| Message ID | 1445299319-14921-2-git-send-email-moritz.fischer@ettus.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
?On 20-10-15 02:01, Moritz Fischer wrote: > This gets rid of the code to strip away the header and byteswap. > > Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> > --- > drivers/fpga/zynq-fpga.c | 23 ++++++++++------------- > 1 file changed, 10 insertions(+), 13 deletions(-) > > diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c > index 617d382..916c551 100644 > --- a/drivers/fpga/zynq-fpga.c > +++ b/drivers/fpga/zynq-fpga.c > @@ -104,6 +104,8 @@ > #define INIT_POLL_TIMEOUT 2500000 > /* Delay for polling reset bits */ > #define INIT_POLL_DELAY 20 > +/* Sync sequence for firmware */ > +#define SYNC_SEQUENCE "\x66\x55\x99\xAA" > > /* Masks for controlling stuff in SLCR */ > /* Disable all Level shifters */ > @@ -301,24 +303,19 @@ static int zynq_fpga_ops_write(struct fpga_manager *mgr, > > memcpy(kbuf, buf, count); > > - /* look for the sync word */ > + /* look for the sync sequence */ > for (i = 0; i < count - 4; i++) { > - if (memcmp(kbuf + i, "\xAA\x99\x55\x66", 4) == 0) { > - dev_dbg(priv->dev, "Found swapped sync word\n"); > + if (memcmp(kbuf + i, SYNC_SEQUENCE, 4) == 0) { > + dev_dbg(priv->dev, "Found sync sequence"); > break; > } > } Regarding this check, and judging from the code, I'd say that any file with a non word-aligned sync word is broken. So you could speed this up considerably by walking through the array word-by-word instread of byte-by-byte. Checking the whole 4MB buffer from beginning to end doesn't make it really efficient either, if you're going to visit all that memory in case the stream is invalid, you might as well send it to the hardware, I wouldn't be surprised if that even takes less effort than going through it byte-by-byte. I for one would rather see this check removed, the hardware handles it just fine and also catches more likely errors (e.g. sending a 7030 bitstream to a 7015 chip is something that the driver cannot catch anyway, but the hardware detects that error just fine). > - /* remove the header, align the data on word boundary */ > - if (i != count - 4) { > - count -= i; > - memmove(kbuf, kbuf + i, count); > - } > - > - /* fixup endianness of the data */ > - for (i = 0; i < count; i += 4) { > - u32 *p = (u32 *)&kbuf[i]; > - *p = swab32(*p); > + /* if we detect something obviously broken, bail ... */ > + if ((count - 4) == i) { > + dev_err(priv->dev, "No sync sequence found, invalid bitstream."); > + err = -EINVAL; > + goto out_free; > } > > /* enable clock */ > Kind regards, Mike Looijmans System Expert TOPIC Embedded Products Eindhovenseweg 32-C, NL-5683 KH Best Postbus 440, NL-5680 AK Best Telefoon: +31 (0) 499 33 69 79 Telefax: +31 (0) 499 33 69 70 E-mail: mike.looijmans@topicproducts.com Website: www.topicproducts.com Please consider the environment before printing this e-mail Visit us at : Aerospace Electrical Systems Expo Europe which will be held from 17.11.2015 till 19.11.2015, Findorffstra?e 101 Bremen, Germany, Hall 5, stand number C65 http://www.aesexpo.eu
?On 20-10-15 02:01, Moritz Fischer wrote: > This gets rid of the code to strip away the header and byteswap. > > Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> > --- > drivers/fpga/zynq-fpga.c | 23 ++++++++++------------- > 1 file changed, 10 insertions(+), 13 deletions(-) > > diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c > index 617d382..916c551 100644 > --- a/drivers/fpga/zynq-fpga.c > +++ b/drivers/fpga/zynq-fpga.c > @@ -104,6 +104,8 @@ > #define INIT_POLL_TIMEOUT 2500000 > /* Delay for polling reset bits */ > #define INIT_POLL_DELAY 20 > +/* Sync sequence for firmware */ > +#define SYNC_SEQUENCE "\x66\x55\x99\xAA" > > /* Masks for controlling stuff in SLCR */ > /* Disable all Level shifters */ > @@ -301,24 +303,19 @@ static int zynq_fpga_ops_write(struct fpga_manager *mgr, > > memcpy(kbuf, buf, count); > > - /* look for the sync word */ > + /* look for the sync sequence */ > for (i = 0; i < count - 4; i++) { > - if (memcmp(kbuf + i, "\xAA\x99\x55\x66", 4) == 0) { > - dev_dbg(priv->dev, "Found swapped sync word\n"); > + if (memcmp(kbuf + i, SYNC_SEQUENCE, 4) == 0) { > + dev_dbg(priv->dev, "Found sync sequence"); > break; > } > } Regarding this check, and judging from the code, I'd say that any file with a non word-aligned sync word is broken. So you could speed this up considerably by walking through the array word-by-word