On 24/06/2020 16:24, Leonardo Bras wrote:
> As of today, if a DDW is created and can't map the whole partition, it's
> removed and the default DMA window "ibm,dma-window" is used instead.
>
> Usually this DDW is bigger than the default DMA window, so it would be
> better to make use of it instead.
>
> Signed-off-by: Leonardo Bras <leobra...@gmail.com>
> ---
> arch/powerpc/platforms/pseries/iommu.c | 28 +++++++++++++++++---------
> 1 file changed, 19 insertions(+), 9 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/iommu.c
> b/arch/powerpc/platforms/pseries/iommu.c
> index 4fcf00016fb1..2d217cda4075 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -685,7 +685,7 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus
> *bus)
> struct iommu_table *tbl;
> struct device_node *dn, *pdn;
> struct pci_dn *ppci;
> - const __be32 *dma_window = NULL;
> + const __be32 *dma_window = NULL, *alt_dma_window = NULL;
>
> dn = pci_bus_to_OF_node(bus);
>
> @@ -699,8 +699,13 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus
> *bus)
> break;
> }
>
> + /* If there is a DDW available, use it instead */
> + alt_dma_window = of_get_property(pdn, DIRECT64_PROPNAME, NULL);
It is not necessarily "direct" anymore as the name suggests, you may
want to change that. DMA64_PROPNAME, may be. Thanks,
> + if (alt_dma_window)
> + dma_window = alt_dma_window;
> +
> if (dma_window == NULL) {
> - pr_debug(" no ibm,dma-window property !\n");
> + pr_debug(" no ibm,dma-window nor
> linux,direct64-ddr-window-info property !\n");
> return;
> }
>
> @@ -1166,16 +1171,19 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> device_node *pdn)
> query.page_size);
> goto out_failed;
> }
> +
> /* verify the window * number of ptes will map the partition */
> - /* check largest block * page size > max memory hotplug addr */
> max_addr = ddw_memory_hotplug_max();
> if (query.largest_available_block < (max_addr >> page_shift)) {
> - dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu "
> - "%llu-sized pages\n", max_addr,
> query.largest_available_block,
> - 1ULL << page_shift);
> - goto out_failed;
> + dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu
> %llu-sized pages\n",
> + max_addr, query.largest_available_block,
> + 1ULL << page_shift);
> +
> + len = order_base_2(query.largest_available_block << page_shift);
> + } else {
> + len = order_base_2(max_addr);
> }
> - len = order_base_2(max_addr);
> +
> win64 = kzalloc(sizeof(struct property), GFP_KERNEL);
> if (!win64) {
> dev_info(&dev->dev,
> @@ -1229,7 +1237,9 @@ static u64 enable_ddw(struct pci_dev *dev, struct
> device_node *pdn)
> list_add(&window->list, &direct_window_list);
> spin_unlock(&direct_window_list_lock);
>
> - dma_addr = be64_to_cpu(ddwprop->dma_base);
> + /* Only returns the dma_addr if DDW maps the whole partition */
> + if (len == order_base_2(max_addr))
> + dma_addr = be64_to_cpu(ddwprop->dma_base);
> goto out_unlock;
>
> out_free_window:
>
--
Alexey
