Re: [PATCH v2] platform/x86: dell-laptop: Allocate buffer on heap rather than globally

From: Andy Shevchenko
Date: Wed Jan 31 2018 - 13:41:04 EST


On Wed, Jan 31, 2018 at 7:47 PM, Mario Limonciello
<mario.limonciello@xxxxxxxx> wrote:
> There is no longer a need for the buffer to be defined in
> first 4GB physical address space.
>
> Furthermore there may be race conditions with multiple different functions
> working on a module wide buffer causing incorrect results.
>

Pushed to my review and testing queue, thanks!

> Fixes: 549b4930f057658dc50d8010e66219233119a4d8
> Suggested-by: Pali Rohar <pali.rohar@xxxxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxxx>
> ---
> drivers/platform/x86/dell-laptop.c | 188 ++++++++++++++++++++-----------------
> 1 file changed, 103 insertions(+), 85 deletions(-)
>
> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
> index fc2dfc8..a7b1419 100644
> --- a/drivers/platform/x86/dell-laptop.c
> +++ b/drivers/platform/x86/dell-laptop.c
> @@ -78,7 +78,6 @@ static struct platform_driver platform_driver = {
> }
> };
>
> -static struct calling_interface_buffer *buffer;
> static struct platform_device *platform_device;
> static struct backlight_device *dell_backlight_device;
> static struct rfkill *wifi_rfkill;
> @@ -322,7 +321,8 @@ static const struct dmi_system_id dell_quirks[] __initconst = {
> { }
> };
>
> -static void dell_set_arguments(u32 arg0, u32 arg1, u32 arg2, u32 arg3)
> +static void dell_fill_request(struct calling_interface_buffer *buffer,
> + u32 arg0, u32 arg1, u32 arg2, u32 arg3)
> {
> memset(buffer, 0, sizeof(struct calling_interface_buffer));
> buffer->input[0] = arg0;
> @@ -331,7 +331,8 @@ static void dell_set_arguments(u32 arg0, u32 arg1, u32 arg2, u32 arg3)
> buffer->input[3] = arg3;
> }
>
> -static int dell_send_request(u16 class, u16 select)
> +static int dell_send_request(struct calling_interface_buffer *buffer,
> + u16 class, u16 select)
> {
> int ret;
>
> @@ -468,21 +469,22 @@ static int dell_rfkill_set(void *data, bool blocked)
> int disable = blocked ? 1 : 0;
> unsigned long radio = (unsigned long)data;
> int hwswitch_bit = (unsigned long)data - 1;
> + struct calling_interface_buffer buffer;
> int hwswitch;
> int status;
> int ret;
>
> - dell_set_arguments(0, 0, 0, 0);
> - ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> + dell_fill_request(&buffer, 0, 0, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> if (ret)
> return ret;
> - status = buffer->output[1];
> + status = buffer.output[1];
>
> - dell_set_arguments(0x2, 0, 0, 0);
> - ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> + dell_fill_request(&buffer, 0x2, 0, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> if (ret)
> return ret;
> - hwswitch = buffer->output[1];
> + hwswitch = buffer.output[1];
>
> /* If the hardware switch controls this radio, and the hardware
> switch is disabled, always disable the radio */
> @@ -490,8 +492,8 @@ static int dell_rfkill_set(void *data, bool blocked)
> (status & BIT(0)) && !(status & BIT(16)))
> disable = 1;
>
> - dell_set_arguments(1 | (radio<<8) | (disable << 16), 0, 0, 0);
> - ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> + dell_fill_request(&buffer, 1 | (radio<<8) | (disable << 16), 0, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> return ret;
> }
>
> @@ -500,9 +502,11 @@ static void dell_rfkill_update_sw_state(struct rfkill *rfkill, int radio,
> {
> if (status & BIT(0)) {
> /* Has hw-switch, sync sw_state to BIOS */
> + struct calling_interface_buffer buffer;
> int block = rfkill_blocked(rfkill);
> - dell_set_arguments(1 | (radio << 8) | (block << 16), 0, 0, 0);
> - dell_send_request(CLASS_INFO, SELECT_RFKILL);
> + dell_fill_request(&buffer,
> + 1 | (radio << 8) | (block << 16), 0, 0, 0);
> + dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> } else {
> /* No hw-switch, sync BIOS state to sw_state */
> rfkill_set_sw_state(rfkill, !!(status & BIT(radio + 16)));
> @@ -519,21 +523,22 @@ static void dell_rfkill_update_hw_state(struct rfkill *rfkill, int radio,
