On Fri, Nov 14, 2025 at 3:52 AM Yo-Jung Leo Lin (AMD) <[email protected]> wrote: > > Add two sysfs files as interfaces to inspect or change UMA carveout > size. These files are: > > - uma_carveout_options: a read-only file listing all the available > UMA allocation options and their index. > > - uma_carveout: a file that is both readable and writable. On read, > it shows the index of the current setting. Writing a valid index > into this file allows users to change the UMA carveout size to that > option on the next boot.
Would it be cleaner to combine these? Reading the file would show the indexed list of options with a * next to the currently selected one and then writing the index to the file would cause the change to take effect on the next reboot. Alex > > Co-developed-by: Mario Limonciello (AMD) <[email protected]> > Signed-off-by: Mario Limonciello (AMD) <[email protected]> > Signed-off-by: Yo-Jung Leo Lin (AMD) <[email protected]> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c | 127 > +++++++++++++++++++++++++++++++ > 1 file changed, 127 insertions(+) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c > index 444ab4102168..b9378f34eb79 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c > @@ -30,6 +30,7 @@ > #include <linux/power_supply.h> > #include <linux/pm_runtime.h> > #include <linux/suspend.h> > +#include <linux/device.h> > #include <acpi/video.h> > #include <acpi/actbl.h> > > @@ -1247,6 +1248,125 @@ int amdgpu_acpi_get_mem_info(struct amdgpu_device > *adev, int xcc_id, > return -ENOENT; > } > > +static ssize_t uma_carveout_options_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct amdgpu_uma_carveout_info *uma_info = > &amdgpu_acpi_priv.atcs.uma_info; > + ssize_t size = 0; > + > + if (!uma_info || !uma_info->num_entries) > + return -ENODEV; > + > + for (int i = 0; i < uma_info->num_entries; i++) { > + size += sysfs_emit_at(buf, size, "%d: %s (%u GB)\n", > + i, > + uma_info->entries[i].name, > + uma_info->entries[i].memory_carved); > + } > + > + return size; > +} > +static DEVICE_ATTR_RO(uma_carveout_options); > + > +static ssize_t uma_carveout_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return sysfs_emit(buf, "%u\n", > amdgpu_acpi_priv.atcs.uma_info.uma_option_index); > +} > + > +static ssize_t uma_carveout_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct amdgpu_uma_carveout_info *uma_info = > &amdgpu_acpi_priv.atcs.uma_info; > + struct drm_device *ddev = dev_get_drvdata(dev); > + struct amdgpu_device *adev = drm_to_adev(ddev); > + struct amdgpu_uma_carveout_option *opt; > + unsigned long val; > + uint8_t flags; > + int r; > + > + r = kstrtoul(buf, 10, &val); > + if (r) > + return r; > + > + if (val >= uma_info->num_entries) > + return -EINVAL; > + > + opt = &uma_info->entries[val]; > + > + if (!(opt->flags & AMDGPU_UMA_FLAG_AUTO) && > + !(opt->flags & AMDGPU_UMA_FLAG_CUSTOM)) { > + drm_err_once(ddev, "Option %ul not supported due to lack of > Custom/Auto flag", r); > + return -EINVAL; > + } > + > + flags = opt->flags; > + flags &= ~((flags & AMDGPU_UMA_FLAG_AUTO) >> 1); > + > + guard(mutex)(&uma_info->update_lock); > + > + r = amdgpu_acpi_set_uma_allocation_size(adev, val, flags); > + if (r) > + return r; > + > + uma_info->uma_option_index = val; > + > + return count; > +} > +static DEVICE_ATTR_RW(uma_carveout); > + > +static struct attribute *amdgpu_uma_attrs[] = { > + &dev_attr_uma_carveout.attr, > + &dev_attr_uma_carveout_options.attr, > + NULL > +}; > + > +const struct attribute_group amdgpu_uma_attr_group = { > + .attrs = amdgpu_uma_attrs > +}; > + > +static int amdgpu_acpi_uma_option_init(struct amdgpu_device *adev) > +{ > + struct amdgpu_atcs *atcs = &amdgpu_acpi_priv.atcs; > + int rc; > + > + if (!atcs->functions.set_uma_allocation_size) > + return -ENODEV; > + > + rc = amdgpu_atomfirmware_get_uma_carveout_info(adev, &atcs->uma_info); > + if (rc) { > + drm_dbg(adev_to_drm(adev), > + "Failed to parse UMA carveout info from VBIOS: %d\n", > rc); > + goto out_info; > + } > + > + mutex_init(&atcs->uma_info.update_lock); > + > + rc = devm_device_add_group(adev->dev, &amdgpu_uma_attr_group); > + if (rc) { > + drm_dbg(adev_to_drm(adev), "Failed to add UMA carveout sysfs > interfaces %d\n", rc); > + goto out_attr; > + } > + > + return 0; > + > +out_attr: > + mutex_destroy(&atcs->uma_info.update_lock); > +out_info: > + return rc; > +} > + > +static void amdgpu_acpi_uma_option_fini(void) > +{ > + struct amdgpu_uma_carveout_info *uma_info = > &amdgpu_acpi_priv.atcs.uma_info; > + > + mutex_destroy(&uma_info->update_lock); > + uma_info->num_entries = 0; > +} > + > /** > * amdgpu_acpi_event - handle notify events > * > @@ -1291,6 +1411,12 @@ static int amdgpu_acpi_event(struct notifier_block *nb, > int amdgpu_acpi_init(struct amdgpu_device *adev) > { > struct amdgpu_atif *atif = &amdgpu_acpi_priv.atif; > + int rc; > + > + rc = amdgpu_acpi_uma_option_init(adev); > + > + if (rc) > + drm_dbg(adev_to_drm(adev), "Not creating uma carveout > interfaces: %d", rc); > > if (atif->notifications.brightness_change) { > if (adev->dc_enabled) { > @@ -1343,6 +1469,7 @@ void amdgpu_acpi_get_backlight_caps(struct > amdgpu_dm_backlight_caps *caps) > void amdgpu_acpi_fini(struct amdgpu_device *adev) > { > unregister_acpi_notifier(&adev->acpi_nb); > + amdgpu_acpi_uma_option_fini(); > } > > /** > > -- > 2.43.0 >
