* [PATCH] riscv: make ZONE_DMA32 optional
@ 2024-08-27 11:36 Vladimir Kondratiev
2024-08-27 23:10 ` Drew Fustini
` (2 more replies)
0 siblings, 3 replies; 18+ messages in thread
From: Vladimir Kondratiev @ 2024-08-27 11:36 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou
Cc: Vladimir Kondratiev, Andrew Morton, linux-riscv, linux-kernel,
linux-mm
It is not necessary any RISCV platform has ZONE_DMA32.
Example - if platform has no DRAM in [0..4G] region,
it will report failure like below each boot.
[ 0.088709] swapper/0: page allocation failure: order:7, mode:0xcc4(GFP_KERNEL|GFP_DMA32), nodemask=(null),cpuset=/
[ 0.088832] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-rc5 #30
[ 0.088864] Call Trace:
[ 0.088869] [<ffffffff800059f2>] dump_backtrace+0x1c/0x24
[ 0.088910] [<ffffffff805f328c>] show_stack+0x2c/0x38
[ 0.088957] [<ffffffff805fd800>] dump_stack_lvl+0x52/0x74
[ 0.088987] [<ffffffff805fd836>] dump_stack+0x14/0x1c
[ 0.089010] [<ffffffff801a23a8>] warn_alloc+0xf4/0x176
[ 0.089041] [<ffffffff801a3052>] __alloc_pages_noprof+0xc28/0xcb4
[ 0.089067] [<ffffffff80086eda>] atomic_pool_expand+0x62/0x1f8
[ 0.089090] [<ffffffff8080d674>] __dma_atomic_pool_init+0x46/0x9e
[ 0.089115] [<ffffffff8080d762>] dma_atomic_pool_init+0x96/0x11c
[ 0.089139] [<ffffffff80002146>] do_one_initcall+0x5c/0x1b2
[ 0.089158] [<ffffffff8080127c>] kernel_init_freeable+0x214/0x274
[ 0.089190] [<ffffffff805fefd8>] kernel_init+0x1e/0x10a
[ 0.089209] [<ffffffff8060748a>] ret_from_fork+0xe/0x1c
Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com>
---
arch/riscv/Kconfig | 2 +-
mm/Kconfig | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 0f3cd7c3a436..94a573112625 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -50,6 +50,7 @@ config RISCV
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UBSAN
select ARCH_HAS_VDSO_DATA
+ select ARCH_HAS_ZONE_DMA_SET if 64BIT
select ARCH_KEEP_MEMBLOCK if ACPI
select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
@@ -200,7 +201,6 @@ config RISCV
select THREAD_INFO_IN_TASK
select TRACE_IRQFLAGS_SUPPORT
select UACCESS_MEMCPY if !MMU
- select ZONE_DMA32 if 64BIT
config CLANG_SUPPORTS_DYNAMIC_FTRACE
def_bool CC_IS_CLANG
diff --git a/mm/Kconfig b/mm/Kconfig
index b72e7d040f78..97c85da98e89 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1032,7 +1032,7 @@ config ZONE_DMA
config ZONE_DMA32
bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET
depends on !X86_32
- default y if ARM64
+ default y if ARM64 || (RISCV && 64BIT)
config ZONE_DEVICE
bool "Device memory (pmem, HMM, etc...) hotplug support"
--
2.37.3
^ permalink raw reply related [flat|nested] 18+ messages in thread* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-08-27 11:36 [PATCH] riscv: make ZONE_DMA32 optional Vladimir Kondratiev @ 2024-08-27 23:10 ` Drew Fustini 2024-09-20 8:58 ` Palmer Dabbelt 2024-09-20 14:04 ` Christoph Hellwig 2024-09-30 9:55 ` Alexandre Ghiti 2 siblings, 1 reply; 18+ messages in thread From: Drew Fustini @ 2024-08-27 23:10 UTC (permalink / raw) To: Vladimir Kondratiev Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv, linux-kernel, linux-mm On Tue, Aug 27, 2024 at 02:36:11PM +0300, Vladimir Kondratiev wrote: > It is not necessary any RISCV platform has ZONE_DMA32. > > Example - if platform has no DRAM in [0..4G] region, > it will report failure like below each boot. > > [ 0.088709] swapper/0: page allocation failure: order:7, mode:0xcc4(GFP_KERNEL|GFP_DMA32), nodemask=(null),cpuset=/ > [ 0.088832] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-rc5 #30 > [ 0.088864] Call Trace: > [ 0.088869] [<ffffffff800059f2>] dump_backtrace+0x1c/0x24 > [ 0.088910] [<ffffffff805f328c>] show_stack+0x2c/0x38 > [ 0.088957] [<ffffffff805fd800>] dump_stack_lvl+0x52/0x74 > [ 0.088987] [<ffffffff805fd836>] dump_stack+0x14/0x1c > [ 0.089010] [<ffffffff801a23a8>] warn_alloc+0xf4/0x176 > [ 0.089041] [<ffffffff801a3052>] __alloc_pages_noprof+0xc28/0xcb4 > [ 0.089067] [<ffffffff80086eda>] atomic_pool_expand+0x62/0x1f8 > [ 0.089090] [<ffffffff8080d674>] __dma_atomic_pool_init+0x46/0x9e > [ 0.089115] [<ffffffff8080d762>] dma_atomic_pool_init+0x96/0x11c > [ 0.089139] [<ffffffff80002146>] do_one_initcall+0x5c/0x1b2 > [ 0.089158] [<ffffffff8080127c>] kernel_init_freeable+0x214/0x274 > [ 0.089190] [<ffffffff805fefd8>] kernel_init+0x1e/0x10a > [ 0.089209] [<ffffffff8060748a>] ret_from_fork+0xe/0x1c > > Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com> > --- > arch/riscv/Kconfig | 2 +- > mm/Kconfig | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 0f3cd7c3a436..94a573112625 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -50,6 +50,7 @@ config RISCV > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > select ARCH_HAS_UBSAN > select ARCH_HAS_VDSO_DATA > + select ARCH_HAS_ZONE_DMA_SET if 64BIT > select ARCH_KEEP_MEMBLOCK if ACPI > select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU > select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX > @@ -200,7 +201,6 @@ config RISCV > select THREAD_INFO_IN_TASK > select TRACE_IRQFLAGS_SUPPORT > select UACCESS_MEMCPY if !MMU > - select ZONE_DMA32 if 64BIT > > config CLANG_SUPPORTS_DYNAMIC_FTRACE > def_bool CC_IS_CLANG > diff --git a/mm/Kconfig b/mm/Kconfig > index b72e7d040f78..97c85da98e89 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -1032,7 +1032,7 @@ config ZONE_DMA > config ZONE_DMA32 > bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET > depends on !X86_32 > - default y if ARM64 > + default y if ARM64 || (RISCV && 64BIT) > > config ZONE_DEVICE > bool "Device memory (pmem, HMM, etc...) hotplug support" > -- > 2.37.3 > Reviewed-by: Drew Fustini <dfustini@tenstorrent.com> Thanks for sending this patch as I've also encountered that annoying error on systems with DRAM above 4GB. I tested this patch by changing the qemu virt machine to have DRAM starting at 2^32: diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c index cef41c150aaf..3033a2560edb 100644 --- a/hw/riscv/virt.c +++ b/hw/riscv/virt.c @@ -87,7 +87,7 @@ static const MemMapEntry virt_memmap[] = { [VIRT_IMSIC_S] = { 0x28000000, VIRT_IMSIC_MAX_SIZE }, [VIRT_PCIE_ECAM] = { 0x30000000, 0x10000000 }, [VIRT_PCIE_MMIO] = { 0x40000000, 0x40000000 }, - [VIRT_DRAM] = { 0x80000000, 0x0 }, + [VIRT_DRAM] = { 0x100000000, 0x0 }, }; /* PCIe high mmio is fixed for RV32 */ ^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-08-27 23:10 ` Drew Fustini @ 2024-09-20 8:58 ` Palmer Dabbelt 2024-09-20 13:18 ` Drew Fustini 0 siblings, 1 reply; 18+ messages in thread From: Palmer Dabbelt @ 2024-09-20 8:58 UTC (permalink / raw) To: dfustini, Conor Dooley Cc: vladimir.kondratiev, Paul Walmsley, aou, akpm, linux-riscv, linux-kernel, linux-mm On Tue, 27 Aug 2024 16:10:20 PDT (-0700), dfustini@tenstorrent.com wrote: > On Tue, Aug 27, 2024 at 02:36:11PM +0300, Vladimir Kondratiev wrote: >> It is not necessary any RISCV platform has ZONE_DMA32. >> >> Example - if platform has no DRAM in [0..4G] region, >> it will report failure like below each boot. >> >> [ 0.088709] swapper/0: page allocation failure: order:7, mode:0xcc4(GFP_KERNEL|GFP_DMA32), nodemask=(null),cpuset=/ >> [ 0.088832] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-rc5 #30 >> [ 0.088864] Call Trace: >> [ 0.088869] [<ffffffff800059f2>] dump_backtrace+0x1c/0x24 >> [ 0.088910] [<ffffffff805f328c>] show_stack+0x2c/0x38 >> [ 0.088957] [<ffffffff805fd800>] dump_stack_lvl+0x52/0x74 >> [ 0.088987] [<ffffffff805fd836>] dump_stack+0x14/0x1c >> [ 0.089010] [<ffffffff801a23a8>] warn_alloc+0xf4/0x176 >> [ 0.089041] [<ffffffff801a3052>] __alloc_pages_noprof+0xc28/0xcb4 >> [ 0.089067] [<ffffffff80086eda>] atomic_pool_expand+0x62/0x1f8 >> [ 0.089090] [<ffffffff8080d674>] __dma_atomic_pool_init+0x46/0x9e >> [ 0.089115] [<ffffffff8080d762>] dma_atomic_pool_init+0x96/0x11c >> [ 0.089139] [<ffffffff80002146>] do_one_initcall+0x5c/0x1b2 >> [ 0.089158] [<ffffffff8080127c>] kernel_init_freeable+0x214/0x274 >> [ 0.089190] [<ffffffff805fefd8>] kernel_init+0x1e/0x10a >> [ 0.089209] [<ffffffff8060748a>] ret_from_fork+0xe/0x1c >> >> Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com> >> --- >> arch/riscv/Kconfig | 2 +- >> mm/Kconfig | 2 +- >> 2 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >> index 0f3cd7c3a436..94a573112625 100644 >> --- a/arch/riscv/Kconfig >> +++ b/arch/riscv/Kconfig >> @@ -50,6 +50,7 @@ config RISCV >> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST >> select ARCH_HAS_UBSAN >> select ARCH_HAS_VDSO_DATA >> + select ARCH_HAS_ZONE_DMA_SET if 64BIT >> select ARCH_KEEP_MEMBLOCK if ACPI >> select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU >> select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX >> @@ -200,7 +201,6 @@ config RISCV >> select THREAD_INFO_IN_TASK >> select TRACE_IRQFLAGS_SUPPORT >> select UACCESS_MEMCPY if !MMU >> - select ZONE_DMA32 if 64BIT >> >> config CLANG_SUPPORTS_DYNAMIC_FTRACE >> def_bool CC_IS_CLANG >> diff --git a/mm/Kconfig b/mm/Kconfig >> index b72e7d040f78..97c85da98e89 100644 >> --- a/mm/Kconfig >> +++ b/mm/Kconfig >> @@ -1032,7 +1032,7 @@ config ZONE_DMA >> config ZONE_DMA32 >> bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET >> depends on !X86_32 >> - default y if ARM64 >> + default y if ARM64 || (RISCV && 64BIT) >> >> config ZONE_DEVICE >> bool "Device memory (pmem, HMM, etc...) hotplug support" >> -- >> 2.37.3 >> > > Reviewed-by: Drew Fustini <dfustini@tenstorrent.com> > > Thanks for sending this patch as I've also encountered that annoying > error on systems with DRAM above 4GB. > > I tested this patch by changing the qemu virt machine to have DRAM > starting at 2^32: > > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c > index cef41c150aaf..3033a2560edb 100644 > --- a/hw/riscv/virt.c > +++ b/hw/riscv/virt.c > @@ -87,7 +87,7 @@ static const MemMapEntry virt_memmap[] = { > [VIRT_IMSIC_S] = { 0x28000000, VIRT_IMSIC_MAX_SIZE }, > [VIRT_PCIE_ECAM] = { 0x30000000, 0x10000000 }, > [VIRT_PCIE_MMIO] = { 0x40000000, 0x40000000 }, > - [VIRT_DRAM] = { 0x80000000, 0x0 }, > + [VIRT_DRAM] = { 0x100000000, 0x0 }, > }; > > /* PCIe high mmio is fixed for RV32 */ IIRC the ZONE_DMA32 stuff existed for some of the early SiFive systems, where the expansion daughterboard's PCIe controller (via a Xilinx FPGA) could only handle 32-bit DMA addreses. I think there's a similar quirk in the Microsemi PCIe controller on the PolarFire boards, but Conor would know for sure. ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-09-20 8:58 ` Palmer Dabbelt @ 2024-09-20 13:18 ` Drew Fustini 2024-09-23 9:46 ` Ben Dooks 0 siblings, 1 reply; 18+ messages in thread From: Drew Fustini @ 2024-09-20 13:18 UTC (permalink / raw) To: Palmer Dabbelt Cc: dfustini, Conor Dooley, vladimir.kondratiev, Paul Walmsley, aou, akpm, linux-riscv, linux-kernel, linux-mm On Fri, Sep 20, 2024 at 01:58:23AM -0700, Palmer Dabbelt wrote: > On Tue, 27 Aug 2024 16:10:20 PDT (-0700), dfustini@tenstorrent.com wrote: > > On Tue, Aug 27, 2024 at 02:36:11PM +0300, Vladimir Kondratiev wrote: > > > It is not necessary any RISCV platform has ZONE_DMA32. > > > > > > Example - if platform has no DRAM in [0..4G] region, > > > it will report failure like below each boot. > > > > > > [ 0.088709] swapper/0: page allocation failure: order:7, mode:0xcc4(GFP_KERNEL|GFP_DMA32), nodemask=(null),cpuset=/ > > > [ 0.088832] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-rc5 #30 > > > [ 0.088864] Call Trace: > > > [ 0.088869] [<ffffffff800059f2>] dump_backtrace+0x1c/0x24 > > > [ 0.088910] [<ffffffff805f328c>] show_stack+0x2c/0x38 > > > [ 0.088957] [<ffffffff805fd800>] dump_stack_lvl+0x52/0x74 > > > [ 0.088987] [<ffffffff805fd836>] dump_stack+0x14/0x1c > > > [ 0.089010] [<ffffffff801a23a8>] warn_alloc+0xf4/0x176 > > > [ 0.089041] [<ffffffff801a3052>] __alloc_pages_noprof+0xc28/0xcb4 > > > [ 0.089067] [<ffffffff80086eda>] atomic_pool_expand+0x62/0x1f8 > > > [ 0.089090] [<ffffffff8080d674>] __dma_atomic_pool_init+0x46/0x9e > > > [ 0.089115] [<ffffffff8080d762>] dma_atomic_pool_init+0x96/0x11c > > > [ 0.089139] [<ffffffff80002146>] do_one_initcall+0x5c/0x1b2 > > > [ 0.089158] [<ffffffff8080127c>] kernel_init_freeable+0x214/0x274 > > > [ 0.089190] [<ffffffff805fefd8>] kernel_init+0x1e/0x10a > > > [ 0.089209] [<ffffffff8060748a>] ret_from_fork+0xe/0x1c > > > > > > Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com> > > > --- > > > arch/riscv/Kconfig | 2 +- > > > mm/Kconfig | 2 +- > > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > > index 0f3cd7c3a436..94a573112625 100644 > > > --- a/arch/riscv/Kconfig > > > +++ b/arch/riscv/Kconfig > > > @@ -50,6 +50,7 @@ config RISCV > > > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > > > select ARCH_HAS_UBSAN > > > select ARCH_HAS_VDSO_DATA > > > + select ARCH_HAS_ZONE_DMA_SET if 64BIT > > > select ARCH_KEEP_MEMBLOCK if ACPI > > > select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU > > > select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX > > > @@ -200,7 +201,6 @@ config RISCV > > > select THREAD_INFO_IN_TASK > > > select TRACE_IRQFLAGS_SUPPORT > > > select UACCESS_MEMCPY if !MMU > > > - select ZONE_DMA32 if 64BIT > > > > > > config CLANG_SUPPORTS_DYNAMIC_FTRACE > > > def_bool CC_IS_CLANG > > > diff --git a/mm/Kconfig b/mm/Kconfig > > > index b72e7d040f78..97c85da98e89 100644 > > > --- a/mm/Kconfig > > > +++ b/mm/Kconfig > > > @@ -1032,7 +1032,7 @@ config ZONE_DMA > > > config ZONE_DMA32 > > > bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET > > > depends on !X86_32 > > > - default y if ARM64 > > > + default y if ARM64 || (RISCV && 64BIT) > > > > > > config ZONE_DEVICE > > > bool "Device memory (pmem, HMM, etc...) hotplug support" > > > -- > > > 2.37.3 > > > > > > > Reviewed-by: Drew Fustini <dfustini@tenstorrent.com> > > > > Thanks for sending this patch as I've also encountered that annoying > > error on systems with DRAM above 4GB. > > > > I tested this patch by changing the qemu virt machine to have DRAM > > starting at 2^32: > > > > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c > > index cef41c150aaf..3033a2560edb 100644 > > --- a/hw/riscv/virt.c > > +++ b/hw/riscv/virt.c > > @@ -87,7 +87,7 @@ static const MemMapEntry virt_memmap[] = { > > [VIRT_IMSIC_S] = { 0x28000000, VIRT_IMSIC_MAX_SIZE }, > > [VIRT_PCIE_ECAM] = { 0x30000000, 0x10000000 }, > > [VIRT_PCIE_MMIO] = { 0x40000000, 0x40000000 }, > > - [VIRT_DRAM] = { 0x80000000, 0x0 }, > > + [VIRT_DRAM] = { 0x100000000, 0x0 }, > > }; > > > > /* PCIe high mmio is fixed for RV32 */ > > IIRC the ZONE_DMA32 stuff existed for some of the early SiFive systems, > where the expansion daughterboard's PCIe controller (via a Xilinx FPGA) > could only handle 32-bit DMA addreses. I think there's a similar quirk in > the Microsemi PCIe controller on the PolarFire boards, but Conor would know > for sure. I don't think this patch would affect those systems that need ZONE_DMA2. I believe it just makes it possible to disable it in the kernel config. The platform I'm working on has no memory below 4GB and all the PCIe devices that I care about are not 32-bit constrained. Therefore I just want to be able to turn it off in my .config. Thanks, Drew ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-09-20 13:18 ` Drew Fustini @ 2024-09-23 9:46 ` Ben Dooks 0 siblings, 0 replies; 18+ messages in thread From: Ben Dooks @ 2024-09-23 9:46 UTC (permalink / raw) To: Drew Fustini, Palmer Dabbelt Cc: dfustini, Conor Dooley, vladimir.kondratiev, Paul Walmsley, aou, akpm, linux-riscv, linux-kernel, linux-mm On 20/09/2024 14:18, Drew Fustini wrote: > On Fri, Sep 20, 2024 at 01:58:23AM -0700, Palmer Dabbelt wrote: >> On Tue, 27 Aug 2024 16:10:20 PDT (-0700), dfustini@tenstorrent.com wrote: >>> On Tue, Aug 27, 2024 at 02:36:11PM +0300, Vladimir Kondratiev wrote: >>>> It is not necessary any RISCV platform has ZONE_DMA32. >>>> >>>> Example - if platform has no DRAM in [0..4G] region, >>>> it will report failure like below each boot. >>>> >>>> [ 0.088709] swapper/0: page allocation failure: order:7, mode:0xcc4(GFP_KERNEL|GFP_DMA32), nodemask=(null),cpuset=/ >>>> [ 0.088832] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-rc5 #30 >>>> [ 0.088864] Call Trace: >>>> [ 0.088869] [<ffffffff800059f2>] dump_backtrace+0x1c/0x24 >>>> [ 