Add basic .seq_show and .write functions for use with DRM cgroup control files. This is based on original work from Kenny Ho and extracted from patches [1] and [2]. Has been simplified to remove having different file types and functions for each.
[1] https://lists.freedesktop.org/archives/dri-devel/2020-February/254986.html [2] https://lists.freedesktop.org/archives/dri-devel/2020-February/254990.html
Co-developed-by: Kenny Ho Kenny.Ho@amd.com Signed-off-by: Brian Welty brian.welty@intel.com --- include/drm/drm_cgroup.h | 5 ++ kernel/cgroup/drm.c | 102 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 107 insertions(+)
diff --git a/include/drm/drm_cgroup.h b/include/drm/drm_cgroup.h index 43caf1b6a0de..12526def9fbf 100644 --- a/include/drm/drm_cgroup.h +++ b/include/drm/drm_cgroup.h @@ -1,5 +1,6 @@ /* SPDX-License-Identifier: MIT * Copyright 2019 Advanced Micro Devices, Inc. + * Copyright © 2021 Intel Corporation */ #ifndef __DRM_CGROUP_H__ #define __DRM_CGROUP_H__ @@ -15,6 +16,10 @@ struct drm_device; struct drmcg_props { };
+enum drmcg_res_type { + __DRMCG_TYPE_LAST, +}; + #ifdef CONFIG_CGROUP_DRM
void drmcg_bind(struct drm_minor (*(*acq_dm)(unsigned int minor_id)), diff --git a/kernel/cgroup/drm.c b/kernel/cgroup/drm.c index 836929c27de8..aece11faa0bc 100644 --- a/kernel/cgroup/drm.c +++ b/kernel/cgroup/drm.c @@ -5,6 +5,7 @@ */ #include <linux/bitmap.h> #include <linux/mutex.h> +#include <linux/seq_file.h> #include <linux/slab.h> #include <linux/cgroup.h> #include <linux/cgroup_drm.h> @@ -12,6 +13,7 @@ #include <drm/drm_drv.h> #include <drm/drm_device.h> #include <drm/drm_cgroup.h> +#include <drm/drm_ioctl.h>
static struct drmcg *root_drmcg __read_mostly;
@@ -222,6 +224,106 @@ drmcg_css_alloc(struct cgroup_subsys_state *parent_css) return &drmcg->css; }
+static int drmcg_apply_value(struct drmcg_device_resource *ddr, + enum drmcg_res_type type, char *buf) +{ + int ret = 0; + unsigned long val; + + switch (type) { + default: + break; + } + + return ret; +} + +static int drmcg_seq_show_fn(int id, void *ptr, void *data) +{ + struct drm_minor *minor = ptr; + struct seq_file *sf = data; + struct drmcg *drmcg = css_to_drmcg(seq_css(sf)); + enum drmcg_res_type type = seq_cft(sf)->private; + struct drmcg_device_resource *ddr; + + if (minor->type != DRM_MINOR_PRIMARY) + return 0; + + ddr = drmcg->dev_resources[minor->index]; + if (ddr == NULL) + return 0; + + seq_printf(sf, "%d:%d ", DRM_MAJOR, minor->index); + switch (type) { + default: + seq_puts(sf, "\n"); + break; + } + + return 0; +} + +static int drmcg_seq_show(struct seq_file *sf, void *v) +{ + return drm_minor_for_each(&drmcg_seq_show_fn, sf); +} + +static ssize_t drmcg_write(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) +{ + struct drmcg *drmcg = css_to_drmcg(of_css(of)); + enum drmcg_res_type type = of_cft(of)->private; + char *cft_name = of_cft(of)->name; + char *limits = strstrip(buf); + struct drmcg_device_resource *ddr; + struct drm_minor *dm; + char *line; + char sattr[256]; + int minor, ret = 0; + + while (!ret && limits != NULL) { + line = strsep(&limits, "\n"); + + if (sscanf(line, + __stringify(DRM_MAJOR)":%u %255[^\t\n]", + &minor, sattr) != 2) { + pr_err("drmcg: error parsing %s ", cft_name); + pr_cont_cgroup_name(drmcg->css.cgroup); + pr_cont("\n"); + + continue; + } + + mutex_lock(&drmcg_mutex); + if (acquire_drm_minor) + dm = acquire_drm_minor(minor); + else + dm = NULL; + mutex_unlock(&drmcg_mutex); + + if (IS_ERR_OR_NULL(dm)) { + pr_err("drmcg: invalid minor %d for %s ", + minor, cft_name); + pr_cont_cgroup_name(drmcg->css.cgroup); + pr_cont("\n"); + + continue; + } + + mutex_lock(&dm->dev->drmcg_mutex); + ddr = drmcg->dev_resources[minor]; + ret = drmcg_apply_value(ddr, type, sattr); + mutex_unlock(&dm->dev->drmcg_mutex); + + mutex_lock(&drmcg_mutex); + if (put_drm_dev) + put_drm_dev(dm->dev); /* release from acquire_drm_minor */ + mutex_unlock(&drmcg_mutex); + } + + return ret ?: nbytes; +} + struct cftype files[] = { { } /* terminate */ };