| Message ID | 20250325110407.81107-8-tzimmermann@suse.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | drm/format-helper: Add helpers for line conversion | expand |
On 25/03/2025 11:31, Thomas Zimmermann wrote: > For ease of implementation, existing line-conversion functions > for 16-bit formats write each pixel individually. Optimize the > performance by writing mulitple pixels in single 64-bit and 32-bit > stores. With the commit message typo fixed, mulitple => multiple Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com> > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> > --- > drivers/gpu/drm/drm_format_helper.c | 40 ++++++++++++++++++++++++++++- > 1 file changed, 39 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c > index b9c9c712aa9c..66137df85725 100644 > --- a/drivers/gpu/drm/drm_format_helper.c > +++ b/drivers/gpu/drm/drm_format_helper.c > @@ -262,10 +262,48 @@ static __always_inline void drm_fb_xfrm_line_32to16(void *dbuf, const void *sbuf > unsigned int pixels, > u32 (*xfrm_pixel)(u32)) > { > - __le16 *dbuf16 = dbuf; > + __le64 *dbuf64 = dbuf; > + __le32 *dbuf32; > + __le16 *dbuf16; > const __le32 *sbuf32 = sbuf; > const __le32 *send32 = sbuf32 + pixels; > > +#if defined(CONFIG_64BIT) > + /* write 4 pixels at once */ > + send32 -= pixels & GENMASK(1, 0); > + while (sbuf32 < send32) { > + u32 pix[4] = { > + le32_to_cpup(sbuf32++), > + le32_to_cpup(sbuf32++), > + le32_to_cpup(sbuf32++), > + le32_to_cpup(sbuf32++), > + }; > + /* write output bytes in reverse order for little endianness */ > + u64 val64 = ((u64)xfrm_pixel(pix[0])) | > + ((u64)xfrm_pixel(pix[1]) << 16) | > + ((u64)xfrm_pixel(pix[2]) << 32) | > + ((u64)xfrm_pixel(pix[3]) << 48); > + *dbuf64++ = cpu_to_le64(val64); > + } > + send32 += pixels & GENMASK(1, 1); > +#endif > + > + /* write 2 pixels at once */ > + dbuf32 = (__le32 __force *)dbuf64; > + while (sbuf32 < send32) { > + u32 pix[2] = { > + le32_to_cpup(sbuf32++), > + le32_to_cpup(sbuf32++), > + }; > + /* write output bytes in reverse order for little endianness */ > + u32 val32 = xfrm_pixel(pix[0]) | > + (xfrm_pixel(pix[1]) << 16); > + *dbuf32++ = cpu_to_le32(val32); > + } > + send32 += pixels & GENMASK(0, 0); > + > + /* write trailing pixel */ > + dbuf16 = (__le16 __force *)dbuf32; > while (sbuf32 < send32) > *dbuf16++ = cpu_to_le16(xfrm_pixel(le32_to_cpup(sbuf32++))); > }
On Tue, 25 Mar 2025, Thomas Zimmermann <tzimmermann@suse.de> wrote: > For ease of implementation, existing line-conversion functions > for 16-bit formats write each pixel individually. Optimize the > performance by writing mulitple pixels in single 64-bit and 32-bit > stores. > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> > --- > drivers/gpu/drm/drm_format_helper.c | 40 ++++++++++++++++++++++++++++- > 1 file changed, 39 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c > index b9c9c712aa9c..66137df85725 100644 > --- a/drivers/gpu/drm/drm_format_helper.c > +++ b/drivers/gpu/drm/drm_format_helper.c > @@ -262,10 +262,48 @@ static __always_inline void drm_fb_xfrm_line_32to16(void *dbuf, const void *sbuf > unsigned int pixels, > u32 (*xfrm_pixel)(u32)) > { > - __le16 *dbuf16 = dbuf; > + __le64 *dbuf64 = dbuf; > + __le32 *dbuf32; > + __le16 *dbuf16; > const __le32 *sbuf32 = sbuf; > const __le32 *send32 = sbuf32 + pixels; > > +#if defined(CONFIG_64BIT) > + /* write 4 pixels at once */ > + send32 -= pixels & GENMASK(1, 0); > + while (sbuf32 < send32) { I find the adjusting of send32 before and after the loop with different masks a bit confusing. Would it not suffice to: while (sbuf32 < ALIGN_DOWN(send32, 4)) and leave send32 untouched? With different alignments for 2 pixels at a time. BR, Jani. > + u32 pix[4] = { > + le32_to_cpup(sbuf32++), > + le32_to_cpup(sbuf32++), > + le32_to_cpup(sbuf32++), > + le32_to_cpup(sbuf32++), > + }; > + /* write output bytes in reverse order for little endianness */ > + u64 val64 = ((u64)xfrm_pixel(pix[0])) | > + ((u64)xfrm_pixel(pix[1]) << 16) | > + ((u64)xfrm_pixel(pix[2]) << 32) | > + ((u64)xfrm_pixel(pix[3]) << 48); > + *dbuf64++ = cpu_to_le64(val64); > + } > + send32 += pixels & GENMASK(1, 1); > +#endif > + > + /* write 2 pixels at once */ > + dbuf32 = (__le32 __force *)dbuf64; > + while (sbuf32 < send32) { > + u32 pix[2] = { > + le32_to_cpup(sbuf32++), > + le32_to_cpup(sbuf32++), > + }; > + /* write output bytes in reverse order for little endianness */ > + u32 val32 = xfrm_pixel(pix[0]) | > + (xfrm_pixel(pix[1]) << 16); > + *dbuf32++ = cpu_to_le32(val32); > + } > + send32 += pixels & GENMASK(0, 0); > + > + /* write trailing pixel */ > + dbuf16 = (__le16 __force *)dbuf32; > while (sbuf32 < send32) > *dbuf16++ = cpu_to_le16(xfrm_pixel(le32_to_cpup(sbuf32++))); > }
Hi Am 26.03.25 um 11:53 schrieb Jani Nikula: > On Tue, 25 Mar 2025, Thomas Zimmermann <tzimmermann@suse.de> wrote: >> For ease of implementation, existing line-conversion functions >> for 16-bit formats write each pixel individually. Optimize the >> performance by writing mulitple pixels in single 64-bit and 32-bit >> stores. >> >> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> >> --- >> drivers/gpu/drm/drm_format_helper.c | 40 ++++++++++++++++++++++++++++- >> 1 file changed, 39 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c >> index b9c9c712aa9c..66137df85725 100644 >> --- a/drivers/gpu/drm/drm_format_helper.c >> +++ b/drivers/gpu/drm/drm_format_helper.c >> @@ -262,10 +262,48 @@ static __always_inline void drm_fb_xfrm_line_32to16(void *dbuf, const void *sbuf >> unsigned int pixels, >> u32 (*xfrm_pixel)(u32)) >> { >> - __le16 *dbuf16 = dbuf; >> + __le64 *dbuf64 = dbuf; >> + __le32 *dbuf32; >> + __le16 *dbuf16; >> const __le32 *sbuf32 = sbuf; >> const __le32 *send32 = sbuf32 + pixels; >> >> +#if defined(CONFIG_64BIT) >> + /* write 4 pixels at once */ >> + send32 -= pixels & GENMASK(1, 0); >> + while (sbuf32 < send32) { > I find the adjusting of send32 before and after the loop with different > masks a bit confusing. Would it not suffice to: > > while (sbuf32 < ALIGN_DOWN(send32, 4)) > > and leave send32 untouched? With different alignments for 2 pixels at