0.088910] [<ffffffff805f328c>] show_stack+0x2c/0x38 >>>> [ 0.088957] [<ffffffff805fd800>] dump_stack_lvl+0x52/0x74 >>>> [ 0.088987] [<ffffffff805fd836>] dump_stack+0x14/0x1c >>>> [ 0.089010] [<ffffffff801a23a8>] warn_alloc+0xf4/0x176 >>>> [ 0.089041] [<ffffffff801a3052>] __alloc_pages_noprof+0xc28/0xcb4 >>>> [ 0.089067] [<ffffffff80086eda>] atomic_pool_expand+0x62/0x1f8 >>>> [ 0.089090] [<ffffffff8080d674>] __dma_atomic_pool_init+0x46/0x9e >>>> [ 0.089115] [<ffffffff8080d762>] dma_atomic_pool_init+0x96/0x11c >>>> [ 0.089139] [<ffffffff80002146>] do_one_initcall+0x5c/0x1b2 >>>> [ 0.089158] [<ffffffff8080127c>] kernel_init_freeable+0x214/0x274 >>>> [ 0.089190] [<ffffffff805fefd8>] kernel_init+0x1e/0x10a >>>> [ 0.089209] [<ffffffff8060748a>] ret_from_fork+0xe/0x1c >>>> >>>> Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com> >>>> --- >>>> arch/riscv/Kconfig | 2 +- >>>> mm/Kconfig | 2 +- >>>> 2 files changed, 2 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >>>> index 0f3cd7c3a436..94a573112625 100644 >>>> --- a/arch/riscv/Kconfig >>>> +++ b/arch/riscv/Kconfig >>>> @@ -50,6 +50,7 @@ config RISCV >>>> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST >>>> select ARCH_HAS_UBSAN >>>> select ARCH_HAS_VDSO_DATA >>>> + select ARCH_HAS_ZONE_DMA_SET if 64BIT >>>> select ARCH_KEEP_MEMBLOCK if ACPI >>>> select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU >>>> select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX >>>> @@ -200,7 +201,6 @@ config RISCV >>>> select THREAD_INFO_IN_TASK >>>> select TRACE_IRQFLAGS_SUPPORT >>>> select UACCESS_MEMCPY if !MMU >>>> - select ZONE_DMA32 if 64BIT >>>> >>>> config CLANG_SUPPORTS_DYNAMIC_FTRACE >>>> def_bool CC_IS_CLANG >>>> diff --git a/mm/Kconfig b/mm/Kconfig >>>> index b72e7d040f78..97c85da98e89 100644 >>>> --- a/mm/Kconfig >>>> +++ b/mm/Kconfig >>>> @@ -1032,7 +1032,7 @@ config ZONE_DMA >>>> config ZONE_DMA32 >>>> bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET >>>> depends on !X86_32 >>>> - default y if ARM64 >>>> + default y if ARM64 || (RISCV && 64BIT) >>>> >>>> config ZONE_DEVICE >>>> bool "Device memory (pmem, HMM, etc...) hotplug support" >>>> -- >>>> 2.37.3 >>>> >>> >>> Reviewed-by: Drew Fustini <dfustini@tenstorrent.com> >>> >>> Thanks for sending this patch as I've also encountered that annoying >>> error on systems with DRAM above 4GB. >>> >>> I tested this patch by changing the qemu virt machine to have DRAM >>> starting at 2^32: >>> >>> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c >>> index cef41c150aaf..3033a2560edb 100644 >>> --- a/hw/riscv/virt.c >>> +++ b/hw/riscv/virt.c >>> @@ -87,7 +87,7 @@ static const MemMapEntry virt_memmap[] = { >>> [VIRT_IMSIC_S] = { 0x28000000, VIRT_IMSIC_MAX_SIZE }, >>> [VIRT_PCIE_ECAM] = { 0x30000000, 0x10000000 }, >>> [VIRT_PCIE_MMIO] = { 0x40000000, 0x40000000 }, >>> - [VIRT_DRAM] = { 0x80000000, 0x0 }, >>> + [VIRT_DRAM] = { 0x100000000, 0x0 }, >>> }; >>> >>> /* PCIe high mmio is fixed for RV32 */ >> >> IIRC the ZONE_DMA32 stuff existed for some of the early SiFive systems, >> where the expansion daughterboard's PCIe controller (via a Xilinx FPGA) >> could only handle 32-bit DMA addreses. I think there's a similar quirk in >> the Microsemi PCIe controller on the PolarFire boards, but Conor would know >> for sure. The Fu740 SoC has a mirror of part of DRAM in 32bit space specifically I think for PCIe where something may be attached via a PCIe-PCI bridge. > I don't think this patch would affect those systems that need ZONE_DMA2. > I believe it just makes it possible to disable it in the kernel config. > The platform I'm working on has no memory below 4GB and all the PCIe > devices that I care about are not 32-bit constrained. Therefore I just > want to be able to turn it off in my .config. > > Thanks, > Drew I tried this a while ago and IIRC you run into issues with DMA allocations from certain drivers that expect this to exist. With new platforms that don't have any memory in DMA32 space this may become more common. I've already had to deal with this for an internal dev project, and it ended up having a couple of hacks into the allocation code to silence warnings/errors. This of course may have been fixed, given this was last year. -- Ben Dooks http://www.codethink.co.uk/ Senior Engineer Codethink - Providing Genius https://www.codethink.co.uk/privacy.html ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-08-27 11:36 [PATCH] riscv: make ZONE_DMA32 optional Vladimir Kondratiev 2024-08-27 23:10 ` Drew Fustini @ 2024-09-20 14:04 ` Christoph Hellwig 2024-09-22 10:06 ` Vladimir Kondratiev 2024-09-30 9:55 ` Alexandre Ghiti 2 siblings, 1 reply; 18+ messages in thread From: Christoph Hellwig @ 2024-09-20 14:04 UTC (permalink / raw) To: Vladimir Kondratiev Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv, linux-kernel, linux-mm On Tue, Aug 27, 2024 at 02:36:11PM +0300, Vladimir Kondratiev wrote: > It is not necessary any RISCV platform has ZONE_DMA32. That is an odd statement. The point of ZONE_DMA32 is to make sure that drivers can always allocate 32-bit DMAable memory, and without ZONE_DMA32 that is very hard to provide unless you always have an IOMMU. > Example - if platform has no DRAM in [0..4G] region, > it will report failure like below each boot. ZONE_DMA32 is supposed to contain the 32-bit dma addressable memory, not 32-bit physical. Take a look at the changes that just went into Linus' tree for that. ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-09-20 14:04 ` Christoph Hellwig @ 2024-09-22 10:06 ` Vladimir Kondratiev 2024-09-24 6:39 ` Christoph Hellwig 0 siblings, 1 reply; 18+ messages in thread From: Vladimir Kondratiev @ 2024-09-22 10:06 UTC (permalink / raw) To: Christoph Hellwig Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org >On Tue, Aug 27, 2024 at 02:36:11PM +0300, Vladimir Kondratiev wrote: >> It is not necessary any RISCV platform has ZONE_DMA32. >That is an odd statement. The point of ZONE_DMA32 is to make sure >that drivers can always allocate 32-bit DMAable memory, and without >ZONE_DMA32 that is very hard to provide unless you always have an >IOMMU. This is the whole point - there are platforms where you can't allocate 32-bit dma-able memory. Unless there's IOMMU or some platform specific tricks, DMA address is same as physical address. In my example, platform has DRAM installed at address 32Gbytes. 32-bit devices would not work on such platform, and attempt to allocate ZONE_DMA32 memory fails and kernel prints warning as in my original post >ZONE_DMA32 is supposed to contain the 32-bit dma addressable memory, >not 32-bit physical. >Take a look at the changes that just went into Linus' tree for that. I re-evaluated with Linus's tree as of now (commit 88264981f208), same error reported if I don't apply my patch: [ 0.191514] DMA: preallocated 512 KiB GFP_KERNEL pool for atomic allocations [ 0.191524] swapper/0: page allocation failure: order:7, mode:0xcc4(GFP_KERNEL|GFP_DMA32), nodemask=(null),cpuset=/,mem s_allowed=0 [ 0.191546] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0 #2 [ 0.191553] Hardware name: ???? (DT) [ 0.191556] Call Trace: [ 0.191560] [<ffffffff800059bc>] dump_backtrace+0x1c/0x24 [ 0.191571] [<ffffffff805d1a3c>] show_stack+0x2c/0x38 [ 0.191578] [<ffffffff805dc1e6>] dump_stack_lvl+0x52/0x74 [ 0.191584] [<ffffffff805dc21c>] dump_stack+0x14/0x1c [ 0.191589] [<ffffffff801a8eec>] warn_alloc+0xf4/0x180 [ 0.191598] [<ffffffff801a98e8>] __alloc_pages_noprof+0x970/0xd94 [ 0.191605] [<ffffffff8008d2ae>] atomic_pool_expand+0x62/0x1f8 [ 0.191615] [<ffffffff8060d6ae>] __dma_atomic_pool_init+0x46/0x9e [ 0.191620] [<ffffffff8060d79c>] dma_atomic_pool_init+0x96/0x11c [ 0.191626] [<ffffffff80002146>] do_one_initcall+0x5c/0x1b2 [ 0.191631] [<ffffffff8060127c>] kernel_init_freeable+0x214/0x274 [ 0.191636] [<ffffffff805dd9e4>] kernel_init+0x1e/0x10a [ 0.191644] [<ffffffff805e6eba>] ret_from_fork+0xe/0x1c [ 0.191709] Mem-Info: [ 0.191714] active_anon:0 inactive_anon:0 isolated_anon:0 [ 0.191714] active_file:0 inactive_file:0 isolated_file:0 [ 0.191714] unevictable:0 dirty:0 writeback:0 [ 0.191714] slab_reclaimable:26 slab_unreclaimable:742 [ 0.191714] mapped:0 shmem:0 pagetables:65 [ 0.191714] sec_pagetables:0 bounce:0 [ 0.191714] kernel_misc_reclaimable:0 [ 0.191714] free:1014355 free_pcp:0 free_cma:0 [ 0.191727] 0 total pagecache pages [ 0.191730] 1048576 pages RAM [ 0.191733] 0 pages HighMem/MovableOnly [ 0.191735] 30264 pages reserved [ 0.191743] DMA: failed to allocate 496 KiB GFP_KERNEL|GFP_DMA32 pool for atomic allocation ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-09-22 10:06 ` Vladimir Kondratiev @ 2024-09-24 6:39 ` Christoph Hellwig 0 siblings, 0 replies; 18+ messages in thread From: Christoph Hellwig @ 2024-09-24 6:39 UTC (permalink / raw) To: Vladimir Kondratiev Cc: Christoph Hellwig, Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Sun, Sep 22, 2024 at 10:06:59AM +0000, Vladimir Kondratiev wrote: > This is the whole point - there are platforms where you can't allocate 32-bit > dma-able memory. Ugg. They will be broke for all kinds of devices (plug in PCIe devices IP IP blocks). > Unless there's IOMMU or some platform specific tricks, > DMA address is same as physical address. Well, that's where the usual platform specific trick is, as the platforms with high DRAM either have a mapping between physical and DMA range (see the dma_ranges concept in the DMA and OF code) or a mirror of the higher addresses. Or very rarely (e.g. sparc) a required IOMMU that is always used. ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-08-27 11:36 [PATCH] riscv: make ZONE_DMA32 optional Vladimir Kondratiev 2024-08-27 23:10 ` Drew Fustini 2024-09-20 14:04 ` Christoph Hellwig @ 2024-09-30 9:55 ` Alexandre Ghiti 2024-10-06 10:44 ` Vladimir Kondratiev 2 siblings, 1 reply; 18+ messages in thread From: Alexandre Ghiti @ 2024-09-30 9:55 UTC (permalink / raw) To: Vladimir Kondratiev, Paul Walmsley, Palmer Dabbelt, Albert Ou Cc: Andrew Morton, linux-riscv, linux-kernel, linux-mm Hi Vladimir, On 27/08/2024 13:36, Vladimir Kondratiev wrote: > It is not necessary any RISCV platform has ZONE_DMA32. > > Example - if platform has no DRAM in [0..4G] region, > it will report failure like below each boot. > > [ 0.088709] swapper/0: page allocation failure: order:7, mode:0xcc4(GFP_KERNEL|GFP_DMA32), nodemask=(null),cpuset=/ > [ 0.088832] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-rc5 #30 > [ 0.088864] Call Trace: > [ 0.088869] [<ffffffff800059f2>] dump_backtrace+0x1c/0x24 > [ 0.088910] [<ffffffff805f328c>] show_stack+0x2c/0x38 > [ 0.088957] [<ffffffff805fd800>] dump_stack_lvl+0x52/0x74 > [ 0.088987] [<ffffffff805fd836>] dump_stack+0x14/0x1c > [ 0.089010] [<ffffffff801a23a8>] warn_alloc+0xf4/0x176 > [ 0.089041] [<ffffffff801a3052>] __alloc_pages_noprof+0xc28/0xcb4 > [ 0.089067] [<ffffffff80086eda>] atomic_pool_expand+0x62/0x1f8 > [ 0.089090] [<ffffffff8080d674>] __dma_atomic_pool_init+0x46/0x9e > [ 0.089115] [<ffffffff8080d762>] dma_atomic_pool_init+0x96/0x11c > [ 0.089139] [<ffffffff80002146>] do_one_initcall+0x5c/0x1b2 > [ 0.089158] [<ffffffff8080127c>] kernel_init_freeable+0x214/0x274 > [ 0.089190] [<ffffffff805fefd8>] kernel_init+0x1e/0x10a > [ 0.089209] [<ffffffff8060748a>] ret_from_fork+0xe/0x1c > > Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com> > --- > arch/riscv/Kconfig | 2 +- > mm/Kconfig | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 0f3cd7c3a436..94a573112625 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -50,6 +50,7 @@ config RISCV > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > select ARCH_HAS_UBSAN > select ARCH_HAS_VDSO_DATA > + select ARCH_HAS_ZONE_DMA_SET if 64BIT > select ARCH_KEEP_MEMBLOCK if ACPI > select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU > select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX > @@ -200,7 +201,6 @@ config RISCV > select THREAD_INFO_IN_TASK > select TRACE_IRQFLAGS_SUPPORT > select UACCESS_MEMCPY if !MMU > - select ZONE_DMA32 if 64BIT > > config CLANG_SUPPORTS_DYNAMIC_FTRACE > def_bool CC_IS_CLANG > diff --git a/mm/Kconfig b/mm/Kconfig > index b72e7d040f78..97c85da98e89 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -1032,7 +1032,7 @@ config ZONE_DMA > config ZONE_DMA32 > bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET > depends on !X86_32 > - default y if ARM64 > + default y if ARM64 || (RISCV && 64BIT) > > config ZONE_DEVICE > bool "Device memory (pmem, HMM, etc...) hotplug support" I'm wondering how distro kernels will deal with that since some platforms will need the ZONE_DMA32 and some others will break when enabled as you have shown. Is there a way to make it optional at runtime instead? Thanks, Alex ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-09-30 9:55 ` Alexandre Ghiti @ 2024-10-06 10:44 ` Vladimir Kondratiev 2024-10-06 10:55 ` [PATCH v1] " Vladimir Kondratiev 2024-10-07 12:17 ` [PATCH] " Ben Dooks 0 siblings, 2 replies; 18+ messages in thread From: Vladimir Kondratiev @ 2024-10-06 10:44 UTC (permalink / raw) To: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou Cc: Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org >I'm wondering how distro kernels will deal with that since some >platforms will need the ZONE_DMA32 and some others will break when >enabled as you have shown. I agree platforms with no ZONE_DMA32 is non-portable, to address this I will add dependency on NONPORTABLE and re-submit shortly. Thanks for pointing that. >Is there a way to make it optional at runtime instead? Unfortunately no, or at least I see no way to do so Thanks, Vladimir ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v1] riscv: make ZONE_DMA32 optional 2024-10-06 10:44 ` Vladimir Kondratiev @ 2024-10-06 10:55 ` Vladimir Kondratiev 2024-10-06 22:58 ` Drew Fustini 2024-10-07 5:41 ` Christoph Hellwig 2024-10-07 12:17 ` [PATCH] " Ben Dooks 1 sibling, 2 replies; 18+ messages in thread From: Vladimir Kondratiev @ 2024-10-06 10:55 UTC (permalink / raw) To: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou Cc: Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org It is not necessary any RISCV platform has ZONE_DMA32. Platforms that not support ZONE_DMA32 should set CONFIG_NONPORTABLE because lack of ZONE_DMA32 makes such platform non-portable indeed Example - if platform has no DRAM in [0..4G] region, it will report failure like below each boot. [ 0.088709] swapper/0: page allocation failure: order:7, mode:0xcc4(GFP_KERNEL|GFP_DMA32), nodemask=(null),cpuset=/ [ 0.088832] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-rc5 #30 [ 0.088864] Call Trace: [ 0.088869] [<ffffffff800059f2>] dump_backtrace+0x1c/0x24 [ 0.088910] [<ffffffff805f328c>] show_stack+0x2c/0x38 [ 0.088957] [<ffffffff805fd800>] dump_stack_lvl+0x52/0x74 [ 0.088987] [<ffffffff805fd836>] dump_stack+0x14/0x1c [ 0.089010] [<ffffffff801a23a8>] warn_alloc+0xf4/0x176 [ 0.089041] [<ffffffff801a3052>] __alloc_pages_noprof+0xc28/0xcb4 [ 0.089067] [<ffffffff80086eda>] atomic_pool_expand+0x62/0x1f8 [ 0.089090] [<ffffffff8080d674>] __dma_atomic_pool_init+0x46/0x9e [ 0.089115] [<ffffffff8080d762>] dma_atomic_pool_init+0x96/0x11c [ 0.089139] [<ffffffff80002146>] do_one_initcall+0x5c/0x1b2 [ 0.089158] [<ffffffff8080127c>] kernel_init_freeable+0x214/0x274 [ 0.089190] [<ffffffff805fefd8>] kernel_init+0x1e/0x10a [ 0.089209] [<ffffffff8060748a>] ret_from_fork+0xe/0x1c Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com> --- arch/riscv/Kconfig | 3 ++- mm/Kconfig | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 0f37596a7707..417c6051b679 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -51,6 +51,7 @@ config RISCV select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UBSAN select ARCH_HAS_VDSO_DATA + select ARCH_HAS_ZONE_DMA_SET if 64BIT && NONPORTABLE select ARCH_KEEP_MEMBLOCK if ACPI select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX @@ -208,7 +209,7 @@ config RISCV select TRACE_IRQFLAGS_SUPPORT select UACCESS_MEMCPY if !MMU select USER_STACKTRACE_SUPPORT - select ZONE_DMA32 if 64BIT + select ZONE_DMA32 if 64BIT && !NONPORTABLE config RUSTC_SUPPORTS_RISCV def_bool y diff --git a/mm/Kconfig b/mm/Kconfig index 4c9f5ea13271..f96f812193a4 