[Intel-xe] [PATCH 1/4] drm/xe: Rework size helper to be a little more correct

Ruhl, Michael J michael.j.ruhl at intel.com
Wed May 3 14:38:34 UTC 2023


>-----Original Message-----
>From: Auld, Matthew <matthew.auld at intel.com>
>Sent: Wednesday, May 3, 2023 10:30 AM
>To: Ruhl, Michael J <michael.j.ruhl at intel.com>; intel-
>xe at lists.freedesktop.org
>Cc: Brost, Matthew <matthew.brost at intel.com>; Kershner, David
><david.kershner at intel.com>; Ghimiray, Himal Prasad
><himal.prasad.ghimiray at intel.com>; Upadhyay, Tejas
><tejas.upadhyay at intel.com>
>Subject: Re: [PATCH 1/4] drm/xe: Rework size helper to be a little more
>correct
>
>On 03/05/2023 15:14, Ruhl, Michael J wrote:
>>> -----Original Message-----
>>> From: Auld, Matthew <matthew.auld at intel.com>
>>> Sent: Wednesday, May 3, 2023 6:41 AM
>>> To: Ruhl, Michael J <michael.j.ruhl at intel.com>; intel-
>>> xe at lists.freedesktop.org
>>> Cc: Brost, Matthew <matthew.brost at intel.com>; Kershner, David
>>> <david.kershner at intel.com>; Ghimiray, Himal Prasad
>>> <himal.prasad.ghimiray at intel.com>; Upadhyay, Tejas
>>> <tejas.upadhyay at intel.com>
>>> Subject: Re: [PATCH 1/4] drm/xe: Rework size helper to be a little more
>>> correct
>>>
>>> On 01/05/2023 12:58, Michael J. Ruhl wrote:
>>>> The _total_vram_size helper is device based and is not complete.
>>>>
>>>> Teach the helper to be tile aware and add the ability to size
>>>> DG1 correctly.
>>>>
>>>> Signed-off-by: Michael J. Ruhl <michael.j.ruhl at intel.com>
>>>> ---
>>>>    drivers/gpu/drm/xe/regs/xe_gt_regs.h   |  2 +-
>>>>    drivers/gpu/drm/xe/xe_mmio.c           | 73 +++++++++++++++++---------
>>>>    drivers/gpu/drm/xe/xe_mmio.h           |  2 +-
>>>>    drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c | 28 +++++-----
>>>>    4 files changed, 64 insertions(+), 41 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>>> b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>>>> index 68e89d71cd1c..780edd4dc1bd 100644
>>>> --- a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>>>> +++ b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>>>> @@ -74,7 +74,7 @@
>>>>    #define VE1_AUX_NV				XE_REG(0x42b8)
>>>>    #define   AUX_INV				REG_BIT(0)
>>>>
>>>> -#define XEHP_TILE0_ADDR_RANGE
>	XE_REG_MCR(0x4900)
>>>> +#define XEHP_TILE_ADDR_RANGE(_idx)		XE_REG_MCR(0x4900
>>> + (_idx) * 4)
>>>>    #define XEHP_FLAT_CCS_BASE_ADDR
>>> 	XE_REG_MCR(0x4910)
>>>>
>>>>    #define CHICKEN_RASTER_1			XE_REG_MCR(0x6204,
>>> XE_REG_OPTION_MASKED)
>>>> diff --git a/drivers/gpu/drm/xe/xe_mmio.c
>>> b/drivers/gpu/drm/xe/xe_mmio.c
>>>> index 3b719c774efa..7d53d382976c 100644
>>>> --- a/drivers/gpu/drm/xe/xe_mmio.c
>>>> +++ b/drivers/gpu/drm/xe/xe_mmio.c
>>>> @@ -148,34 +148,56 @@ static bool xe_pci_resource_valid(struct pci_dev
>>> *pdev, int bar)
>>>>    	return true;
>>>>    }
>>>>
