On 12/16/25 3:43 AM, Lazar, Lijo wrote:
On 12-Dec-25 1:29 PM, Yo-Jung Leo Lin (AMD) wrote:Add a uma/ directory containing 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. Co-developed-by: Mario Limonciello (AMD) <[email protected]> Signed-off-by: Mario Limonciello (AMD) <[email protected]> Reviewed-by: Alex Deucher <[email protected]> Signed-off-by: Yo-Jung Leo Lin (AMD) <[email protected]> ---drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 143 +++++++++++++++++++ ++++++++++1 file changed, 143 insertions(+)diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/ drm/amd/amdgpu/amdgpu_device.cindex 903c4706040d..e78e6982312c 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -36,6 +36,7 @@ #include <linux/pci.h> #include <linux/pci-p2pdma.h> #include <linux/apple-gmux.h> +#include <linux/nospec.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_client_event.h>@@ -417,6 +418,146 @@ static const struct attribute_group amdgpu_board_attrs_group = {.is_visible = amdgpu_board_attrs_is_visible }; +static ssize_t carveout_options_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct drm_device *ddev = dev_get_drvdata(dev); + struct amdgpu_device *adev = drm_to_adev(ddev); + struct amdgpu_uma_carveout_info *uma_info = &adev->uma_info; + uint32_t memory_carved; + ssize_t size = 0; + + if (!uma_info || !uma_info->num_entries) + return -ENODEV; + + for (int i = 0; i < uma_info->num_entries; i++) { + memory_carved = uma_info->entries[i].memory_carved_mb; + if (memory_carved >= SZ_1G/SZ_1M) { + size += sysfs_emit_at(buf, size, "%d: %s (%u GB)\n", + i, + uma_info->entries[i].name, + memory_carved >> 10); + } else { + size += sysfs_emit_at(buf, size, "%d: %s (%u MB)\n", + i, + uma_info->entries[i].name, + memory_carved); + } + } + + return size; +} +static DEVICE_ATTR_RO(carveout_options); + +static ssize_t carveout_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct drm_device *ddev = dev_get_drvdata(dev); + struct amdgpu_device *adev = drm_to_adev(ddev); + + return sysfs_emit(buf, "%u\n", adev->uma_info.uma_option_index);It would be better to show the size along with the index.
This idea complicates userspace parsing because rather than a atoi() parser you now need to do sscanf().
IE - I like it the way it is in the series at the moment.
Regardless, series is - Reviewed-by: Lijo Lazar <[email protected]> Thanks, Lijo+} + +static ssize_t carveout_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct drm_device *ddev = dev_get_drvdata(dev); + struct amdgpu_device *adev = drm_to_adev(ddev); + struct amdgpu_uma_carveout_info *uma_info = &adev->uma_info; + 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; + + val = array_index_nospec(val, uma_info->num_entries); + opt = &uma_info->entries[val]; + + if (!(opt->flags & AMDGPU_UMA_FLAG_AUTO) && + !(opt->flags & AMDGPU_UMA_FLAG_CUSTOM)) {+ drm_err_once(ddev, "Option %lu not supported due to lack of Custom/Auto flag", val);+ 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(carveout); + +static struct attribute *amdgpu_uma_attrs[] = { + &dev_attr_carveout.attr, + &dev_attr_carveout_options.attr, + NULL +}; + +const struct attribute_group amdgpu_uma_attr_group = { + .name = "uma", + .attrs = amdgpu_uma_attrs +}; + +static void amdgpu_uma_sysfs_init(struct amdgpu_device *adev) +{ + int rc; + + if (!(adev->flags & AMD_IS_APU)) + return; + + if (!amdgpu_acpi_is_set_uma_allocation_size_supported()) + return; ++ rc = amdgpu_atomfirmware_get_uma_carveout_info(adev, &adev- >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(&adev->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; + +out_attr: + mutex_destroy(&adev->uma_info.update_lock); +out_info: + return; +} + +static void amdgpu_uma_sysfs_fini(struct amdgpu_device *adev) +{ + struct amdgpu_uma_carveout_info *uma_info = &adev->uma_info; + + if (!amdgpu_acpi_is_set_uma_allocation_size_supported()) + return; + + mutex_destroy(&uma_info->update_lock); + uma_info->num_entries = 0; +} + static void amdgpu_device_get_pcie_info(struct amdgpu_device *adev); /**@@ -4492,6 +4633,7 @@ static int amdgpu_device_sys_interface_init(struct amdgpu_device *adev)amdgpu_fru_sysfs_init(adev); amdgpu_reg_state_sysfs_init(adev); amdgpu_xcp_sysfs_init(adev); + amdgpu_uma_sysfs_init(adev); return r; }@@ -4507,6 +4649,7 @@ static void amdgpu_device_sys_interface_fini(struct amdgpu_device *adev)amdgpu_reg_state_sysfs_fini(adev); amdgpu_xcp_sysfs_fini(adev); + amdgpu_uma_sysfs_fini(adev); } /**
