Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
On Wednesday 24 October 2012, Gregory CLEMENT wrote: > > No, I was thinking of making the underlying functions globally visible > > and have extern declarations in a header file so you can access them > > directly. > > > > Generally speaking, when you run into a problem with common code, your > > first approach should be to fix the common code before you try to work > > around it. > > OK I thought it was done on purpose. But if you consider it needs to be > fixed I will add patch for it in next version. As long as the functions were only used locally in one file, it's better not to make them globally visible as a rule. But if we know that they are needed, that should be made explicit. Please fix this by submitting another patch to make those functions global and then rebase this series on top of that. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
Dear Gregory CLEMENT,
On Wed, 24 Oct 2012 16:39:13 +0200, Gregory CLEMENT wrote:
> > As others said, the prefix is wrong. Since the file is named coherency,
> > maybe just "coherency_" as the prefix? Not sure, though. Shouldn't the
> > file be named coherency-armada-370-xp.c, as we have done for the irq
> > controller file? In that case, the armada_370_xp prefix would make
> > sense
>
> I would prefer to just use coherency_ everywhere and keep the name of
> the file as is. It made sense to suffix the irq file with
> armada-370-xp because the other mvebu SoCs have their own irq
> controller. Whereas, as far as I know the coherency unit is only
> present in the Armada 370/XP.
Well your argumentation may also be seen as an argument to name it
coherency-armada-370-xp.c :-) I don't have a strong opinion on this
though, and we can always rename it later if needed.
> >> int armada_xp_get_cpu_count(void)
> >> {
> >>int reg, cnt;
> >
> > static?
>
> Which function?
> armada_xp_get_cpu_count and armada_370_xp_set_cpu_coherent are exported
> and moreover are not part of this patch set but the SMP one.
Ok, then maybe this function shouldn't be between the DMA operations
implementation and the bus notifier callback.
> Yes indeed code in headsmp.S and armada_xp_smp_prepare_cpus() are
> redundant we can simplify it. I will change it in the SMP series and
> for this series also.
Great, thanks!
> > Do we have a good reason for having
> > armada_370_xp_coherency_iocache_init() separate from
> > armada_370_xp_coherency_iocache_init() ? I.e, what prevents us from
>
> No good reason because they are the same! ;)
Oops, indeed. but I see that you fixed the problem.
> But more seriously, armada_370_xp_coherency_init() is called as an
> early_init call whereas armada_370_xp_coherency_iocache_init() is called
> later by armada_370_xp_dt_init(). I have to check if we can use
> bus_register_notifier() from an early_init call or if we still need to
> call armada_370_xp_coherency_init() as an early_init call.
The early_initcall() is mandatory, see the comment on top of it:
+/* Coherency initialization have to be done before the SMP
+ * initialization of the CPUs*/
+early_initcall(armada_370_xp_coherency_init);
(BTW, there is a missing space between CPUs and the comment terminator).
So, my point was more: is it possible to register the bus notifier
as early as inside an early_initcall() callback.
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
On 10/24/2012 02:27 PM, Thomas Petazzoni wrote:
[...]
I will fixed the spelling and complete the comments as suggested
[...]
>> +struct dma_map_ops armada_xp_dma_ops;
>
> static
OK
>
>> +static inline void armada_xp_sync_io_barrier(void)
>> +{
>> +writel(0x1, coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET);
>> +while (readl(coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET) & 0x1);
>> +}
>> +
>> +dma_addr_t armada_xp_dma_map_page(struct device *dev, struct page *page,
>> + unsigned long offset, size_t size,
>> + enum dma_data_direction dir,
>> + struct dma_attrs *attrs)
>> +{
>> +if (dir != DMA_TO_DEVICE)
>> +armada_xp_sync_io_barrier();
>> +return pfn_to_dma(dev, page_to_pfn(page)) + offset;
>> +}
>> +
>> +
>> +void armada_xp_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
>> + size_t size, enum dma_data_direction dir,
>> + struct dma_attrs *attrs)
>> +{
>> +if (dir != DMA_TO_DEVICE)
>> +armada_xp_sync_io_barrier();
>> +}
>> +
>> +void armada_xp_dma_sync(struct device *dev, dma_addr_t dma_handle,
>> +size_t size, enum dma_data_direction dir)
>> +{
>> +if (dir != DMA_TO_DEVICE)
>> +armada_xp_sync_io_barrier();
>> +}
>
> As others said, the prefix is wrong. Since the file is named coherency,
> maybe just "coherency_" as the prefix? Not sure, though. Shouldn't the
> file be named coherency-armada-370-xp.c, as we have done for the irq
> controller file? In that case, the armada_370_xp prefix would make
> sense
I would prefer to just use coherency_ everywhere and keep the name of
the file as is. It made sense to suffix the irq file with
armada-370-xp because the other mvebu SoCs have their own irq
controller. Whereas, as far as I know the coherency unit is only
present in the Armada 370/XP.