> static void dell_rfkill_query(struct rfkill *rfkill, void *data)
> {
> int radio = ((unsigned long)data & 0xF);
> + struct calling_interface_buffer buffer;
> int hwswitch;
> int status;
> int ret;
>
> - dell_set_arguments(0, 0, 0, 0);
> - ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> - status = buffer->output[1];
> + dell_fill_request(&buffer, 0, 0, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> + status = buffer.output[1];
>
> if (ret != 0 || !(status & BIT(0))) {
> return;
> }
>
> - dell_set_arguments(0, 0x2, 0, 0);
> - ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> - hwswitch = buffer->output[1];
> + dell_fill_request(&buffer, 0, 0x2, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> + hwswitch = buffer.output[1];
>
> if (ret != 0)
> return;
> @@ -550,22 +555,23 @@ static struct dentry *dell_laptop_dir;
>
> static int dell_debugfs_show(struct seq_file *s, void *data)
> {
> + struct calling_interface_buffer buffer;
> int hwswitch_state;
> int hwswitch_ret;
> int status;
> int ret;
>
> - dell_set_arguments(0, 0, 0, 0);
> - ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> + dell_fill_request(&buffer, 0, 0, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> if (ret)
> return ret;
> - status = buffer->output[1];
> + status = buffer.output[1];
>
> - dell_set_arguments(0, 0x2, 0, 0);
> - hwswitch_ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> + dell_fill_request(&buffer, 0, 0x2, 0, 0);
> + hwswitch_ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> if (hwswitch_ret)
> return hwswitch_ret;
> - hwswitch_state = buffer->output[1];
> + hwswitch_state = buffer.output[1];
>
> seq_printf(s, "return:\t%d\n", ret);
> seq_printf(s, "status:\t0x%X\n", status);
> @@ -646,22 +652,23 @@ static const struct file_operations dell_debugfs_fops = {
>
> static void dell_update_rfkill(struct work_struct *ignored)
> {
> + struct calling_interface_buffer buffer;
> int hwswitch = 0;
> int status;
> int ret;
>
> - dell_set_arguments(0, 0, 0, 0);
> - ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> - status = buffer->output[1];
> + dell_fill_request(&buffer, 0, 0, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> + status = buffer.output[1];
>
> if (ret != 0)
> return;
>
> - dell_set_arguments(0, 0x2, 0, 0);
> - ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> + dell_fill_request(&buffer, 0, 0x2, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
>
> if (ret == 0 && (status & BIT(0)))
> - hwswitch = buffer->output[1];
> + hwswitch = buffer.output[1];
>
> if (wifi_rfkill) {
> dell_rfkill_update_hw_state(wifi_rfkill, 1, status, hwswitch);
> @@ -719,6 +726,7 @@ static struct notifier_block dell_laptop_rbtn_notifier = {
>
> static int __init dell_setup_rfkill(void)
> {
> + struct calling_interface_buffer buffer;
> int status, ret, whitelisted;
> const char *product;
>
> @@ -734,9 +742,9 @@ static int __init dell_setup_rfkill(void)
> if (!force_rfkill && !whitelisted)
> return 0;
>
> - dell_set_arguments(0, 0, 0, 0);
> - ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
> - status = buffer->output[1];
> + dell_fill_request(&buffer, 0, 0, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
> + status = buffer.output[1];
>
> /* dell wireless info smbios call is not supported */
> if (ret != 0)
> @@ -889,6 +897,7 @@ static void dell_cleanup_rfkill(void)
>
> static int dell_send_intensity(struct backlight_device *bd)
> {
> + struct calling_interface_buffer buffer;
> struct calling_interface_token *token;
> int ret;
>
> @@ -896,17 +905,21 @@ static int dell_send_intensity(struct backlight_device *bd)
> if (!token)
> return -ENODEV;
>
> - dell_set_arguments(token->location, bd->props.brightness, 0, 0);
> + dell_fill_request(&buffer,
> + token->location, bd->props.brightness, 0, 0);
> if (power_supply_is_system_supplied() > 0)
> - ret = dell_send_request(CLASS_TOKEN_WRITE, SELECT_TOKEN_AC);
> + ret = dell_send_request(&buffer,
> + CLASS_TOKEN_WRITE, SELECT_TOKEN_AC);
> else
