From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ard Biesheuvel Subject: [PATCH 09/11] efi: permit multiple entries in persistent memreserve data structure Date: Thu, 29 Nov 2018 18:12:28 +0100 Message-ID: <20181129171230.18699-10-ard.biesheuvel@linaro.org> References: <20181129171230.18699-1-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181129171230.18699-1-ard.biesheuvel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-efi@vger.kernel.org, Ingo Molnar , Thomas Gleixner Cc: Ard Biesheuvel , linux-kernel@vger.kernel.org, Andy Lutomirski , Arend van Spriel , Bhupesh Sharma , Borislav Petkov , Dave Hansen , Eric Snowberg , Hans de Goede , Joe Perches , Jon Hunter , Julien Thierry , Marc Zyngier , Nathan Chancellor , Peter Zijlstra , Sai Praneeth Prakhya , Sedat Dilek , YiFei Zhu List-Id: linux-efi@vger.kernel.org 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: Marc Zyngier Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/efi.c | 39 +++++++++++++++++-------- drivers/firmware/efi/libstub/arm-stub.c | 2 +- include/linux/efi.h | 13 +++++++-- 3 files changed, 38 insertions(+), 16 deletions(-) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 415849bab233..80b11521627a 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -602,21 +602,33 @@ int __init efi_apply_persistent_mem_reservations(void) while (prsv) { struct linux_efi_memreserve *rsv; - - /* reserve the entry itself */ - memblock_reserve(prsv, sizeof(*rsv)); - - rsv = early_memremap(prsv, sizeof(*rsv)); - if (rsv == NULL) { + u8 *p; + int i; + + /* + * 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; diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 3d36142cf812..9e20159ea5f5 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -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, diff --git a/include/linux/efi.h b/include/linux/efi.h index 2b3b33c83b05..4f27640fdcdc 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -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; - phys_addr_t base; - phys_addr_t size; + 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 */ -- 2.19.1