>>>> -int xe_mmio_total_vram_size(struct xe_device *xe, u64 *vram_size,
>u64
>>> *usable_size)
>>>> +/**
>>>> + * xe_mmio_tile_vram_size - Collect vram size and off set information
>>>> + * @gt: tile to get info for
>>>> + * @vram_size: available vram (size - device reserved portions)
>>>> + * @tile_size: actual vram size
>>>> + * @tile_offset: physical start point in the vram address space
>>>> + *
>>>> + * There are 4 places for size information:
>>>> + * - io size (from pci_resource_len of LMEM bar) (only used for small bar
>>> and DG1)
>>>> + * - TILEx size (actual vram size)
>>>> + * - GSMBASE offset (TILEx - "stolen")
>>>> + * - CSSBASE offset (TILEx - CSS space necessary)
>>>> + *
>>>> + * NOTE: CSSBASE is always a lower/smaller offset then GSMBASE.
>>>> + *
>>>> + * The actual available size of memory is to the CCS or GSM base.
>>>> + * NOTE: multi-tile bases will include the tile offset.
>>>> + *
>>>> + */
>>>> +int xe_mmio_tile_vram_size(struct xe_gt *gt, u64 *vram_size, u64
>>> *tile_size, u64 *tile_offset)
>>>>    {
>>>> -	struct xe_gt *gt = xe_device_get_gt(xe, 0);
>>>> -	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>>>> +	u64 offset;
>>>>    	int err;
>>>>    	u32 reg;
>>>>
>>>> -	if (!xe->info.has_flat_ccs)  {
>>>> -		*vram_size = pci_resource_len(pdev, GEN12_LMEM_BAR);
>>>> -		if (usable_size)
>>>> -			*usable_size = min(*vram_size,
>>>> -					   xe_mmio_read64(gt,
>>> GSMBASE.reg));
>>>> -		return 0;
>>>> -	}
>>>> -
>>>>    	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
>>>>    	if (err)
>>>>    		return err;
>>>>
>>>> -	reg = xe_gt_mcr_unicast_read_any(gt, XEHP_TILE0_ADDR_RANGE);
>>>> -	*vram_size = (u64)REG_FIELD_GET(GENMASK(14, 8), reg) * SZ_1G;
>>>> -	if (usable_size) {
>>>> +	/* actual size */
>>>> +	if (unlikely(gt->xe->info.platform == XE_DG1)) {
>>>> +		*tile_size = pci_resource_len(to_pci_dev(gt->xe->drm.dev),
>>> GEN12_LMEM_BAR);
>>>> +		*tile_offset = 0;
>>>> +	} else {
>>>> +		reg = xe_gt_mcr_unicast_read_any(gt,
>>> XEHP_TILE_ADDR_RANGE(gt->info.id));
>>>> +		*tile_size = (u64)REG_FIELD_GET(GENMASK(14, 8), reg) *
>>> SZ_1G;
>>>> +		*tile_offset = (u64)REG_FIELD_GET(GENMASK(7, 1), reg) *
>>> SZ_1G;
>>>> +	}
>>>> +
>>>> +	/* minus device usage */
>>>> +	if (gt->xe->info.has_flat_ccs) {
>>>>    		reg = xe_gt_mcr_unicast_read_any(gt,
>>> XEHP_FLAT_CCS_BASE_ADDR);
>>>> -		*usable_size = (u64)REG_FIELD_GET(GENMASK(31, 8), reg) *
>>> SZ_64K;
>>>> -		drm_info(&xe->drm, "vram_size: 0x%llx usable_size:
>>> 0x%llx\n",
>>>> -			 *vram_size, *usable_size);
>>>> +		offset = (u64)REG_FIELD_GET(GENMASK(31, 8), reg) *
>>> SZ_64K;
>>>> +	} else {
>>>> +		offset = xe_mmio_read64(gt, GSMBASE.reg);
>>>>    	}
>>>>
>>>> +	/* remove the tile offset so we have just the available size */
>>>> +	*vram_size = offset - *tile_offset;
>>>> +
>>>>    	return xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
>>>>    }
>>>>
