| Message ID | 20210923115840.17813-10-yong.wu@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | MT8195 IOMMU SUPPORT | expand |
Il 23/09/21 13:58, Yong Wu ha scritto: > The tlb_sync_all is called from these three functions: > a) flush_iotlb_all: it will be called for each a iommu HW. > b) tlb_flush_range_sync: it already has for_each_m4u. > c) in irq: When IOMMU HW translation fault, Only need flush itself. > > Thus, No need for_each_m4u in this tlb_sync_all. Remove it. > > Signed-off-by: Yong Wu <yong.wu@mediatek.com> > --- > drivers/iommu/mtk_iommu.c | 18 +++++++----------- > 1 file changed, 7 insertions(+), 11 deletions(-) > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > index 6f4f6624e3ac..0b4c30baa864 100644 > --- a/drivers/iommu/mtk_iommu.c > +++ b/drivers/iommu/mtk_iommu.c > @@ -206,19 +206,15 @@ static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom) > > static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data) > { > - struct list_head *head = data->hw_list; > - > - for_each_m4u(data, head) { > - if (pm_runtime_get_if_in_use(data->dev) <= 0) > - continue; > + if (pm_runtime_get_if_in_use(data->dev) <= 0) > + return; > > - writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, > - data->base + data->plat_data->inv_sel_reg); > - writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE); > - wmb(); /* Make sure the tlb flush all done */ > + writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, > + data->base + data->plat_data->inv_sel_reg); > + writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE); > + wmb(); /* Make sure the tlb flush all done */ There aren't a lot of writes here - not anymore, since you are no longer doing this for_each_m4u()... ...so, please change writel_relaxed() to writel() calls, allowing you to also remove the write barrier at the end (since in the non relaxed version, order is already ensured). > > - pm_runtime_put(data->dev); > - } > + pm_runtime_put(data->dev); > } > > static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size, >
On Tue, 2022-01-04 at 16:55 +0100, AngeloGioacchino Del Regno wrote: > Il 23/09/21 13:58, Yong Wu ha scritto: > > The tlb_sync_all is called from these three functions: > > a) flush_iotlb_all: it will be called for each a iommu HW. > > b) tlb_flush_range_sync: it already has for_each_m4u. > > c) in irq: When IOMMU HW translation fault, Only need flush itself. > > > > Thus, No need for_each_m4u in this tlb_sync_all. Remove it. > > > > Signed-off-by: Yong Wu <yong.wu@mediatek.com> > > --- > > drivers/iommu/mtk_iommu.c | 18 +++++++----------- > > 1 file changed, 7 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > > index 6f4f6624e3ac..0b4c30baa864 100644 > > --- a/drivers/iommu/mtk_iommu.c > > +++ b/drivers/iommu/mtk_iommu.c > > @@ -206,19 +206,15 @@ static struct mtk_iommu_domain > > *to_mtk_domain(struct iommu_domain *dom) > > > > static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data) > > { > > - struct list_head *head = data->hw_list; > > - > > - for_each_m4u(data, head) { > > - if (pm_runtime_get_if_in_use(data->dev) <= 0) > > - continue; > > + if (pm_runtime_get_if_in_use(data->dev) <= 0) > > + return; > > > > - writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, > > - data->base + data->plat_data- > > >inv_sel_reg); > > - writel_relaxed(F_ALL_INVLD, data->base + > > REG_MMU_INVALIDATE); > > - wmb(); /* Make sure the tlb flush all done */ > > + writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, > > + data->base + data->plat_data->inv_sel_reg); > > + writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE); > > + wmb(); /* Make sure the tlb flush all done */ > > There aren't a lot of writes here - not anymore, since you are no > longer doing > this for_each_m4u()... > ...so, please change writel_relaxed() to writel() calls, allowing you > to also > remove the write barrier at the end (since in the non relaxed > version, order is already ensured). In the "writel", the "__iowmb()" runs before "write_relaxed". Then how to guarantee the last register was wrote into the HW. Here the flush all don't have sync(waiting it complete) > > > > > - pm_runtime_put(data->dev); > > - } > > + pm_runtime_put(data->dev); > > } > > > > static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, > > size_t size, > >
