| Message ID | 1542787873-8429-1-git-send-email-miles.chen@mediatek.com (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
| Series | [RFC] of: make MAX_RESERVED_REGIONS configurable | expand |
On Wed, Nov 21, 2018 at 2:11 AM <miles.chen@mediatek.com> wrote: > > From: Miles Chen <miles.chen@mediatek.com> > > When we use more than 32 entries in /resered-memory, > there will be an error message: "not enough space all defined regions.". > We can increase MAX_RESERVED_REGIONS to fix this. > > commit 22f8cc6e3373 ("drivers: of: increase MAX_RESERVED_REGIONS to 32") > increased MAX_RESERVED_REGIONS to 32 but I'm not sure if increasing > MAX_RESERVED_REGIONS to 64 is suitable for everyone. > > In this RFC patch, CONFIG_MAX_OF_RESERVED_REGIONS is added and used as > MAX_RESERVED_REGIONS. Add a sanity test to make sure that > MAX_RESERVED_REGIONS is less than INIT_MEMBLOCK_REGIONS. > Users can configure CONFIG_MAX_OF_RESERVED_REGIONS according to their > need. I don't want a kconfig option for this. I think it should be dynamic instead. The current flow is like this: for each reserved node: - call memblock_reserve - Add info to reserved_mem array I think we should change it to: for each reserved node: - call memblock_reserve - count number of nodes Alloc array using memblock_alloc for each reserved node: - Add info to reserved_mem array Rob
On Wed, 2018-11-21 at 10:39 -0600, Rob Herring wrote: > On Wed, Nov 21, 2018 at 2:11 AM <miles.chen@mediatek.com> wrote: > > > > From: Miles Chen <miles.chen@mediatek.com> > > > > When we use more than 32 entries in /resered-memory, > > there will be an error message: "not enough space all defined regions.". > > We can increase MAX_RESERVED_REGIONS to fix this. > > > > commit 22f8cc6e3373 ("drivers: of: increase MAX_RESERVED_REGIONS to 32") > > increased MAX_RESERVED_REGIONS to 32 but I'm not sure if increasing > > MAX_RESERVED_REGIONS to 64 is suitable for everyone. > > > > In this RFC patch, CONFIG_MAX_OF_RESERVED_REGIONS is added and used as > > MAX_RESERVED_REGIONS. Add a sanity test to make sure that > > MAX_RESERVED_REGIONS is less than INIT_MEMBLOCK_REGIONS. > > Users can configure CONFIG_MAX_OF_RESERVED_REGIONS according to their > > need. > > I don't want a kconfig option for this. I think it should be dynamic instead. > > The current flow is like this: > > for each reserved node: > - call memblock_reserve > - Add info to reserved_mem array > > I think we should change it to: > > for each reserved node: > - call memblock_reserve > - count number of nodes > > Alloc array using memblock_alloc > > for each reserved node: > - Add info to reserved_mem array > thanks for your comment. I reviewed the flow and it might be easier to count the nodes and setup array first: for each reserved node: - count number of nodes Alloc array using memblock_alloc for each reserved node: - call memblock_reserve - Add info to reserved_mem array What do you think? > Rob
On Wed, Nov 21, 2018 at 8:51 PM Miles Chen <miles.chen@mediatek.com> wrote: > > On Wed, 2018-11-21 at 10:39 -0600, Rob Herring wrote: > > On Wed, Nov 21, 2018 at 2:11 AM <miles.chen@mediatek.com> wrote: > > > > > > From: Miles Chen <miles.chen@mediatek.com> > > > > > > When we use more than 32 entries in /resered-memory, > > > there will be an error message: "not enough space all defined regions.". > > > We can increase MAX_RESERVED_REGIONS to fix this. > > > > > > commit 22f8cc6e3373 ("drivers: of: increase MAX_RESERVED_REGIONS to 32") > > > increased MAX_RESERVED_REGIONS to 32 but I'm not sure if increasing > > > MAX_RESERVED_REGIONS to 64 is suitable for everyone. > > > > > > In