Re: [PATCH] media: venus: firmware: Use of_reserved_mem_lookup()

From: Stephan Gerhold
Date: Wed Aug 02 2023 - 05:01:30 EST


Hi Stanimir,

I see that you already tagged the Venus updates for 6.6, but could you
try to still apply this patch as well for 6.6? It's a requirement for
some DT cleanup I'm working on and ideally needs to go in a kernel
release earlier to avoid bisect problems.

AFAICT it's been on the list for more than two months now with two
Reviewed-by, so should be fine to just apply it. :)

Thanks!
Stephan

On Mon, May 29, 2023 at 08:16:14PM +0200, Stephan Gerhold wrote:
> Reserved memory can be either looked up using the generic function
> of_address_to_resource() or using the special of_reserved_mem_lookup().
> The latter has the advantage that it ensures that the referenced memory
> region was really reserved and is not e.g. status = "disabled".
>
> of_reserved_mem also supports allocating reserved memory dynamically at
> boot time. This works only when using of_reserved_mem_lookup() since
> there won't be a fixed address in the device tree.
>
> Switch the code to use of_reserved_mem_lookup(). There is no functional
> difference for static reserved memory allocations.
>
> Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
> ---
> See e.g. [1] for an example of dynamically allocated reserved memory.
> (This patch does *not* depend on [1] and is useful without as well...)
>
> [1]: https://lore.kernel.org/linux-arm-msm/20230510-dt-resv-bottom-up-v1-5-3bf68873dbed@xxxxxxxxxxx/
> ---
> drivers/media/platform/qcom/venus/firmware.c | 24 +++++++++++++-----------
> 1 file changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/venus/firmware.c b/drivers/media/platform/qcom/venus/firmware.c
> index cfb11c551167..2e7ffdaff7b2 100644
> --- a/drivers/media/platform/qcom/venus/firmware.c
> +++ b/drivers/media/platform/qcom/venus/firmware.c
> @@ -10,6 +10,7 @@
> #include <linux/io.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> +#include <linux/of_reserved_mem.h>
> #include <linux/platform_device.h>
> #include <linux/of_device.h>
> #include <linux/firmware/qcom/qcom_scm.h>
> @@ -82,9 +83,9 @@ static int venus_load_fw(struct venus_core *core, const char *fwname,
> phys_addr_t *mem_phys, size_t *mem_size)
> {
> const struct firmware *mdt;
> + struct reserved_mem *rmem;
> struct device_node *node;
> struct device *dev;
> - struct resource r;
> ssize_t fw_size;
> void *mem_va;
> int ret;
> @@ -99,13 +100,16 @@ static int venus_load_fw(struct venus_core *core, const char *fwname,
> return -EINVAL;
> }
>
> - ret = of_address_to_resource(node, 0, &r);
> - if (ret)
> - goto err_put_node;
> + rmem = of_reserved_mem_lookup(node);
> + of_node_put(node);
> + if (!rmem) {
> + dev_err(dev, "failed to lookup reserved memory-region\n");
> + return -EINVAL;
> + }
>
> ret = request_firmware(&mdt, fwname, dev);
> if (ret < 0)
> - goto err_put_node;
> + return ret;
>
> fw_size = qcom_mdt_get_size(mdt);
> if (fw_size < 0) {
> @@ -113,17 +117,17 @@ static int venus_load_fw(struct venus_core *core, const char *fwname,
> goto err_release_fw;
> }
>
> - *mem_phys = r.start;
> - *mem_size = resource_size(&r);
> + *mem_phys = rmem->base;
> + *mem_size = rmem->size;
>
> if (*mem_size < fw_size || fw_size > VENUS_FW_MEM_SIZE) {
> ret = -EINVAL;
> goto err_release_fw;
> }
>
> - mem_va = memremap(r.start, *mem_size, MEMREMAP_WC);
> + mem_va = memremap(*mem_phys, *mem_size, MEMREMAP_WC);
> if (!mem_va) {
> - dev_err(dev, "unable to map memory region: %pR\n", &r);
> + dev_err(dev, "unable to map memory region %pa size %#zx\n", mem_phys, *mem_size);
> ret = -ENOMEM;
> goto err_release_fw;
> }
> @@ -138,8 +142,6 @@ static int venus_load_fw(struct venus_core *core, const char *fwname,
> memunmap(mem_va);
> err_release_fw:
> release_firmware(mdt);
> -err_put_node:
> - of_node_put(node);
> return ret;
> }
>
>
> ---
> base-commit: 9f9f8ca6f012d25428f8605cb36369a449db8508
> change-id: 20230529-venus-of-rmem-f649885114fd
>
> Best regards,
> --
> Stephan Gerhold <stephan@xxxxxxxxxxx>
>