>
>> int armada_xp_get_cpu_count(void)
>> {
>> int reg, cnt;
>
> static?
Which function?
armada_xp_get_cpu_count and armada_370_xp_set_cpu_coherent are exported
and moreover are not part of this patch set but the SMP one.
>
>> @@ -74,6 +115,42 @@ int armada_370_xp_set_cpu_coherent(unsigned int
>> hw_cpu_id, int smp_group_id)
>> return 0;
>> }
>>
>> +static int armada_xp_platform_notifier(struct notifier_block *nb,
>> + unsigned long event, void *__dev)
>> +{
>> +struct device *dev = __dev;
>> +
>> +if (event != BUS_NOTIFY_ADD_DEVICE)
>> +return NOTIFY_DONE;
>> +set_dma_ops(dev, &armada_xp_dma_ops);
>> +
>> +return NOTIFY_OK;
>> +}
>> +
>> +static struct notifier_block armada_xp_platform_nb = {
>> +.notifier_call = armada_xp_platform_notifier,
>> +};
>> +
>> +void __init armada_370_xp_coherency_iocache_init(void)
>> +{
>> +/* When the coherency fabric is available, the Armada XP and
>> + * Aramada 370 are close to a coherent architecture, so we based
>> + * our dma ops on the coherent one, and just changes the
>> + * operations which need a arch io sync */
>> +if (of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric")) {
>> +struct dma_map_ops *dma_ops = &armada_xp_dma_ops;
>> +memcpy(dma_ops, &arm_coherent_dma_ops, sizeof(*dma_ops));
>> +dma_ops->map_page = armada_xp_dma_map_page;
>> +dma_ops->unmap_page = armada_xp_dma_unmap_page;
>> +dma_ops->unmap_sg = arm_dma_ops.unmap_sg;
>> +dma_ops->sync_single_for_cpu = armada_xp_dma_sync;
>> +dma_ops->sync_single_for_device = armada_xp_dma_sync;
>> +dma_ops->sync_sg_for_cpu = arm_dma_ops.sync_sg_for_cpu;
>> +dma_ops->sync_sg_for_device = arm_dma_ops.sync_sg_for_device;
>> +}
>> +bus_register_notifier(&platform_bus_type, &armada_xp_platform_nb);
>
> As Arnd said, I would prefer a lot to have the armada_xp_dma_ops
> structure be initialized statically, even though it means that if the
> arm_coherent_dma_ops structure is changed, we'll have to update here as
> well. But I think it's cleaner.
>
> Also, the bus notifier should be registered only if we have the
> coherency fabric, otherwise it is anyway going to be called, setting
> invalid DMA operations for all the platform devices.
>
> So:
>
> static dma_map_ops armada_370_xp_dma_ops = {
> ...
> };
>
> void __init armada_370_xp_coherency_iocache_init(void)
> {
> if (! of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric"))
> return;
>
> bus_register_notifier(&platform_bus_type, &armada_370_xp_platform_nb);
> }
OK I agree
>
>> int __init armada_370_xp_coherency_init(void)
>> {
>> struct device_node *np;
>> @@ -82,7 +159,17 @@ int __init armada_370_xp_coherency_init(void)
>> if (np) {
>> pr_info("Initializing Coherency fabric\n");
>> coherency_base = of_iomap(np, 0);
>> +coherency
Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
On 10/24/2012 02:24 PM, Arnd Bergmann wrote:
> On Wednesday 24 October 2012, Gregory CLEMENT wrote:
>> On 10/24/2012 01:48 PM, Gregory CLEMENT wrote:
>>> On 10/24/2012 01:36 PM, Arnd Bergmann wrote:
I think it would be cleaner to statically define the operations in a
constant
structure and point directly to the functions you need. If necessary, use
multiple structures.
>>>
>>> My problem was that these functions are not exposed, only arm_dma_op and
>>> arm_coherent_dma_ops are exported.
>>> Or do you think about something like this:
>>
>> struct dma_map_ops *dma_ops = {
>> .alloc =
>> arm_coherent_dma_ops.arm_coherent_dma_alloc,
>> .free = arm_coherent_dma_ops.arm_coherent_dma_free,
>> .mmap = arm_coherent_dma_ops.arm_dma_mmap,
>> .get_sgtable= arm_coherent_dma_ops.arm_dma_get_sgtable,
>> .map_sg = arm_coherent_dma_ops.arm_dma_map_sg,
>> .set_dma_mask = arm_coherent_dma_ops.arm_dma_set_mask,
>> .map_page = armada_xp_dma_map_page,
>> .unmap_page = armada_xp_dma_unmap_page,
>> .unmap_sg = arm_dma_ops.unmap_sg,
>> .sync_single_for_cpu= armada_xp_dma_sync,
>> .sync_single_for_device = armada_xp_dma_sync,
>> .sync_sg_for_cpu= arm_dma_ops.sync_sg_for_cpu,
>> .sync_sg_for_device = arm_dma_ops.sync_sg_for_device,
>> };
>
> No, I was thinking of making the underlying functions globally visible
> and have extern declarations in a header file so you can access them
> directly.