>>>> @@ -183,11 +205,12 @@ int xe_mmio_probe_vram(struct xe_device
>*xe)
>>>>    {
>>>>    	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>>>>    	struct xe_gt *gt;
>>>> -	u8 id;
>>>> -	u64 vram_size;
>>>>    	u64 original_size;
>>>> -	u64 usable_size;
>>>> +	u64 tile_offset;
>>>> +	u64 tile_size;
>>>> +	u64 vram_size;
>>>>    	int err;
>>>> +	u8 id;
>>>>
>>>>    	if (!IS_DGFX(xe)) {
>>>>    		xe->mem.vram.mapping = 0;
>>>> @@ -212,25 +235,25 @@ int xe_mmio_probe_vram(struct xe_device
>*xe)
>>>>    	gt = xe_device_get_gt(xe, 0);
>>>>    	original_size = pci_resource_len(pdev, GEN12_LMEM_BAR);
>>>>
>>>> -	err = xe_mmio_total_vram_size(xe, &vram_size, &usable_size);
>>>> +	err = xe_mmio_tile_vram_size(gt, &vram_size, &tile_size,
>>> &tile_offset);
>>>>    	if (err)
>>>>    		return err;
>>>>
>>>>    	xe_resize_vram_bar(xe, vram_size);
>>>>    	xe->mem.vram.io_start = pci_resource_start(pdev,
>>> GEN12_LMEM_BAR);
>>>> -	xe->mem.vram.io_size = min(usable_size,
>>>> +	xe->mem.vram.io_size = min(vram_size,
>>>>    				   pci_resource_len(pdev,
>>> GEN12_LMEM_BAR));
>>>>    	xe->mem.vram.size = xe->mem.vram.io_size;
>>>>
>>>>    	if (!xe->mem.vram.size)
>>>>    		return -EIO;
>>>>
>>>> -	if (usable_size > xe->mem.vram.io_size)
>>>> +	if (vram_size > xe->mem.vram.io_size)
>>>>    		drm_warn(&xe->drm, "Restricting VRAM size to PCI resource
>>> size (%lluMiB->%lluMiB)\n",
>>>> -			 (u64)usable_size >> 20, (u64)xe->mem.vram.io_size
>>>>> 20);
>>>> +			 (u64)vram_size >> 20, (u64)xe->mem.vram.io_size >>
>>> 20);
>>>>
>>>>    	xe->mem.vram.mapping = ioremap_wc(xe->mem.vram.io_start, xe-
>>>> mem.vram.io_size);
>>>> -	xe->mem.vram.size = min_t(u64, xe->mem.vram.size, usable_size);
>>>> +	xe->mem.vram.size = min_t(u64, xe->mem.vram.size, vram_size);
>>>>
>>>>    	drm_info(&xe->drm, "TOTAL VRAM: %pa, %pa\n", &xe-
>>>> mem.vram.io_start, &xe->mem.vram.size);
>>>>
>>>> diff --git a/drivers/gpu/drm/xe/xe_mmio.h
>>> b/drivers/gpu/drm/xe/xe_mmio.h
>>>> index 1a32e0f52261..556cf3d9e4f5 100644
>>>> --- a/drivers/gpu/drm/xe/xe_mmio.h
>>>> +++ b/drivers/gpu/drm/xe/xe_mmio.h
>>>> @@ -120,6 +120,6 @@ static inline bool xe_mmio_in_range(const struct
>>> xe_mmio_range *range, u32 reg)
>>>>    }
>>>>
>>>>    int xe_mmio_probe_vram(struct xe_device *xe);
>>>> -int xe_mmio_total_vram_size(struct xe_device *xe, u64 *vram_size,
>u64
>>> *flat_ccs_base);
>>>> +int xe_mmio_tile_vram_size(struct xe_gt *gt, u64 *vram_size, u64
>>> *tile_size, u64 *tile_base);
>>>>
>>>>    #endif
>>>> diff --git a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>>> b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>>>> index 9ce0a0585539..a329f12f14fe 100644
>>>> --- a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>>>> +++ b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>>>> @@ -51,27 +51,27 @@ bool
>xe_ttm_stolen_cpu_access_needs_ggtt(struct
>>> xe_device *xe)
