linux/drivers/gpu/drm/ast/ast_drv.c
Thomas Zimmermann e7a1cbca0b drm/gem-shmem: Do not map s/g table by default
The vast majority of drivers that use GEM-SHMEM helpers do not use
an s/g table for imported buffers; specifically all drivers that use
DRM_GEM_SHMEM_DRIVER_OPS. Therefore convert the initializer macro
to DRM_GEM_SHMEM_DRIVER_OPS_NO_MAP_SGT and remove the latter. This
helps to avoid swiotbl errors, such as seen with some Aspeed systems

  ast 0000:07:00.0: swiotlb buffer is full (sz: 3145728 bytes), total 32768 (slots), used 0 (slots)

The error is caused by the system's limited DMA capabilities and can
happen with any GEM-SHMEM-based driver. It results in a performance
penalty.

In the case of vgem and vkms, the devices do not support DMA at all,
which can result in failure to map the buffer object into the kernel's
address space. [1][2] Avoiding the s/g table fixes this problem.

The other drivers based on GEM-SHMEM, imagination, lima, panfrost,
panthor, v3d and virtio, use the s/g table of imported buffers. Neither
driver uses the default initializer, so they won't be affected by
this change.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reported-by: Zenghui Yu <zenghui.yu@linux.dev>
Closes: https://lore.kernel.org/dri-devel/6d22bce3-4533-4cfa-96ba-64352b715741@linux.dev/ # [1]
Reported-by: José Expósito <jose.exposito89@gmail.com>
Closes: https://lore.kernel.org/dri-devel/20250311172054.2903-1-jose.exposito89@gmail.com/ # [2]
Tested-by: Zenghui Yu <zenghui.yu@linux.dev>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Link: https://lore.kernel.org/r/20250630143537.309052-1-tzimmermann@suse.de
2025-07-07 15:23:41 +02:00

