* [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection
@ 2021-09-27 7:21 Bin Meng
2021-09-27 7:21 ` [PATCH v2 2/2] hw/dma: sifive_pdma: Don't run DMA when channel is disclaimed Bin Meng
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: Bin Meng @ 2021-09-27 7:21 UTC (permalink / raw)
To: Alistair Francis, qemu-devel, qemu-riscv
Cc: Frank Chang, Philippe Mathieu-Daudé, Markus Armbruster
At present the codes detect whether the DMA channel is claimed by:
claimed = !!s->chan[ch].control & CONTROL_CLAIM;
As ! has higher precedence over & (bitwise and), this is essentially
claimed = (!!s->chan[ch].control) & CONTROL_CLAIM;
which is wrong, as any non-zero bit set in the control register will
produce a result of a claimed channel.
Fixes: de7c7988d25d ("hw/dma: sifive_pdma: reset Next* registers when Control.claim is set")
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
---
Changes in v2:
- reword the commit message
hw/dma/sifive_pdma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/dma/sifive_pdma.c b/hw/dma/sifive_pdma.c
index b4fd40573a..b8ec7621f3 100644
--- a/hw/dma/sifive_pdma.c
+++ b/hw/dma/sifive_pdma.c
@@ -243,7 +243,7 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
offset &= 0xfff;
switch (offset) {
case DMA_CONTROL:
- claimed = !!s->chan[ch].control & CONTROL_CLAIM;
+ claimed = !!(s->chan[ch].control & CONTROL_CLAIM);
if (!claimed && (value & CONTROL_CLAIM)) {
/* reset Next* registers */
--
2.25.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 2/2] hw/dma: sifive_pdma: Don't run DMA when channel is disclaimed
2021-09-27 7:21 [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection Bin Meng
@ 2021-09-27 7:21 ` Bin Meng
2021-09-28 22:46 ` Alistair Francis
2021-09-28 23:15 ` Alistair Francis
2021-09-27 12:56 ` [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection Philippe Mathieu-Daudé
2021-09-28 22:45 ` Alistair Francis
2 siblings, 2 replies; 7+ messages in thread
From: Bin Meng @ 2021-09-27 7:21 UTC (permalink / raw)
To: Alistair Francis, qemu-devel, qemu-riscv
Cc: Frank Chang, Philippe Mathieu-Daudé, Markus Armbruster
If Control.run bit is set while not preserving the Control.claim
bit, the DMA transfer shall not be started.
The following result is PDMA tested in U-Boot on Unleashed board:
=> mw.l 0x3000000 0x0 <= Disclaim channel 0
=> mw.l 0x3000000 0x1 <= Claim channel 0
=> mw.l 0x3000004 0x55000000 <= wsize = rsize = 5 (2^5 = 32 bytes)
=> mw.q 0x3000008 0x2 <= NextBytes = 2
=> mw.q 0x3000010 0x84000000 <= NextDestination = 0x84000000
=> mw.q 0x3000018 0x84001000 <= NextSource = 0x84001000
=> mw.l 0x84000000 0x87654321 <= Fill test data to dst
=> mw.l 0x84001000 0x12345678 <= Fill test data to src
=> md.l 0x84000000 1; md.l 0x84001000 1 <= Dump src/dst memory contents
84000000: 87654321 !Ce.
84001000: 12345678 xV4.
=> md.l 0x3000000 8 <= Dump PDMA status
03000000: 00000001 55000000 00000002 00000000 .......U........
03000010: 84000000 00000000 84001000 00000000 ................
=> mw.l 0x3000000 0x2 <= Set channel 0 run bit only
=> md.l 0x3000000 8 <= Dump PDMA status
03000000: 00000000 55000000 00000002 00000000 .......U........
03000010: 84000000 00000000 84001000 00000000 ................
=> md.l 0x84000000 1; md.l 0x84001000 1 <= Dump src/dst memory contents
84000000: 87654321 !Ce.
