This patch-set aims to add NOMMU support to RV32.
Many people want to build simple emulators or HDL
models of RISC-V this patch makes it posible to
run linux on them.
Yimin Gu is the original author of this set.
Submitted here:
https://lists.buildroot.org/pipermail/buildroot/2022-November/656134.html
Though Jesse T rewrote the Dconf.
The new set:
https://lists.buildroot.org/pipermail/buildroot/2022-December/658258.html
Jesse Taube (1):
riscv: configs: Add nommu decfconfig for RV32
Yimin Gu (1):
riscv: Kconfig: Allow RV32 to build with no MMU
arch/riscv/Kconfig | 5 ++---
arch/riscv/configs/rv32_nommu_virt_defconfig | 16 ++++++++++++++++
2 files changed, 18 insertions(+), 3 deletions(-)
create mode 100644 arch/riscv/configs/rv32_nommu_virt_defconfig
--
2.39.0
From: Yimin Gu <[email protected]>
Some RISC-V 32bit ores do not have an MMU, and the kernel should be
able to build for them. This patch enables the RV32 to be built with
no MMU support.
Signed-off-by: Yimin Gu <[email protected]>
CC: Jesse Taube <[email protected]>
Tested-By: Waldemar Brodkorb <[email protected]>
Signed-off-by: Jesse Taube <[email protected]>
---
arch/riscv/Kconfig | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 59d18881f35b..49759dbe6a8f 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -163,8 +163,8 @@ config MMU
config PAGE_OFFSET
hex
- default 0xC0000000 if 32BIT
- default 0x80000000 if 64BIT && !MMU
+ default 0xC0000000 if 32BIT && MMU
+ default 0x80000000 if !MMU
default 0xff60000000000000 if 64BIT
config KASAN_SHADOW_OFFSET
@@ -262,7 +262,6 @@ config ARCH_RV32I
select GENERIC_LIB_ASHRDI3
select GENERIC_LIB_LSHRDI3
select GENERIC_LIB_UCMPDI2
- select MMU
config ARCH_RV64I
bool "RV64I"
--
2.39.0
32bit risc-v can be configured to run without MMU. This patch adds
an example configuration for RV32 nommu virtual machine.
Signed-off-by: Jesse Taube <[email protected]>
Cc: Yimin Gu <[email protected]>
---
arch/riscv/configs/rv32_nommu_virt_defconfig | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
create mode 100644 arch/riscv/configs/rv32_nommu_virt_defconfig
diff --git a/arch/riscv/configs/rv32_nommu_virt_defconfig b/arch/riscv/configs/rv32_nommu_virt_defconfig
new file mode 100644
index 000000000000..460907253a80
--- /dev/null
+++ b/arch/riscv/configs/rv32_nommu_virt_defconfig
@@ -0,0 +1,16 @@
+CONFIG_BLK_DEV_INITRD=y
+# CONFIG_MMU is not set
+CONFIG_COMPAT_32BIT_TIME=y
+CONFIG_SOC_VIRT=y
+CONFIG_NONPORTABLE=y
+CONFIG_ARCH_RV32I=y
+CONFIG_BINFMT_FLAT=y
+CONFIG_SLOB=y
+CONFIG_VIRTIO_BLK=y
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_OF_PLATFORM=y
+CONFIG_VIRTIO_MMIO=y
+CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES=y
+CONFIG_EXT2_FS=y
+CONFIG_PRINTK_TIME=y
--
2.39.0
Hi Jesse,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v6.2-rc4 next-20230120]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Jesse-Taube/riscv-Kconfig-Allow-RV32-to-build-with-no-MMU/20230119-132822
patch link: https://lore.kernel.org/r/20230119052642.1112171-2-Mr.Bossman075%40gmail.com
patch subject: [PATCH v1 1/2] riscv: Kconfig: Allow RV32 to build with no MMU
config: riscv-randconfig-c003-20230119 (https://download.01.org/0day-ci/archive/20230120/[email protected]/config)
compiler: riscv32-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/4c6876d890ddeab1fb2cb42889027c6d1dbdd02f
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Jesse-Taube/riscv-Kconfig-Allow-RV32-to-build-with-no-MMU/20230119-132822
git checkout 4c6876d890ddeab1fb2cb42889027c6d1dbdd02f
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=riscv olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
