Commit 382876af authored by Lucas De Marchi's avatar Lucas De Marchi Committed by Matt Roper
Browse files

drm/xe: Move rebar to its own file 



Now that xe_pci.c calls the rebar directly, it doesn't make sense to
keep it in xe_vram.c since it's closer to the PCI initialization than to
the VRAM. Move it to its own file.

While at it, add a better comment to document the possible values for
the vram_bar_size module parameter.

Reviewed-by: default avatarMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Link: https://patch.msgid.link/20251219211650.1908961-5-matthew.d.roper@intel.com


Signed-off-by: default avatarMatt Roper <matthew.d.roper@intel.com>
parent ac1317df

drivers/gpu/drm/xe/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -98,6 +98,7 @@ xe-y += xe_bb.o \ 
	xe_page_reclaim.o \

	xe_pat.o \

	xe_pci.o \

	xe_pci_rebar.o \

	xe_pcode.o \

	xe_pm.o \

	xe_preempt_fence.o \

drivers/gpu/drm/xe/xe_pci.c

+2 −1
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include "xe_macros.h"

#include "xe_mmio.h"

#include "xe_module.h"

#include "xe_pci_rebar.h"

#include "xe_pci_sriov.h"

#include "xe_pci_types.h"

#include "xe_pm.h"
@@ -1021,7 +1022,7 @@ static int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent) 
	if (err)

		return err;



	xe_vram_resize_bar(xe);

	xe_pci_rebar_resize(xe);



	err = xe_device_probe_early(xe);

	/*

drivers/gpu/drm/xe/xe_pci_rebar.c

0 → 100644
+108 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: MIT

/*

 * Copyright © 2025 Intel Corporation

 */



#include <linux/pci.h>

#include <linux/types.h>



#include <drm/drm_print.h>



#include "regs/xe_bars.h"

#include "xe_device_types.h"

#include "xe_module.h"

#include "xe_pci_rebar.h"



static void resize_bar(struct xe_device *xe, int resno, resource_size_t size)

{

	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);

	int bar_size = pci_rebar_bytes_to_size(size);

	int ret;



	ret = pci_resize_resource(pdev, resno, bar_size, 0);

	if (ret) {

		drm_info(&xe->drm, "Failed to resize BAR%d to %dM (%pe). Consider enabling 'Resizable BAR' support in your BIOS\n",

			 resno, 1 << bar_size, ERR_PTR(ret));

		return;

	}



	drm_info(&xe->drm, "BAR%d resized to %dM\n", resno, 1 << bar_size);

}



/*

 * xe_pci_rebar_resize - Resize the LMEMBAR

 * @xe: xe device instance

 *

 * If vram_bar_size module param is set, attempt to set to the requested size

 * else set to maximum possible size.

 */

void xe_pci_rebar_resize(struct xe_device *xe)

{

	int force_vram_bar_size = xe_modparam.force_vram_bar_size;

	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);

	struct pci_bus *root = pdev->bus;

	resource_size_t current_size;

	resource_size_t rebar_size;

	struct resource *root_res;

	int max_size, i;

	u32 pci_cmd;



	/* gather some relevant info */

	current_size = pci_resource_len(pdev, LMEM_BAR);



	if (force_vram_bar_size < 0)

		return;



	/* set to a specific size? */

	if (force_vram_bar_size) {

		rebar_size = pci_rebar_bytes_to_size(force_vram_bar_size *

						     (resource_size_t)SZ_1M);



		if (!pci_rebar_size_supported(pdev, LMEM_BAR, rebar_size)) {

			drm_info(&xe->drm,

				 "Requested size: %lluMiB is not supported by rebar sizes: 0x%llx. Leaving default: %lluMiB\n",

				 (u64)pci_rebar_size_to_bytes(rebar_size) >> 20,

				 pci_rebar_get_possible_sizes(pdev, LMEM_BAR),

				 (u64)current_size >> 20);

			return;

		}



		rebar_size = pci_rebar_size_to_bytes(rebar_size);

		if (rebar_size == current_size)

			return;

	} else {

		max_size = pci_rebar_get_max_size(pdev, LMEM_BAR);

		if (max_size < 0)

			return;

		rebar_size = pci_rebar_size_to_bytes(max_size);



		/* only resize if larger than current */

		if (rebar_size <= current_size)

			return;

	}



	drm_info(&xe->drm, "Attempting to resize bar from %lluMiB -> %lluMiB\n",

		 (u64)current_size >> 20, (u64)rebar_size >> 20);



	while (root->parent)

		root = root->parent;



	pci_bus_for_each_resource(root, root_res, i) {

		if (root_res && root_res->flags & (IORESOURCE_MEM | IORESOURCE_MEM_64) &&

		    (u64)root_res->start > 0x100000000ul)

			break;

