[Skiboot] [PATCH V4 1/3] opal-msg: Add support to increase async completions and msg_free_list

[Cyril Bur]

On Thu, 2017-06-29 at 23:50 +0530, Shilpasri G Bhat wrote:
> Add support to increase the maximum async completions passed to kernel
> and also add helpers to increase the pre-allocation of free buffers in
> msg_free_list.
> 
> Signed-off-by: Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com>
> ---
> - No changes from V3
>  core/init.c        |  2 ++
>  core/opal-msg.c    | 22 ++++++++++++++++++++--
>  core/opal.c        |  1 -
>  include/opal-msg.h |  3 +++
>  4 files changed, 25 insertions(+), 3 deletions(-)
> 
> diff --git a/core/init.c b/core/init.c
> index 02bd30c..c58ef3a 100644
> --- a/core/init.c
> +++ b/core/init.c
> @@ -1055,6 +1055,8 @@ void __noreturn __nomcount main_cpu_entry(const void *fdt)
>  	/* On P9, switch to radix mode by default */
>  	cpu_set_radix_mode();
>  
> +	add_dt_max_async_completions();
> +
>  	load_and_boot_kernel(false);
>  }
>  
> diff --git a/core/opal-msg.c b/core/opal-msg.c
> index 1971467..0ac891d 100644
> --- a/core/opal-msg.c
> +++ b/core/opal-msg.c
> @@ -19,9 +19,12 @@
>  #include <opal-msg.h>
>  #include <opal-api.h>
>  #include <lock.h>
> +#include <device.h>
>  
>  #define OPAL_MAX_MSGS		(OPAL_MSG_TYPE_MAX + OPAL_MAX_ASYNC_COMP - 1)
>  

So this leaves this #define using OPAL_MAX_ASYNC_COMP, but that number
isn't really relevant anymore is it? Since the next patch will change
the max_async_comp variable, which is what you put the in device
tree...

> +static int max_async_comp;
> +
>  struct opal_msg_entry {
>  	struct list_node link;
>  	void (*consumed)(void *data);
> @@ -149,12 +152,12 @@ static int64_t opal_check_completion(uint64_t *buffer, uint64_t size,
>  }
>  opal_call(OPAL_CHECK_ASYNC_COMPLETION, opal_check_completion, 3);
>  
> -void opal_init_msg(void)
> +void alloc_opal_msg_list(int num)
>  {
>  	struct opal_msg_entry *entry;
>  	int i;
>  
> -	for (i = 0; i < OPAL_MAX_MSGS; i++, entry++) {
> +	for (i = 0; i < num; i++, entry++) {
>                  entry = zalloc(sizeof(*entry));
>                  if (!entry)
>                          goto err;
> @@ -170,3 +173,18 @@ err:
>          }
>  }
>  
> +void add_dt_max_async_completions(void)
> +{
> +	dt_add_property_cells(opal_node, "opal-msg-async-num", max_async_comp);
> +}
> +
> +void update_max_async_completions(int num)
> +{
> +	max_async_comp += num;
> +}
> +
> +void opal_init_msg(void)
> +{
> +	max_async_comp = OPAL_MAX_ASYNC_COMP;
> +	alloc_opal_msg_list(OPAL_MAX_MSGS);

I'm confused, you haven't really changed the code since the num you
pass to alloc_opal_msg_list() is what was originally in the for loop.
But you do provide the ability to change max_async_comp. I would expect
that the msg_free_list list would need to grow accordingly (I could be
wrong). Ah so I did some looking around _opal_queue_msg() would grow
the list, perhaps you're correct and we don't want to allocate all of
msg_free_list at boot? But it seems that we do at the moment... just to
avoid runtime malloc() which we don't like doing... Stewart?

It isn't a big change update_max_async_completitions() could do

alloc_opal_msg_list(num);

to add more entries to the list?


Also this makes the both those defines misleading now, especially at
skiboot runtime if the occ code changes max_async_comp. Might I suggest
renaming the defines, I suppose you'd need to turn OPAL_MAX_MSGS into a
function that sums OPAL_MSG_TYPE_MAX and max_async_comp and then
OPAL_MAX_ASYNC_COMP could be OPAL_MIN_ASYNC_COMP or
OPAL_DEFAULT_ASYNC_COMP....

> +}
> diff --git a/core/opal.c b/core/opal.c
> index 8095f73..ebd3937 100644
> --- a/core/opal.c
> +++ b/core/opal.c
> @@ -201,7 +201,6 @@ void add_opal_node(void)
>  	else
>  		dt_add_property_strings(opal_node, "compatible", "ibm,opal-v3");
>  
> -	dt_add_property_cells(opal_node, "opal-msg-async-num", OPAL_MAX_ASYNC_COMP);
>  	dt_add_property_cells(opal_node, "opal-msg-size", sizeof(struct opal_msg));
>  	dt_add_property_u64(opal_node, "opal-base-address", base);
>  	dt_add_property_u64(opal_node, "opal-entry-address", entry);
> diff --git a/include/opal-msg.h b/include/opal-msg.h
> index a75bc4e..982026e 100644
> --- a/include/opal-msg.h
> +++ b/include/opal-msg.h
> @@ -37,5 +37,8 @@ int _opal_queue_msg(enum opal_msg_type msg_type, void *data,
>  			(u64[]) {__VA_ARGS__});
>  
>  void opal_init_msg(void);
> +void alloc_opal_msg_list(int num);
> +void update_max_async_completions(int num);
> +void add_dt_max_async_completions(void);
>  
>  #endif /* __OPALMSG_H */