[Intel-xe] [PATCH 2/3] drm/xe: Size GT device memory correctly

Ruhl, Michael J michael.j.ruhl at intel.com
Fri Apr 28 17:36:59 UTC 2023


>-----Original Message-----
>From: Auld, Matthew <matthew.auld at intel.com>
>Sent: Friday, April 28, 2023 5:33 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>
>Subject: Re: [PATCH 2/3] drm/xe: Size GT device memory correctly
>
>On 27/04/2023 20:52, Michael J. Ruhl wrote:
>> The current method of sizing GT device memory is not quite right.
>>
>> Update the algorithm to use the relevant HW information and offsets
>> to set up the sizing correctly.
>>
>> Update the stolen memory sizing to reflect the changes, and to be
>> GT specific.
>>
>> Signed-off-by: Michael J. Ruhl <michael.j.ruhl at intel.com>
>> ---
>>   drivers/gpu/drm/xe/regs/xe_gt_regs.h   |   3 +-
>>   drivers/gpu/drm/xe/xe_device_types.h   |   4 +-
>>   drivers/gpu/drm/xe/xe_gt_types.h       |  12 +-
>>   drivers/gpu/drm/xe/xe_mmio.c           | 156 ++++++++++++++++---------
>>   drivers/gpu/drm/xe/xe_mmio.h           |   4 +-
>>   drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c |  25 ++--
>>   6 files changed, 131 insertions(+), 73 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> index 05a03129dc54..dac24b99f526 100644
>> --- a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> +++ b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
>> @@ -75,7 +75,8 @@
>>   #define GEN12_VE1_AUX_NV			_MMIO(0x42b8)
>>   #define   AUX_INV				REG_BIT(0)
>>
>> -#define XEHP_TILE0_ADDR_RANGE			MCR_REG(0x4900)
>> +#define XEHP_TILE_ADDR_RANGE(_idx)		MCR_REG(0x4900 +
>(_idx) * 4)
>> +
>>   #define XEHP_FLAT_CCS_BASE_ADDR
>	MCR_REG(0x4910)
>>
>>   #define CHICKEN_RASTER_1			MCR_REG(0x6204)
>> diff --git a/drivers/gpu/drm/xe/xe_device_types.h
>b/drivers/gpu/drm/xe/xe_device_types.h
>> index 24dc5d2e9e05..ebd297ff6fcd 100644
>> --- a/drivers/gpu/drm/xe/xe_device_types.h
>> +++ b/drivers/gpu/drm/xe/xe_device_types.h
>> @@ -1,6 +1,6 @@
>>   /* SPDX-License-Identifier: MIT */
>>   /*
>> - * Copyright © 2022 Intel Corporation
>> + * Copyright © 2022-2023 Intel Corporation
>>    */
>>
>>   #ifndef _XE_DEVICE_TYPES_H_
>> @@ -202,6 +202,8 @@ struct xe_device {
>>   			 * known as small-bar.
>>   			 */
>>   			resource_size_t io_size;
>> +			/** @base: Offset to apply for Device Physical
>Address control */
>> +			resource_size_t base;
>>   			/** @mapping: pointer to VRAM mappable space */
>>   			void *__iomem mapping;
>>   		} vram;
>> diff --git a/drivers/gpu/drm/xe/xe_gt_types.h
>b/drivers/gpu/drm/xe/xe_gt_types.h
>> index 7c47d67aa8be..a2417cc2f696 100644
>> --- a/drivers/gpu/drm/xe/xe_gt_types.h
>> +++ b/drivers/gpu/drm/xe/xe_gt_types.h
>> @@ -1,6 +1,6 @@
>>   /* SPDX-License-Identifier: MIT */
>>   /*
>> - * Copyright © 2022 Intel Corporation
>> + * Copyright © 2022-2023 Intel Corporation
>>    */
>>
>>   #ifndef _XE_GT_TYPES_H_
>> @@ -149,12 +149,14 @@ struct xe_gt {
>>   			 * @io_size: IO size of this VRAM instance
>>   			 *
>>   			 * This represents how much of this VRAM we can
>access
>> -			 * via the CPU through the VRAM BAR. This can be
>smaller
>> -			 * than @size, in which case only part of VRAM is CPU
>> -			 * accessible (typically the first 256M). This
>> -			 * configuration is known as small-bar.
>> +			 * via the CPU through the VRAM BAR.
>> +			 * This can be smaller than the actual @size, in which
>> +			 * case only part of VRAM is CPU accessible (typically
>> +			 * the first 256M). This configuration is known as small-
>bar.
>>   			 */
>>   			resource_size_t io_size;
>> +			/** @base: offset of VRAM starting base */
>> +			resource_size_t base;
>>   			/** @size: size of VRAM. */
>>   			resource_size_t size;
>>   			/** @mapping: pointer to VRAM mappable space */
>> diff --git a/drivers/gpu/drm/xe/xe_mmio.c
>b/drivers/gpu/drm/xe/xe_mmio.c
>> index 6c1591a4f43e..60c1b92a87f7 100644
>> --- a/drivers/gpu/drm/xe/xe_mmio.c
>> +++ b/drivers/gpu/drm/xe/xe_mmio.c
>> @@ -3,6 +3,8 @@
>>    * Copyright © 2021-2023 Intel Corporation
>>    */
>>
>> +#include <linux/minmax.h>
>> +
>>   #include "xe_mmio.h"
>>
>>   #include <drm/drm_managed.h>
>> @@ -184,32 +186,83 @@ int xe_determine_lmem_bar_size(struct
>xe_device *xe)
>>   	if (!xe->mem.vram.io_size)
>>   		return -EIO;
>>
>> +	xe->mem.vram.base = 0; /* DPA offset */
>> +
>>   	/* set up a map to the total memory area. */
>>   	xe->mem.vram.mapping = ioremap_wc(xe->mem.vram.io_start, xe-
>>mem.vram.io_size);
>>
>>   	return 0;
>>   }
>>
>> +/*
>> + * 4 possible sizes:
>> + * - io size (from pci_resource_len of LMEM bar)
>> + * - TILEx size
>> + * - GSMBASE offset (TILEx - "stolen")
>> + * - CSSBASE offset (TILEx - CSS space necessary)
>> + *
>> + * NOTE: CSSBASE is always 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.
>
>Needs kernel-doc I think, since this is non-static.
>
>> + */
>> +int xe_mmio_vram_tile_size(struct xe_gt *gt, u64 *vram_size, u64
>*tile_size, u64 *tile_offset)
>> +{
>> +	u64 offset;
>> +	int err;
>> +	u32 reg;
>> +
>> +	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
>> +	if (err)
>> +		return err;
>> +
>> +	if (gt->xe->info.has_flat_ccs) {
>> +		reg = xe_gt_mcr_unicast_read_any(gt,
>XEHP_FLAT_CCS_BASE_ADDR);
>> +		offset = (u64)REG_FIELD_GET(GENMASK(31, 8), reg) *
>SZ_64K;
>> +	} else {
>> +		offset = xe_mmio_read64(gt, GEN12_GSMBASE.reg);
>> +	}
>> +
>> +	if (unlikely(gt->xe->info.platform == XE_DG1)) {
>> +		*tile_size = offset;
>
>This looks to be the "usable size", the stolen setup needs to know the
>"tile size". I think for DG1, which I guess is special, best we can do
>is use the pci_len() here.