>
> Generally speaking, when you run into a problem with common code, your
> first approach should be to fix the common code before you try to work
> around it.
OK I thought it was done on purpose. But if you consider it needs to be
fixed I will add patch for it in next version.
>
> Arnd
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
Hello,
On Wed, 24 Oct 2012 10:04:01 +0200, Gregory CLEMENT wrote:
> Armada 370 and XP come with an unit called coherency fabric. This unit
> allows to use the Armada XP as a nearly coherent architecture. The
the Armada 370/XP
> coherency mechanism uses snoop filters to ensure the coherency between
> caches, DRAM and devices. This mechanism needs a synchronization
> barrier which guarantees that all memory write initiated by the
write -> writes
> devices has reached their target and do not reside in intermediate
has -> have
> write buffers. That's why the architecture is not totally coherent and
> we need to provide our own functions for some DMA operations.
>
> Beside the use of the coherency fabric, the device units will have to
> set the attribute flag to select the accurate coherency process for
the attribute flag of what?
> the memory transaction. This is done each device driver programs the
> DRAM address windows. The value of the attribute set by the driver is
> retrieved through the orion_addr_map_cfg struct filled during the
> early initialization of the platform.
> diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi
> b/arch/arm/boot/dts/armada-370-xp.dtsi
> index 18ba60b..af22e53 100644
> --- a/arch/arm/boot/dts/armada-370-xp.dtsi
> +++ b/arch/arm/boot/dts/armada-370-xp.dtsi
> @@ -38,7 +38,8 @@
>
> coherency-fabric@d0020200 {
> compatible = "marvell,coherency-fabric";
> - reg = <0xd0020200 0xb0>;
> + reg = <0xd0020200 0xb0>,
> + <0xd0021010 0x1c>;
> };
As others mentioned, documentation update needed.
>
> soc {
> diff --git a/arch/arm/mach-mvebu/addr-map.c b/arch/arm/mach-mvebu/addr-map.c
> index fe454a4..595f6b7 100644
> --- a/arch/arm/mach-mvebu/addr-map.c
> +++ b/arch/arm/mach-mvebu/addr-map.c
> @@ -108,6 +108,9 @@ static int __init armada_setup_cpu_mbus(void)
>
> addr_map_cfg.bridge_virt_base = mbus_unit_addr_decoding_base;
>
> + if (of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric"))
> + addr_map_cfg.hw_io_coherency = 1;
> +
I don't really like to have this of_find_compatible_node(NULL, NULL,
"marvell,coherency-fabric") test in two places, but I don't see a way
around it since armada_setup_cpu_mbus() is called as an initcall, so we
can't pass arguments to it.
> +struct dma_map_ops armada_xp_dma_ops;
static
> +static inline void armada_xp_sync_io_barrier(void)
> +{
> + writel(0x1, coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET);
> + while (readl(coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET) & 0x1);
> +}
> +
> +dma_addr_t armada_xp_dma_map_page(struct device *dev, struct page *page,
> + unsigned long offset, size_t size,
> + enum dma_data_direction dir,
> + struct dma_attrs *attrs)
> +{
> + if (dir != DMA_TO_DEVICE)
> + armada_xp_sync_io_barrier();
> + return pfn_to_dma(dev, page_to_pfn(page)) + offset;
> +}
> +
> +
> +void armada_xp_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
> + size_t size, enum dma_data_direction dir,
> + struct dma_attrs *attrs)
> +{
> + if (dir != DMA_TO_DEVICE)
> + armada_xp_sync_io_barrier();
> +}
> +
> +void armada_xp_dma_sync(struct device *dev, dma_addr_t dma_handle,
> + size_t size, enum dma_data_direction dir)
> +{
> + if (dir != DMA_TO_DEVICE)
> + armada_xp_sync_io_barrier();
> +}
As others said, the prefix is wrong. Since the file is named coherency,
maybe just "coherency_" as the prefix? Not sure, though. Shouldn't the
file be named coherency-armada-370-xp.c, as we have done for the irq
controller file? In that case, the armada_370_xp prefix would make
sense.
> int armada_xp_get_cpu_count(void)
> {
> int reg, cnt;
static?
