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Date: Thu, 19 Jan 2017 00:54:50 +0530
From: Bhupesh Sharma <bhsharma@...hat.com>
To: Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc: Dave Young <dyoung@...hat.com>,
"Rafael J. Wysocki" <rjw@...ysocki.net>,
Len Brown <lenb@...nel.org>,
Matt Fleming <matt@...eblueprint.co.uk>,
"linux-efi@...r.kernel.org" <linux-efi@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"x86@...nel.org" <x86@...nel.org>,
Nicolai Stange <nicstange@...il.com>,
Ingo Molnar <mingo@...nel.org>,
Thomas Gleixner <tglx@...utronix.de>,
"hpa@...or.com" <hpa@...or.com>,
Dan Williams <dan.j.williams@...el.com>,
Mika Penttilä <mika.penttila@...tfour.com>
Subject: Re: [PATCH V3 1/4] efi/x86: move efi bgrt init code to early init code
On Wed, Jan 18, 2017 at 7:30 PM, Ard Biesheuvel
<ard.biesheuvel@...aro.org> wrote:
> On 18 January 2017 at 13:48, Dave Young <dyoung@...hat.com> wrote:
>> Before invoking the arch specific handler, efi_mem_reserve() reserves
>> the given memory region through memblock.
>>
>> efi_bgrt_init will call efi_mem_reserve after mm_init(), at that time
>> memblock is dead and it should not be used any more.
>>
>> efi bgrt code depend on acpi intialization to get the bgrt acpi table,
>> moving bgrt parsing to acpi early boot code can make sure efi_mem_reserve
>> in efi bgrt code still use memblock safely.
>>
>> Signed-off-by: Dave Young <dyoung@...hat.com>
>
> This patch looks fine to me know
>
> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
>
> but before applying it, I'd like
>
> - Bhupesh to confirm that this patch is a move in the right direction
> with regard to enabling BGRT on arm64/ACPI,
I gave the changes from Dave a try on top of the following combination:
4.10-rc3 + efi/next patches not available in 4.10-rc3 + Nicolai's patches
and was able to get the BGRT table working properly with OVMF on a
QEMU-x86_64 machine. So you can add my tested-by for this patch
series.
I think this is the right direction for the ARM64 BGRT handling
patches as well and I will post a RFC in two phases as suggested by
Ard, once Dave's patches are accepted (in efi/next?).
Regards,
Bhupesh
> - an ack from the ACPI maintainers (cc'ed)
>
> Thanks,
> Ard.
>
>
>> ---
>> v1->v2: efi_bgrt_init: check table length first before copying bgrt table
>> error checking in drivers/acpi/bgrt.c
>> v2->v3: drop #ifdef added before; efi-bgrt.h build warning fix
>> since only changed this patch, so I just only resend this one.
>> arch/x86/kernel/acpi/boot.c | 9 +++++
>> arch/x86/platform/efi/efi-bgrt.c | 59 ++++++++++++++++-----------------------
>> arch/x86/platform/efi/efi.c | 5 ---
>> drivers/acpi/bgrt.c | 28 +++++++++++++-----
>> include/linux/efi-bgrt.h | 11 +++----
>> init/main.c | 1
>> 6 files changed, 59 insertions(+), 54 deletions(-)
>>
>> --- linux-x86.orig/arch/x86/kernel/acpi/boot.c
>> +++ linux-x86/arch/x86/kernel/acpi/boot.c
>> @@ -35,6 +35,7 @@
>> #include <linux/bootmem.h>
>> #include <linux/ioport.h>
>> #include <linux/pci.h>
>> +#include <linux/efi-bgrt.h>
>>
>> #include <asm/irqdomain.h>
>> #include <asm/pci_x86.h>
>> @@ -1557,6 +1558,12 @@ int __init early_acpi_boot_init(void)
>> return 0;
>> }
>>
>> +static int __init acpi_parse_bgrt(struct acpi_table_header *table)
>> +{
>> + efi_bgrt_init(table);
>> + return 0;
>> +}
>> +
>> int __init acpi_boot_init(void)
>> {
>> /* those are executed after early-quirks are executed */
>> @@ -1581,6 +1588,8 @@ int __init acpi_boot_init(void)
>> acpi_process_madt();
>>
>> acpi_table_parse(ACPI_SIG_HPET, acpi_parse_hpet);
>> + if (IS_ENABLED(CONFIG_ACPI_BGRT))
>> + acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
>>
>> if (!acpi_noirq)
>> x86_init.pci.init = pci_acpi_init;
>> --- linux-x86.orig/arch/x86/platform/efi/efi-bgrt.c
>> +++ linux-x86/arch/x86/platform/efi/efi-bgrt.c
>> @@ -19,8 +19,7 @@
>> #include <linux/efi.h>
>> #include <linux/efi-bgrt.h>
>>
>> -struct acpi_table_bgrt *bgrt_tab;
>> -void *__initdata bgrt_image;
>> +struct acpi_table_bgrt bgrt_tab;
>> size_t __initdata bgrt_image_size;
>>
>> struct bmp_header {
>> @@ -28,66 +27,58 @@ struct bmp_header {
>> u32 size;
>> } __packed;
>>
>> -void __init efi_bgrt_init(void)
>> +void __init efi_bgrt_init(struct acpi_table_header *table)
>> {
>> - acpi_status status;
>> void *image;
>> struct bmp_header bmp_header;
>> + struct acpi_table_bgrt *bgrt = &bgrt_tab;
>>
>> if (acpi_disabled)
>> return;
>>
>> - status = acpi_get_table("BGRT", 0,
>> - (struct acpi_table_header **)&bgrt_tab);
>> - if (ACPI_FAILURE(status))
>> - return;
>> -
>> - if (bgrt_tab->header.length < sizeof(*bgrt_tab)) {
>> + if (table->length < sizeof(bgrt_tab)) {
>> pr_notice("Ignoring BGRT: invalid length %u (expected %zu)\n",
>> - bgrt_tab->header.length, sizeof(*bgrt_tab));
>> + table->length, sizeof(bgrt_tab));
>> return;
>> }
>> - if (bgrt_tab->version != 1) {
>> + *bgrt = *(struct acpi_table_bgrt *)table;
>> + if (bgrt->version != 1) {
>> pr_notice("Ignoring BGRT: invalid version %u (expected 1)\n",
>> - bgrt_tab->version);
>> - return;
>> + bgrt->version);
>> + goto out;
>> }
>> - if (bgrt_tab->status & 0xfe) {
>> + if (bgrt->status & 0xfe) {
>> pr_notice("Ignoring BGRT: reserved status bits are non-zero %u\n",
>> - bgrt_tab->status);
>> - return;
>> + bgrt->status);
>> + goto out;
>> }
>> - if (bgrt_tab->image_type != 0) {
>> + if (bgrt->image_type != 0) {
>> pr_notice("Ignoring BGRT: invalid image type %u (expected 0)\n",
>> - bgrt_tab->image_type);
>> - return;
>> + bgrt->image_type);
>> + goto out;
>> }
>> - if (!bgrt_tab->image_address) {
>> + if (!bgrt->image_address) {
>> pr_notice("Ignoring BGRT: null image address\n");
>> - return;
>> + goto out;
>> }
>>
>> - image = memremap(bgrt_tab->image_address, sizeof(bmp_header), MEMREMAP_WB);
>> + image = early_memremap(bgrt->image_address, sizeof(bmp_header));
>> if (!image) {
>> pr_notice("Ignoring BGRT: failed to map image header memory\n");
>> - return;
>> + goto out;
>> }
>>
>> memcpy(&bmp_header, image, sizeof(bmp_header));
>> - memunmap(image);
>> + early_memunmap(image, sizeof(bmp_header));
>> if (bmp_header.id != 0x4d42) {
>> pr_notice("Ignoring BGRT: Incorrect BMP magic number 0x%x (expected 0x4d42)\n",
>> bmp_header.id);
>> - return;
>> + goto out;
>> }
>> bgrt_image_size = bmp_header.size;
>> + efi_mem_reserve(bgrt->image_address, bgrt_image_size);
>>
>> - bgrt_image = memremap(bgrt_tab->image_address, bmp_header.size, MEMREMAP_WB);
>> - if (!bgrt_image) {
>> - pr_notice("Ignoring BGRT: failed to map image memory\n");
>> - bgrt_image = NULL;
>> - return;
>> - }
>> -
>> - efi_mem_reserve(bgrt_tab->image_address, bgrt_image_size);
>> + return;
>> +out:
>> + memset(bgrt, 0, sizeof(bgrt_tab));
>> }
>> --- linux-x86.orig/drivers/acpi/bgrt.c
>> +++ linux-x86/drivers/acpi/bgrt.c
>> @@ -15,40 +15,41 @@
>> #include <linux/sysfs.h>
>> #include <linux/efi-bgrt.h>
>>
>> +static void *bgrt_image;
>> static struct kobject *bgrt_kobj;
>>
>> static ssize_t show_version(struct device *dev,
>> struct device_attribute *attr, char *buf)
>> {
>> - return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->version);
>> + return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.version);
>> }
