Hi Sughosh On Mon, 10 Jun 2024 at 15:25, Sughosh Ganu <sughosh.g...@linaro.org> wrote: > > On Mon, 10 Jun 2024 at 17:40, Ilias Apalodimas > <ilias.apalodi...@linaro.org> wrote: > > > > On Fri, 7 Jun 2024 at 21:54, Sughosh Ganu <sughosh.g...@linaro.org> wrote: > > > > > > There are events that would be used to notify other interested modules > > > of any changes in available and occupied memory. This would happen > > > when a module allocates or reserves memory, or frees up memory. These > > > changes in memory map should be notified to other interested modules > > > so that the allocated memory does not get overwritten. Add an event > > > handler in the EFI memory module to update the EFI memory map > > > accordingly when such changes happen. As a consequence, any subsequent > > > memory request would honour the updated memory map and only available > > > memory would be allocated from. > > > > So the question here, is why do we need a notifier chain overall? > > Can't we change the EFI subsystem and allocate memory with lmb now? > > And any special functions we have in EFI (e.g allocate aligned memory) > > can migrate to lmb() > > Like we discussed offline, that was my initial attempt -- to use the > LMB allocation API's from inside the EFI allocate pages module. But I > was facing a lot of corner case issues, primarily in keeping the two > memory maps the same.
I think it would worth discussing this a bit more. I like the idea of having a single allocator more than having events to update memory reservations > Which is why I moved to the current > implementation of notifying other modules, and that too only for the > addresses in the RAM region. The notification to 'other modules' i still done by updating the static memory map though no? So what corner cases we couldn't solve by having a single allocator? Thanks /Ilias > > -sughosh > > > > > Cheers > > /Ilias > > > > > > Signed-off-by: Sughosh Ganu <sughosh.g...@linaro.org> > > > --- > > > lib/efi_loader/efi_memory.c | 70 ++++++++++++++++++++++++++++++------- > > > 1 file changed, 58 insertions(+), 12 deletions(-) > > > > > > diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c > > > index 435e580fb3..93244161b0 100644 > > > --- a/lib/efi_loader/efi_memory.c > > > +++ b/lib/efi_loader/efi_memory.c > > > @@ -73,6 +73,10 @@ struct efi_pool_allocation { > > > #if CONFIG_IS_ENABLED(MEM_MAP_UPDATE_NOTIFY) > > > extern bool is_addr_in_ram(uintptr_t addr); > > > > > > +static efi_status_t __efi_add_memory_map_pg(u64 start, u64 pages, > > > + int memory_type, > > > + bool overlap_only_ram); > > > + > > > static void efi_map_update_notify(u64 addr, u64 size, u8 op) > > > { > > > struct event_efi_mem_map_update efi_map = {0}; > > > @@ -84,6 +88,34 @@ static void efi_map_update_notify(u64 addr, u64 size, > > > u8 op) > > > if (is_addr_in_ram((uintptr_t)addr)) > > > event_notify(EVT_EFI_MEM_MAP_UPDATE, &efi_map, > > > sizeof(efi_map)); > > > } > > > + > > > +static int lmb_mem_map_update_sync(void *ctx, struct event *event) > > > +{ > > > + u8 op; > > > + u64 addr; > > > + u64 pages; > > > + efi_status_t status; > > > + struct event_lmb_map_update *lmb_map = &event->data.lmb_map; > > > + > > > + addr = (uintptr_t)map_sysmem(lmb_map->base, 0); > > > + pages = efi_size_in_pages(lmb_map->size + (addr & EFI_PAGE_MASK)); > > > + op = lmb_map->op; > > > + addr &= ~EFI_PAGE_MASK; > > > + > > > + if (op != MAP_OP_RESERVE && op != MAP_OP_FREE) { > > > + log_debug("Invalid map update op received (%d)\n", op); > > > + return -1; > > > + } > > > + > > > + status = __efi_add_memory_map_pg(addr, pages, > > > + op == MAP_OP_FREE ? > > > + EFI_CONVENTIONAL_MEMORY : > > > + EFI_BOOT_SERVICES_DATA, > > > + true); > > > + > > > + return status == EFI_SUCCESS ? 0 : -1; > > > +} > > > +EVENT_SPY_FULL(EVT_LMB_MAP_UPDATE, lmb_mem_map_update_sync); > > > #endif /* MEM_MAP_UPDATE_NOTIFY */ > > > > > > /** > > > @@ -275,18 +307,9 @@ static s64 efi_mem_carve_out(struct efi_mem_list > > > *map, > > > return EFI_CARVE_LOOP_AGAIN; > > > } > > > > > > -/** > > > - * efi_add_memory_map_pg() - add pages to the memory map > > > - * > > > - * @start: start address, must be a multiple of EFI_PAGE_SIZE > > > - * @pages: number of pages to add > > > - * @memory_type: type of memory added > > > - * @overlap_only_ram: region may only overlap RAM > > > - * Return: status code > > > - */ > > > -static efi_status_t efi_add_memory_map_pg(u64 start, u64 pages, > > > - int memory_type, > > > - bool overlap_only_ram) > > > +static efi_status_t __efi_add_memory_map_pg(u64 start, u64 pages, > > > + int memory_type, > > > + bool overlap_only_ram) > > > { > > > struct list_head *lhandle; > > > struct efi_mem_list *newlist; > > > @@ -395,6 +418,29 @@ static efi_status_t efi_add_memory_map_pg(u64 start, > > > u64 pages, > > > } > > > } > > > > > > + return EFI_SUCCESS; > > > +} > > > + > > > +/** > > > + * efi_add_memory_map_pg() - add pages to the memory map > > > + * > > > + * @start: start address, must be a multiple of EFI_PAGE_SIZE > > > + * @pages: number of pages to add > > > + * @memory_type: type of memory added > > > + * @overlap_only_ram: region may only overlap RAM > > > + * Return: status code > > > + */ > > > +static efi_status_t efi_add_memory_map_pg(u64 start, u64 pages, > > > + int memory_type, > > > + bool overlap_only_ram) > > > +{ > > > + efi_status_t status; > > > + > > > + status = __efi_add_memory_map_pg(start, pages, memory_type, > > > + overlap_only_ram); > > > + if (status != EFI_SUCCESS) > > > + return status; > > > + > > > if (CONFIG_IS_ENABLED(MEM_MAP_UPDATE_NOTIFY)) > > > efi_map_update_notify(start, pages << EFI_PAGE_SHIFT, > > > memory_type == > > > EFI_CONVENTIONAL_MEMORY ? > > > -- > > > 2.34.1 > > >