Messages in this thread | | | Subject | Re: [PATCH v2 2/6] powerpc/pseries/iommu: Update call to ibm,query-pe-dma-windows | From | Alexey Kardashevskiy <> | Date | Thu, 2 Jul 2020 10:18:21 +1000 |
| |
On 02/07/2020 00:04, Leonardo Bras wrote: > On Wed, 2020-07-01 at 18:17 +1000, Alexey Kardashevskiy wrote: >> >>> +#define DDW_EXT_SIZE 0 >>> +#define DDW_EXT_RESET_DMA_WIN 1 >>> +#define DDW_EXT_QUERY_OUT_SIZE 2 >> >> #define DDW_EXT_LAST (DDW_EXT_QUERY_OUT_SIZE + 1) >> ... >> >> >>> + >>> static struct iommu_table_group *iommu_pseries_alloc_group(int node) >>> { >>> struct iommu_table_group *table_group; >>> @@ -339,7 +343,7 @@ struct direct_window { >>> /* Dynamic DMA Window support */ >>> struct ddw_query_response { >>> u32 windows_available; >>> - u32 largest_available_block; >>> + u64 largest_available_block; >>> u32 page_size; >>> u32 migration_capable; >>> }; >>> @@ -875,13 +879,29 @@ static int find_existing_ddw_windows(void) >>> machine_arch_initcall(pseries, find_existing_ddw_windows); >>> >>> static int query_ddw(struct pci_dev *dev, const u32 *ddw_avail, >>> - struct ddw_query_response *query) >>> + struct ddw_query_response *query, >>> + struct device_node *parent) >>> { >>> struct device_node *dn; >>> struct pci_dn *pdn; >>> - u32 cfg_addr; >>> + u32 cfg_addr, query_out[5], ddw_ext[DDW_EXT_QUERY_OUT_SIZE + 1]; >> >> ... and use DDW_EXT_LAST here. > > Because of the growing nature of ddw-extensions, I intentionally let > this be (DDW_EXT_QUERY_OUT_SIZE + 1). If we create a DDW_EXT_LAST, it > will be incremented in the future if more extensions come to exist. > > I mean, I previously saw no reason for allocating space for extensions > after the desired one, as they won't be used here.
Ah, my bad, you're right.
> >> >> >>> u64 buid; >>> - int ret; >>> + int ret, out_sz; >>> + >>> + /* >>> + * From LoPAR level 2.8, "ibm,ddw-extensions" index 3 can rule how many >>> + * output parameters ibm,query-pe-dma-windows will have, ranging from >>> + * 5 to 6. >>> + */ >>> + >>> + ret = of_property_read_u32_array(parent, "ibm,ddw-extensions", >>> + &ddw_ext[0], >>> + DDW_EXT_QUERY_OUT_SIZE + 1); > > In this case, I made sure not to cross (DDW_EXT_QUERY_OUT_SIZE + 1) > while reading the extensions from the property. > > What do you think about it?
I think you want something like:
static inline int ddw_read_ext(const struct device_node *np, int extnum, u32 *ret) { retun of_property_read_u32_index(np, "ibm,ddw-extensions", extnum + 1, ret); }
These "+1"'s all over the place are confusing.
-- Alexey
| |