* [PATCH 3/3] mach64: optimize wait_for_fifo
@ 2018-08-25 19:54 Mikulas Patocka
2018-08-27 12:55 ` Ville Syrjälä
0 siblings, 1 reply; 3+ messages in thread
From: Mikulas Patocka @ 2018-08-25 19:54 UTC (permalink / raw)
To: Ville Syrjälä, Bartlomiej Zolnierkiewicz; +Cc: linux-fbdev, dri-devel
This is a simple optimization for fifo waiting that improves scrolling
performance by 5%. If the queue has more free entries that what we
consume, we can skip the costly register read next time.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
---
drivers/video/fbdev/aty/atyfb.h | 12 ++++++++----
drivers/video/fbdev/aty/mach64_accel.c | 4 +++-
2 files changed, 11 insertions(+), 5 deletions(-)
Index: linux-stable/drivers/video/fbdev/aty/atyfb.h
=================================--- linux-stable.orig/drivers/video/fbdev/aty/atyfb.h 2018-08-25 21:49:16.000000000 +0200
+++ linux-stable/drivers/video/fbdev/aty/atyfb.h 2018-08-25 21:52:51.000000000 +0200
@@ -147,6 +147,7 @@ struct atyfb_par {
u16 pci_id;
u32 accel_flags;
int blitter_may_be_busy;
+ unsigned fifo_space;
int asleep;
int lock_blank;
unsigned long res_start;
@@ -346,10 +347,13 @@ extern int aty_init_cursor(struct fb_inf
* Hardware acceleration
*/
-static inline void wait_for_fifo(u16 entries, const struct atyfb_par *par)
+static inline void wait_for_fifo(u16 entries, struct atyfb_par *par)
{
- while ((aty_ld_le32(FIFO_STAT, par) & 0xffff) >
- ((u32) (0x8000 >> entries)));
+ unsigned fifo_space = par->fifo_space;
+ while (entries > fifo_space) {
+ fifo_space = 16 - fls(aty_ld_le32(FIFO_STAT, par) & 0xffff);
+ }
+ par->fifo_space = fifo_space - entries;
}
static inline void wait_for_idle(struct atyfb_par *par)
@@ -359,7 +363,7 @@ static inline void wait_for_idle(struct
par->blitter_may_be_busy = 0;
}
-extern void aty_reset_engine(const struct atyfb_par *par);
+extern void aty_reset_engine(struct atyfb_par *par);
extern void aty_init_engine(struct atyfb_par *par, struct fb_info *info);
void atyfb_copyarea(struct fb_info *info, const struct fb_copyarea *area);
Index: linux-stable/drivers/video/fbdev/aty/mach64_accel.c
=================================--- linux-stable.orig/drivers/video/fbdev/aty/mach64_accel.c 2018-08-25 21:49:16.000000000 +0200
+++ linux-stable/drivers/video/fbdev/aty/mach64_accel.c 2018-08-25 21:49:16.000000000 +0200
@@ -37,7 +37,7 @@ static u32 rotation24bpp(u32 dx, u32 dir
return ((rotation << 8) | DST_24_ROTATION_ENABLE);
}
-void aty_reset_engine(const struct atyfb_par *par)
+void aty_reset_engine(struct atyfb_par *par)
{
/* reset engine */
aty_st_le32(GEN_TEST_CNTL,
@@ -50,6 +50,8 @@ void aty_reset_engine(const struct atyfb
/* HOST errors */
aty_st_le32(BUS_CNTL,
aty_ld_le32(BUS_CNTL, par) | BUS_HOST_ERR_ACK | BUS_FIFO_ERR_ACK, par);
+
+ par->fifo_space = 0;
}
static void reset_GTC_3D_engine(const struct atyfb_par *par)
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH 3/3] mach64: optimize wait_for_fifo
2018-08-25 19:54 [PATCH 3/3] mach64: optimize wait_for_fifo Mikulas Patocka
@ 2018-08-27 12:55 ` Ville Syrjälä
2018-10-08 10:38 ` Bartlomiej Zolnierkiewicz
0 siblings, 1 reply; 3+ messages in thread
From: Ville Syrjälä @ 2018-08-27 12:55 UTC (permalink / raw)
To: Mikulas Patocka; +Cc: linux-fbdev, dri-devel, Bartlomiej Zolnierkiewicz
On Sat, Aug 25, 2018 at 03:54:17PM -0400, Mikulas Patocka wrote:
> This is a simple optimization for fifo waiting that improves scrolling
> performance by 5%. If the queue has more free entries that what we
> consume, we can skip the costly register read next time.
>
> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
>
> ---
> drivers/video/fbdev/aty/atyfb.h | 12 ++++++++----
> drivers/video/fbdev/aty/mach64_accel.c | 4 +++-
> 2 files changed, 11 insertions(+), 5 deletions(-)
>
> Index: linux-stable/drivers/video/fbdev/aty/atyfb.h
> =================================> --- linux-stable.orig/drivers/video/fbdev/aty/atyfb.h 2018-08-25 21:49:16.000000000 +0200
> +++ linux-stable/drivers/video/fbdev/aty/atyfb.h 2018-08-25 21:52:51.000000000 +0200
> @@ -147,6 +147,7 @@ struct atyfb_par {
> u16 pci_id;
> u32 accel_flags;
> int blitter_may_be_busy;
> + unsigned fifo_space;
> int asleep;
> int lock_blank;
> unsigned long res_start;
> @@ -346,10 +347,13 @@ extern int aty_init_cursor(struct fb_inf
> * Hardware acceleration
> */
>
> -static inline void wait_for_fifo(u16 entries, const struct atyfb_par *par)
> +static inline void wait_for_fifo(u16 entries, struct atyfb_par *par)
> {
> - while ((aty_ld_le32(FIFO_STAT, par) & 0xffff) >
> - ((u32) (0x8000 >> entries)));
> + unsigned fifo_space = par->fifo_space;
> + while (entries > fifo_space) {
> + fifo_space = 16 - fls(aty_ld_le32(FIFO_STAT, par) & 0xffff);
I don't recall off hand which way this register works, but based
on the existing code this looks correct.
