On Thu, 2017-03-16 at 20:33 -0700, Sukadev Bhattiprolu wrote:
> Define helpers to allocate/free VAS window objects. These will
> be used in follow-on patches when opening/closing windows.
>
> Signed-off-by: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
> ---
> drivers/misc/vas/vas-window.c | 74 +++++++++++++++++++++++++++++++++++++++++-
> -
> 1 file changed, 72 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/misc/vas/vas-window.c b/drivers/misc/vas/vas-window.c
> index edf5c9f..9233bf5 100644
> --- a/drivers/misc/vas/vas-window.c
> +++ b/drivers/misc/vas/vas-window.c
> @@ -119,7 +119,7 @@ static void unmap_wc_mmio_bars(struct vas_window *window)
> * OS/User Window Context (UWC) MMIO Base Address Region for the given
> window.
> * Map these bus addresses and save the mapped kernel addresses in @window.
> */
> -int map_wc_mmio_bars(struct vas_window *window)
> +static int map_wc_mmio_bars(struct vas_window *window)
> {
> int len;
> uint64_t start;
> @@ -472,8 +472,78 @@ int init_winctx_regs(struct vas_window *window, struct
> vas_winctx *winctx)
> return 0;
> }
>
> -/* stub for now */
> +DEFINE_SPINLOCK(vas_ida_lock);
> +
> +void vas_release_window_id(struct ida *ida, int winid)
> +{
> + spin_lock(&vas_ida_lock);
> + ida_remove(ida, winid);
> + spin_unlock(&vas_ida_lock);
> +}
> +
> +int vas_assign_window_id(struct ida *ida)
> +{
> + int rc, winid;
> +
> + rc = ida_pre_get(ida, GFP_KERNEL);
> + if (!rc)
> + return -EAGAIN;
> +
> + spin_lock(&vas_ida_lock);
> + rc = ida_get_new_above(ida, 0, &winid);
> + spin_unlock(&vas_ida_lock);
> +
> + if (rc)
> + return rc;
> +
> + if (winid > VAS_MAX_WINDOWS_PER_CHIP) {
> + pr_err("VAS: Too many (%d) open windows\n", winid);
> + vas_release_window_id(ida, winid);
> + return -EAGAIN;
> + }
> +
> + return winid;
> +}
> +
> +static void vas_window_free(struct vas_window *window)
> +{
> + unmap_wc_mmio_bars(window);
> + kfree(window->paste_addr_name);
> + kfree(window);
> +}
> +
> +static struct vas_window *vas_window_alloc(struct vas_instance *vinst, int
> id)
> +{
> + struct vas_window *window;
> +
> + window = kzalloc(sizeof(*window), GFP_KERNEL);
> + if (!window)
> + return NULL;
> +
> + window->vinst = vinst;
> + window->winid = id;
> +
> + if (map_wc_mmio_bars(window))
> + goto out_free;
> +
> + return window;
> +
> +out_free:
> + kfree(window);
> + return NULL;
> +}
> +
> int vas_window_reset(struct vas_instance *vinst, int winid)
>
This interface seems a little weird to me. Needing an alloc in a hardware reset
path seems a bit strange.
Maybe the data structures are the issue. A window is a hardware construct.
Something that uses it should probably be called something else like a context.
Something that references a window should just be the vas_instance + winid.
You should be able to reset this hardware window by referencing structures
already allocated. Something associated with the struct vas_instance.
Mikey
> {
> + struct vas_window *window;
> +
> + window = vas_window_alloc(vinst, winid);
> + if (!window)
> + return -ENOMEM;
> +
> + reset_window_regs(window);
> +
> + vas_window_free(window);
> +
> return 0;
> }