> @@ -74,6 +115,42 @@ int armada_370_xp_set_cpu_coherent(unsigned int
> hw_cpu_id, int smp_group_id)
> return 0;
> }
>
> +static int armada_xp_platform_notifier(struct notifier_block *nb,
> +unsigned long event, void *__dev)
> +{
> + struct device *dev = __dev;
> +
> + if (event != BUS_NOTIFY_ADD_DEVICE)
> + return NOTIFY_DONE;
> + set_dma_ops(dev, &armada_xp_dma_ops);
> +
> + return NOTIFY_OK;
> +}
> +
> +static struct notifier_block armada_xp_platform_nb = {
> + .notifier_call = armada_xp_platform_notifier,
> +};
> +
> +void __init armada_370_xp_coherency_iocache_init(void)
> +{
> + /* When the coherency fabric is available, the Armada XP and
> + * Aramada 370 are close to a coherent architecture, so we based
> + * our dma ops on the coherent one, and just changes the
> + * operations which need a arch io sync */
> + if (of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric")) {
> + struct dma_map_ops *dma_ops = &armada_xp_dma_ops;
> +
Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
On Wednesday 24 October 2012, Gregory CLEMENT wrote:
> On 10/24/2012 01:48 PM, Gregory CLEMENT wrote:
> > On 10/24/2012 01:36 PM, Arnd Bergmann wrote:
> >>
> >> I think it would be cleaner to statically define the operations in a
> >> constant
> >> structure and point directly to the functions you need. If necessary, use
> >> multiple structures.
> >
> > My problem was that these functions are not exposed, only arm_dma_op and
> > arm_coherent_dma_ops are exported.
> > Or do you think about something like this:
>
> struct dma_map_ops *dma_ops = {
> .alloc = arm_coherent_dma_ops.arm_coherent_dma_alloc,
> .free = arm_coherent_dma_ops.arm_coherent_dma_free,
> .mmap = arm_coherent_dma_ops.arm_dma_mmap,
> .get_sgtable= arm_coherent_dma_ops.arm_dma_get_sgtable,
> .map_sg = arm_coherent_dma_ops.arm_dma_map_sg,
> .set_dma_mask = arm_coherent_dma_ops.arm_dma_set_mask,
> .map_page = armada_xp_dma_map_page,
> .unmap_page = armada_xp_dma_unmap_page,
> .unmap_sg = arm_dma_ops.unmap_sg,
> .sync_single_for_cpu= armada_xp_dma_sync,
> .sync_single_for_device = armada_xp_dma_sync,
> .sync_sg_for_cpu= arm_dma_ops.sync_sg_for_cpu,
> .sync_sg_for_device = arm_dma_ops.sync_sg_for_device,
> };
No, I was thinking of making the underlying functions globally visible
and have extern declarations in a header file so you can access them
directly.
Generally speaking, when you run into a problem with common code, your
first approach should be to fix the common code before you try to work
around it.
Arnd
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Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
On 10/24/2012 01:48 PM, Gregory CLEMENT wrote:
> On 10/24/2012 01:36 PM, Arnd Bergmann wrote:
>> On Wednesday 24 October 2012, Gregory CLEMENT wrote:
>>> +void __init armada_370_xp_coherency_iocache_init(void)
>>> +{
>>> + /* When the coherency fabric is available, the Armada XP and
>>> +* Aramada 370 are close to a coherent architecture, so we based
>>> +* our dma ops on the coherent one, and just changes the
>>> +* operations which need a arch io sync */
>>> + if (of_find_compatible_node(NULL, NULL,
>>> "marvell,coherency-fabric")) {
>>> + struct dma_map_ops *dma_ops = &armada_xp_dma_ops;
>>> + memcpy(dma_ops, &arm_coherent_dma_ops, sizeof(*dma_ops));
>>> + dma_ops->map_page = armada_xp_dma_map_page;
>>> + dma_ops->unmap_page = armada_xp_dma_unmap_page;
>>> + dma_ops->unmap_sg = arm_dma_ops.unmap_sg;
>>> + dma_ops->sync_single_for_cpu = armada_xp_dma_sync;
>>> + dma_ops->sync_single_for_device = armada_xp_dma_sync;
>>> + dma_ops->sync_sg_for_cpu = arm_dma_ops.sync_sg_for_cpu;
>>> + dma_ops->sync_sg_for_device =
>>> arm_dma_ops.sync_sg_for_device;
>>> + }
>>> + bus_register_notifier(&platform_bus_type, &armada_xp_platform_nb);
>>
>> I think it would be cleaner to statically define the operations in a constant
>> structure and point directly to the functions you need. If necessary, use
>> multiple structures.
>
> My problem was that these functions are not exposed, only arm_dma_op and
> arm_coherent_dma_ops are exported.
