Re: [PATCH v6 06/11] powerpc/pseries/iommu: Add ddw_property_create() and refactor enable_ddw()
From: Frederic Barrat <hidden>
Date: 2021-08-27 16:56:14
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On 17/08/2021 08:39, Leonardo Bras wrote:
Code used to create a ddw property that was previously scattered in enable_ddw() is now gathered in ddw_property_create(), which deals with allocation and filling the property, letting it ready for of_property_add(), which now occurs in sequence. This created an opportunity to reorganize the second part of enable_ddw(): Without this patch enable_ddw() does, in order: kzalloc() property & members, create_ddw(), fill ddwprop inside property, ddw_list_new_entry(), do tce_setrange_multi_pSeriesLP_walk in all memory, of_add_property(), and list_add(). With this patch enable_ddw() does, in order: create_ddw(), ddw_property_create(), of_add_property(), ddw_list_new_entry(), do tce_setrange_multi_pSeriesLP_walk in all memory, and list_add(). This change requires of_remove_property() in case anything fails after of_add_property(), but we get to do tce_setrange_multi_pSeriesLP_walk in all memory, which looks the most expensive operation, only if everything else succeeds. Also, the error path got remove_ddw() replaced by a new helper __remove_dma_window(), which only removes the new DDW with an rtas-call. For this, a new helper clean_dma_window() was needed to clean anything that could left if walk_system_ram_range() fails. Signed-off-by: Leonardo Bras <redacted> Reviewed-by: Alexey Kardashevskiy <redacted> ---
Thanks for fixing the error paths Reviewed-by: Frederic Barrat <redacted>
quoted hunk ↗ jump to hunk
arch/powerpc/platforms/pseries/iommu.c | 129 ++++++++++++++++--------- 1 file changed, 84 insertions(+), 45 deletions(-)diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index b34b473bbdc1..00392582fe10 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c@@ -795,17 +795,10 @@ static int __init disable_ddw_setup(char *str) early_param("disable_ddw", disable_ddw_setup); -static void remove_dma_window(struct device_node *np, u32 *ddw_avail, - struct property *win) +static void clean_dma_window(struct device_node *np, struct dynamic_dma_window_prop *dwp) { - struct dynamic_dma_window_prop *dwp; - u64 liobn; int ret; - dwp = win->value; - liobn = (u64)be32_to_cpu(dwp->liobn); - - /* clear the whole window, note the arg is in kernel pages */ ret = tce_clearrange_multi_pSeriesLP(0, 1ULL << (be32_to_cpu(dwp->window_shift) - PAGE_SHIFT), dwp); if (ret)@@ -814,18 +807,39 @@ static void remove_dma_window(struct device_node *np, u32 *ddw_avail, else pr_debug("%pOF successfully cleared tces in window.\n", np); +} + +/* + * Call only if DMA window is clean. + */ +static void __remove_dma_window(struct device_node *np, u32 *ddw_avail, u64 liobn) +{ + int ret; ret = rtas_call(ddw_avail[DDW_REMOVE_PE_DMA_WIN], 1, 1, NULL, liobn); if (ret) - pr_warn("%pOF: failed to remove direct window: rtas returned " + pr_warn("%pOF: failed to remove DMA window: rtas returned " "%d to ibm,remove-pe-dma-window(%x) %llx\n", np, ret, ddw_avail[DDW_REMOVE_PE_DMA_WIN], liobn); else - pr_debug("%pOF: successfully removed direct window: rtas returned " + pr_debug("%pOF: successfully removed DMA window: rtas returned " "%d to ibm,remove-pe-dma-window(%x) %llx\n", np, ret, ddw_avail[DDW_REMOVE_PE_DMA_WIN], liobn); } +static void remove_dma_window(struct device_node *np, u32 *ddw_avail, + struct property *win) +{ + struct dynamic_dma_window_prop *dwp; + u64 liobn; + + dwp = win->value; + liobn = (u64)be32_to_cpu(dwp->liobn); + + clean_dma_window(np, dwp); + __remove_dma_window(np, ddw_avail, liobn); +} + static void remove_ddw(struct device_node *np, bool remove_prop) { struct property *win;@@ -1153,6 +1167,35 @@ static int iommu_get_page_shift(u32 query_page_size) return 0; } +static struct property *ddw_property_create(const char *propname, u32 liobn, u64 dma_addr, + u32 