Hmm, thought I had convinced myself that this was "correct"...  I will look again.

>> +		*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;
>> +	}
>> +
>> +	/* 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);
>> +}
>> +
>>   int xe_mmio_probe_vram(struct xe_device *xe)
>>   {
>> +	resource_size_t io_size;
>> +	u64 available_size = 0;
>> +	u64 total_size = 0;
>>   	struct xe_gt *gt;
>> +	u64 tile_offset;
>> +	u64 tile_size;
>> +	u64 vram_size;
>>   	int err;
>>   	u8 id;
>>
>>   	if (!IS_DGFX(xe)) {
>> -		xe->mem.vram.mapping = 0;
>> -		xe->mem.vram.io_start = 0;
>> -		xe->mem.vram.io_size = 0;
>> -
>> -		for_each_gt(gt, xe, id) {
>> -			gt->mem.vram.mapping = 0;
>> -			gt->mem.vram.size = 0;
>> -			gt->mem.vram.io_start = 0;
>> -			gt->mem.vram.io_size = 0;
>> -		}
>> +		memset(&xe->mem.vram, 0, sizeof(xe->mem.vram));
>> +		for_each_gt(gt, xe, id)
>> +			memset(&gt->mem.vram, 0, sizeof(gt->mem.vram));
>
>It looks like this is already zeroed with kzalloc.

Yeah I was wondering why this was being "re-zeroed".

I will confirm and remove the zeroing...

Thanks!