>>>>    	return GRAPHICS_VERx100(xe) < 1270 && !IS_DGFX(xe);
>>>>    }
>>>>
>>>> -static s64 detect_bar2_dgfx(struct xe_device *xe, struct
>>> xe_ttm_stolen_mgr *mgr)
>>>> +static s64 detect_bar2_dgfx(struct xe_gt *gt, struct xe_ttm_stolen_mgr
>>> *mgr)
>>>>    {
>>>> -	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>>>> -	struct xe_gt *gt = to_gt(xe);
>>>> -	u64 vram_size, stolen_size;
>>>> -	int err;
>>>> +	u64 stolen_size;
>>>> +	u64 tile_offset;
>>>> +	u64 tile_size;
>>>> +	u64 vram_size;
>>>>
>>>> -	err = xe_mmio_total_vram_size(xe, &vram_size, NULL);
>>>> -	if (err) {
>>>> -		drm_info(&xe->drm, "Querying total vram size failed\n");
>>>> +	if (xe_mmio_tile_vram_size(gt, &vram_size, &tile_size, &tile_offset))
>>> {
>>>> +		drm_info(&gt->xe->drm, "Querying total vram size failed\n");
>>>>    		return 0;
>>>>    	}
>>>>
>>>>    	/* Use DSM base address instead for stolen memory */
>>>> -	mgr->stolen_base = xe_mmio_read64(gt, DSMBASE.reg) &
>>> BDSM_MASK;
>>>> -	if (drm_WARN_ON(&xe->drm, vram_size < mgr->stolen_base))
>>>> +	mgr->stolen_base = (xe_mmio_read64(gt, DSMBASE.reg) &
>>> BDSM_MASK) - tile_offset;
>>>> +	if (drm_WARN_ON(&gt->xe->drm, tile_size < mgr->stolen_base))
>>>>    		return 0;
>>>>
>>>> -	stolen_size = vram_size - mgr->stolen_base;
>>>> -	if (mgr->stolen_base + stolen_size <= pci_resource_len(pdev, 2))
>>>> -		mgr->io_base = pci_resource_start(pdev, 2) + mgr-
>>>> stolen_base;
>>>> +	stolen_size = tile_size - mgr->stolen_base;
>>>> +
>>>> +	if (mgr->stolen_base + stolen_size <= tile_size)
>>>
>>> I think needs to be the pci_len() here.
>>
>> For a PVC that would be 128GB for length.  That will encompass both tiles,
>and I think that the
>> this will not check correctly.
>>
>> tile_size == pci_len() for DG1...
>>
>> Is that your concern?
>>
>> I think that he "stolen" area has to be constrained to the tile size, not the
>complete area.
>> Am I missing something here?
>
>Just that we want mgr->io_base here to be zero on small-bar, which then
>signals that stolen is not directly CPU accessible. Also we only care
>about the root tile here.

Ahh, ok.  

Umm, so 

size = min(gt.vram.io_size, tile_size)

?

The stolen area is defined per GT, so I updated for the possibility of others... Should we 
restrict it for GT0 only?

M

>>
>> Thanks
>>
>> Mike
>>
>>>> +		mgr->io_base = gt->mem.vram.io_start + mgr->stolen_base;
>>>>
>>>>    	/*
>>>>    	 * There may be few KB of platform dependent reserved memory at
>>> the end
>>>> @@ -139,7 +139,7 @@ void xe_ttm_stolen_mgr_init(struct xe_device
>*xe)
>>>>    	int err;
>>>>
>>>>    	if (IS_DGFX(xe))
>>>> -		stolen_size = detect_bar2_dgfx(xe, mgr);
>>>> +		stolen_size = detect_bar2_dgfx(to_gt(xe), mgr);
>>>>    	else if (GRAPHICS_VERx100(xe) >= 1270)
>>>>    		stolen_size = detect_bar2_integrated(xe, mgr);
>>>>    	else


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