* [PATCH kernel] powerps/pseries/dma: Add support for 2M IOMMU page size
@ 2021-09-28 10:15 Alexey Kardashevskiy
2021-09-28 17:35 ` Leonardo Brás
2021-09-29 7:00 ` Frederic Barrat
0 siblings, 2 replies; 3+ messages in thread
From: Alexey Kardashevskiy @ 2021-09-28 10:15 UTC (permalink / raw)
To: linuxppc-dev
Cc: Leonardo Bras, Brian J King, Alexey Kardashevskiy, Travis Pizel,
Frederic Barrat, Leonardo Augusto Guimaraes Garcia,
Murilo Vicentini
The upcoming PAPR spec adds a 2M page size, bit 23 right after the 16G page
size in the "ibm,query-pe-dma-window" call.
This adds support for the new page size. Since the new page size is out
of sorted order, this changes the loop to not assume that shift[] is
sorted.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
This might not work if PHYP keeps rejecting new window requests for less
than 32768 TCEs. This is needed:
https://github.com/aik/linux/commit/8cc8fa5ba5b3b4a18efbc9d81d9e5b85ca7c8a95
---
arch/powerpc/platforms/pseries/iommu.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index c741689a5165..237bf405b0cb 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1159,14 +1159,15 @@ static void reset_dma_window(struct pci_dev *dev, struct device_node *par_dn)
/* Return largest page shift based on "IO Page Sizes" output of ibm,query-pe-dma-window. */
static int iommu_get_page_shift(u32 query_page_size)
{
- /* Supported IO page-sizes according to LoPAR */
+ /* Supported IO page-sizes according to LoPAR, note that 2M is out of order */
const int shift[] = {
__builtin_ctzll(SZ_4K), __builtin_ctzll(SZ_64K), __builtin_ctzll(SZ_16M),
__builtin_ctzll(SZ_32M), __builtin_ctzll(SZ_64M), __builtin_ctzll(SZ_128M),
- __builtin_ctzll(SZ_256M), __builtin_ctzll(SZ_16G)
+ __builtin_ctzll(SZ_256M), __builtin_ctzll(SZ_16G), __builtin_ctzll(SZ_2M)
};
int i = ARRAY_SIZE(shift) - 1;
+ int ret = 0;
/*
* On LoPAR, ibm,query-pe-dma-window outputs "IO Page Sizes" using a bit field:
@@ -1176,11 +1177,10 @@ static int iommu_get_page_shift(u32 query_page_size)
*/
for (; i >= 0 ; i--) {
if (query_page_size & (1 << i))
- return shift[i];
+ ret = max(ret, shift[i]);
}
- /* No valid page size found. */
- return 0;
+ return ret;
}
static struct property *ddw_property_create(const char *propname, u32 liobn, u64 dma_addr,
--
2.30.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH kernel] powerps/pseries/dma: Add support for 2M IOMMU page size
2021-09-28 10:15 [PATCH kernel] powerps/pseries/dma: Add support for 2M IOMMU page size Alexey Kardashevskiy
@ 2021-09-28 17:35 ` Leonardo Brás
2021-09-29 7:00 ` Frederic Barrat
1 sibling, 0 replies; 3+ messages in thread
From: Leonardo Brás @ 2021-09-28 17:35 UTC (permalink / raw)
To: Alexey Kardashevskiy, linuxppc-dev
Cc: Frederic Barrat, Murilo Vicentini, Travis Pizel,
Leonardo Augusto Guimaraes Garcia, Brian J King
Hello Alexey,
On Tue, 2021-09-28 at 20:15 +1000, Alexey Kardashevskiy wrote:
> The upcoming PAPR spec adds a 2M page size, bit 23 right after the 16G
> page
> size in the "ibm,query-pe-dma-window" call.