this RFC patch, CONFIG_MAX_OF_RESERVED_REGIONS is added and used as > > > MAX_RESERVED_REGIONS. Add a sanity test to make sure that > > > MAX_RESERVED_REGIONS is less than INIT_MEMBLOCK_REGIONS. > > > Users can configure CONFIG_MAX_OF_RESERVED_REGIONS according to their > > > need. > > > > I don't want a kconfig option for this. I think it should be dynamic instead. > > > > The current flow is like this: > > > > for each reserved node: > > - call memblock_reserve > > - Add info to reserved_mem array > > > > I think we should change it to: > > > > for each reserved node: > > - call memblock_reserve > > - count number of nodes > > > > Alloc array using memblock_alloc > > > > for each reserved node: > > - Add info to reserved_mem array > > > > thanks for your comment. > > I reviewed the flow and it might be easier to count the > nodes and setup array first: > > for each reserved node: > - count number of nodes > > Alloc array using memblock_alloc > > > for each reserved node: > - call memblock_reserve The order here is wrong. It is important that you reserve the memory blocks before doing any allocations. > - Add info to reserved_mem array > > What do you think? > > > Rob > >
On Sat, 2018-11-24 at 14:56 -0600, Rob Herring wrote: > On Wed, Nov 21, 2018 at 8:51 PM Miles Chen <miles.chen@mediatek.com> wrote: > > > > On Wed, 2018-11-21 at 10:39 -0600, Rob Herring wrote: > > > On Wed, Nov 21, 2018 at 2:11 AM <miles.chen@mediatek.com> wrote: > > > > > > > > From: Miles Chen <miles.chen@mediatek.com> > > > > > > > > When we use more than 32 entries in /resered-memory, > > > > there will be an error message: "not enough space all defined regions.". > > > > We can increase MAX_RESERVED_REGIONS to fix this. > > > > > > > > commit 22f8cc6e3373 ("drivers: of: increase MAX_RESERVED_REGIONS to 32") > > > > increased MAX_RESERVED_REGIONS to 32 but I'm not sure if increasing > > > > MAX_RESERVED_REGIONS to 64 is suitable for everyone. > > > > > > > > In this RFC patch, CONFIG_MAX_OF_RESERVED_REGIONS is added and used as > > > > MAX_RESERVED_REGIONS. Add a sanity test to make sure that > > > > MAX_RESERVED_REGIONS is less than INIT_MEMBLOCK_REGIONS. > > > > Users can configure CONFIG_MAX_OF_RESERVED_REGIONS according to their > > > > need. > > > > > > I don't want a kconfig option for this. I think it should be dynamic instead. > > > > > > The current flow is like this: > > > > > > for each reserved node: > > > - call memblock_reserve > > > - Add info to reserved_mem array > > > > > > I think we should change it to: > > > > > > for each reserved node: > > > - call memblock_reserve > > > - count number of nodes > > > > > > Alloc array using memblock_alloc > > > > > > for each reserved node: > > > - Add info to reserved_mem array > > > > > > > thanks for your comment. > > > > I reviewed the flow and it might be easier to count the > > nodes and setup array first: > > > > for each reserved node: > > - count number of nodes > > > > Alloc array using memblock_alloc > > > > > > for each reserved node: > > - call memblock_reserve > > The order here is wrong. It is important that you reserve the memory > blocks before doing any allocations. thanks for pointing that out. You are right. I'll follow your suggestion. > > > - Add info to reserved_mem array > > > > What do you think? > > > > > Rob > > > >
