2021-11-15 07:34:18

by Calvin Zhang

Subject: [PATCH v2] of: make MAX_RESERVED_REGIONS configurable

MAX_RESERVED_REGIONS has changed several times. Max reserved regions
count grows bigger as more SOC subsystems require reserved regions.

Add a Kconfig for it so that when properly configured, the static
reserved_mem array consumes less memory on systems with few reserved
regions.

Signed-off-by: Calvin Zhang <[email protected]>
---
drivers/of/Kconfig | 10 ++++++++++
drivers/of/of_reserved_mem.c | 3 +--
2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 80b5fd44ab1c..47ffff9f6aba 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -73,6 +73,16 @@ config OF_IRQ
config OF_RESERVED_MEM
def_bool OF_EARLY_FLATTREE

+config OF_MAX_RESERVED_REGIONS
+ int "Maximum count of reserved regions"
+ depends on OF_RESERVED_MEM
+ default 64
+ help
+ Reserved regions in /reserved-memory node includes static
+ reservations with fixed location and dynamic ones for device
+ CMA regions. This parameter sets the maximum number of reserved
+ regions in the system.
+
config OF_RESOLVE
bool

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 9c0fb962c22b..d90ae4c03011 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -25,8 +25,7 @@

#include "of_private.h"

-#define MAX_RESERVED_REGIONS 64
-static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
+static struct reserved_mem reserved_mem[CONFIG_OF_MAX_RESERVED_REGIONS];
static int reserved_mem_count;

static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
--
2.30.2

2021-11-15 14:06:20

by Rob Herring

Subject: Re: [PATCH v2] of: make MAX_RESERVED_REGIONS configurable

On Mon, Nov 15, 2021 at 1:33 AM Calvin Zhang <[email protected]> wrote:
>
> MAX_RESERVED_REGIONS has changed several times. Max reserved regions
> count grows bigger as more SOC subsystems require reserved regions.
>
> Add a Kconfig for it so that when properly configured, the static
> reserved_mem array consumes less memory on systems with few reserved
> regions.

Please read prior discussions:

https://lore.kernel.org/all/?q=of+MAX_RESERVED_REGIONS

And these 2 in particular:

https://lore.kernel.org/all/CAL_JsqJQcWsguwfehAoaRf4o-2VqXxSzKzTqg7s4+N1bp=6V5Q@mail.gmail.com/
https://lore.kernel.org/all/CAL_JsqLGvUYQmCGXLgSO+6kFj2i87dpaTbMGbyu5oMt=eeu35A@mail.gmail.com/

2021-11-16 00:22:11

by Calvin Zhang

Subject: Re: [PATCH v2] of: make MAX_RESERVED_REGIONS configurable

On Mon, Nov 15, 2021 at 08:05:45AM -0600, Rob Herring wrote:
>On Mon, Nov 15, 2021 at 1:33 AM Calvin Zhang <[email protected]> wrote:
>>
>> MAX_RESERVED_REGIONS has changed several times. Max reserved regions
>> count grows bigger as more SOC subsystems require reserved regions.
>>
>> Add a Kconfig for it so that when properly configured, the static
>> reserved_mem array consumes less memory on systems with few reserved
>> regions.
>
>Please read prior discussions:
>
>https://lore.kernel.org/all/?q=of+MAX_RESERVED_REGIONS
>
>And these 2 in particular:
>
>https://lore.kernel.org/all/CAL_JsqJQcWsguwfehAoaRf4o-2VqXxSzKzTqg7s4+N1bp=6V5Q@mail.gmail.com/
>https://lore.kernel.org/all/CAL_JsqLGvUYQmCGXLgSO+6kFj2i87dpaTbMGbyu5oMt=eeu35A@mail.gmail.com/
>
OK. I will try to make the array dynamic.

Thanks,
Calvin