Messages in this thread | | | Date | Fri, 13 Jan 2023 17:32:46 +0530 | Subject | Re: [PATCH] pstore/ram: Rework logic for detecting ramoops | From | Mukesh Ojha <> |
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Hi Kees,
Thanks for your comments.
On 1/13/2023 3:09 AM, Kees Cook wrote: > On Wed, Jan 11, 2023 at 02:37:45PM +0530, Mukesh Ojha wrote: >> The reserved memory region for ramoops is assumed to be at a fixed >> and known location when read from the devicetree. This is not desirable >> in environments where it is preferred the region to be dynamically >> allocated at runtime, as opposed to being fixed at compile time. >> >> Also, Some of the platforms might be still expecting dedicated >> memory region for ramoops node where the region is known >> beforehand and platform_get_resource() is used in that case. >> >> So, Add logic to detect the start and size of the ramoops memory >> region by looking up reserved memory region with >> of_reserved_mem_lookup() when platform_get_resource() failed. >> >> Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com> > > Thanks for the patch! Notes below... > >> --- >> fs/pstore/ram.c | 19 ++++++++++++++----- >> 1 file changed, 14 insertions(+), 5 deletions(-) >> >> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c >> index ade66db..e4bbba1 100644 >> --- a/fs/pstore/ram.c >> +++ b/fs/pstore/ram.c >> @@ -20,6 +20,7 @@ >> #include <linux/compiler.h> >> #include <linux/of.h> >> #include <linux/of_address.h> >> +#include <linux/of_reserved_mem.h> >> >> #include "internal.h" >> #include "ram_internal.h" >> @@ -643,6 +644,7 @@ static int ramoops_parse_dt(struct platform_device *pdev, >> { >> struct device_node *of_node = pdev->dev.of_node; >> struct device_node *parent_node; >> + struct reserved_mem *rmem; >> struct resource *res; >> u32 value; >> int ret; >> @@ -651,13 +653,20 @@ static int ramoops_parse_dt(struct platform_device *pdev, >> >> res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> if (!res) { >> - dev_err(&pdev->dev, >> - "failed to locate DT /reserved-memory resource\n"); >> - return -EINVAL; >> + rmem = of_reserved_mem_lookup(of_node); >> + if (rmem) { >> + pdata->mem_size = rmem->size; >> + pdata->mem_address = rmem->base; >> + } else { >> + dev_err(&pdev->dev, >> + "failed to locate DT /reserved-memory resource\n"); >> + return -EINVAL; >> + } > > Since the "else" case returns, the traditional code pattern is to leave > the other case "inline" (an indented), like so: > > if (!rmem) { > dev_err(&pdev->dev, > "failed to locate DT /reserved-memory resource\n"); > return -EINVAL; > } > pdata->mem_size = rmem->size; > pdata->mem_address = rmem->base; >
Fixed it in v2.
> >> + } else { >> + pdata->mem_size = resource_size(res); >> + pdata->mem_address = res->start; >> } > > Since this change the potential interface with DT, can you also update > the documentation in: > > Documentation/devicetree/bindings/reserved-memory/ramoops.yaml > > Or maybe my understanding of DT parsing is lacking and this change is > doing something slightly different? >
Have updated the docs in v2;
-Mukesh
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