M

>>   		return 0;
>>   	}
>>
>> +	/* Get the size of the gt0 vram for later accessibility comparison */
>> +	gt = xe_device_get_gt(xe, 0);
>> +	err = xe_mmio_vram_tile_size(gt, &vram_size, &tile_size,
>&tile_offset);
>> +	if (err)
>> +		return err;
>> +
>>   	err = xe_determine_lmem_bar_size(xe);
>>   	if (err)
>>   		return err;
>> @@ -217,57 +270,53 @@ int xe_mmio_probe_vram(struct xe_device *xe)
>>   	drm_info(&xe->drm, "VISIBLE VRAM: %pa, %pa\n", &xe-
>>mem.vram.io_start,
>>   		 &xe->mem.vram.io_size);
>>
>> -	/* FIXME: Assuming equally partitioned VRAM, incorrect */
>> -	if (xe->info.tile_count > 1) {
>> -		u8 adj_tile_count = xe->info.tile_count;
>> -		resource_size_t size, io_start, io_size;
>> +	/* small bar issues will only cover gt0 sizes */
>> +	if (xe->mem.vram.io_size < vram_size)
>> +		drm_warn(&xe->drm, "Restricting VRAM size to PCI resource
>size (0x%llx->0x%llx)\n",
>> +			 vram_size, (u64)xe->mem.vram.io_size);
>>
>> -		for_each_gt(gt, xe, id)
>> -			if (xe_gt_is_media_type(gt))
>> -				--adj_tile_count;
>> +	io_size = xe->mem.vram.io_size;
>>
>> -		XE_BUG_ON(!adj_tile_count);
>> +	/* gt specific ranges */
>> +	for_each_gt(gt, xe, id) {
>> +		if (xe_gt_is_media_type(gt))
>> +			continue;
>>
>> -		size = xe->mem.vram.io_size / adj_tile_count;
>> -		io_start = xe->mem.vram.io_start;
>> -		io_size = xe->mem.vram.io_size;
>> +		err = xe_mmio_vram_tile_size(gt, &vram_size, &tile_size,
>&tile_offset);
>> +		if (err)
>> +			return err;
>>
>> -		for_each_gt(gt, xe, id) {
>> -			if (id && !xe_gt_is_media_type(gt)) {
>> -				io_size -= min(io_size, size);
>> -				io_start += io_size;
>> -			}
>> +		gt->mem.vram.io_start = xe->mem.vram.io_start +
>tile_offset;
>>
>> -			gt->mem.vram.size = size;
>> -
>> -			/*
>> -			 * XXX: multi-tile small-bar might be wild. Hopefully
>> -			 * full tile without any mappable vram is not
>something
>> -			 * we care about.
>> -			 */
>> -
>> -			gt->mem.vram.io_size = min(size, io_size);
>> -			if (io_size) {
>> -				gt->mem.vram.io_start = io_start;
>> -				gt->mem.vram.mapping = xe-
>>mem.vram.mapping +
>> -					(io_start - xe->mem.vram.io_start);
>> -			} else {
>> -				drm_err(&xe->drm, "Tile without any CPU
>visible VRAM. Aborting.\n");
>> -				return -ENODEV;
>> -			}
>> +		/* io_size "could be 0" for small-bar systems, so no CPU access
>*/
>> +		gt->mem.vram.io_size = min_t(u64, vram_size, io_size);
>
>If io_size == 0, I think we should still keep the:
>
>    drm_err(&xe->drm, "Tile without any CPU visible VRAM. Aborting.\n");
>    return -ENODEV;
>
>Driver load will anyway fail without that, but the error will likely be
>something way more obscure than the above.

I had "allowed" this because of our offline discussion... Think I misunderstood.

I will re-add the fail.