instread of byte-by-byte. Checking the whole 4MB buffer from beginning to end doesn't make it really efficient either, if you're going to visit all that memory in case the stream is invalid, you might as well send it to the hardware, I wouldn't be surprised if that even takes less effort than going through it byte-by-byte. I for one would rather see this check removed, the hardware handles it just fine and also catches more likely errors (e.g. sending a 7030 bitstream to a 7015 chip is something that the driver cannot catch anyway, but the hardware detects that error just fine). > - /* remove the header, align the data on word boundary */ > - if (i != count - 4) { > - count -= i; > - memmove(kbuf, kbuf + i, count); > - } > - > - /* fixup endianness of the data */ > - for (i = 0; i < count; i += 4) { > - u32 *p = (u32 *)&kbuf[i]; > - *p = swab32(*p); > + /* if we detect something obviously broken, bail ... */ > + if ((count - 4) == i) { > + dev_err(priv->dev, "No sync sequence found, invalid bitstream."); > + err = -EINVAL; > + goto out_free; > } > > /* enable clock */ > Kind regards, Mike Looijmans System Expert TOPIC Embedded Products Eindhovenseweg 32-C, NL-5683 KH Best Postbus 440, NL-5680 AK Best Telefoon: +31 (0) 499 33 69 79 Telefax: +31 (0) 499 33 69 70 E-mail: mike.looijmans@topicproducts.com Website: www.topicproducts.com Please consider the environment before printing this e-mail Visit us at : Aerospace Electrical Systems Expo Europe which will be held from 17.11.2015 till 19.11.2015, Findorffstra?e 101 Bremen, Germany, Hall 5, stand number C65 http://www.aesexpo.eu
On 20-10-15 02:01, Moritz Fischer wrote: > This gets rid of the code to strip away the header and byteswap. > > Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> > --- > drivers/fpga/zynq-fpga.c | 23 ++++++++++------------- > 1 file changed, 10 insertions(+), 13 deletions(-) > > diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c > index 617d382..916c551 100644 > --- a/drivers/fpga/zynq-fpga.c > +++ b/drivers/fpga/zynq-fpga.c > @@ -104,6 +104,8 @@ > #define INIT_POLL_TIMEOUT 2500000 > /* Delay for polling reset bits */ > #define INIT_POLL_DELAY 20 > +/* Sync sequence for firmware */ > +#define SYNC_SEQUENCE "\x66\x55\x99\xAA" > > /* Masks for controlling stuff in SLCR */ > /* Disable all Level shifters */ > @@ -301,24 +303,19 @@ static int zynq_fpga_ops_write(struct fpga_manager *mgr, > > memcpy(kbuf, buf, count); > > - /* look for the sync word */ > + /* look for the sync sequence */ > for (i = 0; i < count - 4; i++) { > - if (memcmp(kbuf + i, "\xAA\x99\x55\x66", 4) == 0) { > - dev_dbg(priv->dev, "Found swapped sync word\n"); > + if (memcmp(kbuf + i, SYNC_SEQUENCE, 4) == 0) { > + dev_dbg(priv->dev, "Found sync sequence"); > break; > } > } Regarding this check, and judging from the code, I'd say that any file with a non word-aligned sync word is broken. So you could speed this up considerably by walking through the array word-by-word instread of byte-by-byte. Checking the whole 4MB buffer from beginning to end doesn't make it really efficient either, if you're going to visit all that memory in case the stream is invalid, you might as well send it to the hardware, I wouldn't be surprised if that even takes less effort than going through it byte-by-byte. I for one would rather see this check removed, the hardware handles it just fine and also catches more likely errors (e.g. sending a 7030 bitstream to a 7015 chip is something that the driver cannot catch anyway, but the hardware detects that error just fine). > - /* remove the header, align the data on word boundary */ > - if (i != count - 4) { > - count -= i; > - memmove(kbuf, kbuf + i, count); > - } > - > - /* fixup endianness of the data */ > - for (i = 0; i < count; i += 4) { > - u32 *p = (u32 *)&kbuf[i]; > - *p = swab32(*p); > + /* if we detect something obviously broken, bail ... */ > + if ((count - 4) == i) { > + dev_err(priv->dev, "No sync sequence found, invalid bitstream."); > + err = -EINVAL; > + goto out_free; > } > > /* enable clock */ >