> Or do you think about something like this:
>
> struct dma_map_ops *dma_ops = {
> .alloc = arm_dma_ops.arm_coherent_dma_alloc,
> .free = arm_dma_ops.arm_coherent_dma_free,
> .mmap = arm_dma_ops.arm_dma_mmap,
> .get_sgtable= arm_dma_ops.arm_dma_get_sgtable,
> .map_sg = arm_dma_ops.arm_dma_map_sg,
> .set_dma_mask = arm_dma_ops.arm_dma_set_mask,
> .map_page = armada_xp_dma_map_page,
> .unmap_page = armada_xp_dma_unmap_page,
> .unmap_sg = arm_dma_ops.unmap_sg,
> .sync_single_for_cpu= armada_xp_dma_sync,
> .sync_single_for_device = armada_xp_dma_sync,
> .sync_sg_for_cpu= arm_dma_ops.sync_sg_for_cpu,
> .sync_sg_for_device = arm_dma_ops.sync_sg_for_device,
> };
I was too fast to reply this struct is wrong, it should be as this one:
struct dma_map_ops *dma_ops = {
.alloc = arm_coherent_dma_ops.arm_coherent_dma_alloc,
.free = arm_coherent_dma_ops.arm_coherent_dma_free,
.mmap = arm_coherent_dma_ops.arm_dma_mmap,
.get_sgtable= arm_coherent_dma_ops.arm_dma_get_sgtable,
.map_sg = arm_coherent_dma_ops.arm_dma_map_sg,
.set_dma_mask = arm_coherent_dma_ops.arm_dma_set_mask,
.map_page = armada_xp_dma_map_page,
.unmap_page = armada_xp_dma_unmap_page,
.unmap_sg = arm_dma_ops.unmap_sg,
.sync_single_for_cpu= armada_xp_dma_sync,
.sync_single_for_device = armada_xp_dma_sync,
.sync_sg_for_cpu= arm_dma_ops.sync_sg_for_cpu,
.sync_sg_for_device = arm_dma_ops.sync_sg_for_device,
};
Thanks,
Gregory
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Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
On 10/24/2012 10:25 AM, Andrew Lunn wrote:
> On Wed, Oct 24, 2012 at 10:04:01AM +0200, Gregory CLEMENT wrote:
>> Armada 370 and XP come with an unit called coherency fabric. This unit
>> allows to use the Armada XP as a nearly coherent architecture. The
>> coherency mechanism uses snoop filters to ensure the coherency between
>> caches, DRAM and devices. This mechanism needs a synchronization
>> barrier which guarantees that all memory write initiated by the
>> devices has reached their target and do not reside in intermediate
>> write buffers. That's why the architecture is not totally coherent and
>> we need to provide our own functions for some DMA operations.
>>
>> Beside the use of the coherency fabric, the device units will have to
>> set the attribute flag to select the accurate coherency process for
>> the memory transaction. This is done each device driver programs the
>> DRAM address windows. The value of the attribute set by the driver is
>> retrieved through the orion_addr_map_cfg struct filled during the
>> early initialization of the platform.
>>
>> Signed-off-by: Gregory CLEMENT
>> Reviewed-by: Yehuda Yitschak
>> ---
>> arch/arm/boot/dts/armada-370-xp.dtsi |3 +-
>> arch/arm/mach-mvebu/addr-map.c |3 ++
>> arch/arm/mach-mvebu/armada-370-xp.c |1 +
>> arch/arm/mach-mvebu/coherency.c | 87
>> ++
>> arch/arm/mach-mvebu/common.h |2 +
>> 5 files changed, 95 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi
>> b/arch/arm/boot/dts/armada-370-xp.dtsi
>> index 18ba60b..af22e53 100644
>> --- a/arch/arm/boot/dts/armada-370-xp.dtsi
>> +++ b/arch/arm/boot/dts/armada-370-xp.dtsi
>> @@ -38,7 +38,8 @@
>>
>> coherency-fabric@d0020200 {
>> compatible = "marvell,coherency-fabric";
>> -reg = <0xd0020200 0xb0>;
>> +reg = <0xd0020200 0xb0>,
>> + <0xd0021010 0x1c>;
>> };
>
> ...
>
>> int __init armada_370_xp_coherency_init(void)
>> {
>> struct device_node *np;
>> @@ -82,7 +159,17 @@ int __init armada_370_xp_coherency_init(void)
>> if (np) {
>> pr_info("Initializing Coherency fabric\n");
>> coherency_base = of_iomap(np, 0);
>> +coherency_cpu_base = of_iomap(np, 1);
>
> Is this already in the binding documentation?