483 lines
12 KiB
C

/*
* Copyright 2012 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
*/
/*
* Authors: Dave Airlie <airlied@redhat.com>
*/
#include <linux/aperture.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pci.h>
#include <drm/clients/drm_client_setup.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fbdev_shmem.h>
#include <drm/drm_gem_shmem_helper.h>
#include <drm/drm_module.h>
#include <drm/drm_probe_helper.h>
#include "ast_drv.h"
static int ast_modeset = -1;
MODULE_PARM_DESC(modeset, "Disable/Enable modesetting");
module_param_named(modeset, ast_modeset, int, 0400);
/*
* DRM driver
*/
DEFINE_DRM_GEM_FOPS(ast_fops);
static const struct drm_driver ast_driver = {
.driver_features = DRIVER_ATOMIC |
DRIVER_GEM |
DRIVER_MODESET,
.fops = &ast_fops,
.name = DRIVER_NAME,
.desc = DRIVER_DESC,
.major = DRIVER_MAJOR,
.minor = DRIVER_MINOR,
.patchlevel = DRIVER_PATCHLEVEL,
DRM_GEM_SHMEM_DRIVER_OPS,
DRM_FBDEV_SHMEM_DRIVER_OPS,
};
/*
* PCI driver
*/
#define PCI_VENDOR_ASPEED 0x1a03
#define AST_VGA_DEVICE(id, info) { \
.class = PCI_BASE_CLASS_DISPLAY << 16, \
.class_mask = 0xff0000, \
.vendor = PCI_VENDOR_ASPEED, \
.device = id, \
.subvendor = PCI_ANY_ID, \
.subdevice = PCI_ANY_ID, \
.driver_data = (unsigned long) info }
static const struct pci_device_id ast_pciidlist[] = {
AST_VGA_DEVICE(PCI_CHIP_AST2000, NULL),
AST_VGA_DEVICE(PCI_CHIP_AST2100, NULL),
{0, 0, 0},
};
MODULE_DEVICE_TABLE(pci, ast_pciidlist);
static bool ast_is_vga_enabled(void __iomem *ioregs)
{
u8 vgaer = __ast_read8(ioregs, AST_IO_VGAER);
return vgaer & AST_IO_VGAER_VGA_ENABLE;
}
static void ast_enable_vga(void __iomem *ioregs)
{
__ast_write8(ioregs, AST_IO_VGAER, AST_IO_VGAER_VGA_ENABLE);
__ast_write8(ioregs, AST_IO_VGAMR_W, AST_IO_VGAMR_IOSEL);
}
/*
* Run this function as part of the HW device cleanup; not
* when the DRM device gets released.
*/
static void ast_enable_mmio_release(void *data)
{
void __iomem *ioregs = (void __force __iomem *)data;
/* enable standard VGA decode */
__ast_write8_i(ioregs, AST_IO_VGACRI, 0xa1, AST_IO_VGACRA1_MMIO_ENABLED);
}
static int ast_enable_mmio(struct device *dev, void __iomem *ioregs)
{
void *data = (void __force *)ioregs;
__ast_write8_i(ioregs, AST_IO_VGACRI, 0xa1,
AST_IO_VGACRA1_MMIO_ENABLED |
AST_IO_VGACRA1_VGAIO_DISABLED);
return devm_add_action_or_reset(dev, ast_enable_mmio_release, data);
}
static void ast_open_key(void __iomem *ioregs)
{
__ast_write8_i(ioregs, AST_IO_VGACRI, 0x80, AST_IO_VGACR80_PASSWORD);
}
static int ast_detect_chip(struct pci_dev *pdev,
void __iomem *regs, void __iomem *ioregs,
enum ast_chip *chip_out,
enum ast_config_mode *config_mode_out)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
enum ast_config_mode config_mode = ast_use_defaults;
uint32_t scu_rev = 0xffffffff;
enum ast_chip chip;
u32 data;
u8 vgacrd0, vgacrd1;
/*
* Find configuration mode and read SCU revision
*/
/* Check if we have device-tree properties */
if (np && !of_property_read_u32(np, "aspeed,scu-revision-id", &data)) {
/* We do, disable P2A access */
config_mode = ast_use_dt;
scu_rev = data;
} else if (pdev->device == PCI_CHIP_AST2000) { // Not all families have a P2A bridge
/*
* The BMC will set SCU 0x40 D[12] to 1 if the P2 bridge
* is disabled. We force using P2A if VGA only mode bit
* is set D[7]
*/
vgacrd0 = __ast_read8_i(ioregs, AST_IO_VGACRI, 0xd0);
vgacrd1 = __ast_read8_i(ioregs, AST_IO_VGACRI, 0xd1);
if (!(vgacrd0 & 0x80) || !(vgacrd1 & 0x10)) {
/*
* We have a P2A bridge and it is enabled.
*/
/* Patch AST2500/AST2510 */
if ((pdev->revision & 0xf0) == 0x40) {
if (!(vgacrd0 & AST_IO_VGACRD0_VRAM_INIT_STATUS_MASK))
ast_patch_ahb_2500(regs);
}
/* Double check that it's actually working */
data = __ast_read32(regs, 0xf004);
if ((data != 0xffffffff) && (data != 0x00)) {
config_mode = ast_use_p2a;
/* Read SCU7c (silicon revision register) */
__ast_write32(regs, 0xf004, 0x1e6e0000);
__ast_write32(regs, 0xf000, 0x1);
scu_rev = __ast_read32(regs, 0x1207c);
}
}
}
switch (config_mode) {
case ast_use_defaults:
dev_info(dev, "Using default configuration\n");
break;
case ast_use_dt:
dev_info(dev, "Using device-tree for configuration\n");
break;
case ast_use_p2a:
dev_info(dev, "Using P2A bridge for configuration\n");
break;
}
/*
* Identify chipset
*/
if (pdev->revision >= 0x50) {
chip = AST2600;
dev_info(dev, "AST 2600 detected\n");
} else if (pdev->revision >= 0x40) {
switch (scu_rev & 0x300) {
case 0x0100:
chip = AST2510;
dev_info(dev, "AST 2510 detected\n");
break;
default:
chip = AST2500;
dev_info(dev, "AST 2500 detected\n");
break;
}
} else if (pdev->revision >= 0x30) {
switch (scu_rev & 0x300) {
case 0x0100:
chip = AST1400;
dev_info(dev, "AST 1400 detected\n");
break;
default:
chip = AST2400;
dev_info(dev, "AST 2400 detected\n");
break;
}
} else if (pdev->revision >= 0x20) {
switch (scu_rev & 0x300) {
case 0x0000:
chip = AST1300;
dev_info(dev, "AST 1300 detected\n");
break;
default:
chip = AST2300;
dev_info(dev, "AST 2300 detected\n");
