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

diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index 37a6583993d1ddbffe03ea9de5f62170e0deea09..a6749dd6a72580a678d52d7ce5ee59e5600f7181 100644 (file)
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -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 \

diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
index 9d0dbbb9836244bfca80e24a9e06ff2a7b9f2bfc..a1fdca451ce0ba5eb1f3a4b0f35a64d6823b3be2 100644 (file)
--- a/drivers/gpu/drm/xe/xe_pci.c
+++ b/drivers/gpu/drm/xe/xe_pci.c
@@ -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);
        /*

diff --git a/drivers/gpu/drm/xe/xe_pci_rebar.c b/drivers/gpu/drm/xe/xe_pci_rebar.c
new file mode 100644 (file)
index 0000000..a55950d
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_pci_rebar.c
@@ -0,0 +1,108 @@
+// 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);
+}

diff --git a/drivers/gpu/drm/xe/xe_pci_rebar.h b/drivers/gpu/drm/xe/xe_pci_rebar.h
new file mode 100644 (file)
index 0000000..8677921
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_pci_rebar.h
@@ -0,0 +1,13 @@
+/* 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

diff --git a/drivers/gpu/drm/xe/xe_vram.c b/drivers/gpu/drm/xe/xe_vram.c
index 1b9e9b028975dd355b7fec13c7987f06d3ceab18..c64d98bf1723f30053f5ddbdbb926fae21b3ca6a 100644 (file)
--- a/drivers/gpu/drm/xe/xe_vram.c
+++ b/drivers/gpu/drm/xe/xe_vram.c
@@ -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))

diff --git a/drivers/gpu/drm/xe/xe_vram.h b/drivers/gpu/drm/xe/xe_vram.h
index 13505cfb184dc4de4f6ddb053bbdb99472e6abd6..72860f714fc6651062f02602a8e65d9f906bf9ad 100644 (file)
--- a/drivers/gpu/drm/xe/xe_vram.h
+++ b/drivers/gpu/drm/xe/xe_vram.h
@@ -11,7 +11,6 @@
 struct xe_device;
 struct xe_vram_region;
 
-void xe_vram_resize_bar(struct xe_device *xe);
 int xe_vram_probe(struct xe_device *xe);
 
 struct xe_vram_region *xe_vram_region_alloc(struct xe_device *xe, u8 id, u32 placement);