Il 09/01/22 03:48, Yong Wu ha scritto: > On Tue, 2022-01-04 at 16:55 +0100, AngeloGioacchino Del Regno wrote: >> Il 23/09/21 13:58, Yong Wu ha scritto: >>> The tlb_sync_all is called from these three functions: >>> a) flush_iotlb_all: it will be called for each a iommu HW. >>> b) tlb_flush_range_sync: it already has for_each_m4u. >>> c) in irq: When IOMMU HW translation fault, Only need flush itself. >>> >>> Thus, No need for_each_m4u in this tlb_sync_all. Remove it. >>> >>> Signed-off-by: Yong Wu <yong.wu@mediatek.com> >>> --- >>> drivers/iommu/mtk_iommu.c | 18 +++++++----------- >>> 1 file changed, 7 insertions(+), 11 deletions(-) >>> >>> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c >>> index 6f4f6624e3ac..0b4c30baa864 100644 >>> --- a/drivers/iommu/mtk_iommu.c >>> +++ b/drivers/iommu/mtk_iommu.c >>> @@ -206,19 +206,15 @@ static struct mtk_iommu_domain >>> *to_mtk_domain(struct iommu_domain *dom) >>> >>> static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data) >>> { >>> - struct list_head *head = data->hw_list; >>> - >>> - for_each_m4u(data, head) { >>> - if (pm_runtime_get_if_in_use(data->dev) <= 0) >>> - continue; >>> + if (pm_runtime_get_if_in_use(data->dev) <= 0) >>> + return; >>> >>> - writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, >>> - data->base + data->plat_data- >>>> inv_sel_reg); >>> - writel_relaxed(F_ALL_INVLD, data->base + >>> REG_MMU_INVALIDATE); >>> - wmb(); /* Make sure the tlb flush all done */ >>> + writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, >>> + data->base + data->plat_data->inv_sel_reg); >>> + writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE); >>> + wmb(); /* Make sure the tlb flush all done */ >> >> There aren't a lot of writes here - not anymore, since you are no >> longer doing >> this for_each_m4u()... >> ...so, please change writel_relaxed() to writel() calls, allowing you >> to also >> remove the write barrier at the end (since in the non relaxed >> version, order is already ensured). > > In the "writel", the "__iowmb()" runs before "write_relaxed". Then how > to guarantee the last register was wrote into the HW. Here the flush > all don't have sync(waiting it complete) > That's right, I'm sorry for the invalid proposal. Though, there's something else to mention here... if writing (F_INVLD_EN1 | F_INVLD_EN0) to inv_sel_reg is *required* to happen before writing F_ALL_INVLD to REG_MMU_INVALIDATE (which I think is exactly the case here), then, in order to ensure write ordering, you should still use writel() instead of the relaxed accessor; after which, since (as you mentioned) there is no sync readback loop, you can keep that wmb() at the end. >> >>> >>> - pm_runtime_put(data->dev); >>> - } >>> + pm_runtime_put(data->dev); >>> } >>> >>> static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, >>> size_t size, >>> >