84001000: 12345678 xV4.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
---
(no changes since v1)
hw/dma/sifive_pdma.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/hw/dma/sifive_pdma.c b/hw/dma/sifive_pdma.c
index b8ec7621f3..85fe34f5f3 100644
--- a/hw/dma/sifive_pdma.c
+++ b/hw/dma/sifive_pdma.c
@@ -232,7 +232,7 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
{
SiFivePDMAState *s = opaque;
int ch = SIFIVE_PDMA_CHAN_NO(offset);
- bool claimed;
+ bool claimed, run;
if (ch >= SIFIVE_PDMA_CHANS) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid channel no %d\n",
@@ -244,6 +244,7 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
switch (offset) {
case DMA_CONTROL:
claimed = !!(s->chan[ch].control & CONTROL_CLAIM);
+ run = !!(s->chan[ch].control & CONTROL_RUN);
if (!claimed && (value & CONTROL_CLAIM)) {
/* reset Next* registers */
@@ -254,13 +255,19 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
s->chan[ch].next_src = 0;
}
+ /* claim bit can only be cleared when run is low */
+ if (run && !(value & CONTROL_CLAIM)) {
+ value |= CONTROL_CLAIM;
+ }
+
s->chan[ch].control = value;
/*
* If channel was not claimed before run bit is set,
+ * or if the channel is disclaimed when run was low,
* DMA won't run.
*/
- if (!claimed) {
+ if (!claimed || (!run && !(value & CONTROL_CLAIM))) {
s->chan[ch].control &= ~CONTROL_RUN;
return;
}
--
2.25.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection
2021-09-27 7:21 [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection Bin Meng
2021-09-27 7:21 ` [PATCH v2 2/2] hw/dma: sifive_pdma: Don't run DMA when channel is disclaimed Bin Meng
@ 2021-09-27 12:56 ` Philippe Mathieu-Daudé
2021-09-27 13:14 ` Bin Meng
2021-09-28 22:45 ` Alistair Francis
2 siblings, 1 reply; 7+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-09-27 12:56 UTC (permalink / raw)
To: Bin Meng, Alistair Francis, qemu-devel, qemu-riscv
Cc: Frank Chang, Markus Armbruster
On 9/27/21 09:21, Bin Meng wrote:
> At present the codes detect whether the DMA channel is claimed by:
>
> claimed = !!s->chan[ch].control & CONTROL_CLAIM;
>
> As ! has higher precedence over & (bitwise and), this is essentially
>
> claimed = (!!s->chan[ch].control) & CONTROL_CLAIM;
>
> which is wrong, as any non-zero bit set in the control register will
> produce a result of a claimed channel.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Maybe worth adding:
Reported using GCC 9.3.0 on Ubuntu 20.04:
suggest parentheses around operand of ‘!’ or change ‘&’ to ‘&&’ or ‘!’
to ‘~’ [-Werror=parentheses]
> Fixes: de7c7988d25d ("hw/dma: sifive_pdma: reset Next* registers when Control.claim is set")
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
>
> ---
>
> Changes in v2:
> - reword the commit message
>
> hw/dma/sifive_pdma.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/dma/sifive_pdma.c b/hw/dma/sifive_pdma.c
> index b4fd40573a..b8ec7621f3 100644
> --- a/hw/dma/sifive_pdma.c
> +++ b/hw/dma/sifive_pdma.c
> @@ -243,7 +243,7 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
> offset &= 0xfff;
> switch (offset) {
> case DMA_CONTROL:
> - claimed = !!s->chan[ch].control & CONTROL_CLAIM;
> + claimed = !!(s->chan[ch].control & CONTROL_CLAIM);
>
> if (!claimed && (value & CONTROL_CLAIM)) {
> /* reset Next* registers */
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection
2021-09-27 12:56 ` [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection Philippe Mathieu-Daudé
@ 2021-09-27 13:14 ` Bin Meng
0 siblings, 0 replies; 7+ messages in thread
From: Bin Meng @ 2021-09-27 13:14 UTC (permalink / raw)
To: Philippe Mathieu-Daudé
Cc: Frank Chang, open list:RISC-V, Alistair Francis,
qemu-devel@nongnu.org Developers, Markus Armbruster
Hi Philippe,
On Mon, Sep 27, 2021 at 8:56 PM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>
> On 9/27/21 09:21, Bin Meng wrote:
> > At present the codes detect whether the DMA channel is claimed by:
> >
> > claimed = !!s->chan[ch].control & CONTROL_CLAIM;
> >
> > As ! has higher precedence over & (bitwise and), this is essentially
> >
> > claimed = (!!s->chan[ch].control) & CONTROL_CLAIM;
> >
> > which is wrong, as any non-zero bit set in the control register will
> > produce a result of a claimed channel.
