wifi: rtw89: debugfs: specify buffer size allocated by devm_kazlloc() for reading

Some debufs entries need output buffer over default size 4K. Since reading
of many debugfs entries is to access IO, it costs time to dynamically
re-allocate larger buffer and access IO again and again. Add an option to
specify the size it needs.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250122060310.31976-5-pkshih@realtek.com

diff --git a/drivers/net/wireless/realtek/rtw89/debug.c b/drivers/net/wireless/realtek/rtw89/debug.c
index db0e7a4beb07e06e4ffaaccd318829a7050733b4..f3ec18860797bfbc580a40cd42c5e88ff3f9e020 100644 (file)
--- a/drivers/net/wireless/realtek/rtw89/debug.c
+++ b/drivers/net/wireless/realtek/rtw89/debug.c
@@ -23,6 +23,10 @@ MODULE_PARM_DESC(debug_mask, "Debugging mask");
 #endif
 
 #ifdef CONFIG_RTW89_DEBUGFS
+struct rtw89_debugfs_priv_opt {
+       size_t rsize;
+};
+
 struct rtw89_debugfs_priv {
        struct rtw89_dev *rtwdev;
        ssize_t (*cb_read)(struct rtw89_dev *rtwdev,
@@ -31,6 +35,7 @@ struct rtw89_debugfs_priv {
        ssize_t (*cb_write)(struct rtw89_dev *rtwdev,
                            struct rtw89_debugfs_priv *debugfs_priv,
                            const char *buf, size_t count);
+       struct rtw89_debugfs_priv_opt opt;
        union {
                u32 cb_data;
                struct {
@@ -55,6 +60,8 @@ struct rtw89_debugfs_priv {
                        u8 sel;
                } mac_mem;
        };
+       ssize_t rused;
+       char *rbuf;
 };
 
 struct rtw89_debugfs {
@@ -120,23 +127,31 @@ static ssize_t rtw89_debugfs_file_read(struct file *file, char __user *userbuf,
                                       size_t count, loff_t *ppos)
 {
        struct rtw89_debugfs_priv *debugfs_priv = file->private_data;
+       struct rtw89_debugfs_priv_opt *opt = &debugfs_priv->opt;
        struct rtw89_dev *rtwdev = debugfs_priv->rtwdev;
-       size_t bufsz = PAGE_SIZE;
+       size_t bufsz = opt->rsize ? opt->rsize : PAGE_SIZE;
        char *buf;
        ssize_t n;
 
-       buf = kvmalloc(bufsz, GFP_KERNEL);
+       if (!debugfs_priv->rbuf)
+               debugfs_priv->rbuf = devm_kzalloc(rtwdev->dev, bufsz, GFP_KERNEL);
+
+       buf = debugfs_priv->rbuf;
        if (!buf)
-               return 0;
+               return -ENOMEM;
+
+       if (*ppos) {
+               n = debugfs_priv->rused;
+               goto out;
+       }
 
        n = debugfs_priv->cb_read(rtwdev, debugfs_priv, buf, bufsz);
        rtw89_might_trailing_ellipsis(buf, bufsz, n);
 
-       n = simple_read_from_buffer(userbuf, count, ppos, buf, n);
-
-       kvfree(buf);
+       debugfs_priv->rused = n;
 
-       return n;
+out:
+       return simple_read_from_buffer(userbuf, count, ppos, buf, n);
 }
 
 static ssize_t rtw89_debugfs_file_write(struct file *file,
@@ -4157,42 +4172,55 @@ rtw89_debug_priv_disable_dm_set(struct rtw89_dev *rtwdev,
        return count;
 }
 
-#define rtw89_debug_priv_get(name)                             \
+#define rtw89_debug_priv_get(name, opts...)                    \
 {                                                              \
        .cb_read = rtw89_debug_priv_ ##name## _get,             \
+       .opt = { opts },                                        \
 }
 
-#define rtw89_debug_priv_set(name)                             \
+#define rtw89_debug_priv_set(name, opts...)                    \
 {                                                              \
        .cb_write = rtw89_debug_priv_ ##name## _set,            \
+       .opt = { opts },                                        \
 }
 
-#define rtw89_debug_priv_select_and_get(name)                  \
+#define rtw89_debug_priv_select_and_get(name, opts...)         \
 {                                                              \
        .cb_write = rtw89_debug_priv_ ##name## _select,         \
        .cb_read = rtw89_debug_priv_ ##name## _get,             \
+       .opt = { opts },                                        \
 }
 
-#define rtw89_debug_priv_set_and_get(name)                     \
+#define rtw89_debug_priv_set_and_get(name, opts...)            \
 {                                                              \
        .cb_write = rtw89_debug_priv_ ##name## _set,            \
        .cb_read = rtw89_debug_priv_ ##name## _get,             \
+       .opt = { opts },                                        \
 }
 
+#define RSIZE_8K .rsize = 0x2000
+#define RSIZE_12K .rsize = 0x3000
+#define RSIZE_16K .rsize = 0x4000
+#define RSIZE_20K .rsize = 0x5000
+#define RSIZE_32K .rsize = 0x8000
+#define RSIZE_64K .rsize = 0x10000
+#define RSIZE_128K .rsize = 0x20000
+#define RSIZE_1M .rsize = 0x100000
+
 static const struct rtw89_debugfs rtw89_debugfs_templ = {
        .read_reg = rtw89_debug_priv_select_and_get(read_reg),
        .write_reg = rtw89_debug_priv_set(write_reg),
        .read_rf = rtw89_debug_priv_select_and_get(read_rf),
        .write_rf = rtw89_debug_priv_set(write_rf),
-       .rf_reg_dump = rtw89_debug_priv_get(rf_reg_dump),
-       .txpwr_table = rtw89_debug_priv_get(txpwr_table),
-       .mac_reg_dump = rtw89_debug_priv_select_and_get(mac_reg_dump),
-       .mac_mem_dump = rtw89_debug_priv_select_and_get(mac_mem_dump),
-       .mac_dbg_port_dump = rtw89_debug_priv_select_and_get(mac_dbg_port_dump),
+       .rf_reg_dump = rtw89_debug_priv_get(rf_reg_dump, RSIZE_8K),
+       .txpwr_table = rtw89_debug_priv_get(txpwr_table, RSIZE_20K),
+       .mac_reg_dump = rtw89_debug_priv_select_and_get(mac_reg_dump, RSIZE_128K),
+       .mac_mem_dump = rtw89_debug_priv_select_and_get(mac_mem_dump, RSIZE_16K),
+       .mac_dbg_port_dump = rtw89_debug_priv_select_and_get(mac_dbg_port_dump, RSIZE_1M),
        .send_h2c = rtw89_debug_priv_set(send_h2c),
        .early_h2c = rtw89_debug_priv_set_and_get(early_h2c),
        .fw_crash = rtw89_debug_priv_set_and_get(fw_crash),
-       .btc_info = rtw89_debug_priv_get(btc_info),
+       .btc_info = rtw89_debug_priv_get(btc_info, RSIZE_12K),
        .btc_manual = rtw89_debug_priv_set(btc_manual),
        .fw_log_manual = rtw89_debug_priv_set(fw_log_manual),
        .phy_info = rtw89_debug_priv_get(phy_info),