[PATCH v8 4/8] efi_loader: add a function to remove memory from the EFI map
Ilias Apalodimas
ilias.apalodimas at linaro.org
Wed Mar 12 11:18:27 CET 2025
Hi Heinrich
On Wed, 12 Mar 2025 at 12:13, Heinrich Schuchardt <xypron.glpk at gmx.de>
wrote:
> On 12.03.25 09:54, Sughosh Ganu wrote:
> > From: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> >
> > With upcoming changes supporting pmem nodes, we need to remove the
> > pmem area from the EFI memory map. Add a function to do that.
> >
> > Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> > Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> > Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> > ---
> > Changes since V7: None
> >
> > include/efi_loader.h | 18 ++++++++++++
> > lib/efi_loader/efi_memory.c | 56 ++++++++++++++++++++++++++-----------
> > 2 files changed, 58 insertions(+), 16 deletions(-)
> >
> > diff --git a/include/efi_loader.h b/include/efi_loader.h
> > index e9c10819ba2..c20c98c6476 100644
> > --- a/include/efi_loader.h
> > +++ b/include/efi_loader.h
> > @@ -878,6 +878,24 @@ efi_status_t efi_get_memory_map(efi_uintn_t
> *memory_map_size,
> > /* Adds a range into the EFI memory map */
> > efi_status_t efi_add_memory_map(u64 start, u64 size, int memory_type);
> >
> > +/**
> > + * efi_update_memory_map() - update the memory map by adding/removing
> pages
> > + *
> > + * @start: start address, must be a multiple of
> > + * EFI_PAGE_SIZE
> > + * @pages: number of pages to add
> > + * @memory_type: type of memory added
> > + * @overlap_conventional: region may only overlap free(conventional)
> > + * memory
> > + * @remove: remove memory map
> > + * Return: status code
> > + */
> > +efi_status_t efi_update_memory_map(u64 start, u64 pages, int
> memory_type,
> > + bool overlap_conventional, bool remove);
>
> Why do we have so many functions that are all doing nearly the same thing:
>
> * efi_map_update_notify()
> * efi_update_memory_map()
> * efi_remove_memory_map()
> * efi_add_memory_map_pg()
>
> I start failing to understand when to use which. This is getting as
> gruesome as LMB.
>
We are not there yet!
> Can't we have a single exported function with a properly defined
> interface to cover all use cases
>
We actually do,
efi_update_memory_map() is what all the functions call with the correct
arguments.
The reset were added to make the thing easier not harder. You want to
remove the wrappers?
Thanks
/Ilias
Best regards
>
> Heinrich
>
> > +
> > +/* Remove memory from the EFI memory map */
> > +efi_status_t efi_remove_memory_map(u64 start, u64 size, int
> memory_type);
> > +
> > /* Called by board init to initialize the EFI drivers */
> > efi_status_t efi_driver_init(void);
> > /* Called when a block device is added */
> > diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> > index 6d00b186250..3fec40b6de5 100644
> > --- a/lib/efi_loader/efi_memory.c
> > +++ b/lib/efi_loader/efi_memory.c
> > @@ -258,7 +258,7 @@ static s64 efi_mem_carve_out(struct efi_mem_list
> *map,
> > }
> >
> > /**
> > - * efi_add_memory_map_pg() - add pages to the memory map
> > + * efi_update_memory_map() - update the memory map by adding/removing
> pages
> > *
> > * @start: start address, must be a multiple of
> > * EFI_PAGE_SIZE
> > @@ -266,12 +266,11 @@ static s64 efi_mem_carve_out(struct efi_mem_list
> *map,
> > * @memory_type: type of memory added
> > * @overlap_conventional: region may only overlap free(conventional)
> > * memory
> > + * @remove: remove memory map
> > * Return: status code
> > */
> > -static
> > -efi_status_t efi_add_memory_map_pg(u64 start, u64 pages,
> > - int memory_type,
> > - bool overlap_conventional)
> > +efi_status_t efi_update_memory_map(u64 start, u64 pages, int
> memory_type,
> > + bool overlap_conventional, bool remove)
> > {
> > struct efi_mem_list *lmem;
> > struct efi_mem_list *newlist;
> > @@ -279,9 +278,9 @@ efi_status_t efi_add_memory_map_pg(u64 start, u64
> pages,
> > uint64_t carved_pages = 0;
> > struct efi_event *evt;
> >
> > - EFI_PRINT("%s: 0x%llx 0x%llx %d %s\n", __func__,
> > + EFI_PRINT("%s: 0x%llx 0x%llx %d %s %s\n", __func__,
> > start, pages, memory_type, overlap_conventional ?
