From mboxrd@z Thu Jan 1 00:00:00 1970 From: jhugo@codeaurora.org (Jeffrey Hugo) Date: Sun, 12 Feb 2017 13:10:56 -0700 Subject: [PATCH v2 2/2] efi: arm-stub: Round up FDT allocation to mapping size In-Reply-To: <1486676573-19237-2-git-send-email-ard.biesheuvel@linaro.org> References: <1486676573-19237-1-git-send-email-ard.biesheuvel@linaro.org> <1486676573-19237-2-git-send-email-ard.biesheuvel@linaro.org> Message-ID: <9355065f-5782-e935-e8dc-9f6c0676b7f2@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2/9/2017 2:42 PM, Ard Biesheuvel wrote: > The FDT is mapped via a fixmap entry that is at least 2 MB in size and > 2 MB aligned on 4 KB page size kernels. > > On UEFI systems, the FDT allocation may share this 2 MB block with a > reserved region, or another memory region that we should never map, > unless we account for this in the size of the allocation (the alignment > is already 2 MB) > > So instead of taking guesses at the needed space, simply allocate 2 MB > immediately. The allocation will be recorded as a EFI_LOADER_DATA, and > the kernel only memblock_reserve()'s the actual size of the FDT, so the > unused space will be released to the kernel. > > Signed-off-by: Ard Biesheuvel > --- Reviewed-By: Jeffrey Hugo > arch/arm64/include/asm/efi.h | 1 + > drivers/firmware/efi/libstub/fdt.c | 57 +++++++++----------- > 2 files changed, 25 insertions(+), 33 deletions(-) > > diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h > index 342e90d6d204..f642565fc1d0 100644 > --- a/arch/arm64/include/asm/efi.h > +++ b/arch/arm64/include/asm/efi.h > @@ -1,6 +1,7 @@ > #ifndef _ASM_EFI_H > #define _ASM_EFI_H > > +#include > #include > #include > #include > diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c > index 260c4b4b492e..41f457be64e8 100644 > --- a/drivers/firmware/efi/libstub/fdt.c > +++ b/drivers/firmware/efi/libstub/fdt.c > @@ -206,6 +206,10 @@ static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg, > return update_fdt_memmap(p->new_fdt_addr, map); > } > > +#ifndef MAX_FDT_SIZE > +#define MAX_FDT_SIZE SZ_2M > +#endif > + > /* > * Allocate memory for a new FDT, then add EFI, commandline, and > * initrd related fields to the FDT. This routine increases the > @@ -233,7 +237,6 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, > u32 desc_ver; > unsigned long mmap_key; > efi_memory_desc_t *memory_map, *runtime_map; > - unsigned long new_fdt_size; > efi_status_t status; > int runtime_entry_count = 0; > struct efi_boot_memmap map; > @@ -262,41 +265,29 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, > "Exiting boot services and installing virtual address map...\n"); > > map.map = &memory_map; > + status = efi_high_alloc(sys_table, MAX_FDT_SIZE, EFI_FDT_ALIGN, > + new_fdt_addr, max_addr); > + if (status != EFI_SUCCESS) { > + pr_efi_err(sys_table, > + "Unable to allocate memory for new device tree.\n"); > + goto fail; > + } > + > /* > - * Estimate size of new FDT, and allocate memory for it. We > - * will allocate a bigger buffer if this ends up being too > - * small, so a rough guess is OK here. > + * Now that we have done our final memory allocation (and free) > + * we can get the memory map key needed for exit_boot_services(). > */ > - new_fdt_size = fdt_size + EFI_PAGE_SIZE; > - while (1) { > - status = efi_high_alloc(sys_table, new_fdt_size, EFI_FDT_ALIGN, > - new_fdt_addr, max_addr); > - if (status != EFI_SUCCESS) { > - pr_efi_err(sys_table, "Unable to allocate memory for new device tree.\n"); > - goto fail; > - } > - > - status = update_fdt(sys_table, > - (void *)fdt_addr, fdt_size, > - (void *)*new_fdt_addr, new_fdt_size, > - cmdline_ptr, initrd_addr, initrd_size); > + status = efi_get_memory_map(sys_table, &map); > + if (status != EFI_SUCCESS) > + goto fail_free_new_fdt; > > - /* Succeeding the first time is the expected case. */ > - if (status == EFI_SUCCESS) > - break; > + status = update_fdt(sys_table, (void *)fdt_addr, fdt_size, > + (void *)*new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr, > + initrd_addr, initrd_size); > > - if (status == EFI_BUFFER_TOO_SMALL) { > - /* > - * We need to allocate more space for the new > - * device tree, so free existing buffer that is > - * too small. > - */ > - efi_free(sys_table, new_fdt_size, *new_fdt_addr); > - new_fdt_size += EFI_PAGE_SIZE; > - } else { > - pr_efi_err(sys_table, "Unable to construct new device tree.\n"); > - goto fail_free_new_fdt; > - } > + if (status != EFI_SUCCESS) { > + pr_efi_err(sys_table, "Unable to construct new device tree.\n"); > + goto fail_free_new_fdt; > } > > priv.runtime_map = runtime_map; > @@ -340,7 +331,7 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, > pr_efi_err(sys_table, "Exit boot services failed.\n"); > > fail_free_new_fdt: > - efi_free(sys_table, new_fdt_size, *new_fdt_addr); > + efi_free(sys_table, MAX_FDT_SIZE, *new_fdt_addr); > > fail: > sys_table->boottime->free_pool(runtime_map); > -- Jeffrey Hugo Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.