ID_KEY    0x8a0b
>>   #define GUC_KLV_VF_CFG_BEGIN_CONTEXT_ID_LEN    1u
>> +/*
>> + * Workaround keys:
>> + */
>> +enum xe_guc_klv_ids {
>> +    
>> GUC_WORKAROUND_KLV_BLOCK_INTERRUPTS_WHEN_MGSR_BLOCKED                = 
>> 0x9002,
>> +};
>> +
>>   #endif
>> diff --git a/drivers/gpu/drm/xe/xe_guc_ads.c 
>> b/drivers/gpu/drm/xe/xe_guc_ads.c
>> index ee48cf01fe22..3d2048747230 100644
>> --- a/drivers/gpu/drm/xe/xe_guc_ads.c
>> +++ b/drivers/gpu/drm/xe/xe_guc_ads.c
>> @@ -7,6 +7,8 @@
>>   #include <drm/drm_managed.h>
>> +#include <generated/xe_wa_oob.h>
>> +
>>   #include "regs/xe_engine_regs.h"
>>   #include "regs/xe_gt_regs.h"
>>   #include "regs/xe_guc_regs.h"
>> @@ -19,6 +21,7 @@
>>   #include "xe_map.h"
>>   #include "xe_mmio.h"
>>   #include "xe_platform_types.h"
>> +#include "xe_wa.h"
>>   /* Slack of a few additional entries per engine */
>>   #define ADS_REGSET_EXTRA_MAX    8
>> @@ -281,8 +284,30 @@ static size_t calculate_golden_lrc_size(struct 
>> xe_guc_ads *ads)
>>   #define GUC_VER(maj, min, pat)    (((maj) << 16) | ((min) << 8) | 
>> (pat))
>> +static u32 guc_waklv_opt_in(struct xe_guc_ads *ads,
>> +                enum xe_guc_klv_ids klv_id, u32 offset, u32 remain)
> If going straight to a generic helper, I would recommend following the 
> i915 version - move the += size / -= size inside the helper rather than 
> duplicating for each call.
Sure, I will move this calculation inside function.
> 
> Also, not sure opt_in is the best name. There could be future KLVs that 
> take parameters (it did almost happen already but the direction changed 
> for other reasons) which would still be an opt in. Hence the i915 
> version is called guc_waklv_enable_simple.
I will use guc_waklv_apply here.
> 
>> +{
>> +    u32 size;
>> +    u32 klv_entry[] = {
>> +        /* 16:16 key/length */
>> +        FIELD_PREP(GUC_KLV_0_KEY, klv_id) |
>> +        FIELD_PREP(GUC_KLV_0_LEN, 0),
>> +        /* 0 dwords data */
>> +    };
>> +
>> +    size = sizeof(klv_entry);
>> +
>> +    if (remain < size)
>> +        drm_warn(&ads_to_xe(ads)->drm, "Cannot apply guc wa klv_id 
>> %d\n", klv_id);
> The message says 'cannot apply' and the copy is skipped but the size is 
> still returned and overflow will still happen.
Sure will fix this.

Badal
> 
> John.
> 
> 
>> +    else
>> +        xe_map_memcpy_to(ads_to_xe(ads), ads_to_map(ads), offset,
>> +                 klv_entry, size);
>> +    return size;
>> +}
>> +
>>   static void guc_waklv_init(struct xe_guc_ads *ads)
>>   {
>> +    struct xe_gt *gt = ads_to_gt(ads);
>>       u32 addr_ggtt, offset, remain, size;
>>       struct xe_uc_fw *uc_fw = &ads_to_guc(ads)->fw;
>>       struct xe_uc_fw_version *version = 
>> &uc_fw->versions.found[XE_UC_FW_VER_RELEASE];
>> @@ -293,15 +318,13 @@ static void guc_waklv_init(struct xe_guc_ads *ads)
>>       offset = guc_ads_waklv_offset(ads);
>>       remain = guc_ads_waklv_size(ads);
>> -    /*
>> -     * Add workarounds here:
>> -     *
>> -     * if (want_wa_<name>) {
>> -     *      size = guc_waklv_<name>(guc, offset, remain);
>> -     *      offset += size;
>> -     *      remain -= size;
>> -     * }
>> -     */
>> +    if (XE_WA(gt, 14019882105)) {
>> +        size = guc_waklv_opt_in(ads,
>> +                    
>> GUC_WORKAROUND_KLV_BLOCK_INTERRUPTS_WHEN_MGSR_BLOCKED,
>> +                    offset, remain);
>> +        offset += size;
>> +        remain -= size;
>> +    }
>>       size = guc_ads_waklv_size(ads) - remain;
>>       if (!size)
>> diff --git a/drivers/gpu/drm/xe/xe_wa_oob.rules 
>> b/drivers/gpu/drm/xe/xe_wa_oob.rules
>> index 48cdba1cbf95..a8d15f004b6c 100644
>> --- a/drivers/gpu/drm/xe/xe_wa_oob.rules
>> +++ b/drivers/gpu/drm/xe/xe_wa_oob.rules
>> @@ -19,3 +19,4 @@
>>           GRAPHICS_VERSION_RANGE(1270, 1274)
>>           MEDIA_VERSION(1300)
>>           PLATFORM(DG2)
>> +14019882105    GRAPHICS_VERSION(2004), GRAPHICS_STEP(A0, B0)
>