	}



	if (!root_res) {

		drm_info(&xe->drm, "Can't resize VRAM BAR - platform support is missing. Consider enabling 'Resizable BAR' support in your BIOS\n");

		return;

	}



	pci_read_config_dword(pdev, PCI_COMMAND, &pci_cmd);

	pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd & ~PCI_COMMAND_MEMORY);



	resize_bar(xe, LMEM_BAR, rebar_size);



	pci_assign_unassigned_bus_resources(pdev->bus);

	pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd);

}

drivers/gpu/drm/xe/xe_pci_rebar.h

0 → 100644
+13 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: MIT */

/*

 * Copyright © 2025 Intel Corporation

 */



#ifndef _XE_PCI_REBAR_H_

#define _XE_PCI_REBAR_H_



struct xe_device;



void xe_pci_rebar_resize(struct xe_device *xe);



#endif

drivers/gpu/drm/xe/xe_vram.c

+0 −91
Original line number Diff line number Diff line
@@ -25,97 +25,6 @@ 
#include "xe_vram.h"

#include "xe_vram_types.h"



static void resize_bar(struct xe_device *xe, int resno, resource_size_t size)

{

	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);

	int bar_size = pci_rebar_bytes_to_size(size);

	int ret;



	ret = pci_resize_resource(pdev, resno, bar_size, 0);

	if (ret) {

		drm_info(&xe->drm, "Failed to resize BAR%d to %dM (%pe). Consider enabling 'Resizable BAR' support in your BIOS\n",

			 resno, 1 << bar_size, ERR_PTR(ret));

		return;

	}



	drm_info(&xe->drm, "BAR%d resized to %dM\n", resno, 1 << bar_size);

}



/*

 * if force_vram_bar_size is set, attempt to set to the requested size

 * else set to maximum possible size

 */

void xe_vram_resize_bar(struct xe_device *xe)

{

	int force_vram_bar_size = xe_modparam.force_vram_bar_size;

	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);

	struct pci_bus *root = pdev->bus;

	resource_size_t current_size;

	resource_size_t rebar_size;

	struct resource *root_res;

	int max_size, i;

	u32 pci_cmd;



	/* gather some relevant info */

	current_size = pci_resource_len(pdev, LMEM_BAR);



	if (force_vram_bar_size < 0)

		return;



	/* set to a specific size? */

	if (force_vram_bar_size) {

		rebar_size = pci_rebar_bytes_to_size(force_vram_bar_size *

						     (resource_size_t)SZ_1M);



		if (!pci_rebar_size_supported(pdev, LMEM_BAR, rebar_size)) {

			drm_info(&xe->drm,

				 "Requested size: %lluMiB is not supported by rebar sizes: 0x%llx. Leaving default: %lluMiB\n",

				 (u64)pci_rebar_size_to_bytes(rebar_size) >> 20,

				 pci_rebar_get_possible_sizes(pdev, LMEM_BAR),

				 (u64)current_size >> 20);

			return;

		}



		rebar_size = pci_rebar_size_to_bytes(rebar_size);

		if (rebar_size == current_size)

			return;

	} else {

		max_size = pci_rebar_get_max_size(pdev, LMEM_BAR);

		if (max_size < 0)

			return;

		rebar_size = pci_rebar_size_to_bytes(max_size);



		/* only resize if larger than current */

		if (rebar_size <= current_size)

			return;

	}



	drm_info(&xe->drm, "Attempting to resize bar from %lluMiB -> %lluMiB\n",

		 (u64)current_size >> 20, (u64)rebar_size >> 20);



	while (root->parent)

		root = root->parent;



	pci_bus_for_each_resource(root, root_res, i) {

		if (root_res && root_res->flags & (IORESOURCE_MEM | IORESOURCE_MEM_64) &&

		    (u64)root_res->start > 0x100000000ul)

			break;

	}



	if (!root_res) {

		drm_info(&xe->drm, "Can't resize VRAM BAR - platform support is missing. Consider enabling 'Resizable BAR' support in your BIOS\n");

		return;

	}



	pci_read_config_dword(pdev, PCI_COMMAND, &pci_cmd);

	pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd & ~PCI_COMMAND_MEMORY);



	resize_bar(xe, LMEM_BAR, rebar_size);



	pci_assign_unassigned_bus_resources(pdev->bus);

	pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd);

}



static bool resource_is_valid(struct pci_dev *pdev, int bar)

{

	if (!pci_resource_flags(pdev, bar))