break;
}
} else if (pdev->revision >= 0x10) {
switch (scu_rev & 0x0300) {
case 0x0200:
chip = AST1100;
dev_info(dev, "AST 1100 detected\n");
break;
case 0x0100:
chip = AST2200;
dev_info(dev, "AST 2200 detected\n");
break;
case 0x0000:
chip = AST2150;
dev_info(dev, "AST 2150 detected\n");
break;
default:
chip = AST2100;
dev_info(dev, "AST 2100 detected\n");
break;
}
} else {
chip = AST2000;
dev_info(dev, "AST 2000 detected\n");
}
*chip_out = chip;
*config_mode_out = config_mode;
return 0;
}
static int ast_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
struct device *dev = &pdev->dev;
int ret;
void __iomem *regs;
void __iomem *ioregs;
enum ast_config_mode config_mode;
enum ast_chip chip;
struct drm_device *drm;
bool need_post = false;
ret = aperture_remove_conflicting_pci_devices(pdev, ast_driver.name);
if (ret)
return ret;
ret = pcim_enable_device(pdev);
if (ret)
return ret;
regs = pcim_iomap_region(pdev, 1, "ast");
if (IS_ERR(regs))
return PTR_ERR(regs);
if (pdev->revision >= 0x40) {
/*
* On AST2500 and later models, MMIO is enabled by
* default. Adopt it to be compatible with ARM.
*/
resource_size_t len = pci_resource_len(pdev, 1);
if (len < AST_IO_MM_OFFSET)
return -EIO;
if ((len - AST_IO_MM_OFFSET) < AST_IO_MM_LENGTH)
return -EIO;
ioregs = regs + AST_IO_MM_OFFSET;
} else if (pci_resource_flags(pdev, 2) & IORESOURCE_IO) {
/*
* Map I/O registers if we have a PCI BAR for I/O.
*/
resource_size_t len = pci_resource_len(pdev, 2);
if (len < AST_IO_MM_LENGTH)
return -EIO;
ioregs = pcim_iomap_region(pdev, 2, "ast");
if (IS_ERR(ioregs))
return PTR_ERR(ioregs);
} else {
/*
* Anything else is best effort.
*/
resource_size_t len = pci_resource_len(pdev, 1);
if (len < AST_IO_MM_OFFSET)
return -EIO;
if ((len - AST_IO_MM_OFFSET) < AST_IO_MM_LENGTH)
return -EIO;
ioregs = regs + AST_IO_MM_OFFSET;
dev_info(dev, "Platform has no I/O space, using MMIO\n");
}
if (!ast_is_vga_enabled(ioregs)) {
dev_info(dev, "VGA not enabled on entry, requesting chip POST\n");
need_post = true;
}
/*
* If VGA isn't enabled, we need to enable now or subsequent
* access to the scratch registers will fail.
*/
if (need_post)
ast_enable_vga(ioregs);
/* Enable extended register access */
ast_open_key(ioregs);
ret = ast_enable_mmio(dev, ioregs);
if (ret)
return ret;
ret = ast_detect_chip(pdev, regs, ioregs, &chip, &config_mode);
if (ret)
return ret;
drm = ast_device_create(pdev, &ast_driver, chip, config_mode, regs, ioregs, need_post);
if (IS_ERR(drm))
return PTR_ERR(drm);
pci_set_drvdata(pdev, drm);
ret = drm_dev_register(drm, ent->driver_data);
if (ret)
return ret;
drm_client_setup(drm, NULL);
return 0;
}
static void ast_pci_remove(struct pci_dev *pdev)
{
struct drm_device *dev = pci_get_drvdata(pdev);
drm_dev_unregister(dev);
drm_atomic_helper_shutdown(dev);
}
static void ast_pci_shutdown(struct pci_dev *pdev)
{
drm_atomic_helper_shutdown(pci_get_drvdata(pdev));
}
static int ast_drm_freeze(struct drm_device *dev)
{
int error;
error = drm_mode_config_helper_suspend(dev);
if (error)
return error;
pci_save_state(to_pci_dev(dev->dev));
return 0;
}
static int ast_drm_thaw(struct drm_device *dev)
{
struct ast_device *ast = to_ast_device(dev);
int ret;
ast_enable_vga(ast->ioregs);
ast_open_key(ast->ioregs);
ast_enable_mmio(dev->dev, ast->ioregs);
ret = ast_post_gpu(ast);
if (ret)
return ret;
return drm_mode_config_helper_resume(dev);
}
static int ast_drm_resume(struct drm_device *dev)
{
if (pci_enable_device(to_pci_dev(dev->dev)))
return -EIO;
return ast_drm_thaw(dev);
}
static int ast_pm_suspend(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct drm_device *ddev = pci_get_drvdata(pdev);
int error;
error = ast_drm_freeze(ddev);
if (error)
return error;
pci_disable_device(pdev);
pci_set_power_state(pdev, PCI_D3hot);
return 0;
}
static int ast_pm_resume(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct drm_device *ddev = pci_get_drvdata(pdev);
return ast_drm_resume(ddev);
}
static int ast_pm_freeze(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct drm_device *ddev = pci_get_drvdata(pdev);
return ast_drm_freeze(ddev);
}
static int ast_pm_thaw(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct drm_device *ddev = pci_get_drvdata(pdev);
return ast_drm_thaw(ddev);
}
static int ast_pm_poweroff(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct drm_device *ddev = pci_get_drvdata(pdev);
return ast_drm_freeze(ddev);
}
static const struct dev_pm_ops ast_pm_ops = {
.suspend = ast_pm_suspend,
.resume = ast_pm_resume,
.freeze = ast_pm_freeze,
.thaw = ast_pm_thaw,
.poweroff = ast_pm_poweroff,
.restore = ast_pm_resume,
};
static struct pci_driver ast_pci_driver = {
.name = DRIVER_NAME,
.id_table = ast_pciidlist,
.probe = ast_pci_probe,
.remove = ast_pci_remove,
.shutdown = ast_pci_shutdown,
.driver.pm = &ast_pm_ops,
};
drm_module_pci_driver_if_modeset(ast_pci_driver, ast_modeset);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL and additional rights");