>
> This adds support for the new page size. Since the new page size is out
> of sorted order, this changes the loop to not assume that shift[] is
> sorted.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
>
> This might not work if PHYP keeps rejecting new window requests for
> less
> than 32768 TCEs. This is needed:
> https://github.com/aik/linux/commit/8cc8fa5ba5b3b4a18efbc9d81d9e5b85ca7c8a95
>
>
> ---
> arch/powerpc/platforms/pseries/iommu.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/iommu.c
> b/arch/powerpc/platforms/pseries/iommu.c
> index c741689a5165..237bf405b0cb 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -1159,14 +1159,15 @@ static void reset_dma_window(struct pci_dev
> *dev, struct device_node *par_dn)
> /* Return largest page shift based on "IO Page Sizes" output of
> ibm,query-pe-dma-window. */
> static int iommu_get_page_shift(u32 query_page_size)
> {
> - /* Supported IO page-sizes according to LoPAR */
> + /* Supported IO page-sizes according to LoPAR, note that 2M is
> out of order */
> const int shift[] = {
> __builtin_ctzll(SZ_4K), __builtin_ctzll(SZ_64K),
> __builtin_ctzll(SZ_16M),
> __builtin_ctzll(SZ_32M), __builtin_ctzll(SZ_64M),
> __builtin_ctzll(SZ_128M),
> - __builtin_ctzll(SZ_256M), __builtin_ctzll(SZ_16G)
> + __builtin_ctzll(SZ_256M), __builtin_ctzll(SZ_16G),
> __builtin_ctzll(SZ_2M)
> };
>
> int i = ARRAY_SIZE(shift) - 1;
> + int ret = 0;
>
> /*
> * On LoPAR, ibm,query-pe-dma-window outputs "IO Page Sizes"
> using a bit field:
> @@ -1176,11 +1177,10 @@ static int iommu_get_page_shift(u32
> query_page_size)
> */
> for (; i >= 0 ; i--) {
> if (query_page_size & (1 << i))
> - return shift[i];
> + ret = max(ret, shift[i]);
> }
>
> - /* No valid page size found. */
> - return 0;
> + return ret;
> }
>
> static struct property *ddw_property_create(const char *propname, u32
> liobn, u64 dma_addr,
Looks great to me.
FWIW:
Reviewed-by: Leonardo Bras <leobras.c@gmail.com>
Best regards,
Leonardo
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH kernel] powerps/pseries/dma: Add support for 2M IOMMU page size
2021-09-28 10:15 [PATCH kernel] powerps/pseries/dma: Add support for 2M IOMMU page size Alexey Kardashevskiy
2021-09-28 17:35 ` Leonardo Brás
@ 2021-09-29 7:00 ` Frederic Barrat
1 sibling, 0 replies; 3+ messages in thread
From: Frederic Barrat @ 2021-09-29 7:00 UTC (permalink / raw)
To: Alexey Kardashevskiy, linuxppc-dev
Cc: Leonardo Augusto Guimaraes Garcia, Leonardo Bras, Travis Pizel,
Brian J King, Murilo Vicentini
On 28/09/2021 12:15, Alexey Kardashevskiy wrote:
> The upcoming PAPR spec adds a 2M page size, bit 23 right after the 16G page
> size in the "ibm,query-pe-dma-window" call.
>
> This adds support for the new page size. Since the new page size is out
> of sorted order, this changes the loop to not assume that shift[] is
> sorted.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
Looks ok to me
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
>
> This might not work if PHYP keeps rejecting new window requests for less
> than 32768 TCEs. This is needed:
> https://github.com/aik/linux/commit/8cc8fa5ba5b3b4a18efbc9d81d9e5b85ca7c8a95
>
>
> ---
> arch/powerpc/platforms/pseries/iommu.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
> index c741689a5165..237bf405b0cb 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -1159,14 +1159,15 @@ static void reset_dma_window(struct pci_dev *dev, struct device_node *par_dn)
> /* Return largest page shift based on "IO Page Sizes" output of ibm,query-pe-dma-window. */
> static int iommu_get_page_shift(u32 query_page_size)
> {
> - /* Supported IO page-sizes according to LoPAR */
> + /* Supported IO page-sizes according to LoPAR, note that 2M is out of order */
> const int shift[] = {
> __builtin_ctzll(SZ_4K), __builtin_ctzll(SZ_64K), __builtin_ctzll(SZ_16M),
> __builtin_ctzll(SZ_32M), __builtin_ctzll(SZ_64M), __builtin_ctzll(SZ_128M),
> - __builtin_ctzll(SZ_256M), __builtin_ctzll(SZ_16G)
> + __builtin_ctzll(SZ_256M), __builtin_ctzll(SZ_16G), __builtin_ctzll(SZ_2M)
> };
>
> int i = ARRAY_SIZE(shift) - 1;
> + int ret = 0;
>
> /*
> * On LoPAR, ibm,query-pe-dma-window outputs "IO Page Sizes" using a bit field:
> @@ -1176,11 +1177,10 @@ static int iommu_get_page_shift(u32 query_page_size)
> */
> for (; i >= 0 ; i--) {
> if (query_page_size & (1 << i))
> - return shift[i];
> + ret = max(ret, shift[i]);
> }
>
> - /* No valid page size found. */
> - return 0;
> + return ret;
> }
>
> static struct property *ddw_property_create(const char *propname, u32 liobn, u64 dma_addr,
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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