From 97e7dc523acaa335d44517b06ef5609b3ee65c6a Mon Sep 17 00:00:00 2001 From: Nishanth Aravamudan Date: Fri, 10 Jan 2014 15:10:41 -0800 Subject: [PATCH] Revert "pseries/iommu: Remove DDW on kexec" After reverting 25ebc45b93452d0bc60271f178237123c4b26808 ("powerpc/pseries/iommu: remove default window before attempting DDW manipulation"), we no longer remove the base window in enable_ddw. Therefore, we no longer need to reset the DMA window state in find_existing_ddw_windows(). We can instead go back to what was done before, which simply reuses the previous configuration, if any. Further, this removes the final caller of the reset-pe-dma-windows call, so remove those functions. This fixes an EEH on kdump with the ipr driver. The EEH occurs, because the initcall removes the DDW configuration (64-bit DMA window), but doesn't ensure the ops are via the IOMMU -- a DMA operation occurs during probe (still investigating this) and we EEH. This reverts commit 14b6f00f8a4fdec5ccd45a0710284de301a61628. Signed-off-by: Nishanth Aravamudan Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/pseries/iommu.c | 63 ++++++-------------------- 1 file changed, 14 insertions(+), 49 deletions(-) diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index bb2e16c5ae27..33b552ffbe57 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -787,68 +787,33 @@ static u64 find_existing_ddw(struct device_node *pdn) return dma_addr; } -static void __restore_default_window(struct eeh_dev *edev, - u32 ddw_restore_token) -{ - u32 cfg_addr; - u64 buid; - int ret; - - /* - * Get the config address and phb buid of the PE window. - * Rely on eeh to retrieve this for us. - * Retrieve them from the pci device, not the node with the - * dma-window property - */ - cfg_addr = edev->config_addr; - if (edev->pe_config_addr) - cfg_addr = edev->pe_config_addr; - buid = edev->phb->buid; - - do { - ret = rtas_call(ddw_restore_token, 3, 1, NULL, cfg_addr, - BUID_HI(buid), BUID_LO(buid)); - } while (rtas_busy_delay(ret)); - pr_info("ibm,reset-pe-dma-windows(%x) %x %x %x returned %d\n", - ddw_restore_token, cfg_addr, BUID_HI(buid), BUID_LO(buid), ret); -} - static int find_existing_ddw_windows(void) { + int len; struct device_node *pdn; + struct direct_window *window; const struct dynamic_dma_window_prop *direct64; - const u32 *ddw_extensions; if (!firmware_has_feature(FW_FEATURE_LPAR)) return 0; for_each_node_with_property(pdn, DIRECT64_PROPNAME) { - direct64 = of_get_property(pdn, DIRECT64_PROPNAME, NULL); + direct64 = of_get_property(pdn, DIRECT64_PROPNAME, &len); if (!direct64) continue; - /* - * We need to ensure the IOMMU table is active when we - * return from the IOMMU setup so that the common code - * can clear the table or find the holes. To that end, - * first, remove any existing DDW configuration. - */ - remove_ddw(pdn); + window = kzalloc(sizeof(*window), GFP_KERNEL); + if (!window || len < sizeof(struct dynamic_dma_window_prop)) { + kfree(window); + remove_ddw(pdn); + continue; + } - /* - * Second, if we are running on a new enough level of - * firmware where the restore API is present, use it to - * restore the 32-bit window, which was removed in - * create_ddw. - * If the API is not present, then create_ddw couldn't - * have removed the 32-bit window in the first place, so - * removing the DDW configuration should be sufficient. - */ - ddw_extensions = of_get_property(pdn, "ibm,ddw-extensions", - NULL); - if (ddw_extensions && ddw_extensions[0] > 0) - __restore_default_window(of_node_to_eeh_dev(pdn), - ddw_extensions[1]); + window->device = pdn; + window->prop = direct64; + spin_lock(&direct_window_list_lock); + list_add(&window->list, &direct_window_list); + spin_unlock(&direct_window_list_lock); } return 0; -- 2.30.2