>> static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
>>
>> static ssize_t show_status(struct device *dev,
>> struct device_attribute *attr, char *buf)
>> {
>> - return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->status);
>> + return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.status);
>> }
>> static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
>>
>> static ssize_t show_type(struct device *dev,
>> struct device_attribute *attr, char *buf)
>> {
>> - return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_type);
>> + return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_type);
>> }
>> static DEVICE_ATTR(type, S_IRUGO, show_type, NULL);
>>
>> static ssize_t show_xoffset(struct device *dev,
>> struct device_attribute *attr, char *buf)
>> {
>> - return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_x);
>> + return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_x);
>> }
>> static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL);
>>
>> static ssize_t show_yoffset(struct device *dev,
>> struct device_attribute *attr, char *buf)
>> {
>> - return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_y);
>> + return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_y);
>> }
>> static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
>>
>> @@ -84,15 +85,24 @@ static int __init bgrt_init(void)
>> {
>> int ret;
>>
>> - if (!bgrt_image)
>> + if (!bgrt_tab.image_address)
>> return -ENODEV;
>>
>> + bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
>> + MEMREMAP_WB);
>> + if (!bgrt_image) {
>> + pr_notice("Ignoring BGRT: failed to map image memory\n");
>> + return -ENOMEM;
>> + }
>> +
>> bin_attr_image.private = bgrt_image;
>> bin_attr_image.size = bgrt_image_size;
>>
>> bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
>> - if (!bgrt_kobj)
>> - return -EINVAL;
>> + if (!bgrt_kobj) {
>> + ret = -EINVAL;
>> + goto out_memmap;
>> + }
>>
>> ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
>> if (ret)
>> @@ -102,6 +112,8 @@ static int __init bgrt_init(void)
>>
>> out_kobject:
>> kobject_put(bgrt_kobj);
>> +out_memmap:
>> + memunmap(bgrt_image);
>> return ret;
>> }
>> device_initcall(bgrt_init);
>> --- linux-x86.orig/include/linux/efi-bgrt.h
>> +++ linux-x86/include/linux/efi-bgrt.h
>> @@ -1,20 +1,19 @@
>> #ifndef _LINUX_EFI_BGRT_H
>> #define _LINUX_EFI_BGRT_H
>>
>> -#ifdef CONFIG_ACPI_BGRT
>> -
>> #include <linux/acpi.h>
>>
>> -void efi_bgrt_init(void);
>> +#ifdef CONFIG_ACPI_BGRT
>> +
>> +void efi_bgrt_init(struct acpi_table_header *table);
>>
>> /* The BGRT data itself; only valid if bgrt_image != NULL. */
>> -extern void *bgrt_image;
>> extern size_t bgrt_image_size;
>> -extern struct acpi_table_bgrt *bgrt_tab;
>> +extern struct acpi_table_bgrt bgrt_tab;
>>
>> #else /* !CONFIG_ACPI_BGRT */
>>
>> -static inline void efi_bgrt_init(void) {}
>> +static inline void efi_bgrt_init(struct acpi_table_header *table) {}
>>
>> #endif /* !CONFIG_ACPI_BGRT */
>>
>> --- linux-x86.orig/arch/x86/platform/efi/efi.c
>> +++ linux-x86/arch/x86/platform/efi/efi.c
>> @@ -542,11 +542,6 @@ void __init efi_init(void)
>> efi_print_memmap();
>> }
>>
>> -void __init efi_late_init(void)
>> -{
>> - efi_bgrt_init();
>> -}
>> -
>> void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
>> {
>> u64 addr, npages;
>> --- linux-x86.orig/init/main.c
>> +++ linux-x86/init/main.c
>> @@ -663,7 +663,6 @@ asmlinkage __visible void __init start_k
>> sfi_init_late();
>>
>> if (efi_enabled(EFI_RUNTIME_SERVICES)) {
>> - efi_late_init();
>> efi_free_boot_services();
>> }
>>
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