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Commit 5f0b0ecf authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Ingo Molnar
Browse files

efi: Permit multiple entries in persistent memreserve data structure 



In preparation of updating efi_mem_reserve_persistent() to cause less
fragmentation when dealing with many persistent reservations, update
the struct definition and the code that handles it currently so it
can describe an arbitrary number of reservations using a single linked
list entry. The actual optimization will be implemented in a subsequent
patch.

Tested-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-10-ard.biesheuvel@linaro.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 3db5e0ba

drivers/firmware/efi/efi.c

+27 −12
Original line number Diff line number Diff line
@@ -602,21 +602,33 @@ int __init efi_apply_persistent_mem_reservations(void) 


		while (prsv) {

			struct linux_efi_memreserve *rsv;

			u8 *p;

			int i;



			/* reserve the entry itself */

			memblock_reserve(prsv, sizeof(*rsv));



			rsv = early_memremap(prsv, sizeof(*rsv));

			if (rsv == NULL) {

			/*

			 * Just map a full page: that is what we will get

			 * anyway, and it permits us to map the entire entry

			 * before knowing its size.

			 */

			p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),

					   PAGE_SIZE);

			if (p == NULL) {

				pr_err("Could not map UEFI memreserve entry!\n");

				return -ENOMEM;

			}



			if (rsv->size)

				memblock_reserve(rsv->base, rsv->size);

			rsv = (void *)(p + prsv % PAGE_SIZE);



			/* reserve the entry itself */

			memblock_reserve(prsv, EFI_MEMRESERVE_SIZE(rsv->size));



			for (i = 0; i < atomic_read(&rsv->count); i++) {

				memblock_reserve(rsv->entry[i].base,

						 rsv->entry[i].size);

			}



			prsv = rsv->next;

			early_memunmap(rsv, sizeof(*rsv));

			early_memunmap(p, PAGE_SIZE);

		}

	}
@@ -985,6 +997,7 @@ static int __init efi_memreserve_map_root(void) 
int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)

{

	struct linux_efi_memreserve *rsv;

	int rsvsize = EFI_MEMRESERVE_SIZE(1);

	int rc;



	if (efi_memreserve_root == (void *)ULONG_MAX)
@@ -996,12 +1009,14 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) 
			return rc;

	}



	rsv = kmalloc(sizeof(*rsv), GFP_ATOMIC);

	rsv = kmalloc(rsvsize, GFP_ATOMIC);

	if (!rsv)

		return -ENOMEM;



	rsv->base = addr;

	rsv->size = size;

	rsv->size = 1;

	atomic_set(&rsv->count, 1);

	rsv->entry[0].base = addr;

	rsv->entry[0].size = size;



	spin_lock(&efi_mem_reserve_persistent_lock);

	rsv->next = efi_memreserve_root->next;

drivers/firmware/efi/libstub/arm-stub.c

+1 −1
Original line number Diff line number Diff line
@@ -86,8 +86,8 @@ void install_memreserve_table(efi_system_table_t *sys_table_arg) 
	}



	rsv->next = 0;

	rsv->base = 0;

	rsv->size = 0;

	atomic_set(&rsv->count, 0);



	status = efi_call_early(install_configuration_table,

				&memreserve_table_guid,

include/linux/efi.h

+10 −3
Original line number Diff line number Diff line
@@ -1712,9 +1712,16 @@ extern struct efi_runtime_work efi_rts_work; 
extern struct workqueue_struct *efi_rts_wq;



struct linux_efi_memreserve {

	phys_addr_t	next;

	int		size;			// allocated size of the array

	atomic_t	count;			// number of entries used

	phys_addr_t	next;			// pa of next struct instance

	struct {

		phys_addr_t	base;

		phys_addr_t	size;

	} entry[0];

};



#define EFI_MEMRESERVE_SIZE(count) (sizeof(struct linux_efi_memreserve) + \

	(count) * sizeof(((struct linux_efi_memreserve *)0)->entry[0]))



#endif /* _LINUX_EFI_H */