> - ret = dell_send_request(CLASS_TOKEN_WRITE, SELECT_TOKEN_BAT);
> + ret = dell_send_request(&buffer,
> + CLASS_TOKEN_WRITE, SELECT_TOKEN_BAT);
>
> return ret;
> }
>
> static int dell_get_intensity(struct backlight_device *bd)
> {
> + struct calling_interface_buffer buffer;
> struct calling_interface_token *token;
> int ret;
>
> @@ -914,14 +927,17 @@ static int dell_get_intensity(struct backlight_device *bd)
> if (!token)
> return -ENODEV;
>
> - dell_set_arguments(token->location, 0, 0, 0);
> + dell_fill_request(&buffer, token->location, 0, 0, 0);
> if (power_supply_is_system_supplied() > 0)
> - ret = dell_send_request(CLASS_TOKEN_READ, SELECT_TOKEN_AC);
> + ret = dell_send_request(&buffer,
> + CLASS_TOKEN_READ, SELECT_TOKEN_AC);
> else
> - ret = dell_send_request(CLASS_TOKEN_READ, SELECT_TOKEN_BAT);
> + ret = dell_send_request(&buffer,
> + CLASS_TOKEN_READ, SELECT_TOKEN_BAT);
>
> if (ret == 0)
> - ret = buffer->output[1];
> + ret = buffer.output[1];
> +
> return ret;
> }
>
> @@ -1186,31 +1202,33 @@ static enum led_brightness kbd_led_level;
>
> static int kbd_get_info(struct kbd_info *info)
> {
> + struct calling_interface_buffer buffer;
> u8 units;
> int ret;
>
> - dell_set_arguments(0, 0, 0, 0);
> - ret = dell_send_request(CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
> + dell_fill_request(&buffer, 0, 0, 0, 0);
> + ret = dell_send_request(&buffer,
> + CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
> if (ret)
> return ret;
>
> - info->modes = buffer->output[1] & 0xFFFF;
> - info->type = (buffer->output[1] >> 24) & 0xFF;
> - info->triggers = buffer->output[2] & 0xFF;
> - units = (buffer->output[2] >> 8) & 0xFF;
> - info->levels = (buffer->output[2] >> 16) & 0xFF;
> + info->modes = buffer.output[1] & 0xFFFF;
> + info->type = (buffer.output[1] >> 24) & 0xFF;
> + info->triggers = buffer.output[2] & 0xFF;
> + units = (buffer.output[2] >> 8) & 0xFF;
> + info->levels = (buffer.output[2] >> 16) & 0xFF;
>
> if (quirks && quirks->kbd_led_levels_off_1 && info->levels)
> info->levels--;
>
> if (units & BIT(0))
> - info->seconds = (buffer->output[3] >> 0) & 0xFF;
> + info->seconds = (buffer.output[3] >> 0) & 0xFF;
> if (units & BIT(1))
> - info->minutes = (buffer->output[3] >> 8) & 0xFF;
> + info->minutes = (buffer.output[3] >> 8) & 0xFF;
> if (units & BIT(2))
> - info->hours = (buffer->output[3] >> 16) & 0xFF;
> + info->hours = (buffer.output[3] >> 16) & 0xFF;
> if (units & BIT(3))
> - info->days = (buffer->output[3] >> 24) & 0xFF;
> + info->days = (buffer.output[3] >> 24) & 0xFF;
>
> return ret;
> }
> @@ -1270,31 +1288,34 @@ static int kbd_set_level(struct kbd_state *state, u8 level)
>
> static int kbd_get_state(struct kbd_state *state)
> {
> + struct calling_interface_buffer buffer;
> int ret;
>
> - dell_set_arguments(0x1, 0, 0, 0);
> - ret = dell_send_request(CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
> + dell_fill_request(&buffer, 0, 0, 0, 0);
> + ret = dell_send_request(&buffer,
> + CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
> if (ret)
> return ret;
>
> - state->mode_bit = ffs(buffer->output[1] & 0xFFFF);
> + state->mode_bit = ffs(buffer.output[1] & 0xFFFF);
> if (state->mode_bit != 0)
> state->mode_bit--;
>
> - state->triggers = (buffer->output[1] >> 16) & 0xFF;
> - state->timeout_value = (buffer->output[1] >> 24) & 0x3F;
> - state->timeout_unit = (buffer->output[1] >> 30) & 0x3;
> - state->als_setting = buffer->output[2] & 0xFF;
> - state->als_value = (buffer->output[2] >> 8) & 0xFF;
> - state->level = (buffer->output[2] >> 16) & 0xFF;
> - state->timeout_value_ac = (buffer->output[2] >> 24) & 0x3F;
> - state->timeout_unit_ac = (buffer->output[2] >> 30) & 0x3;
> + state->triggers = (buffer.output[1] >> 16) & 0xFF;
> + state->timeout_value = (buffer.output[1] >> 24) & 0x3F;
> + state->timeout_unit = (buffer.output[1] >> 30) & 0x3;
> + state->als_setting = buffer.output[2] & 0xFF;
> + state->als_value = (buffer.output[2] >> 8) & 0xFF;
> + state->level = (buffer.output[2] >> 16) & 0xFF;
> + state->timeout_value_ac = (buffer.output[2] >> 24) & 0x3F;