riscv32-linux-ld: drivers/clk/clk-k210.o: in function `k210_pll_get_rate':
>> drivers/clk/clk-k210.c:498: undefined reference to `__udivdi3'
vim +498 drivers/clk/clk-k210.c
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 480
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 481 static unsigned long k210_pll_get_rate(struct clk_hw *hw,
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 482 unsigned long parent_rate)
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 483 {
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 484 struct k210_pll *pll = to_k210_pll(hw);
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 485 u32 reg = readl(pll->reg);
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 486 u32 r, f, od;
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 487
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 488 if (reg & K210_PLL_BYPASS)
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 489 return parent_rate;
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 490
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 491 if (!(reg & K210_PLL_PWRD))
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 492 return 0;
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 493
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 494 r = FIELD_GET(K210_PLL_CLKR, reg) + 1;
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 495 f = FIELD_GET(K210_PLL_CLKF, reg) + 1;
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 496 od = FIELD_GET(K210_PLL_CLKOD, reg) + 1;
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 497
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 @498 return (u64)parent_rate * f / (r * od);
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 499 }
c6ca7616f7d5c2 Damien Le Moal 2021-02-10 500
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests
Hello!
Since you'll have to re-submit, making sure that allowing !MMU on rv32
doesn't break the build due to canaan k210 drivers being enabled despite
relying on 64-bit divisions, I've got some nits for you.
On Thu, Jan 19, 2023 at 12:26:41AM -0500, Jesse Taube wrote:
> From: Yimin Gu <[email protected]>
>
> Some RISC-V 32bit ores do not have an MMU, and the kernel should be
s/ores/cores
> able to build for them. This patch enables the RV32 to be built with
> no MMU support.
>
> Signed-off-by: Yimin Gu <[email protected]>
> CC: Jesse Taube <[email protected]>
> Tested-By: Waldemar Brodkorb <[email protected]>
And the automation complains that this tag is not "Tested-by:"
Thanks,
Conor.
> Signed-off-by: Jesse Taube <[email protected]>
> ---
> arch/riscv/Kconfig | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 59d18881f35b..49759dbe6a8f 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -163,8 +163,8 @@ config MMU
>
> config PAGE_OFFSET
> hex
> - default 0xC0000000 if 32BIT
> - default 0x80000000 if 64BIT && !MMU
> + default 0xC0000000 if 32BIT && MMU
> + default 0x80000000 if !MMU
> default 0xff60000000000000 if 64BIT
>
> config KASAN_SHADOW_OFFSET
> @@ -262,7 +262,6 @@ config ARCH_RV32I
> select GENERIC_LIB_ASHRDI3
> select GENERIC_LIB_LSHRDI3
> select GENERIC_LIB_UCMPDI2
> - select MMU
>
> config ARCH_RV64I
> bool "RV64I"
> --
> 2.39.0
>
>
Hey Jesse,
Same here w/ a single nit.
I'll leave judging whether supporting rv32 nommu is worthwhile to others!
On Thu, Jan 19, 2023 at 12:26:42AM -0500, Jesse Taube wrote:
> riscv: configs: Add nommu decfconfig for RV32
typo: defconfig
Thanks,
Conor.
> 32bit risc-v can be configured to run without MMU. This patch adds
> an example configuration for RV32 nommu virtual machine.
