Re: [PATCH] fw_cfg: avoid unused function warning

From: Marc-Andrà Lureau
Date: Wed Feb 28 2018 - 09:23:00 EST


Hi

On Wed, Feb 28, 2018 at 2:33 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> The newly introduced fw_cfg_dma_transfer() function is unused when
> CONFIG_CRASH_CORE is disabled:
>
> drivers/firmware/qemu_fw_cfg.c:89:16: error: 'fw_cfg_dma_transfer' defined but not used [-Werror=unused-function]
> static ssize_t fw_cfg_dma_transfer(void *address, u32 length, u32 control)
>
> This moves it into the #ifdef section that hides its caller to avoid the
> warning.
>
> Fixes: 47e78bfb5426 ("fw_cfg: write vmcoreinfo details")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

I don't know from which tree you found this, I suppose from
mst/linux-next (which btw, I don't know which version got partially
applied).

This is a regression in v13, because dma read is last patch now, as RFC.
Fixed in upcoming v16.

thanks

> ---
> drivers/firmware/qemu_fw_cfg.c | 60 +++++++++++++++++++++---------------------
> 1 file changed, 30 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
> index 3015e77aebca..f002bb40519b 100644
> --- a/drivers/firmware/qemu_fw_cfg.c
> +++ b/drivers/firmware/qemu_fw_cfg.c
> @@ -66,6 +66,36 @@ static void fw_cfg_sel_endianness(u16 key)
> iowrite16(key, fw_cfg_reg_ctrl);
> }
>
> +/* read chunk of given fw_cfg blob (caller responsible for sanity-check) */
> +static ssize_t fw_cfg_read_blob(u16 key,
> + void *buf, loff_t pos, size_t count)
> +{
> + u32 glk = -1U;
> + acpi_status status;
> +
> + /* If we have ACPI, ensure mutual exclusion against any potential
> + * device access by the firmware, e.g. via AML methods:
> + */
> + status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk);
> + if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) {
> + /* Should never get here */
> + WARN(1, "fw_cfg_read_blob: Failed to lock ACPI!\n");
> + memset(buf, 0, count);
> + return -EINVAL;
> + }
> +
> + mutex_lock(&fw_cfg_dev_lock);
> + fw_cfg_sel_endianness(key);
> + while (pos-- > 0)
> + ioread8(fw_cfg_reg_data);
> + ioread8_rep(fw_cfg_reg_data, buf, count);
> + mutex_unlock(&fw_cfg_dev_lock);
> +
> + acpi_release_global_lock(glk);
> + return count;
> +}
> +
> +#ifdef CONFIG_CRASH_CORE
> static inline bool fw_cfg_dma_enabled(void)
> {
> return (fw_cfg_rev & FW_CFG_VERSION_DMA) && fw_cfg_reg_dma;
> @@ -124,36 +154,6 @@ static ssize_t fw_cfg_dma_transfer(void *address, u32 length, u32 control)
> return ret;
> }
>
> -/* read chunk of given fw_cfg blob (caller responsible for sanity-check) */
> -static ssize_t fw_cfg_read_blob(u16 key,
> - void *buf, loff_t pos, size_t count)
> -{
> - u32 glk = -1U;
> - acpi_status status;
> -
> - /* If we have ACPI, ensure mutual exclusion against any potential
> - * device access by the firmware, e.g. via AML methods:
> - */
> - status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk);
> - if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) {
> - /* Should never get here */
> - WARN(1, "fw_cfg_read_blob: Failed to lock ACPI!\n");
> - memset(buf, 0, count);
> - return -EINVAL;
> - }
> -
> - mutex_lock(&fw_cfg_dev_lock);
> - fw_cfg_sel_endianness(key);
> - while (pos-- > 0)
> - ioread8(fw_cfg_reg_data);
> - ioread8_rep(fw_cfg_reg_data, buf, count);
> - mutex_unlock(&fw_cfg_dev_lock);
> -
> - acpi_release_global_lock(glk);
> - return count;
> -}
> -
> -#ifdef CONFIG_CRASH_CORE
> /* write chunk of given fw_cfg blob (caller responsible for sanity-check) */
> static ssize_t fw_cfg_write_blob(u16 key,
> void *buf, loff_t pos, size_t count)
> --
> 2.9.0
>