> > - "yes" : "no");
> > + "yes" : "no", remove ? "remove" : "add");
> >
> > if (memory_type >= EFI_MAX_MEMORY_TYPE)
> > return EFI_INVALID_PARAMETER;
> > @@ -364,7 +363,10 @@ efi_status_t efi_add_memory_map_pg(u64 start, u64
> pages,
> > }
> >
> > /* Add our new map */
> > - list_add_tail(&newlist->link, &efi_mem);
> > + if (!remove)
> > + list_add_tail(&newlist->link, &efi_mem);
> > + else
> > + free(newlist);
> >
> > /* And make sure memory is listed in descending order */
> > efi_mem_sort();
> > @@ -401,7 +403,29 @@ efi_status_t efi_add_memory_map(u64 start, u64
> size, int memory_type)
> > pages = efi_size_in_pages(size + (start & EFI_PAGE_MASK));
> > start &= ~EFI_PAGE_MASK;
> >
> > - return efi_add_memory_map_pg(start, pages, memory_type, false);
> > + return efi_update_memory_map(start, pages, memory_type, false,
> false);
> > +}
> > +
> > +/**
> > + * efi_remove_memory_map() - remove memory area to the memory map
> > + *
> > + * @start: start address of the memory area
> > + * @size: length in bytes of the memory area
> > + * @memory_type: type of memory removed
> > + *
> > + * Return: status code
> > + *
> > + * This function automatically aligns the start and size of the memory
> area
> > + * to EFI_PAGE_SIZE.
> > + */
> > +efi_status_t efi_remove_memory_map(u64 start, u64 size, int memory_type)
> > +{
> > + u64 pages;
> > +
> > + pages = efi_size_in_pages(size + (start & EFI_PAGE_MASK));
> > + start &= ~EFI_PAGE_MASK;
> > +
> > + return efi_update_memory_map(start, pages, memory_type, false,
> true);
> > }
> >
> > /**
> > @@ -502,7 +526,7 @@ efi_status_t efi_allocate_pages(enum
> efi_allocate_type type,
> >
> > efi_addr = (u64)(uintptr_t)map_sysmem(addr, 0);
> > /* Reserve that map in our memory maps */
> > - ret = efi_add_memory_map_pg(efi_addr, pages, memory_type, true);
> > + ret = efi_update_memory_map(efi_addr, pages, memory_type, true,
> false);
> > if (ret != EFI_SUCCESS) {
> > /* Map would overlap, bail out */
> > lmb_free_flags(addr, (u64)pages << EFI_PAGE_SHIFT, flags);
> > @@ -823,8 +847,8 @@ static void add_u_boot_and_runtime(void)
> > uboot_stack_size) & ~EFI_PAGE_MASK;
> > uboot_pages = ((uintptr_t)map_sysmem(gd->ram_top - 1, 0) -
> > uboot_start + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
> > - efi_add_memory_map_pg(uboot_start, uboot_pages,
> EFI_BOOT_SERVICES_CODE,
> > - false);
> > + efi_update_memory_map(uboot_start, uboot_pages,
> EFI_BOOT_SERVICES_CODE,
> > + false, false);
> > #if defined(__aarch64__)
> > /*
> > * Runtime Services must be 64KiB aligned according to the
> > @@ -842,8 +866,8 @@ static void add_u_boot_and_runtime(void)
> > runtime_end = (uintptr_t)__efi_runtime_stop;
> > runtime_end = (runtime_end + runtime_mask) & ~runtime_mask;
> > runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
> > - efi_add_memory_map_pg(runtime_start, runtime_pages,
> > - EFI_RUNTIME_SERVICES_CODE, false);
> > + efi_update_memory_map(runtime_start, runtime_pages,
> > + EFI_RUNTIME_SERVICES_CODE, false, false);
> > }
> >
> > int efi_memory_init(void)
> > @@ -878,11 +902,11 @@ int efi_map_update_notify(phys_addr_t addr,
> phys_size_t size,
> > pages = efi_size_in_pages(size + (efi_addr & EFI_PAGE_MASK));
> > efi_addr &= ~EFI_PAGE_MASK;
> >
> > - status = efi_add_memory_map_pg(efi_addr, pages,
> > + status = efi_update_memory_map(efi_addr, pages,
> > op == LMB_MAP_OP_RESERVE ?
> > EFI_BOOT_SERVICES_DATA :
> > EFI_CONVENTIONAL_MEMORY,
> > - false);
> > + false, false);
> > if (status != EFI_SUCCESS) {
> > log_err("LMB Map notify failure %lu\n",
> > status & ~EFI_ERROR_MASK);
>
>
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