On Thu, 2020-07-16 at 04:16 -0300, Leonardo Bras wrote:
> > From LoPAR level 2.8, "ibm,ddw-extensions" index 3 can make the
> > number of
>
> outputs from "ibm,query-pe-dma-windows" go from 5 to 6.
>
> This change of output size is meant to expand the address size of
> largest_available_block PE TCE from 32-bit to 64-bit, which ends up
> shifting page_size and migration_capable.
>
> This ends up requiring the update of
> ddw_query_response->largest_available_block from u32 to u64, and
> manually
> assigning the values from the buffer into this struct, according to
> output size.
>
> Also, a routine was created for helping reading the ddw extensions as
> suggested by LoPAR: First reading the size of the extension array
> from
> index 0, checking if the property exists, and then returning it's
> value.
>
> Signed-off-by: Leonardo Bras <leobra...@gmail.com>
> ---
> arch/powerpc/platforms/pseries/iommu.c | 91 +++++++++++++++++++++++-
> --
> 1 file changed, 81 insertions(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/iommu.c
> b/arch/powerpc/platforms/pseries/iommu.c
> index ac0d6376bdad..1a933c4e8bba 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -47,6 +47,12 @@ enum {
> DDW_APPLICABLE_SIZE
> };
>
> +enum {
> + DDW_EXT_SIZE = 0,
> + DDW_EXT_RESET_DMA_WIN = 1,
> + DDW_EXT_QUERY_OUT_SIZE = 2
> +};
> +
> static struct iommu_table_group *iommu_pseries_alloc_group(int node)
> {
> struct iommu_table_group *table_group;
> @@ -342,7 +348,7 @@ 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;
> };
> @@ -877,14 +883,62 @@ static int find_existing_ddw_windows(void)
> }
> machine_arch_initcall(pseries, find_existing_ddw_windows);
>
> +/**
> + * ddw_read_ext - Get the value of an DDW extension
> + * @np: device node from which the extension value is
> to be read.
> + * @extnum: index number of the extension.
> + * @value: pointer to return value, modified when extension is
> available.
> + *
> + * Checks if "ibm,ddw-extensions" exists for this node, and get the
> value
> + * on index 'extnum'.
> + * It can be used only to check if a property exists, passing value
> == NULL.
> + *
> + * Returns:
> + * 0 if extension successfully read
> + * -EINVAL if the "ibm,ddw-extensions" does not exist,
> + * -ENODATA if "ibm,ddw-extensions" does not have a value, and
> + * -EOVERFLOW if "ibm,ddw-extensions" does not contain this
> extension.
> + */
> +static inline int ddw_read_ext(const struct device_node *np, int
> extnum,
> + u32 *value)
> +{
> + static const char propname[] = "ibm,ddw-extensions";
> + u32 count;
> + int ret;
> +
> + ret = of_property_read_u32_index(np, propname, DDW_EXT_SIZE,
> &count);
> + if (ret)
> + return ret;
> +
> + if (count < extnum)
> + return -EOVERFLOW;
> +
> + if (!value)
> + value = &count;
> +
> + return of_property_read_u32_index(np, propname, extnum, value);
> +}
> +
> 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, ext_query, query_out[5];
> 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 = ddw_read_ext(parent, DDW_EXT_QUERY_OUT_SIZE, &ext_query);
> + if (!ret && ext_query == 1)
> + out_sz = 6;
> + else
> + out_sz = 5;
>
> /*
> * Get the config address and phb buid of the PE window.
> @@ -897,11 +951,28 @@ static int query_ddw(struct pci_dev *dev, const
> u32 *ddw_avail,
> buid = pdn->phb->buid;
> cfg_addr = ((pdn->busno << 16) | (pdn->devfn << 8));
>
> - ret = rtas_call(ddw_avail[DDW_QUERY_PE_DMA_WIN], 3, 5, (u32
> *)query,
> + ret = rtas_call(ddw_avail[DDW_QUERY_PE_DMA_WIN], 3, out_sz,
> query_out,
> cfg_addr, BUID_HI(buid), BUID_LO(buid));
> - dev_info(&dev->dev, "ibm,query-pe-dma-windows(%x) %x %x %x"
> - " returned %d\n", ddw_avail[DDW_QUERY_PE_DMA_WIN],
> cfg_addr,
> - BUID_HI(buid), BUID_LO(buid), ret);
> + dev_info(&dev->dev, "ibm,query-pe-dma-windows(%x) %x %x %x
> returned %d\n",
> + ddw_avail[DDW_QUERY_PE_DMA_WIN], cfg_addr,
> BUID_HI(buid),
> + BUID_LO(buid), ret);
> +
> + switch (out_sz) {
> + case 5:
> + query->windows_available = query_out[0];
> + query->largest_available_block = query_out[1];
> + query->page_size = query_out[2];
> + query->migration_capable = query_out[3];
> + break;
> + case 6:
> + query->windows_available = query_out[0];
> + query->largest_available_block = ((u64)query_out[1] <<
> 32) |
> + query_out[2];
> + query->page_size = query_out[3];
> + query->migration_capable = query_out[4];
> + break;
> + }
> +
> return ret;
> }
>
> @@ -1049,7 +1120,7 @@ static u64 enable_ddw(struct pci_dev *dev,
> struct device_node *pdn)
> * of page sizes: supported and supported for migrate-dma.
> */
> dn = pci_device_to_OF_node(dev);
> - ret = query_ddw(dev, ddw_avail, &query);
> + ret = query_ddw(dev, ddw_avail, &query, pdn);
> if (ret != 0)
> goto out_failed;
>
> @@ -1077,7 +1148,7 @@ static u64 enable_ddw(struct pci_dev *dev,
> struct device_node *pdn)
> /* 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
> %u "
> + 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;
Tested-by: David Dai <z...@linux.vnet.ibm.com>