> + state->timeout_unit_ac = (buffer.output[2] >> 30) & 0x3;
>
> return ret;
> }
>
> static int kbd_set_state(struct kbd_state *state)
> {
> + struct calling_interface_buffer buffer;
> int ret;
> u32 input1;
> u32 input2;
> @@ -1307,8 +1328,9 @@ static int kbd_set_state(struct kbd_state *state)
> input2 |= (state->level & 0xFF) << 16;
> input2 |= (state->timeout_value_ac & 0x3F) << 24;
> input2 |= (state->timeout_unit_ac & 0x3) << 30;
> - dell_set_arguments(0x2, input1, input2, 0);
> - ret = dell_send_request(CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
> + dell_fill_request(&buffer, 0x2, input1, input2, 0);
> + ret = dell_send_request(&buffer,
> + CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
>
> return ret;
> }
> @@ -1335,6 +1357,7 @@ static int kbd_set_state_safe(struct kbd_state *state, struct kbd_state *old)
>
> static int kbd_set_token_bit(u8 bit)
> {
> + struct calling_interface_buffer buffer;
> struct calling_interface_token *token;
> int ret;
>
> @@ -1345,14 +1368,15 @@ static int kbd_set_token_bit(u8 bit)
> if (!token)
> return -EINVAL;
>
> - dell_set_arguments(token->location, token->value, 0, 0);
> - ret = dell_send_request(CLASS_TOKEN_WRITE, SELECT_TOKEN_STD);
> + dell_fill_request(&buffer, token->location, token->value, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_TOKEN_WRITE, SELECT_TOKEN_STD);
>
> return ret;
> }
>
> static int kbd_get_token_bit(u8 bit)
> {
> + struct calling_interface_buffer buffer;
> struct calling_interface_token *token;
> int ret;
> int val;
> @@ -1364,9 +1388,9 @@ static int kbd_get_token_bit(u8 bit)
> if (!token)
> return -EINVAL;
>
> - dell_set_arguments(token->location, 0, 0, 0);
> - ret = dell_send_request(CLASS_TOKEN_READ, SELECT_TOKEN_STD);
> - val = buffer->output[1];
> + dell_fill_request(&buffer, token->location, 0, 0, 0);
> + ret = dell_send_request(&buffer, CLASS_TOKEN_READ, SELECT_TOKEN_STD);
> + val = buffer.output[1];
>
> if (ret)
> return ret;
> @@ -2102,6 +2126,7 @@ static struct notifier_block dell_laptop_notifier = {
>
> int dell_micmute_led_set(int state)
> {
> + struct calling_interface_buffer buffer;
> struct calling_interface_token *token;
>
> if (state == 0)
> @@ -2114,8 +2139,8 @@ int dell_micmute_led_set(int state)
> if (!token)
> return -ENODEV;
>
> - dell_set_arguments(token->location, token->value, 0, 0);
> - dell_send_request(CLASS_TOKEN_WRITE, SELECT_TOKEN_STD);
> + dell_fill_request(&buffer, token->location, token->value, 0, 0);
> + dell_send_request(&buffer, CLASS_TOKEN_WRITE, SELECT_TOKEN_STD);
>
> return state;
> }
> @@ -2146,13 +2171,6 @@ static int __init dell_init(void)
> if (ret)
> goto fail_platform_device2;
>
> - buffer = kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
> - if (!buffer) {
> - ret = -ENOMEM;
> - goto fail_buffer;
> - }
> -
> -
> ret = dell_setup_rfkill();
>
> if (ret) {
> @@ -2177,10 +2195,13 @@ static int __init dell_init(void)
>
> token = dell_smbios_find_token(BRIGHTNESS_TOKEN);
> if (token) {
> - dell_set_arguments(token->location, 0, 0, 0);
> - ret = dell_send_request(CLASS_TOKEN_READ, SELECT_TOKEN_AC);
> + struct calling_interface_buffer buffer;
> +
> + dell_fill_request(&buffer, token->location, 0, 0, 0);
> + ret = dell_send_request(&buffer,
> + CLASS_TOKEN_READ, SELECT_TOKEN_AC);
> if (ret)
> - max_intensity = buffer->output[3];
> + max_intensity = buffer.output[3];
> }
>
> if (max_intensity) {
> @@ -2214,8 +2235,6 @@ static int __init dell_init(void)
> fail_get_brightness:
> backlight_device_unregister(dell_backlight_device);
> fail_backlight:
> - kfree(buffer);
> -fail_buffer:
> dell_cleanup_rfkill();
> fail_rfkill:
> platform_device_del(platform_device);
> @@ -2235,7 +2254,6 @@ static void __exit dell_exit(void)
> touchpad_led_exit();
> kbd_led_exit();
> backlight_device_unregister(dell_backlight_device);
> - kfree(buffer);
> dell_cleanup_rfkill();
> if (platform_device) {
> platform_device_unregister(platform_device);
> --
> 2.7.4
>



--
With Best Regards,
Andy Shevchenko