On Mon, 2022-01-10 at 10:16 +0100, AngeloGioacchino Del Regno wrote: > Il 09/01/22 03:48, Yong Wu ha scritto: > > On Tue, 2022-01-04 at 16:55 +0100, AngeloGioacchino Del Regno > > wrote: > > > Il 23/09/21 13:58, Yong Wu ha scritto: > > > > The tlb_sync_all is called from these three functions: > > > > a) flush_iotlb_all: it will be called for each a iommu HW. > > > > b) tlb_flush_range_sync: it already has for_each_m4u. > > > > c) in irq: When IOMMU HW translation fault, Only need flush > > > > itself. > > > > > > > > Thus, No need for_each_m4u in this tlb_sync_all. Remove it. > > > > > > > > Signed-off-by: Yong Wu <yong.wu@mediatek.com> > > > > --- > > > > drivers/iommu/mtk_iommu.c | 18 +++++++----------- > > > > 1 file changed, 7 insertions(+), 11 deletions(-) > > > > > > > > diff --git a/drivers/iommu/mtk_iommu.c > > > > b/drivers/iommu/mtk_iommu.c > > > > index 6f4f6624e3ac..0b4c30baa864 100644 > > > > --- a/drivers/iommu/mtk_iommu.c > > > > +++ b/drivers/iommu/mtk_iommu.c > > > > @@ -206,19 +206,15 @@ static struct mtk_iommu_domain > > > > *to_mtk_domain(struct iommu_domain *dom) > > > > > > > > static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data > > > > *data) > > > > { > > > > - struct list_head *head = data->hw_list; > > > > - > > > > - for_each_m4u(data, head) { > > > > - if (pm_runtime_get_if_in_use(data->dev) <= 0) > > > > - continue; > > > > + if (pm_runtime_get_if_in_use(data->dev) <= 0) > > > > + return; > > > > > > > > - writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, > > > > - data->base + data->plat_data- > > > > > inv_sel_reg); > > > > > > > > - writel_relaxed(F_ALL_INVLD, data->base + > > > > REG_MMU_INVALIDATE); > > > > - wmb(); /* Make sure the tlb flush all done */ > > > > + writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, > > > > + data->base + data->plat_data- > > > > >inv_sel_reg); > > > > + writel_relaxed(F_ALL_INVLD, data->base + > > > > REG_MMU_INVALIDATE); > > > > + wmb(); /* Make sure the tlb flush all done */ > > > > > > There aren't a lot of writes here - not anymore, since you are no > > > longer doing > > > this for_each_m4u()... > > > ...so, please change writel_relaxed() to writel() calls, allowing > > > you > > > to also > > > remove the write barrier at the end (since in the non relaxed > > > version, order is already ensured). > > > > In the "writel", the "__iowmb()" runs before "write_relaxed". Then > > how > > to guarantee the last register was wrote into the HW. Here the > > flush > > all don't have sync(waiting it complete) > > > > That's right, I'm sorry for the invalid proposal. > > Though, there's something else to mention here... if writing > (F_INVLD_EN1 | F_INVLD_EN0) to inv_sel_reg is *required* to happen > before > writing F_ALL_INVLD to REG_MMU_INVALIDATE (which I think is exactly > the > case here), then, in order to ensure write ordering, you should still > use > writel() instead of the relaxed accessor; after which, since (as you > mentioned) > there is no sync readback loop, you can keep that wmb() at the end. The writel_relaxed also makes sure the order. I did try this: https://patchwork.kernel.org/project/linux-mediatek/patch/1570627143-29441-3-git-send-email-yong.wu@mediatek.com/ > > > > > > > > > > > > - pm_runtime_put(data->dev); > > > > - } > > > > + pm_runtime_put(data->dev); > > > > } > > > > > > > > static void mtk_iommu_tlb_flush_range_sync(unsigned long > > > > iova, > > > > size_t size, > > > > > >
Il 10/01/22 11:59, Yong Wu ha scritto: > On Mon, 2022-01-10 at 10:16 +0100, AngeloGioacchino Del Regno wrote: >> Il 09/01/22 03:48, Yong Wu ha scritto: >>> On Tue, 2022-01-04 at 16:55 +0100, AngeloGioacchino Del Regno >>> wrote: >>>> Il 23/09/21 13:58, Yong Wu ha scritto: >>>>> The tlb_sync_all is called from these three functions: >>>>> a) flush_iotlb_all: it will be called for each a iommu HW. >>>>> b) tlb_flush_range_sync: it already has for_each_m4u. >>>>> c) in irq: When IOMMU HW translation fault, Only need flush >>>>> itself. >>>>> >>>>> Thus, No need for_each_m4u in this tlb_sync_all. Remove it. >>>>> >>>>> Signed-off-by: Yong Wu <yong.wu@mediatek.com> >>>>> --- >>>>> drivers/iommu/mtk_iommu.c | 18 +++++++----------- >>>>> 1 file changed, 7 insertions(+), 11 deletions(-) >>>>> >>>>> diff --git a/drivers/iommu/mtk_iommu.c >>>>> b/drivers/iommu/mtk_iommu.c >>>>> index 6f4f6624e3ac..0b4c30baa864 100644 >>>>> --- a/drivers/iommu/mtk_iommu.c >>>>> +++ b/drivers/iommu/mtk_iommu.c >>>>> @@ -206,19 +206,15 @@ static struct mtk_iommu_domain >>>>> *to_mtk_domain(struct iommu_domain *dom) >>>>> >>>>> static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data >>>>> *data) >>>>> { >>>>> - struct list_head *head = data->hw_list; >>>>> - >>>>> - for_each_m4u(data, head) { >>>>> - if (pm_runtime_get_if_in_use(data->dev) <= 0) >>>>> - continue; >>>>> + if (pm_runtime_get_if_in_use(data->dev) <= 0) >>>>> + return; >>>>> >>>>> - writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, >>>>> - data->base + data->plat_data- >>>>>> inv_sel_reg); >>>>> >>>>> - writel_relaxed(F_ALL_INVLD, data->base + >>>>> REG_MMU_INVALIDATE); >>>>> - wmb(); /* Make sure the tlb flush all done */ >>>>> + writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, >>>>> + data->base + data->plat_data- >>>>>> inv_sel_reg); >>>>> + writel_relaxed(F_ALL_INVLD, data->base + >>>>> REG_MMU_INVALIDATE); >>>>> + wmb(); /* Make sure the tlb flush all done */ >>>> >>>> There aren't a lot of writes here - not anymore, since you are no >>>> longer doing >>>> this for_each_m4u()... >>>> ...so, please change writel_relaxed() to writel() calls, allowing >>>> you >>>> to also >>>> remove the write barrier at the end (since in the non relaxed >>>> version, order is already ensured). >>> >>> In the "writel", the "__iowmb()" runs before "write_relaxed". Then >>> how >>> to guarantee the last register was wrote into the HW. Here the >>> flush >>> all don't have sync(waiting it complete) >>> >> >> That's right, I'm sorry for the invalid proposal. >> >> Though, there's something else to mention here... if writing >> (F_INVLD_EN1 | F_INVLD_EN0) to inv_sel_reg is *required* to happen >> before >> writing F_ALL_INVLD to REG_MMU_INVALIDATE (which I think is exactly >> the >> case here), then, in order to ensure write ordering, you should still >> use >> writel() instead of the relaxed accessor; after which, since (as you >> mentioned) >> there is no sync readback loop, you can keep that wmb() at the end. > > The writel_relaxed also makes sure the order. I did try this: > > > https://patchwork.kernel.org/project/linux-mediatek/patch/1570627143-29441-3-git-send-email-yong.wu@mediatek.com/ > Ok, that's fair. Means that this patch is fine as it is. I'll release by R-b on Dafna's patch, as suggested. Thank you, - Angelo
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 6f4f6624e3ac..0b4c30baa864 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -206,19 +206,15 @@ static struct mtk_iommu_domain *to_mtk_domain(struct iommu_domain *dom) static void mtk_iommu_tlb_flush_all(struct mtk_iommu_data *data) { - struct list_head *head = data->hw_list; - - for_each_m4u(data, head) { - if (pm_runtime_get_if_in_use(data->dev) <= 0) - continue; + if (pm_runtime_get_if_in_use(data->dev) <= 0) + return; - writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, - data->base + data->plat_data->inv_sel_reg); - writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE); - wmb(); /* Make sure the tlb flush all done */ + writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, + data->base + data->plat_data->inv_sel_reg); + writel_relaxed(F_ALL_INVLD, data->base + REG_MMU_INVALIDATE); + wmb(); /* Make sure the tlb flush all done */ - pm_runtime_put(data->dev); - } + pm_runtime_put(data->dev); } static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
The tlb_sync_all is called from these three functions: a) flush_iotlb_all: it will be called for each a iommu HW. b) tlb_flush_range_sync: it already has for_each_m4u. c) in irq: When IOMMU HW translation fault, Only need flush itself. Thus, No need for_each_m4u in this tlb_sync_all. Remove it. Signed-off-by: Yong Wu <yong.wu@mediatek.com> --- drivers/iommu/mtk_iommu.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-)