Hi Mike, On Mon, Oct 19, 2015 at 10:24 PM, Mike Looijmans <mike.looijmans@topic.nl> wrote: > On 20-10-15 02:01, Moritz Fischer wrote: >> >> This gets rid of the code to strip away the header and byteswap. >> >> Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> >> --- >> drivers/fpga/zynq-fpga.c | 23 ++++++++++------------- >> 1 file changed, 10 insertions(+), 13 deletions(-) >> >> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c >> index 617d382..916c551 100644 >> --- a/drivers/fpga/zynq-fpga.c >> +++ b/drivers/fpga/zynq-fpga.c >> @@ -104,6 +104,8 @@ >> #define INIT_POLL_TIMEOUT 2500000 >> /* Delay for polling reset bits */ >> #define INIT_POLL_DELAY 20 >> +/* Sync sequence for firmware */ >> +#define SYNC_SEQUENCE "\x66\x55\x99\xAA" >> >> /* Masks for controlling stuff in SLCR */ >> /* Disable all Level shifters */ >> @@ -301,24 +303,19 @@ static int zynq_fpga_ops_write(struct fpga_manager >> *mgr, >> >> memcpy(kbuf, buf, count); >> >> - /* look for the sync word */ >> + /* look for the sync sequence */ >> for (i = 0; i < count - 4; i++) { >> - if (memcmp(kbuf + i, "\xAA\x99\x55\x66", 4) == 0) { >> - dev_dbg(priv->dev, "Found swapped sync word\n"); >> + if (memcmp(kbuf + i, SYNC_SEQUENCE, 4) == 0) { >> + dev_dbg(priv->dev, "Found sync sequence"); >> break; >> } >> } > > > Regarding this check, and judging from the code, I'd say that any file with > a non word-aligned sync word is broken. So you could speed this up > considerably by walking through the array word-by-word instread of > byte-by-byte. True. > > Checking the whole 4MB buffer from beginning to end doesn't make it really > efficient either, if you're going to visit all that memory in case the > stream is invalid, you might as well send it to the hardware, I wouldn't be > surprised if that even takes less effort than going through it byte-by-byte. You raised a good point here. I was hesitant to put in the additional check, in my tests the reloading took no noticeable time, which was good enough for my application, so I figured rather be more 'defensive'. Probably overly defensive, as the reloading entity would have to check for success in either case before attempting to use the FPGA afterwards. > I for one would rather see this check removed, the hardware handles it just > fine and also catches more likely errors (e.g. sending a 7030 bitstream to a > 7015 chip is something that the driver cannot catch anyway, but the hardware > detects that error just fine). Fair enough. I'll remove it for v2, makes the code even easier :-) Thanks for the feedback, Moritz
?Sorry for having sent that out about three times, I was cleverly being fooled into believing the mail didn't get delivered. I also want to apologize for adding yet another message to that list. I'm sorry, it won't happen again. On 20-10-15 08:57, Mike Looijmans wrote: ... Kind regards, Mike Looijmans System Expert TOPIC Embedded Products Eindhovenseweg 32-C, NL-5683 KH Best Postbus 440, NL-5680 AK Best Telefoon: +31 (0) 499 33 69 79 Telefax: +31 (0) 499 33 69 70 E-mail: mike.looijmans@topicproducts.com Website: www.topicproducts.com Please consider the environment before printing this e-mail Visit us at : Aerospace Electrical Systems Expo Europe which will be held from 17.11.2015 till 19.11.2015, Findorffstrasse 101 Bremen, Germany, Hall 5, stand number C65 http://www.aesexpo.eu
diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c index 617d382..916c551 100644 --- a/drivers/fpga/zynq-fpga.c +++ b/drivers/fpga/zynq-fpga.c @@ -104,6 +104,8 @@ #define INIT_POLL_TIMEOUT 2500000 /* Delay for polling reset bits */ #define INIT_POLL_DELAY 20 +/* Sync sequence for firmware */ +#define SYNC_SEQUENCE "\x66\x55\x99\xAA" /* Masks for controlling stuff in SLCR */ /* Disable all Level shifters */ @@ -301,24 +303,19 @@ static int zynq_fpga_ops_write(struct fpga_manager *mgr, memcpy(kbuf, buf, count); - /* look for the sync word */ + /* look for the sync sequence */ for (i = 0; i < count - 4; i++) { - if (memcmp(kbuf + i, "\xAA\x99\x55\x66", 4) == 0) { - dev_dbg(priv->dev, "Found swapped sync word\n"); + if (memcmp(kbuf + i, SYNC_SEQUENCE, 4) == 0) { + dev_dbg(priv->dev, "Found sync sequence"); break; } } - /* remove the header, align the data on word boundary */ - if (i != count - 4) { - count -= i; - memmove(kbuf, kbuf + i, count); - } - - /* fixup endianness of the data */ - for (i = 0; i < count; i += 4) { - u32 *p = (u32 *)&kbuf[i]; - *p = swab32(*p); + /* if we detect something obviously broken, bail ... */ + if ((count - 4) == i) { + dev_err(priv->dev, "No sync sequence found, invalid bitstream."); + err = -EINVAL; + goto out_free; } /* enable clock */
This gets rid of the code to strip away the header and byteswap. Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> --- drivers/fpga/zynq-fpga.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-)