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1057,7 +1057,7 @@ config ZONE_DMA config ZONE_DMA32 bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET depends on !X86_32 - default y if ARM64 + default y if ARM64 || (RISCV && 64BIT) config ZONE_DEVICE bool "Device memory (pmem, HMM, etc...) hotplug support" -- 2.43.0 ^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v1] riscv: make ZONE_DMA32 optional 2024-10-06 10:55 ` [PATCH v1] " Vladimir Kondratiev @ 2024-10-06 22:58 ` Drew Fustini 2024-10-07 5:41 ` Christoph Hellwig 1 sibling, 0 replies; 18+ messages in thread From: Drew Fustini @ 2024-10-06 22:58 UTC (permalink / raw) To: Vladimir Kondratiev Cc: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Sun, Oct 06, 2024 at 10:55:39AM +0000, Vladimir Kondratiev wrote: > It is not necessary any RISCV platform has ZONE_DMA32. > Platforms that not support ZONE_DMA32 should set > CONFIG_NONPORTABLE because lack of ZONE_DMA32 > makes such platform non-portable indeed I think requiring CONFIG_NONPORTABLE is a good idea. However, it seems this patch was sent as a reply to the existing discussion thread. Thanks, Drew ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v1] riscv: make ZONE_DMA32 optional 2024-10-06 10:55 ` [PATCH v1] " Vladimir Kondratiev 2024-10-06 22:58 ` Drew Fustini @ 2024-10-07 5:41 ` Christoph Hellwig 2024-10-07 6:17 ` Vladimir Kondratiev 1 sibling, 1 reply; 18+ messages in thread From: Christoph Hellwig @ 2024-10-07 5:41 UTC (permalink / raw) To: Vladimir Kondratiev Cc: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Sun, Oct 06, 2024 at 10:55:39AM +0000, Vladimir Kondratiev wrote: > It is not necessary any RISCV platform has ZONE_DMA32. > Platforms that not support ZONE_DMA32 should set > CONFIG_NONPORTABLE because lack of ZONE_DMA32 > makes such platform non-portable indeed Well, this doesn't get any more true by just irgnoring the previous discussion and just reposting :( ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v1] riscv: make ZONE_DMA32 optional 2024-10-07 5:41 ` Christoph Hellwig @ 2024-10-07 6:17 ` Vladimir Kondratiev 2024-10-07 6:22 ` Christoph Hellwig 0 siblings, 1 reply; 18+ messages in thread From: Vladimir Kondratiev @ 2024-10-07 6:17 UTC (permalink / raw) To: Christoph Hellwig Cc: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org >Well, this doesn't get any more true by just irgnoring the previous >discussion and just reposting :( Sorry, this wasn't the intention. Perhaps I messed with the message-id, I see my "patch v1" in one mail thread together with the previous discussion, but not in the other thread. Anyway, I think making ZONE_DMA32 selection depend on NONPORTABLE answers the concern that was raised ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v1] riscv: make ZONE_DMA32 optional 2024-10-07 6:17 ` Vladimir Kondratiev @ 2024-10-07 6:22 ` Christoph Hellwig 2024-10-07 11:39 ` Nick Kossifidis 2024-10-07 13:03 ` Vladimir Kondratiev 0 siblings, 2 replies; 18+ messages in thread From: Christoph Hellwig @ 2024-10-07 6:22 UTC (permalink / raw) To: Vladimir Kondratiev Cc: Christoph Hellwig, Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Mon, Oct 07, 2024 at 06:17:14AM +0000, Vladimir Kondratiev wrote: > >Well, this doesn't get any more true by just irgnoring the previous > >discussion and just reposting :( > > Sorry, this wasn't the intention. Perhaps I messed with the message-id, I see my "patch v1" in one mail thread together with the previous discussion, but not in the other thread. > > Anyway, I think making ZONE_DMA32 selection depend on NONPORTABLE answers the concern > that was raised It doesn't at all. For one not having ZONE_DMA32 is going to break a lot of things. Drivers do expect 32-bit addressable memory. And because SOC designers know this there usually is a way to provide it, e.g. by doing window translations between cpu physical and bus physical address. Please go back to your data sheet or talk to the designers. And if there really is not way to provide this, the right way is just to stop the runtime allocation that triggered you to do this if ZONE_DMA32 is empty, not to add a non-portable option. ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v1] riscv: make ZONE_DMA32 optional 2024-10-07 6:22 ` Christoph Hellwig @ 2024-10-07 11:39 ` Nick Kossifidis 2024-10-07 13:03 ` Vladimir Kondratiev 1 sibling, 0 replies; 18+ messages in thread From: Nick Kossifidis @ 2024-10-07 11:39 UTC (permalink / raw) To: Christoph Hellwig, Vladimir Kondratiev Cc: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On 10/7/24 09:22, Christoph Hellwig wrote: > On Mon, Oct 07, 2024 at 06:17:14AM +0000, Vladimir Kondratiev wrote: >>> Well, this doesn't get any more true by just irgnoring the previous >>> discussion and just reposting :( >> >> Sorry, this wasn't the intention. Perhaps I messed with the message-id, I see my "patch v1" in one mail thread together with the previous discussion, but not in the other thread. >> >> Anyway, I think making ZONE_DMA32 selection depend on NONPORTABLE answers the concern >> that was raised > > It doesn't at all. > > For one not having ZONE_DMA32 is going to break a lot of things. > Drivers do expect 32-bit addressable memory. And because SOC designers > know this there usually is a way to provide it, e.g. by doing window > translations between cpu physical and bus physical address. Please go > back to your data sheet or talk