>
> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>
> Maybe worth adding:
>
> Reported using GCC 9.3.0 on Ubuntu 20.04:
>
> suggest parentheses around operand of ‘!’ or change ‘&’ to ‘&&’ or ‘!’
> to ‘~’ [-Werror=parentheses]
Actually GCC does not report this as CONTROL_CLAIM happens to be 1 in
this case, as I wrote in the v1 commit message. :)
Regards,
Bin
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection
2021-09-27 7:21 [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection Bin Meng
2021-09-27 7:21 ` [PATCH v2 2/2] hw/dma: sifive_pdma: Don't run DMA when channel is disclaimed Bin Meng
2021-09-27 12:56 ` [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection Philippe Mathieu-Daudé
@ 2021-09-28 22:45 ` Alistair Francis
2 siblings, 0 replies; 7+ messages in thread
From: Alistair Francis @ 2021-09-28 22:45 UTC (permalink / raw)
To: Bin Meng
Cc: open list:RISC-V, Frank Chang, qemu-devel@nongnu.org Developers,
Markus Armbruster, Alistair Francis, Philippe Mathieu-Daudé
On Mon, Sep 27, 2021 at 5:21 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> At present the codes detect whether the DMA channel is claimed by:
>
> claimed = !!s->chan[ch].control & CONTROL_CLAIM;
>
> As ! has higher precedence over & (bitwise and), this is essentially
>
> claimed = (!!s->chan[ch].control) & CONTROL_CLAIM;
>
> which is wrong, as any non-zero bit set in the control register will
> produce a result of a claimed channel.
>
> Fixes: de7c7988d25d ("hw/dma: sifive_pdma: reset Next* registers when Control.claim is set")
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
>
> ---
>
> Changes in v2:
> - reword the commit message
>
> hw/dma/sifive_pdma.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/dma/sifive_pdma.c b/hw/dma/sifive_pdma.c
> index b4fd40573a..b8ec7621f3 100644
> --- a/hw/dma/sifive_pdma.c
> +++ b/hw/dma/sifive_pdma.c
> @@ -243,7 +243,7 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
> offset &= 0xfff;
> switch (offset) {
> case DMA_CONTROL:
> - claimed = !!s->chan[ch].control & CONTROL_CLAIM;
> + claimed = !!(s->chan[ch].control & CONTROL_CLAIM);
>
> if (!claimed && (value & CONTROL_CLAIM)) {
> /* reset Next* registers */
> --
> 2.25.1
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] hw/dma: sifive_pdma: Don't run DMA when channel is disclaimed
2021-09-27 7:21 ` [PATCH v2 2/2] hw/dma: sifive_pdma: Don't run DMA when channel is disclaimed Bin Meng
@ 2021-09-28 22:46 ` Alistair Francis
2021-09-28 23:15 ` Alistair Francis
1 sibling, 0 replies; 7+ messages in thread
From: Alistair Francis @ 2021-09-28 22:46 UTC (permalink / raw)
To: Bin Meng
Cc: open list:RISC-V, Frank Chang, qemu-devel@nongnu.org Developers,
Markus Armbruster, Alistair Francis, Philippe Mathieu-Daudé
On Mon, Sep 27, 2021 at 5:22 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> If Control.run bit is set while not preserving the Control.claim
> bit, the DMA transfer shall not be started.