No indeed, the documentation should be completed. I will do it
the V2
>
>Thanks
> Andrew
>
> ___
> linux-arm-kernel mailing list
> linux-arm-ker...@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
On 10/24/2012 01:36 PM, Arnd Bergmann wrote:
> On Wednesday 24 October 2012, Gregory CLEMENT wrote:
>> +void __init armada_370_xp_coherency_iocache_init(void)
>> +{
>> + /* When the coherency fabric is available, the Armada XP and
>> +* Aramada 370 are close to a coherent architecture, so we based
>> +* our dma ops on the coherent one, and just changes the
>> +* operations which need a arch io sync */
>> + if (of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric"))
>> {
>> + struct dma_map_ops *dma_ops = &armada_xp_dma_ops;
>> + memcpy(dma_ops, &arm_coherent_dma_ops, sizeof(*dma_ops));
>> + dma_ops->map_page = armada_xp_dma_map_page;
>> + dma_ops->unmap_page = armada_xp_dma_unmap_page;
>> + dma_ops->unmap_sg = arm_dma_ops.unmap_sg;
>> + dma_ops->sync_single_for_cpu = armada_xp_dma_sync;
>> + dma_ops->sync_single_for_device = armada_xp_dma_sync;
>> + dma_ops->sync_sg_for_cpu = arm_dma_ops.sync_sg_for_cpu;
>> + dma_ops->sync_sg_for_device = arm_dma_ops.sync_sg_for_device;
>> + }
>> + bus_register_notifier(&platform_bus_type, &armada_xp_platform_nb);
>
> I think it would be cleaner to statically define the operations in a constant
> structure and point directly to the functions you need. If necessary, use
> multiple structures.
My problem was that these functions are not exposed, only arm_dma_op and
arm_coherent_dma_ops are exported.
Or do you think about something like this:
struct dma_map_ops *dma_ops = {
.alloc = arm_dma_ops.arm_coherent_dma_alloc,
.free = arm_dma_ops.arm_coherent_dma_free,
.mmap = arm_dma_ops.arm_dma_mmap,
.get_sgtable= arm_dma_ops.arm_dma_get_sgtable,
.map_sg = arm_dma_ops.arm_dma_map_sg,
.set_dma_mask = arm_dma_ops.arm_dma_set_mask,
.map_page = armada_xp_dma_map_page,
.unmap_page = armada_xp_dma_unmap_page,
.unmap_sg = arm_dma_ops.unmap_sg,
.sync_single_for_cpu= armada_xp_dma_sync,
.sync_single_for_device = armada_xp_dma_sync,
.sync_sg_for_cpu= arm_dma_ops.sync_sg_for_cpu,
.sync_sg_for_device = arm_dma_ops.sync_sg_for_device,
};
>
> Arnd
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
On Wednesday 24 October 2012, Gregory CLEMENT wrote:
> +void __init armada_370_xp_coherency_iocache_init(void)
> +{
> + /* When the coherency fabric is available, the Armada XP and
> +* Aramada 370 are close to a coherent architecture, so we based
> +* our dma ops on the coherent one, and just changes the
> +* operations which need a arch io sync */
> + if (of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric")) {
> + struct dma_map_ops *dma_ops = &armada_xp_dma_ops;
> + memcpy(dma_ops, &arm_coherent_dma_ops, sizeof(*dma_ops));
> + dma_ops->map_page = armada_xp_dma_map_page;
> + dma_ops->unmap_page = armada_xp_dma_unmap_page;
> + dma_ops->unmap_sg = arm_dma_ops.unmap_sg;
> + dma_ops->sync_single_for_cpu = armada_xp_dma_sync;
> + dma_ops->sync_single_for_device = armada_xp_dma_sync;
> + dma_ops->sync_sg_for_cpu = arm_dma_ops.sync_sg_for_cpu;
> + dma_ops->sync_sg_for_device = arm_dma_ops.sync_sg_for_device;
> + }
> + bus_register_notifier(&platform_bus_type, &armada_xp_platform_nb);
I think it would be cleaner to statically define the operations in a constant
structure and point directly to the functions you need. If necessary, use
multiple structures.
Arnd
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RE: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
> -Original Message-
> From: Gregory CLEMENT [mailto:gregory.clem...@free-electrons.com]
> Sent: Wednesday, October 24, 2012 10:04 AM
> To: Jason Cooper; Andrew Lunn; Gregory Clement
> Cc: linux-arm-ker...@lists.infradead.org; Arnd Bergmann; Olof Johansson;
> Russell King; Rob Herring; Ben Dooks; Ian Molton; Nicolas Pitre; Lior
> Amsalem; Maen Suleiman; Tawfik Bayouk; Shadi Ammouri; Eran Ben-Avi;
> Yehuda Yitschak; Nadav Haklai; Ike Pan; Jani Monoses; Chris Van Hoof; Dan
> Frazier; Thomas Petazzoni; Leif Lindholm; Jon Masters; David Marlin;
> Sebastian Hesselbarth; linux-kernel@vger.kernel.org
> Subject: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
>
> Armada 370 and XP come with an unit called coherency fabric. This unit
> allows to use the Armada XP as a nearly coherent architecture. The
> coherency mechanism uses snoop filters to ensure the coherency between
> caches, DRAM and devices. This mechanism needs a synchronization barrier
> which guarantees that all memory write initiated by the devices has
> reached their target and do not reside in intermediate write buffers. That's
> why the architecture is not totally coherent and we need to provide our
> own functions for some DMA operations.