>
> Signed-off-by: Jesse Taube <[email protected]>
> Cc: Yimin Gu <[email protected]>
> ---
> arch/riscv/configs/rv32_nommu_virt_defconfig | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
> create mode 100644 arch/riscv/configs/rv32_nommu_virt_defconfig
>
> diff --git a/arch/riscv/configs/rv32_nommu_virt_defconfig b/arch/riscv/configs/rv32_nommu_virt_defconfig
> new file mode 100644
> index 000000000000..460907253a80
> --- /dev/null
> +++ b/arch/riscv/configs/rv32_nommu_virt_defconfig
> @@ -0,0 +1,16 @@
> +CONFIG_BLK_DEV_INITRD=y
> +# CONFIG_MMU is not set
> +CONFIG_COMPAT_32BIT_TIME=y
> +CONFIG_SOC_VIRT=y
> +CONFIG_NONPORTABLE=y
> +CONFIG_ARCH_RV32I=y
> +CONFIG_BINFMT_FLAT=y
> +CONFIG_SLOB=y
> +CONFIG_VIRTIO_BLK=y
> +CONFIG_SERIAL_8250=y
> +CONFIG_SERIAL_8250_CONSOLE=y
> +CONFIG_SERIAL_OF_PLATFORM=y
> +CONFIG_VIRTIO_MMIO=y
> +CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES=y
> +CONFIG_EXT2_FS=y
> +CONFIG_PRINTK_TIME=y
> --
> 2.39.0
>
>
On 1/20/23 02:59, Conor Dooley wrote:
> Hello!
>
> Since you'll have to re-submit, making sure that allowing !MMU on rv32
> doesn't break the build due to canaan k210 drivers being enabled despite
> relying on 64-bit divisions, I've got some nits for you.
Not sure what driver needs 64bit, but sense !MMU was only selected by
64BIT. This should work.
diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs
index 69774bb362d6..b9835b8ede86 100644
--- a/arch/riscv/Kconfig.socs
+++ b/arch/riscv/Kconfig.socs
@@ -43,7 +43,7 @@ config SOC_VIRT
config SOC_CANAAN
bool "Canaan Kendryte K210 SoC"
- depends on !MMU
+ depends on !MMU && 64BIT
select CLINT_TIMER if RISCV_M_MODE
select SERIAL_SIFIVE if TTY
select SERIAL_SIFIVE_CONSOLE if TTY
> On Thu, Jan 19, 2023 at 12:26:41AM -0500, Jesse Taube wrote:
>> From: Yimin Gu <[email protected]>
>>
>> Some RISC-V 32bit ores do not have an MMU, and the kernel should be
>
> s/ores/cores
OH thanks sorry for the spelling mistakes.
Thanks,
Jesse Taube
>> able to build for them. This patch enables the RV32 to be built with
>> no MMU support.
>>
>> Signed-off-by: Yimin Gu <[email protected]>
>> CC: Jesse Taube <[email protected]>
>> Tested-By: Waldemar Brodkorb <[email protected]>
>
> And the automation complains that this tag is not "Tested-by:"
>
> Thanks,
> Conor.
>
>> Signed-off-by: Jesse Taube <[email protected]>
>> ---
>> arch/riscv/Kconfig | 5 ++---
>> 1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> index 59d18881f35b..49759dbe6a8f 100644
>> --- a/arch/riscv/Kconfig
>> +++ b/arch/riscv/Kconfig
>> @@ -163,8 +163,8 @@ config MMU
>>
>> config PAGE_OFFSET
>> hex
>> - default 0xC0000000 if 32BIT
>> - default 0x80000000 if 64BIT && !MMU
>> + default 0xC0000000 if 32BIT && MMU
>> + default 0x80000000 if !MMU
>> default 0xff60000000000000 if 64BIT
>>
>> config KASAN_SHADOW_OFFSET
>> @@ -262,7 +262,6 @@ config ARCH_RV32I
>> select GENERIC_LIB_ASHRDI3
>> select GENERIC_LIB_LSHRDI3
>> select GENERIC_LIB_UCMPDI2
>> - select MMU
>>
>> config ARCH_RV64I
>> bool "RV64I"
>> --
>> 2.39.0
>>
>>
Hey Jesse,
On Fri, Jan 20, 2023 at 12:39:06PM -0500, Jesse Taube wrote:
> On 1/20/23 02:59, Conor Dooley wrote:
> > Since you'll have to re-submit, making sure that allowing !MMU on rv32
> > doesn't break the build due to canaan k210 drivers being enabled despite
> > relying on 64-bit divisions, I've got some nits for you.
> Not sure what driver needs 64bit, but sense !MMU was only selected by 64BIT.
LKP reported a build error for it:
https://lore.kernel.org/linux-riscv/[email protected]/
> This should work.
> diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs
> index 69774bb362d6..b9835b8ede86 100644
> --- a/arch/riscv/Kconfig.socs
> +++ b/arch/riscv/Kconfig.socs
> @@ -43,7 +43,7 @@ config SOC_VIRT
>
> config SOC_CANAAN
> bool "Canaan Kendryte K210 SoC"
> - depends on !MMU
> + depends on !MMU && 64BIT
> select CLINT_TIMER if RISCV_M_MODE
> select SERIAL_SIFIVE if TTY
> select SERIAL_SIFIVE_CONSOLE if TTY
I don't think this is the correct fix for the problem - the drivers
really should not do implicit 64-bit divisions IMO.
Linux has division helpers for them in math64.h.
None of the other SoCs have a dependency on 64BIT and I'd not been keen
on adding on here.
I suspect the fix is as simple as the below, but I'd need to go test it.
Thanks,
Conor.
--- 8< ---
From ecfa79ad1b24f68cfccb77d666e443293d52d066 Mon Sep 17 00:00:00 2001
From: Conor Dooley <[email protected]>
Date: Fri, 20 Jan 2023 20:36:29 +0000
Subject: [PATCH] clk: k210: remove an implicit 64-bit division
The K210 clock driver depends on SOC_CANAAN, which is only selectable
when !MMU on RISC-V. !MMU is not possible on 32-bit yet, but patches
have been sent for its enabling. The kernel test robot reported this
implicit 64-bit division there.
Replace the implicit division with an explicit one.
Reported-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/linux-riscv/[email protected]/
Signed-off-by: Conor Dooley <[email protected]>
---
Since it was always guarded such that it only ever built for 64-bit, I
am not sure that a fixes tag is needed, but it would be:
Fixes: c6ca7616f7d5 ("clk: Add RISC-V Canaan Kendryte K210 clock driver")
---
drivers/clk/clk-k210.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clk/clk-k210.c b/drivers/clk/clk-k210.c
index 67a7cb3503c3..17c5bfb384ad 100644
--- a/drivers/clk/clk-k210.c
+++ b/drivers/clk/clk-k210.c
@@ -495,7 +495,7 @@ static unsigned long k210_pll_get_rate(struct clk_hw *hw,
f = FIELD_GET(K210_PLL_CLKF, reg) + 1;
od = FIELD_GET(K210_PLL_CLKOD, reg) + 1;
- return (u64)parent_rate * f / (r * od);
+ return div_u64(parent_rate * f, r * od);
}
static const struct clk_ops k210_pll_ops = {
--
2.39.0
On Fri, Jan 20, 2023 at 08:44:10PM +0000, Conor Dooley wrote:
> On Fri, Jan 20, 2023 at 12:39:06PM -0500, Jesse Taube wrote:
> > On 1/20/23 02:59, Conor Dooley wrote:
> > > Since you'll have to re-submit, making sure that allowing !MMU on rv32
> > > doesn't break the build due to canaan k210 drivers being enabled despite
> > > relying on 64-bit divisions, I've got some nits for you.
> > Not sure what driver needs 64bit, but sense !MMU was only selected by 64BIT.
>
> LKP reported a build error for it:
> https://lore.kernel.org/linux-riscv/[email protected]/
>
> > This should work.
> > diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs
> > index 69774bb362d6..b9835b8ede86 100644
> > --- a/arch/riscv/Kconfig.socs
> > +++ b/arch/riscv/Kconfig.socs
> > @@ -43,7 +43,7 @@ config SOC_VIRT
> >
> > config SOC_CANAAN
> > bool "Canaan Kendryte K210 SoC"
> > - depends on !MMU
> > + depends on !MMU && 64BIT
> > select CLINT_TIMER if RISCV_M_MODE
> > select SERIAL_SIFIVE if TTY
> > select SERIAL_SIFIVE_CONSOLE if TTY
>
> I don't think this is the correct fix for the problem - the drivers
> really should not do implicit 64-bit divisions IMO.
> Linux has division helpers for them in math64.h.
> None of the other SoCs have a dependency on 64BIT and I'd not been keen
> on adding on here.
>
> I suspect the fix is as simple as the below, but I'd need to go test it.
>
> Thanks,
> Conor.