>
> The following result is PDMA tested in U-Boot on Unleashed board:
>
> => mw.l 0x3000000 0x0 <= Disclaim channel 0
> => mw.l 0x3000000 0x1 <= Claim channel 0
> => mw.l 0x3000004 0x55000000 <= wsize = rsize = 5 (2^5 = 32 bytes)
> => mw.q 0x3000008 0x2 <= NextBytes = 2
> => mw.q 0x3000010 0x84000000 <= NextDestination = 0x84000000
> => mw.q 0x3000018 0x84001000 <= NextSource = 0x84001000
> => mw.l 0x84000000 0x87654321 <= Fill test data to dst
> => mw.l 0x84001000 0x12345678 <= Fill test data to src
> => md.l 0x84000000 1; md.l 0x84001000 1 <= Dump src/dst memory contents
> 84000000: 87654321 !Ce.
> 84001000: 12345678 xV4.
> => md.l 0x3000000 8 <= Dump PDMA status
> 03000000: 00000001 55000000 00000002 00000000 .......U........
> 03000010: 84000000 00000000 84001000 00000000 ................
> => mw.l 0x3000000 0x2 <= Set channel 0 run bit only
> => md.l 0x3000000 8 <= Dump PDMA status
> 03000000: 00000000 55000000 00000002 00000000 .......U........
> 03000010: 84000000 00000000 84001000 00000000 ................
> => md.l 0x84000000 1; md.l 0x84001000 1 <= Dump src/dst memory contents
> 84000000: 87654321 !Ce.
> 84001000: 12345678 xV4.
>
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Alistair
>
> ---
>
> (no changes since v1)
>
> hw/dma/sifive_pdma.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/hw/dma/sifive_pdma.c b/hw/dma/sifive_pdma.c
> index b8ec7621f3..85fe34f5f3 100644
> --- a/hw/dma/sifive_pdma.c
> +++ b/hw/dma/sifive_pdma.c
> @@ -232,7 +232,7 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
> {
> SiFivePDMAState *s = opaque;
> int ch = SIFIVE_PDMA_CHAN_NO(offset);
> - bool claimed;
> + bool claimed, run;
>
> if (ch >= SIFIVE_PDMA_CHANS) {
> qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid channel no %d\n",
> @@ -244,6 +244,7 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
> switch (offset) {
> case DMA_CONTROL:
> claimed = !!(s->chan[ch].control & CONTROL_CLAIM);
> + run = !!(s->chan[ch].control & CONTROL_RUN);
>
> if (!claimed && (value & CONTROL_CLAIM)) {
> /* reset Next* registers */
> @@ -254,13 +255,19 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
> s->chan[ch].next_src = 0;
> }
>
> + /* claim bit can only be cleared when run is low */
> + if (run && !(value & CONTROL_CLAIM)) {
> + value |= CONTROL_CLAIM;
> + }
> +
> s->chan[ch].control = value;
>
> /*
> * If channel was not claimed before run bit is set,
> + * or if the channel is disclaimed when run was low,
> * DMA won't run.
> */
> - if (!claimed) {
> + if (!claimed || (!run && !(value & CONTROL_CLAIM))) {
> s->chan[ch].control &= ~CONTROL_RUN;
> return;
> }
> --
> 2.25.1
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] hw/dma: sifive_pdma: Don't run DMA when channel is disclaimed
2021-09-27 7:21 ` [PATCH v2 2/2] hw/dma: sifive_pdma: Don't run DMA when channel is disclaimed Bin Meng
2021-09-28 22:46 ` Alistair Francis
@ 2021-09-28 23:15 ` Alistair Francis
1 sibling, 0 replies; 7+ messages in thread
From: Alistair Francis @ 2021-09-28 23:15 UTC (permalink / raw)
To: Bin Meng
Cc: open list:RISC-V, Frank Chang, qemu-devel@nongnu.org Developers,
Markus Armbruster, Alistair Francis, Philippe Mathieu-Daudé
On Mon, Sep 27, 2021 at 5:22 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> If Control.run bit is set while not preserving the Control.claim
> bit, the DMA transfer shall not be started.