>> +
>> +		gt->mem.vram.base = xe->mem.vram.base + tile_offset;
>> +		gt->mem.vram.size = vram_size;
>> +		gt->mem.vram.mapping = xe->mem.vram.mapping +
>tile_offset;
>> +
>> +		drm_info(&xe->drm, "VRAM[%u, %u]: %pa, %pa\n", id, gt-
>>info.vram_id,
>> +			 &gt->mem.vram.io_start, &gt->mem.vram.size);
>> +
>> +		if (gt->mem.vram.io_size < gt->mem.vram.size)
>> +			drm_info(&xe->drm, "VRAM[%u, %u]: CPU access
>limited to %pa\n", id,
>> +				 gt->info.vram_id, &gt->mem.vram.io_size);
>> +
>> +		/* calculate total size using tile size to get the correct HW sizing
>*/
>> +		total_size += tile_size;
>> +		available_size += vram_size;
>>
>> -			drm_info(&xe->drm, "VRAM[%u, %u]: %pa, %pa\n",
>> -				 id, gt->info.vram_id, &gt-
>>mem.vram.io_start,
>> -				 &gt->mem.vram.size);
>> +		if (total_size > xe->mem.vram.io_size) {
>> +			drm_warn(&xe->drm, "VRAM: %pa is larger than
>resource %pa\n",
>> +				 &total_size, &xe->mem.vram.io_size);
>>   		}
>> -	} else {
>> -		gt->mem.vram.size = xe->mem.vram.io_size;
>> -		gt->mem.vram.io_start = xe->mem.vram.io_start;
>> -		gt->mem.vram.io_size = xe->mem.vram.io_size;
>> -		gt->mem.vram.mapping = xe->mem.vram.mapping;
>>
>> -		drm_info(&xe->drm, "VRAM: %pa\n", &gt->mem.vram.size);
>> +		io_size -= min_t(u64, tile_size, io_size);
>>   	}
>> +
>> +	drm_info(&xe->drm, "Available VRAM: %pa, %pa\n", &xe-
>>mem.vram.io_start,
>> +		 &available_size);
>> +
>>   	return 0;
>>   }
>>
>> @@ -287,9 +336,6 @@ static void xe_mmio_probe_tiles(struct xe_device
>*xe)
>>   	if (xe->info.media_verx100 >= 1300)
>>   		xe->info.tile_count *= 2;
>>
>> -	drm_info(&xe->drm, "tile_count: %d, adj_tile_count %d\n",
>> -		 xe->info.tile_count, adj_tile_count);
>> -
>>   	if (xe->info.tile_count > 1) {
>>   		const int mmio_bar = 0;
>>   		size_t size;
>> diff --git a/drivers/gpu/drm/xe/xe_mmio.h
>b/drivers/gpu/drm/xe/xe_mmio.h
>> index 1a32e0f52261..1c588db0b074 100644
>> --- a/drivers/gpu/drm/xe/xe_mmio.h
>> +++ b/drivers/gpu/drm/xe/xe_mmio.h
>> @@ -1,6 +1,6 @@
>>   /* SPDX-License-Identifier: MIT */
>>   /*
>> - * Copyright © 2021 Intel Corporation
>> + * Copyright © 2021-2023 Intel Corporation
>>    */
>>
>>   #ifndef _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_vram_tile_size(struct xe_gt *gt, u64 *vram_size, u64
>*tile_size, u64 *tile_offset);
>>
>>   #endif
>> diff --git a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>> index 9136c035db0e..acc11f580db4 100644
>> --- a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>> +++ b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
>> @@ -12,9 +12,11 @@
>>   #include <drm/ttm/ttm_range_manager.h>
>>
>>   #include "regs/xe_regs.h"
>> +#include "regs/xe_gt_regs.h"
>>   #include "xe_bo.h"
>>   #include "xe_device.h"
>>   #include "xe_gt.h"
>> +#include "xe_gt_mcr.h"
>>   #include "xe_mmio.h"
>>   #include "xe_res_cursor.h"
>>   #include "xe_ttm_stolen_mgr.h"
>> @@ -51,21 +53,26 @@ 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)
>>   {
>> -	u64 vram_size, stolen_size;
>> +	u64 stolen_size;
>> +	u64 tile_offset;
>> +	u64 tile_size;
>> +	u64 vram_size;
>>
>> -	vram_size = xe->mem.vram.io_size;
>> +	if (drm_WARN_ON(&gt->xe->drm,
>> +			xe_mmio_vram_tile_size(gt, &vram_size, &tile_size,
>&tile_offset)) < 0)
>> +		return 0;
>>
>>   	/* Use DSM base address instead for stolen memory */
>> -	mgr->stolen_base = xe_mmio_read64(to_gt(xe),
>GEN12_DSMBASE.reg) & GEN12_BDSM_MASK;
>> -	if (drm_WARN_ON(&xe->drm, vram_size < mgr->stolen_base))
>> +	mgr->stolen_base = (xe_mmio_read64(gt, GEN12_DSMBASE.reg) &
>GEN12_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;
>> +	stolen_size = tile_size - mgr->stolen_base;
>>
>> -	if (mgr->stolen_base + stolen_size <= vram_size)
>> -		mgr->io_base = xe->mem.vram.io_start + mgr->stolen_base;
>> +	if (mgr->stolen_base + stolen_size <= tile_size)
>> +		mgr->io_base = gt->mem.vram.io_start + mgr->stolen_base;
>>
>>   	/*
>>   	 * There may be few KB of platform dependent reserved memory at
>the end
>> @@ -133,7 +140,7 @@ 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


More information about the Intel-xe mailing list