diff options
| -rw-r--r-- | arch/powerpc/platforms/pseries/iommu.c | 73 |
1 files changed, 66 insertions, 7 deletions
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index 4e33147825cc..e4198700ed1a 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -1067,6 +1067,38 @@ static phys_addr_t ddw_memory_hotplug_max(void) } /* + * Platforms supporting the DDW option starting with LoPAR level 2.7 implement + * ibm,ddw-extensions, which carries the rtas token for + * ibm,reset-pe-dma-windows. + * That rtas-call can be used to restore the default DMA window for the device. + */ +static void reset_dma_window(struct pci_dev *dev, struct device_node *par_dn) +{ + int ret; + u32 cfg_addr, reset_dma_win; + u64 buid; + struct device_node *dn; + struct pci_dn *pdn; + + ret = ddw_read_ext(par_dn, DDW_EXT_RESET_DMA_WIN, &reset_dma_win); + if (ret) + return; + + dn = pci_device_to_OF_node(dev); + pdn = PCI_DN(dn); + buid = pdn->phb->buid; + cfg_addr = (pdn->busno << 16) | (pdn->devfn << 8); + + ret = rtas_call(reset_dma_win, 3, 1, NULL, cfg_addr, BUID_HI(buid), + BUID_LO(buid)); + if (ret) + dev_info(&dev->dev, + "ibm,reset-pe-dma-windows(%x) %x %x %x returned %d ", + reset_dma_win, cfg_addr, BUID_HI(buid), BUID_LO(buid), + ret); +} + +/* * If the PE supports dynamic dma windows, and there is space for a table * that can map all pages in a linear offset, then setup such a table, * and record the dma-offset in the struct device. @@ -1090,6 +1122,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) struct property *win64; struct dynamic_dma_window_prop *ddwprop; struct failed_ddw_pdn *fpdn; + bool default_win_removed = false; mutex_lock(&direct_window_init_mutex); @@ -1133,14 +1166,38 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) if (ret != 0) goto out_failed; + /* + * If there is no window available, remove the default DMA window, + * if it's present. This will make all the resources available to the + * new DDW window. + * If anything fails after this, we need to restore it, so also check + * for extensions presence. + */ if (query.windows_available == 0) { - /* - * no additional windows are available for this device. - * We might be able to reallocate the existing window, - * trading in for a larger page size. - */ - dev_dbg(&dev->dev, "no free dynamic windows"); - goto out_failed; + struct property *default_win; + int reset_win_ext; + + default_win = of_find_property(pdn, "ibm,dma-window", NULL); + if (!default_win) + goto out_failed; + + reset_win_ext = ddw_read_ext(pdn, DDW_EXT_RESET_DMA_WIN, NULL); + if (reset_win_ext) + goto out_failed; + + remove_dma_window(pdn, ddw_avail, default_win); + default_win_removed = true; + + /* Query again, to check if the window is available */ + ret = query_ddw(dev, ddw_avail, &query, pdn); + if (ret != 0) + goto out_failed; + + if (query.windows_available == 0) { + /* no windows are available for this device. */ + dev_dbg(&dev->dev, "no free dynamic windows"); + goto out_failed; + } } if (query.page_size & 4) { page_shift = 24; /* 16MB */ @@ -1231,6 +1288,8 @@ out_free_prop: kfree(win64); out_failed: + if (default_win_removed) + reset_dma_window(dev, pdn); fpdn = kzalloc(sizeof(*fpdn), GFP_KERNEL); if (!fpdn) |