page_shift, u32 window_shift) +{ + struct dynamic_dma_window_prop *ddwprop; + struct property *win64; + + win64 = kzalloc(sizeof(*win64), GFP_KERNEL); + if (!win64) + return NULL; + + win64->name = kstrdup(propname, GFP_KERNEL); + ddwprop = kzalloc(sizeof(*ddwprop), GFP_KERNEL); + win64->value = ddwprop; + win64->length = sizeof(*ddwprop); + if (!win64->name || !win64->value) { + kfree(win64->name); + kfree(win64->value); + kfree(win64); + return NULL; + } + + ddwprop->liobn = cpu_to_be32(liobn); + ddwprop->dma_base = cpu_to_be64(dma_addr); + ddwprop->tce_shift = cpu_to_be32(page_shift); + ddwprop->window_shift = cpu_to_be32(window_shift); + + return win64; +} + /* * 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,@@ -1171,12 +1214,12 @@ static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn) struct ddw_query_response query; struct ddw_create_response create; int page_shift; + u64 win_addr; struct device_node *dn; u32 ddw_avail[DDW_APPLICABLE_SIZE]; struct direct_window *window; struct property *win64; bool ddw_enabled = false; - struct dynamic_dma_window_prop *ddwprop; struct failed_ddw_pdn *fpdn; bool default_win_removed = false; bool pmem_present;@@ -1293,72 +1336,68 @@ static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn) 1ULL << page_shift); goto out_failed; } - win64 = kzalloc(sizeof(struct property), GFP_KERNEL); - if (!win64) { - dev_info(&dev->dev, - "couldn't allocate property for 64bit dma window\n"); - goto out_failed; - } - win64->name = kstrdup(DIRECT64_PROPNAME, GFP_KERNEL); - win64->value = ddwprop = kmalloc(sizeof(*ddwprop), GFP_KERNEL); - win64->length = sizeof(*ddwprop); - if (!win64->name || !win64->value) { - dev_info(&dev->dev, - "couldn't allocate property name and value\n"); - goto out_free_prop; - } ret = create_ddw(dev, ddw_avail, &create, page_shift, len); if (ret != 0) - goto out_free_prop; - - ddwprop->liobn = cpu_to_be32(create.liobn); - ddwprop->dma_base = cpu_to_be64(((u64)create.addr_hi << 32) | - create.addr_lo); - ddwprop->tce_shift = cpu_to_be32(page_shift); - ddwprop->window_shift = cpu_to_be32(len); + goto out_failed; dev_dbg(&dev->dev, "created tce table LIOBN 0x%x for %pOF\n", create.liobn, dn); - window = ddw_list_new_entry(pdn, ddwprop); + win_addr = ((u64)create.addr_hi << 32) | create.addr_lo; + win64 = ddw_property_create(DIRECT64_PROPNAME, create.liobn, win_addr, + page_shift, len); + if (!win64) { + dev_info(&dev->dev, + "couldn't allocate property, property name, or value\n"); + goto out_remove_win; + } + + ret = of_add_property(pdn, win64); + if (ret) { + dev_err(&dev->dev, "unable to add dma window property for %pOF: %d", + pdn, ret); + goto out_free_prop; + } + + window = ddw_list_new_entry(pdn, win64->value); if (!window) - goto out_clear_window; + goto out_del_prop; ret = walk_system_ram_range(0, memblock_end_of_DRAM() >> PAGE_SHIFT, win64->value, tce_setrange_multi_pSeriesLP_walk); if (ret) { dev_info(&dev->dev, "failed to map direct window for %pOF: %d\n", dn, ret); - goto out_free_window; - } - ret = of_add_property(pdn, win64); - if (ret) { - dev_err(&dev->dev, "unable to add dma window property for %pOF: %d", - pdn, ret); - goto out_free_window; + /* Make sure to clean DDW if any TCE was set*/ + clean_dma_window(pdn, win64->value); + goto out_del_list; } spin_lock(&direct_window_list_lock); list_add(&window->list, &direct_window_list); spin_unlock(&direct_window_list_lock); - dev->dev.archdata.dma_offset = be64_to_cpu(ddwprop->dma_base); + dev->dev.archdata.dma_offset = win_addr; ddw_enabled = true; goto out_unlock; -out_free_window: +out_del_list: kfree(window); -out_clear_window: - remove_ddw(pdn, true); +out_del_prop: + of_remove_property(pdn, win64); out_free_prop: kfree(win64->name); kfree(win64->value); kfree(win64); +out_remove_win: + /* DDW is clean, so it's ok to call this directly. */ + __remove_dma_window(pdn, ddw_avail, create.liobn); + out_failed: if (default_win_removed) reset_dma_window(dev, pdn);