Reviewed-by: Ville Syrjälä <syrjala@sci.fi>
> + }
> + par->fifo_space = fifo_space - entries;
> }
>
> static inline void wait_for_idle(struct atyfb_par *par)
> @@ -359,7 +363,7 @@ static inline void wait_for_idle(struct
> par->blitter_may_be_busy = 0;
> }
>
> -extern void aty_reset_engine(const struct atyfb_par *par);
> +extern void aty_reset_engine(struct atyfb_par *par);
> extern void aty_init_engine(struct atyfb_par *par, struct fb_info *info);
>
> void atyfb_copyarea(struct fb_info *info, const struct fb_copyarea *area);
> Index: linux-stable/drivers/video/fbdev/aty/mach64_accel.c
> =================================> --- linux-stable.orig/drivers/video/fbdev/aty/mach64_accel.c 2018-08-25 21:49:16.000000000 +0200
> +++ linux-stable/drivers/video/fbdev/aty/mach64_accel.c 2018-08-25 21:49:16.000000000 +0200
> @@ -37,7 +37,7 @@ static u32 rotation24bpp(u32 dx, u32 dir
> return ((rotation << 8) | DST_24_ROTATION_ENABLE);
> }
>
> -void aty_reset_engine(const struct atyfb_par *par)
> +void aty_reset_engine(struct atyfb_par *par)
> {
> /* reset engine */
> aty_st_le32(GEN_TEST_CNTL,
> @@ -50,6 +50,8 @@ void aty_reset_engine(const struct atyfb
> /* HOST errors */
> aty_st_le32(BUS_CNTL,
> aty_ld_le32(BUS_CNTL, par) | BUS_HOST_ERR_ACK | BUS_FIFO_ERR_ACK, par);
> +
> + par->fifo_space = 0;
> }
>
> static void reset_GTC_3D_engine(const struct atyfb_par *par)
--
Ville Syrjälä
syrjala@sci.fi
http://www.sci.fi/~syrjala/
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH 3/3] mach64: optimize wait_for_fifo
2018-08-27 12:55 ` Ville Syrjälä
@ 2018-10-08 10:38 ` Bartlomiej Zolnierkiewicz
0 siblings, 0 replies; 3+ messages in thread
From: Bartlomiej Zolnierkiewicz @ 2018-10-08 10:38 UTC (permalink / raw)
To: Ville Syrjälä; +Cc: linux-fbdev, Mikulas Patocka, dri-devel
On 08/27/2018 02:55 PM, Ville Syrj채l채 wrote:
> On Sat, Aug 25, 2018 at 03:54:17PM -0400, Mikulas Patocka wrote:
>> This is a simple optimization for fifo waiting that improves scrolling
>> performance by 5%. If the queue has more free entries that what we
>> consume, we can skip the costly register read next time.
>>
>> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
>>
>> ---
>> drivers/video/fbdev/aty/atyfb.h | 12 ++++++++----
>> drivers/video/fbdev/aty/mach64_accel.c | 4 +++-
>> 2 files changed, 11 insertions(+), 5 deletions(-)
>>
>> Index: linux-stable/drivers/video/fbdev/aty/atyfb.h
>> =================================>> --- linux-stable.orig/drivers/video/fbdev/aty/atyfb.h 2018-08-25 21:49:16.000000000 +0200
>> +++ linux-stable/drivers/video/fbdev/aty/atyfb.h 2018-08-25 21:52:51.000000000 +0200
>> @@ -147,6 +147,7 @@ struct atyfb_par {
>> u16 pci_id;
>> u32 accel_flags;
>> int blitter_may_be_busy;
>> + unsigned fifo_space;
>> int asleep;
>> int lock_blank;
>> unsigned long res_start;
>> @@ -346,10 +347,13 @@ extern int aty_init_cursor(struct fb_inf
>> * Hardware acceleration
>> */
>>
>> -static inline void wait_for_fifo(u16 entries, const struct atyfb_par *par)
>> +static inline void wait_for_fifo(u16 entries, struct atyfb_par *par)
>> {
>> - while ((aty_ld_le32(FIFO_STAT, par) & 0xffff) >
>> - ((u32) (0x8000 >> entries)));
>> + unsigned fifo_space = par->fifo_space;
>> + while (entries > fifo_space) {
>> + fifo_space = 16 - fls(aty_ld_le32(FIFO_STAT, par) & 0xffff);
>
> I don't recall off hand which way this register works, but based
> on the existing code this looks correct.
>
> Reviewed-by: Ville Syrj채l채 <syrjala@sci.fi>
Patch queued for 4.20, thanks.
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-10-08 10:38 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-08-25 19:54 [PATCH 3/3] mach64: optimize wait_for_fifo Mikulas Patocka
2018-08-27 12:55 ` Ville Syrjälä
2018-10-08 10:38 ` Bartlomiej Zolnierkiewicz
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).