On 10/12/2020 10:42, Nicolas Saenz Julienne wrote:
> Add the following functions to get a specific device's DMA ranges:
> - dev_get_dma_range()
> - ofnode_get_dma_range()
> - of_get_dma_range()
> - fdt_get_dma_range()
> They are specially useful in oder to be able validate a physical address
> space range into a bus's and to convert addresses from and to address
> spaces.
>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulie...@suse.de>
>
> ---
> Changes since v1:
> - Fix wrong arguments in of_get_dma_range()'s call to
> of_translate_dma_address()
> - Fix build in SPL/TPL and no LIBFDT supprt
> - Add missing declaration in 'core/read.c'
> - Address Matthias' comments
>
> common/fdt_support.c | 73 ++++++++++++++++++++++++++++++++++++++++++
> drivers/core/of_addr.c | 71 ++++++++++++++++++++++++++++++++++++++++
> drivers/core/ofnode.c | 9 ++++++
> drivers/core/read.c | 9 ++++++
> include/dm/of_addr.h | 17 ++++++++++
> include/dm/ofnode.h | 16 +++++++++
> include/dm/read.h | 21 ++++++++++++
> include/fdt_support.h | 14 ++++++++
> 8 files changed, 230 insertions(+)
>
> diff --git a/common/fdt_support.c b/common/fdt_support.c
> index 5ae75df3c6..4bcd6720d2 100644
> --- a/common/fdt_support.c
> +++ b/common/fdt_support.c
> @@ -1342,6 +1342,79 @@ u64 fdt_translate_dma_address(const void *blob, int
> node_offset,
> return __of_translate_address(blob, node_offset, in_addr, "dma-ranges");
> }
>
> +int fdt_get_dma_range(const void *blob, int node, phys_addr_t *cpu,
> + dma_addr_t *bus, u64 *size)
> +{
> + bool found_dma_ranges = false;
> + struct of_bus *bus_node;
> + const fdt32_t *ranges;
> + int na, ns, pna, pns;
> + int parent = node;
> + int ret = 0;
> + int len;
> +
> + /* Find the closest dma-ranges property */
> + while (parent >= 0) {
> + ranges = fdt_getprop(blob, parent, "dma-ranges", &len);
> +
> + /* Ignore empty ranges, they imply no translation required */
> + if (ranges && len > 0)
> + break;
> +
> + /* Once we find 'dma-ranges', then a missing one is an error */
> + if (found_dma_ranges && !ranges) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + if (ranges)
> + found_dma_ranges = true;
> +
> + parent = fdt_parent_offset(blob, parent);
> + }
> +
> + if (!ranges || parent < 0) {
> + debug("no dma-ranges found for node %s\n",
> + fdt_get_name(blob, node, NULL));
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + /* switch to that node */
> + node = parent;
> + parent = fdt_parent_offset(blob, node);
> + if (parent < 0) {
> + printf("Found dma-ranges in root node, shoudln't happen\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + /* Get the address sizes both for the bus and its parent */
> + bus_node = of_match_bus(blob, node);
> + bus_node->count_cells(blob, node, &na, &ns);
> + if (!OF_CHECK_COUNTS(na, ns)) {
> + printf("%s: Bad cell count for %s\n", __FUNCTION__,
> + fdt_get_name(blob, node, NULL));
> + return -EINVAL;
> + goto out;
> + }
> +
> + bus_node = of_match_bus(blob, parent);
> + bus_node->count_cells(blob, parent, &pna, &pns);
> + if (!OF_CHECK_COUNTS(pna, pns)) {
> + printf("%s: Bad cell count for %s\n", __FUNCTION__,
> + fdt_get_name(blob, parent, NULL));
> + return -EINVAL;
> + goto out;
> + }
> +
> + *bus = fdt_read_number(ranges, na);
> + *cpu = fdt_translate_dma_address(blob, node, ranges + na);
> + *size = fdt_read_number(ranges + na + pna, ns);
> +out:
> + return ret;
> +}
> +
> /**
> * fdt_node_offset_by_compat_reg: Find a node that matches compatiable and
> * who's reg property matches a physical cpu address
> diff --git a/drivers/core/of_addr.c b/drivers/core/of_addr.c
> index ca34d84922..b1d6165b0a 100644
> --- a/drivers/core/of_addr.c
> +++ b/drivers/core/of_addr.c
> @@ -325,6 +325,77 @@ u64 of_translate_dma_address(const struct device_node
> *dev, const __be32 *in_add
> return __of_translate_address(dev, in_addr, "dma-ranges");
> }
>
> +int of_get_dma_range(const struct device_node *dev, phys_addr_t *cpu,
> + dma_addr_t *bus, u64 *size)
> +{
> + bool found_dma_ranges = false;
> + struct device_node *parent;
> + struct of_bus *bus_node;
> + int na, ns, pna, pns;
> + const __be32 *ranges;
> + int ret = 0;
> + int len;
> +
> + /* Find the closest dma-ranges property */
> + while (dev) {
> + ranges = of_get_property(dev, "dma-ranges", &len);
> +
> + /* Ignore empty ranges, they imply no translation required */
> + if (ranges && len > 0)
> + break;
> +
> + /* Once we find 'dma-ranges', then a missing one is an error */
> + if (found_dma_ranges && !ranges) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + if (ranges)
> + found_dma_ranges = true;
> +
> + dev = of_get_parent(dev);
> + }
> +
> + if (!dev || !ranges) {
> + debug("no dma-ranges found for node %s\n",
> + of_node_full_name(dev));
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + /* switch to that node */
> + parent = of_get_parent(dev);
> + if (!parent) {
> + printf("Found dma-ranges in root node, shoudln't happen\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
Although the function is a dummy, we should put of_node_put() here, to be in
sync with the rest of the code.
Regards,
Matthias
