| Message ID | 20240126235425.12233-8-quic_obabatun@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Dynamic allocation of reserved_mem array. | expand |
On Fri, Jan 26, 2024 at 03:53:46PM -0800, Oreoluwa Babatunde wrote: > Call early_fdt_scan_reserved_mem() in place of > early_init_fdt_scan_reserved_mem() to carry out the first stage of the > reserved memory processing only. > > The early_fdt_scan_reserved_mem() function is used to scan through the > DT and mark all the reserved memory regions as reserved or nomap as > needed, as well as allocate the memory required by the > dynamically-placed > reserved memory regions. > > The second stage of the reserved memory processing is done by > fdt_init_reserved_mem(). This function is used to store the information > of the statically-placed reserved memory nodes in the reserved_mem > array as well as call the region specific initialization function on all > the stored reserved memory regions. > > The call to fdt_init_reserved_mem() is placed right after > early_fdt_scan_reserved_mem() since memblock allocated memory should > already be writable at this point. > > Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com> > --- > arch/loongarch/kernel/setup.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c > index edf2bba80130..72b164d3ace0 100644 > --- a/arch/loongarch/kernel/setup.c > +++ b/arch/loongarch/kernel/setup.c > @@ -30,6 +30,7 @@ > #include <linux/dma-map-ops.h> > #include <linux/libfdt.h> > #include <linux/of_fdt.h> > +#include <linux/of_reserved_mem.h> > #include <linux/of_address.h> > #include <linux/suspend.h> > #include <linux/swiotlb.h> > @@ -390,8 +391,9 @@ static void __init arch_mem_init(char **cmdline_p) > > check_kernel_sections_mem(); > > - early_init_fdt_scan_reserved_mem(); > + early_fdt_scan_reserved_mem(); Looking at the loongarch code, there's an existing problem with the order of init. This is done after unflattening and copying the DT. That means the kernel could freely allocate memory for the DT in a reserved region. Rob
On 1/31/2024 7:27 AM, Rob Herring wrote: > On Fri, Jan 26, 2024 at 03:53:46PM -0800, Oreoluwa Babatunde wrote: >> Call early_fdt_scan_reserved_mem() in place of >> early_init_fdt_scan_reserved_mem() to carry out the first stage of the >> reserved memory processing only. >> >> The early_fdt_scan_reserved_mem() function is used to scan through the >> DT and mark all the reserved memory regions as reserved or nomap as >> needed, as well as allocate the memory required by the >> dynamically-placed >> reserved memory regions. >> >> The second stage of the reserved memory processing is done by >> fdt_init_reserved_mem(). This function is used to store the information >> of the statically-placed reserved memory nodes in the reserved_mem >> array as well as call the region specific initialization function on all >> the stored reserved memory regions. >> >> The call to fdt_init_reserved_mem() is placed right after >> early_fdt_scan_reserved_mem() since memblock allocated memory should >> already be writable at this point. >> >> Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com> >> --- >> arch/loongarch/kernel/setup.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c >> index edf2bba80130..72b164d3ace0 100644 >> --- a/arch/loongarch/kernel/setup.c >> +++ b/arch/loongarch/kernel/setup.c >> @@ -30,6 +30,7 @@ >> #include <linux/dma-map-ops.h> >> #include <linux/libfdt.h> >> #include <linux/of_fdt.h> >> +#include <linux/of_reserved_mem.h> >> #include <linux/of_address.h> >> #include <linux/suspend.h> >> #include <linux/swiotlb.h> >> @@ -390,8 +391,9 @@ static void __init arch_mem_init(char **cmdline_p) >> >> check_kernel_sections_mem(); >> >> - early_init_fdt_scan_reserved_mem(); >> + early_fdt_scan_reserved_mem(); > Looking at the loongarch code, there's an existing problem with the > order of init. This is done after unflattening and copying the DT. That > means the kernel could freely allocate memory for the DT in a reserved > region. > > Rob Same here, I think we should be able to move the call to early_init_fdt_scan_reserved_mem() higher in the init sequence without having any issues. Will try this out and see. Regards, Oreoluwa
diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c index edf2bba80130..72b164d3ace0 100644 --- a/arch/loongarch/kernel/setup.c +++ b/arch/loongarch/kernel/setup.c @@ -30,6 +30,7 @@ #include <linux/dma-map-ops.h> #include <linux/libfdt.h> #include <linux/of_fdt.h> +#include <linux/of_reserved_mem.h> #include <linux/of_address.h> #include <linux/suspend.h> #include <linux/swiotlb.h> @@ -390,8 +391,9 @@ static void __init arch_mem_init(char **cmdline_p) check_kernel_sections_mem(); - early_init_fdt_scan_reserved_mem(); + early_fdt_scan_reserved_mem(); + fdt_init_reserved_mem(); /* * In order to reduce the possibility of kernel panic when failed to * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
Call early_fdt_scan_reserved_mem() in place of early_init_fdt_scan_reserved_mem() to carry out the first stage of the reserved memory processing only. The early_fdt_scan_reserved_mem() function is used to scan through the DT and mark all the reserved memory regions as reserved or nomap as needed, as well as allocate the memory required by the dynamically-placed reserved memory regions. The second stage of the reserved memory processing is done by fdt_init_reserved_mem(). This function is used to store the information of the statically-placed reserved memory nodes in the reserved_mem array as well as call the region specific initialization function on all the stored reserved memory regions. The call to fdt_init_reserved_mem() is placed right after early_fdt_scan_reserved_mem() since memblock allocated memory should already be writable at this point. Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com> --- arch/loongarch/kernel/setup.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)