>
> Beside the use of the coherency fabric, the device units will have to set the
> attribute flag to select the accurate coherency process for the memory
> transaction. This is done each device driver programs the DRAM address
> windows. The value of the attribute set by the driver is retrieved through
> the orion_addr_map_cfg struct filled during the early initialization of the
> platform.
>
> Signed-off-by: Gregory CLEMENT
> Reviewed-by: Yehuda Yitschak
> ---
> arch/arm/boot/dts/armada-370-xp.dtsi |3 +-
> arch/arm/mach-mvebu/addr-map.c |3 ++
> arch/arm/mach-mvebu/armada-370-xp.c |1 +
> arch/arm/mach-mvebu/coherency.c | 87
> ++
> arch/arm/mach-mvebu/common.h |2 +
> 5 files changed, 95 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi
> b/arch/arm/boot/dts/armada-370-xp.dtsi
> index 18ba60b..af22e53 100644
> --- a/arch/arm/boot/dts/armada-370-xp.dtsi
> +++ b/arch/arm/boot/dts/armada-370-xp.dtsi
> @@ -38,7 +38,8 @@
>
> coherency-fabric@d0020200 {
> compatible = "marvell,coherency-fabric";
> - reg = <0xd0020200 0xb0>;
> + reg = <0xd0020200 0xb0>,
> + <0xd0021010 0x1c>;
> };
>
> soc {
> diff --git a/arch/arm/mach-mvebu/addr-map.c b/arch/arm/mach-
> mvebu/addr-map.c index fe454a4..595f6b7 100644
> --- a/arch/arm/mach-mvebu/addr-map.c
> +++ b/arch/arm/mach-mvebu/addr-map.c
> @@ -108,6 +108,9 @@ static int __init armada_setup_cpu_mbus(void)
>
> addr_map_cfg.bridge_virt_base = mbus_unit_addr_decoding_base;
>
> + if (of_find_compatible_node(NULL, NULL, "marvell,coherency-
> fabric"))
> + addr_map_cfg.hw_io_coherency = 1;
> +
> /*
>* Disable, clear and configure windows.
>*/
> diff --git a/arch/arm/mach-mvebu/armada-370-xp.c b/arch/arm/mach-
> mvebu/armada-370-xp.c
> index 41431a1..3517f7d 100644
> --- a/arch/arm/mach-mvebu/armada-370-xp.c
> +++ b/arch/arm/mach-mvebu/armada-370-xp.c
> @@ -49,6 +49,7 @@ struct sys_timer armada_370_xp_timer = {
>
> static void __init armada_370_xp_dt_init(void) {
> + armada_370_xp_coherency_iocache_init();
> of_platform_populate(NULL, of_default_bus_match_table, NULL,
> NULL); }
>
> diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-
> mvebu/coherency.c index 71e27ba..a596ca9 100644
> --- a/arch/arm/mach-mvebu/coherency.c
> +++ b/arch/arm/mach-mvebu/coherency.c
> @@ -22,6 +22,10 @@
> #include
> #include
> #include
> +#include
> +#include
> +#include
> +
> #include "armada-370-xp.h"
>
> /* Some functions in this file are called very early during SMP @@ -31,16
> +35,53 @@
> * value matching its virtual mapping
> */
> static void __iomem *coherency_base = ARMADA_370_XP_REGS_VIRT_BASE
> + 0x20200;
> +static void __iomem *coherency_cpu_base;
> +
> +struct dma_map_ops armada_xp_dma_ops;
>
> /* Coherency fabric registers */
> #define COHERENCY_FABRIC_CTL_OFFSET 0x0
> #define COHERENCY_FABRIC_CFG_OFFSET 0x4
>
> +#define IO_SYNC_BARRIER_CTL_OFFSET 0x0
> +
> static struct of_device_id of_coherency_table[] = {
> {.compatible = "marvell,coherency-fabric"},
> { /* end of list */ },
> };
>
> +static inline void armada_xp_sync_io_barrier(voi
[PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
Armada 370 and XP come with an unit called coherency fabric. This unit
allows to use the Armada XP as a nearly coherent architecture. The
coherency mechanism uses snoop filters to ensure the coherency between
caches, DRAM and devices. This mechanism needs a synchronization
barrier which guarantees that all memory write initiated by the
devices has reached their target and do not reside in intermediate
write buffers. That's why the architecture is not totally coherent and
we need to provide our own functions for some DMA operations.