a > time. Makes sense. Best regards Thomas > > > BR, > Jani. > > >> + u32 pix[4] = { >> + le32_to_cpup(sbuf32++), >> + le32_to_cpup(sbuf32++), >> + le32_to_cpup(sbuf32++), >> + le32_to_cpup(sbuf32++), >> + }; >> + /* write output bytes in reverse order for little endianness */ >> + u64 val64 = ((u64)xfrm_pixel(pix[0])) | >> + ((u64)xfrm_pixel(pix[1]) << 16) | >> + ((u64)xfrm_pixel(pix[2]) << 32) | >> + ((u64)xfrm_pixel(pix[3]) << 48); >> + *dbuf64++ = cpu_to_le64(val64); >> + } >> + send32 += pixels & GENMASK(1, 1); >> +#endif >> + >> + /* write 2 pixels at once */ >> + dbuf32 = (__le32 __force *)dbuf64; >> + while (sbuf32 < send32) { >> + u32 pix[2] = { >> + le32_to_cpup(sbuf32++), >> + le32_to_cpup(sbuf32++), >> + }; >> + /* write output bytes in reverse order for little endianness */ >> + u32 val32 = xfrm_pixel(pix[0]) | >> + (xfrm_pixel(pix[1]) << 16); >> + *dbuf32++ = cpu_to_le32(val32); >> + } >> + send32 += pixels & GENMASK(0, 0); >> + >> + /* write trailing pixel */ >> + dbuf16 = (__le16 __force *)dbuf32; >> while (sbuf32 < send32) >> *dbuf16++ = cpu_to_le16(xfrm_pixel(le32_to_cpup(sbuf32++))); >> }
diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c index b9c9c712aa9c..66137df85725 100644 --- a/drivers/gpu/drm/drm_format_helper.c +++ b/drivers/gpu/drm/drm_format_helper.c @@ -262,10 +262,48 @@ static __always_inline void drm_fb_xfrm_line_32to16(void *dbuf, const void *sbuf unsigned int pixels, u32 (*xfrm_pixel)(u32)) { - __le16 *dbuf16 = dbuf; + __le64 *dbuf64 = dbuf; + __le32 *dbuf32; + __le16 *dbuf16; const __le32 *sbuf32 = sbuf; const __le32 *send32 = sbuf32 + pixels; +#if defined(CONFIG_64BIT) + /* write 4 pixels at once */ + send32 -= pixels & GENMASK(1, 0); + while (sbuf32 < send32) { + u32 pix[4] = { + le32_to_cpup(sbuf32++), + le32_to_cpup(sbuf32++), + le32_to_cpup(sbuf32++), + le32_to_cpup(sbuf32++), + }; + /* write output bytes in reverse order for little endianness */ + u64 val64 = ((u64)xfrm_pixel(pix[0])) | + ((u64)xfrm_pixel(pix[1]) << 16) | + ((u64)xfrm_pixel(pix[2]) << 32) | + ((u64)xfrm_pixel(pix[3]) << 48); + *dbuf64++ = cpu_to_le64(val64); + } + send32 += pixels & GENMASK(1, 1); +#endif + + /* write 2 pixels at once */ + dbuf32 = (__le32 __force *)dbuf64; + while (sbuf32 < send32) { + u32 pix[2] = { + le32_to_cpup(sbuf32++), + le32_to_cpup(sbuf32++), + }; + /* write output bytes in reverse order for little endianness */ + u32 val32 = xfrm_pixel(pix[0]) | + (xfrm_pixel(pix[1]) << 16); + *dbuf32++ = cpu_to_le32(val32); + } + send32 += pixels & GENMASK(0, 0); + + /* write trailing pixel */ + dbuf16 = (__le16 __force *)dbuf32; while (sbuf32 < send32) *dbuf16++ = cpu_to_le16(xfrm_pixel(le32_to_cpup(sbuf32++))); }
For ease of implementation, existing line-conversion functions for 16-bit formats write each pixel individually. Optimize the performance by writing mulitple pixels in single 64-bit and 32-bit stores. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> --- drivers/gpu/drm/drm_format_helper.c | 40 ++++++++++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-)