>
> --- 8< ---
> From ecfa79ad1b24f68cfccb77d666e443293d52d066 Mon Sep 17 00:00:00 2001
> From: Conor Dooley <[email protected]>
> Date: Fri, 20 Jan 2023 20:36:29 +0000
> Subject: [PATCH] clk: k210: remove an implicit 64-bit division
>
> The K210 clock driver depends on SOC_CANAAN, which is only selectable
> when !MMU on RISC-V. !MMU is not possible on 32-bit yet, but patches
> have been sent for its enabling. The kernel test robot reported this
> implicit 64-bit division there.
>
> Replace the implicit division with an explicit one.
>
> Reported-by: kernel test robot <[email protected]>
> Link: https://lore.kernel.org/linux-riscv/[email protected]/
> Signed-off-by: Conor Dooley <[email protected]>
> ---
> Since it was always guarded such that it only ever built for 64-bit, I
> am not sure that a fixes tag is needed, but it would be:
> Fixes: c6ca7616f7d5 ("clk: Add RISC-V Canaan Kendryte K210 clock driver")
> ---
> drivers/clk/clk-k210.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clk/clk-k210.c b/drivers/clk/clk-k210.c
> index 67a7cb3503c3..17c5bfb384ad 100644
> --- a/drivers/clk/clk-k210.c
> +++ b/drivers/clk/clk-k210.c
> @@ -495,7 +495,7 @@ static unsigned long k210_pll_get_rate(struct clk_hw *hw,
> f = FIELD_GET(K210_PLL_CLKF, reg) + 1;
> od = FIELD_GET(K210_PLL_CLKOD, reg) + 1;
>
> - return (u64)parent_rate * f / (r * od);
> + return div_u64(parent_rate * f, r * od);
Nope, that's wrong. I omitted the cast...
return div_u64((u64)parent_rate * f, r * od);
> }
>
> static const struct clk_ops k210_pll_ops = {
> --
> 2.39.0
>
> _______________________________________________
> linux-riscv mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-riscv
On 1/20/23 15:48, Conor Dooley wrote:
> On Fri, Jan 20, 2023 at 08:44:10PM +0000, Conor Dooley wrote:
>> On Fri, Jan 20, 2023 at 12:39:06PM -0500, Jesse Taube wrote:
>>> On 1/20/23 02:59, Conor Dooley wrote:
>>>> Since you'll have to re-submit, making sure that allowing !MMU on rv32
>>>> doesn't break the build due to canaan k210 drivers being enabled despite
>>>> relying on 64-bit divisions, I've got some nits for you.
>>> Not sure what driver needs 64bit, but sense !MMU was only selected by 64BIT.
>>
>> LKP reported a build error for it:
>> https://lore.kernel.org/linux-riscv/[email protected]/
>>
>>> This should work.
>>> diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs
>>> index 69774bb362d6..b9835b8ede86 100644
>>> --- a/arch/riscv/Kconfig.socs
>>> +++ b/arch/riscv/Kconfig.socs
>>> @@ -43,7 +43,7 @@ config SOC_VIRT
>>>
>>> config SOC_CANAAN
>>> bool "Canaan Kendryte K210 SoC"
>>> - depends on !MMU
>>> + depends on !MMU && 64BIT
>>> select CLINT_TIMER if RISCV_M_MODE
>>> select SERIAL_SIFIVE if TTY
>>> select SERIAL_SIFIVE_CONSOLE if TTY
>>
>> I don't think this is the correct fix for the problem - the drivers
>> really should not do implicit 64-bit divisions IMO.
>> Linux has division helpers for them in math64.h.
>> None of the other SoCs have a dependency on 64BIT and I'd not been keen
>> on adding on here.
>>
>> I suspect the fix is as simple as the below, but I'd need to go test it.
>>
>> Thanks,
>> Conor.
>>
>> --- 8< ---
>> From ecfa79ad1b24f68cfccb77d666e443293d52d066 Mon Sep 17 00:00:00 2001
>> From: Conor Dooley <[email protected]>
>> Date: Fri, 20 Jan 2023 20:36:29 +0000
>> Subject: [PATCH] clk: k210: remove an implicit 64-bit division
>>
>> The K210 clock driver depends on SOC_CANAAN, which is only selectable
>> when !MMU on RISC-V. !MMU is not possible on 32-bit yet, but patches
>> have been sent for its enabling. The kernel test robot reported this
>> implicit 64-bit division there.