Beside the use of the coherency fabric, the device units will have to
set the attribute flag to select the accurate coherency process for
the memory transaction. This is done each device driver programs the
DRAM address windows. The value of the attribute set by the driver is
retrieved through the orion_addr_map_cfg struct filled during the
early initialization of the platform.
Signed-off-by: Gregory CLEMENT
Reviewed-by: Yehuda Yitschak
---
arch/arm/boot/dts/armada-370-xp.dtsi |3 +-
arch/arm/mach-mvebu/addr-map.c |3 ++
arch/arm/mach-mvebu/armada-370-xp.c |1 +
arch/arm/mach-mvebu/coherency.c | 87 ++
arch/arm/mach-mvebu/common.h |2 +
5 files changed, 95 insertions(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi
b/arch/arm/boot/dts/armada-370-xp.dtsi
index 18ba60b..af22e53 100644
--- a/arch/arm/boot/dts/armada-370-xp.dtsi
+++ b/arch/arm/boot/dts/armada-370-xp.dtsi
@@ -38,7 +38,8 @@
coherency-fabric@d0020200 {
compatible = "marvell,coherency-fabric";
- reg = <0xd0020200 0xb0>;
+ reg = <0xd0020200 0xb0>,
+ <0xd0021010 0x1c>;
};
soc {
diff --git a/arch/arm/mach-mvebu/addr-map.c b/arch/arm/mach-mvebu/addr-map.c
index fe454a4..595f6b7 100644
--- a/arch/arm/mach-mvebu/addr-map.c
+++ b/arch/arm/mach-mvebu/addr-map.c
@@ -108,6 +108,9 @@ static int __init armada_setup_cpu_mbus(void)
addr_map_cfg.bridge_virt_base = mbus_unit_addr_decoding_base;
+ if (of_find_compatible_node(NULL, NULL, "marvell,coherency-fabric"))
+ addr_map_cfg.hw_io_coherency = 1;
+
/*
* Disable, clear and configure windows.
*/
diff --git a/arch/arm/mach-mvebu/armada-370-xp.c
b/arch/arm/mach-mvebu/armada-370-xp.c
index 41431a1..3517f7d 100644
--- a/arch/arm/mach-mvebu/armada-370-xp.c
+++ b/arch/arm/mach-mvebu/armada-370-xp.c
@@ -49,6 +49,7 @@ struct sys_timer armada_370_xp_timer = {
static void __init armada_370_xp_dt_init(void)
{
+ armada_370_xp_coherency_iocache_init();
of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
}
diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
index 71e27ba..a596ca9 100644
--- a/arch/arm/mach-mvebu/coherency.c
+++ b/arch/arm/mach-mvebu/coherency.c
@@ -22,6 +22,10 @@
#include
#include
#include
+#include
+#include
+#include
+
#include "armada-370-xp.h"
/* Some functions in this file are called very early during SMP
@@ -31,16 +35,53 @@
* value matching its virtual mapping
*/
static void __iomem *coherency_base = ARMADA_370_XP_REGS_VIRT_BASE + 0x20200;
+static void __iomem *coherency_cpu_base;
+
+struct dma_map_ops armada_xp_dma_ops;
/* Coherency fabric registers */
#define COHERENCY_FABRIC_CTL_OFFSET 0x0
#define COHERENCY_FABRIC_CFG_OFFSET 0x4
+#define IO_SYNC_BARRIER_CTL_OFFSET0x0
+
static struct of_device_id of_coherency_table[] = {
{.compatible = "marvell,coherency-fabric"},
{ /* end of list */ },
};
+static inline void armada_xp_sync_io_barrier(void)
+{
+ writel(0x1, coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET);
+ while (readl(coherency_cpu_base + IO_SYNC_BARRIER_CTL_OFFSET) & 0x1);
+}
+
+dma_addr_t armada_xp_dma_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ if (dir != DMA_TO_DEVICE)
+ armada_xp_sync_io_barrier();
+ return pfn_to_dma(dev, page_to_pfn(page)) + offset;
+}
+
+
+void armada_xp_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ if (dir != DMA_TO_DEVICE)
+ armada_xp_sync_io_barrier();
+}
+
+void armada_xp_dma_sync(struct device *dev, dma_addr_t dma_handle,
+ size_t size, enum dma_data_direction dir)
+{
+ if (dir != DMA_TO_DEVICE)
+ armada_xp_sync_io_barrier();
+}
+
int armada_xp_get_cpu_count(void)
{
int reg, cnt;
@@ -74,6 +115,42 @@ int armada_370_xp_set_cpu_coherent(unsigned int hw_cpu_id,
int smp_group_id)
return 0;
}
+stat
