Add /proc/gpu#/local_memory API for getting VRAM size

1 files changed, 24 insertions, 0 deletions

diff --git a/device_info_procfs.c b/device_info_procfs.c
index 8fe9709..c8903fc 100644
--- a/device_info_procfs.c
+++ b/device_info_procfs.c
@@ -61,6 +61,30 @@ struct file_operations nvdebug_read_reg_range_file_ops = {
         .llseek = default_llseek,
 };
 
+static ssize_t local_memory_read(struct file *f, char __user *buf, size_t size, loff_t *off) {
+        struct nvdebug_state *g = &g_nvdebug_state[file2parentgpuidx(f)];
+        char out[30];
+        int chars_written;
+        memory_range_t mem_range;
+        if (size < 30 || *off != 0)
+                return 0;
+        mem_range.raw = nvdebug_readl(g, NV_FB_MMU_LOCAL_MEMORY_RANGE);
+        if (mem_range.raw == -1)
+                return -EIO;
+        // 64-bit size has at most 19 characters + 8 for text and termination
+        chars_written = scnprintf(out, 30, "%lld bytes\n", memory_range_to_bytes(mem_range));
+        if (copy_to_user(buf, out, chars_written))
+                printk(KERN_WARNING "Unable to copy all data for %s\n", file_dentry(f)->d_name.name);
+        *off += chars_written;
+        return chars_written;
+}
+
+// Read out size of on-device VRAM
+struct file_operations local_memory_file_ops = {
+        .read = local_memory_read,
+        .llseek = default_llseek,
+};
+
 typedef struct {
         int idx; // Current index in the device_info table
         int length; // Length of device_info table (including unpopulated entries)