Oh I missed the bots email oops.
undefined reference to `__udivdi3'
Poor linker isn't linking with libgcc
>>
>> Replace the implicit division with an explicit one.
>>
>> Reported-by: kernel test robot <[email protected]>
>> Link: https://lore.kernel.org/linux-riscv/[email protected]/
>> Signed-off-by: Conor Dooley <[email protected]>
>> ---
>> Since it was always guarded such that it only ever built for 64-bit, I
>> am not sure that a fixes tag is needed, but it would be:
>> Fixes: c6ca7616f7d5 ("clk: Add RISC-V Canaan Kendryte K210 clock driver")
>> ---
>> drivers/clk/clk-k210.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/clk-k210.c b/drivers/clk/clk-k210.c
>> index 67a7cb3503c3..17c5bfb384ad 100644
>> --- a/drivers/clk/clk-k210.c
>> +++ b/drivers/clk/clk-k210.c
>> @@ -495,7 +495,7 @@ static unsigned long k210_pll_get_rate(struct clk_hw *hw,
>> f = FIELD_GET(K210_PLL_CLKF, reg) + 1;
>> od = FIELD_GET(K210_PLL_CLKOD, reg) + 1;
>>
>> - return (u64)parent_rate * f / (r * od);
>> + return div_u64(parent_rate * f, r * od);
>
> Nope, that's wrong. I omitted the cast...
>
> return div_u64((u64)parent_rate * f, r * od);
Ah that's a much better fix, shall I prepend this to the set and author you?
>
>> }
>>
>> static const struct clk_ops k210_pll_ops = {
>> --
>> 2.39.0
>>
>
>
>
>> _______________________________________________
>> linux-riscv mailing list
>> [email protected]
>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>
> > > diff --git a/drivers/clk/clk-k210.c b/drivers/clk/clk-k210.c
> > > index 67a7cb3503c3..17c5bfb384ad 100644
> > > --- a/drivers/clk/clk-k210.c
> > > +++ b/drivers/clk/clk-k210.c
> > > @@ -495,7 +495,7 @@ static unsigned long k210_pll_get_rate(struct clk_hw *hw,
> > > f = FIELD_GET(K210_PLL_CLKF, reg) + 1;
> > > od = FIELD_GET(K210_PLL_CLKOD, reg) + 1;
> > > - return (u64)parent_rate * f / (r * od);
> > > + return div_u64(parent_rate * f, r * od);
> >
> > Nope, that's wrong. I omitted the cast...
> >
> > return div_u64((u64)parent_rate * f, r * od);
> Ah that's a much better fix, shall I prepend this to the set and author you?
Uh, I'd rather check that it is a functional fix first!
I have the board, so I'll give it a go tomorrow and let you know.
Thanks,
Conor.
On Fri, Jan 20, 2023 at 08:57:38PM +0000, Conor Dooley wrote:
> > > > diff --git a/drivers/clk/clk-k210.c b/drivers/clk/clk-k210.c
> > > > index 67a7cb3503c3..17c5bfb384ad 100644
> > > > --- a/drivers/clk/clk-k210.c
> > > > +++ b/drivers/clk/clk-k210.c
> > > > @@ -495,7 +495,7 @@ static unsigned long k210_pll_get_rate(struct clk_hw *hw,
> > > > f = FIELD_GET(K210_PLL_CLKF, reg) + 1;
> > > > od = FIELD_GET(K210_PLL_CLKOD, reg) + 1;
> > > > - return (u64)parent_rate * f / (r * od);
> > > > + return div_u64(parent_rate * f, r * od);
> > >
> > > Nope, that's wrong. I omitted the cast...
> > >
> > > return div_u64((u64)parent_rate * f, r * od);
>
>
> > Ah that's a much better fix, shall I prepend this to the set and author you?
>
> Uh, I'd rather check that it is a functional fix first!
> I have the board, so I'll give it a go tomorrow and let you know.
Gave it a go, board still works with revised version of this change in
place.
Thanks,
Conor.