to the designers. > > And if there really is not way to provide this, the right way is just > to stop the runtime allocation that triggered you to do this if > ZONE_DMA32 is empty, not to add a non-portable option. > I agree with Christoph on this one, by the time dma_atomic_pool_init() gets called we already know the system's DRAM base for example and if we have 32bit addressable regions (or aliases / translation windows as Christoph mentioned) or not. We could use this info to skip ZONE_DMA32, or just use a command line argument like this RFC proposed: https://lore.kernel.org/linux-arm-kernel/20230201040913.GA4959@hu-cgoldswo-sd.qualcomm.com/T/ There is no reason to configure this at compile time, and completely remove support for ZONE_DMA32. Also NONPORTABLE doesn't address Alex's point on distro kernels, since distro kernels won't set NONPORTABLE. BTW I tried reproducing this with a recent 6.10 kernel and couldn't, our system also has DRAM way above 32bits and this is also on a modified QEMU machine, here is the full log: https://pastebin.com/9HLcphgY You can use this script to reproduce our QEMU setup if interested: https://github.com/CARV-ICS-FORTH/yarvt/tree/eupilot Regards, Nick ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v1] riscv: make ZONE_DMA32 optional 2024-10-07 6:22 ` Christoph Hellwig 2024-10-07 11:39 ` Nick Kossifidis @ 2024-10-07 13:03 ` Vladimir Kondratiev 1 sibling, 0 replies; 18+ messages in thread From: Vladimir Kondratiev @ 2024-10-07 13:03 UTC (permalink / raw) To: Christoph Hellwig Cc: Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou, Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org >And if there really is not way to provide this, the right way is just >to stop the runtime allocation that triggered you to do this if >ZONE_DMA32 is empty, not to add a non-portable option. I think there's 2 different arrangements: 1) CONFIG_ZONE_DMA32=Y means ZONE_DMA32 exists but empty. Currently this is a bug. dma_atomic_pool_init() will fail. 2) CONFIG_ZONE_DMA32=N means ZONE_DMA32 does not exists In this case any code that rely on DMA32 should fail to compile, and this is an intention. Such system can't have drivers that can't work without DMA32 memory I understand your suggestion is to go for the option 1, not allocate atomic_pool_dma32 and later fail all allocations with GFP_DMA32 if requested by the code. This may be valid option but I don't have a vision how to do it properly. Instead I want realize option 2. SOC I am working on is not a general purpose system, it is an automotive SOC that will run very restricted software. It is designed for purpose without support for the 32-bit devices. I want to avoid any code that assumes DMA32 as this is just not valid on my SOC so I deliberately need to break all such code. ^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH] riscv: make ZONE_DMA32 optional 2024-10-06 10:44 ` Vladimir Kondratiev 2024-10-06 10:55 ` [PATCH v1] " Vladimir Kondratiev @ 2024-10-07 12:17 ` Ben Dooks 1 sibling, 0 replies; 18+ messages in thread From: Ben Dooks @ 2024-10-07 12:17 UTC (permalink / raw) To: Vladimir Kondratiev, Alexandre Ghiti, Paul Walmsley, Palmer Dabbelt, Albert Ou Cc: Andrew Morton, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On 06/10/2024 11:44, Vladimir Kondratiev wrote: >> I'm wondering how distro kernels will deal with that since some >> platforms will need the ZONE_DMA32 and some others will break when >> enabled as you have shown. > > I agree platforms with no ZONE_DMA32 is non-portable, > to address this I will add dependency on NONPORTABLE and re-submit > shortly. Thanks for pointing that. So the last time I got to looking at this, the SoC had no memory in the 32bit space and all the on-chip IP blocks where all 64bit DMA capable. The only thing we didn't sort out was anything connected by the DW PCIe core, but we think that could use an inbound translation window. However, software wise we didn't have the time to try and either hack something into the kernel or write some form of IOMMU for the inbound translation unit. We just removed the warnings to get the initial testing through. >> Is there a way to make it optional at runtime instead? > Unfortunately no, or at least I see no way to do so > > Thanks, Vladimir > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv > -- Ben Dooks http://www.codethink.co.uk/ Senior Engineer Codethink - Providing Genius https://www.codethink.co.uk/privacy.html ^ permalink raw reply [flat|nested] 18+ messages in thread
end of thread, other threads:[~2024-10-07 13:03 UTC | newest] Thread overview: 18+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2024-08-27 11:36 [PATCH] riscv: make ZONE_DMA32 optional Vladimir Kondratiev 2024-08-27 23:10 ` Drew Fustini 2024-09-20 8:58 ` Palmer Dabbelt 2024-09-20 13:18 ` Drew Fustini 2024-09-23 9:46 ` Ben Dooks 2024-09-20 14:04 ` Christoph Hellwig 2024-09-22 10:06 ` Vladimir Kondratiev 2024-09-24 6:39 ` Christoph Hellwig 2024-09-30 9:55 ` Alexandre Ghiti 2024-10-06 10:44 ` Vladimir Kondratiev 2024-10-06 10:55 ` [PATCH v1] " Vladimir Kondratiev 2024-10-06 22:58 ` Drew Fustini 2024-10-07 5:41 ` Christoph Hellwig 2024-10-07 6:17 ` Vladimir Kondratiev 2024-10-07 6:22 ` Christoph Hellwig 2024-10-07 11:39 ` Nick Kossifidis 2024-10-07 13:03 ` Vladimir Kondratiev 2024-10-07 12:17 ` [PATCH] " Ben Dooks
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