On Mon, 2018-11-26 at 09:33 +0800, Miles Chen wrote: > On Sat, 2018-11-24 at 14:56 -0600, Rob Herring wrote: > > On Wed, Nov 21, 2018 at 8:51 PM Miles Chen <miles.chen@mediatek.com> wrote: > > > > > > On Wed, 2018-11-21 at 10:39 -0600, Rob Herring wrote: > > > > On Wed, Nov 21, 2018 at 2:11 AM <miles.chen@mediatek.com> wrote: > > > > > > > > > > From: Miles Chen <miles.chen@mediatek.com> > > > > > > > > > > When we use more than 32 entries in /resered-memory, > > > > > there will be an error message: "not enough space all defined regions.". > > > > > We can increase MAX_RESERVED_REGIONS to fix this. > > > > > > > > > > commit 22f8cc6e3373 ("drivers: of: increase MAX_RESERVED_REGIONS to 32") > > > > > increased MAX_RESERVED_REGIONS to 32 but I'm not sure if increasing > > > > > MAX_RESERVED_REGIONS to 64 is suitable for everyone. > > > > > > > > > > In this RFC patch, CONFIG_MAX_OF_RESERVED_REGIONS is added and used as > > > > > MAX_RESERVED_REGIONS. Add a sanity test to make sure that > > > > > MAX_RESERVED_REGIONS is less than INIT_MEMBLOCK_REGIONS. > > > > > Users can configure CONFIG_MAX_OF_RESERVED_REGIONS according to their > > > > > need. > > > > > > > > I don't want a kconfig option for this. I think it should be dynamic instead. > > > > > > > > The current flow is like this: > > > > > > > > for each reserved node: > > > > - call memblock_reserve > > > > - Add info to reserved_mem array > > > > > > > > I think we should change it to: > > > > > > > > for each reserved node: > > > > - call memblock_reserve > > > > - count number of nodes > > > > > > > > Alloc array using memblock_alloc > > > > > > > > for each reserved node: > > > > - Add info to reserved_mem array > > > > > > > > > > thanks for your comment. > > > > > > I reviewed the flow and it might be easier to count the > > > nodes and setup array first: > > > > > > for each reserved node: > > > - count number of nodes > > > > > > Alloc array using memblock_alloc > > > > > > > > > for each reserved node: > > > - call memblock_reserve > > > > The order here is wrong. It is important that you reserve the memory > > blocks before doing any allocations. > > thanks for pointing that out. You are right. I'll follow your > suggestion. I got a problem while implementing this change: the array allocation is done successfully but the kernel does not create mappings for it yet, so the array is not accessible. (kernel will create the mapping later in paging_init()) For example: aarch64 setup_arch() setup_arch() { memblock_init(); /* early_init_fdt_scan_reserved_mem() is called */ paging_init(); } Could you give me some advice, please? Miles > > > > > > - Add info to reserved_mem array > > > > > > What do you think? > > > > > > > Rob > > > > > > > >
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index ad3fcad..63fff2e 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -86,6 +86,15 @@ config OF_RESERVED_MEM help Helpers to allow for reservation of memory regions +config MAX_OF_RESERVED_REGIONS + int "the max number of devicetree reserved memory regions" + depends on OF_RESERVED_MEM + default 32 + help + Setup the max number of devicetree reserved memory regions + If unsure, leave the default value "32". + + config OF_RESOLVE bool diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index 1977ee0..18a7729 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -22,7 +22,7 @@ #include <linux/slab.h> #include <linux/memblock.h> -#define MAX_RESERVED_REGIONS 32 +#define MAX_RESERVED_REGIONS CONFIG_MAX_OF_RESERVED_REGIONS static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS]; static int reserved_mem_count; @@ -246,6 +246,9 @@ void __init fdt_init_reserved_mem(void) { int i; + /* MAX_RESERVED_REGIONS should be bounded by INIT_MEMBLOCK_REGIONS */ + BUILD_BUG_ON(MAX_RESERVED_REGIONS > INIT_MEMBLOCK_REGIONS); + /* check for overlapping reserved regions */ __rmem_check_for_overlap();