>
> The following result is PDMA tested in U-Boot on Unleashed board:
>
> => mw.l 0x3000000 0x0 <= Disclaim channel 0
> => mw.l 0x3000000 0x1 <= Claim channel 0
> => mw.l 0x3000004 0x55000000 <= wsize = rsize = 5 (2^5 = 32 bytes)
> => mw.q 0x3000008 0x2 <= NextBytes = 2
> => mw.q 0x3000010 0x84000000 <= NextDestination = 0x84000000
> => mw.q 0x3000018 0x84001000 <= NextSource = 0x84001000
> => mw.l 0x84000000 0x87654321 <= Fill test data to dst
> => mw.l 0x84001000 0x12345678 <= Fill test data to src
> => md.l 0x84000000 1; md.l 0x84001000 1 <= Dump src/dst memory contents
> 84000000: 87654321 !Ce.
> 84001000: 12345678 xV4.
> => md.l 0x3000000 8 <= Dump PDMA status
> 03000000: 00000001 55000000 00000002 00000000 .......U........
> 03000010: 84000000 00000000 84001000 00000000 ................
> => mw.l 0x3000000 0x2 <= Set channel 0 run bit only
> => md.l 0x3000000 8 <= Dump PDMA status
> 03000000: 00000000 55000000 00000002 00000000 .......U........
> 03000010: 84000000 00000000 84001000 00000000 ................
> => md.l 0x84000000 1; md.l 0x84001000 1 <= Dump src/dst memory contents
> 84000000: 87654321 !Ce.
> 84001000: 12345678 xV4.
>
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Thanks!
Applied to riscv-to-apply.next
Alistair
>
> ---
>
> (no changes since v1)
>
> hw/dma/sifive_pdma.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/hw/dma/sifive_pdma.c b/hw/dma/sifive_pdma.c
> index b8ec7621f3..85fe34f5f3 100644
> --- a/hw/dma/sifive_pdma.c
> +++ b/hw/dma/sifive_pdma.c
> @@ -232,7 +232,7 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
> {
> SiFivePDMAState *s = opaque;
> int ch = SIFIVE_PDMA_CHAN_NO(offset);
> - bool claimed;
> + bool claimed, run;
>
> if (ch >= SIFIVE_PDMA_CHANS) {
> qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid channel no %d\n",
> @@ -244,6 +244,7 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
> switch (offset) {
> case DMA_CONTROL:
> claimed = !!(s->chan[ch].control & CONTROL_CLAIM);
> + run = !!(s->chan[ch].control & CONTROL_RUN);
>
> if (!claimed && (value & CONTROL_CLAIM)) {
> /* reset Next* registers */
> @@ -254,13 +255,19 @@ static void sifive_pdma_write(void *opaque, hwaddr offset,
> s->chan[ch].next_src = 0;
> }
>
> + /* claim bit can only be cleared when run is low */
> + if (run && !(value & CONTROL_CLAIM)) {
> + value |= CONTROL_CLAIM;
> + }
> +
> s->chan[ch].control = value;
>
> /*
> * If channel was not claimed before run bit is set,
> + * or if the channel is disclaimed when run was low,
> * DMA won't run.
> */
> - if (!claimed) {
> + if (!claimed || (!run && !(value & CONTROL_CLAIM))) {
> s->chan[ch].control &= ~CONTROL_RUN;
> return;
> }
> --
> 2.25.1
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-09-28 23:16 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-27 7:21 [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection Bin Meng
2021-09-27 7:21 ` [PATCH v2 2/2] hw/dma: sifive_pdma: Don't run DMA when channel is disclaimed Bin Meng
2021-09-28 22:46 ` Alistair Francis
2021-09-28 23:15 ` Alistair Francis
2021-09-27 12:56 ` [PATCH v2 1/2] hw/dma: sifive_pdma: Fix Control.claim bit detection Philippe Mathieu-Daudé
2021-09-27 13:14 ` Bin Meng
2021-09-28 22:45 ` Alistair Francis
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