Message-ID: <f376978b-095c-7ddd-54b4-1d6d91b3a00f@oracle.com>
Date:   Tue, 11 Jan 2022 09:06:37 -0600
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0)
 Gecko/20100101 Thunderbird/91.4.0
Subject: Re: [PATCH v19 06/13] kexec: move crashk[_low]_res to crash_core
 module
Content-Language: en-US
To:     Zhen Lei <thunder.leizhen@huawei.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
        linux-kernel@vger.kernel.org, Dave Young <dyoung@redhat.com>,
        Baoquan He <bhe@redhat.com>, Vivek Goyal <vgoyal@redhat.com>,
        Eric Biederman <ebiederm@xmission.com>,
        kexec@lists.infradead.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        linux-arm-kernel@lists.infradead.org,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        devicetree@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
        linux-doc@vger.kernel.org
Cc:     Randy Dunlap <rdunlap@infradead.org>,
        Feng Zhou <zhoufeng.zf@bytedance.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        Chen Zhou <dingguo.cz@antgroup.com>
References: <20211228132612.1860-1-thunder.leizhen@huawei.com>
 <20211228132612.1860-7-thunder.leizhen@huawei.com>
From:   john.p.donnelly@oracle.com
In-Reply-To: <20211228132612.1860-7-thunder.leizhen@huawei.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?WkhycWM3VlJJUjJoWTBFcDVIWUNTM2ducGlkNVNrRHZqYjhBUEw4YU9kTFh5?=
 =?utf-8?B?NHNhaDNnM1RIY3M3MEFhVGhRUkVkOVpKM2pUMmVwYWFUZEtQcVBGNXVLMFFO?=
 =?utf-8?B?K1hxazZLNkFzNy9JMld6bDQ0MXV2MlZmMTdiNldoRmpWcUhteTFOeFo2RWQv?=
 =?utf-8?B?Y2RoZDdsNVh3MUczUWliV3czM2UrMXpQNHFndUJoUEFxU2YzcGhOMENOK29r?=
 =?utf-8?B?dmx6eU4wbG1wclB4KzdiV3NXOUlJR3NDSmRMajVJMFJrZGhTaThsNTBCclE5?=
 =?utf-8?B?NkhDQ1U4MWliOWdpZDBtL21hZWN3UGQyQ3RBWklkNDhrY005NzRIUXF3ZlVV?=
 =?utf-8?B?UFRyWGJHbDVMdHRrWk45YVd4YnhONUVQZ3RqcEhLb2Q1dWRuZUk5aC9YQjQw?=
 =?utf-8?B?ekYvMjlTbUh4cFROc2JCNUFUeWF2aitxdXFCcC8rY0VEbnUwV2x0QnU5NEp6?=
 =?utf-8?B?MUZUK2w1dkp3YTBrendDQ29CZ3VwMlduajFUdW01cWdXOFVpSWR4TGU3WEFQ?=
 =?utf-8?B?WGJ3K2kwNm93OW0xWmV3bkJJWThHeHIwZkJHbm9YN1p4YnY1cSs3SXdmZlZv?=
 =?utf-8?B?QjNrUy9Gbk0yMUlhWDVEbHYrdXNIZkpnMXhya3YxZi9hVHluRWJUMUNiVXNa?=
 =?utf-8?B?d0MyRkh6LzRZY2RUTG8yZDN0T2Z6MzdlUXBESTZrS3Q1NUNsRmcrZXI1RGZo?=
 =?utf-8?B?WDYyZ2NzdU1ZSW4wZmVzWCtUZEEzbk9uaG9jQ2FiYnU4L1FUMjNYRDhnMWd0?=
 =?utf-8?B?S2MzZW9IcnVPZGpoR2lTNkU4SnhzTFdCTCt4aEhHVGpXLzdSR0VYOEtoQlV1?=
 =?utf-8?B?T0kwVU1OL09rbWlQUHByV0lZcmN3Vzk1MGlub2tSQnJET3FZUWNMSHdOdTBk?=
 =?utf-8?B?VjJZSmp5TllQNGRpbDhVOEptSXVPajBHNWZzSlBselkxZUZJREFkZStOaU9C?=
 =?utf-8?B?YUw0ZjdEYTJQcHk2Q3U0NWNlblhyN2FDWnhHSTN6S1ZjWFFBcklXdlRCTjQ5?=
 =?utf-8?B?bUtJdXUxVjVPelhiQ1d5dzZqbXpQdndlYk9IMG1EYW15Z21wTnp0ei9QZEJY?=
 =?utf-8?B?dGluQ3BOMWI0QjRCV0ZveC82N3NTZmgvMDlqVE1pV1UzMGZkcGtYNnBsVmRW?=
 =?utf-8?B?bHN6Y1R6V3BGYkJVS3Z0WjA1T0xHTUswSGFRaWV5QUl3elJLckhTb2NIT0pD?=
 =?utf-8?B?T0ZjSXB6NXdwcGtoSDhwcjBKTCtFdEU2L0IrZDR2R0VHTExVQy9wZUJyRDdy?=
 =?utf-8?B?bGVyRmVXMnllTXBPbGtLWFpRd0l3Ni9SOHU5MWNOQTE0dkZoN1hkN21aTGJy?=
 =?utf-8?B?MTQwZnVweTd5TC8vL3VuZDUyL2J6YmptUFNRWjNxbWNzSVo0bDNISnJIZ09a?=
 =?utf-8?B?WHVXSDdCdkQxUSsrYXpxU0wwNWMybEhlTjI4aGF3alpMeEU4bkJ1Ukt6cS9U?=
 =?utf-8?B?dlZWdlQxV3V1NklCRUx0TkU3VERiZzkyeVc4K2dnZUh2V3JLNW1pd2VML3d0?=
 =?utf-8?B?UlhlSHhYMFkzZDNNSGhFUWI1MGlOdGtTell4V2lCdzFoMXZ5eDJEcFRySVZl?=
 =?utf-8?B?UUNTWTBsTVdDUmx6NzFEaHVML0xNUVNMZEllWnN3OHRKNHY5V01OMlhlQnd3?=
 =?utf-8?B?ZUU5SXBjTzFwVDB4MllyL3RHSVRFVE54dkhuZnNISDM0cUN2ZWVDek80Mkli?=
 =?utf-8?B?ZUszcXlZaVM2NUVidSsvU3I1bnMrTk0vOE01YTVLM3gvYzlMZ3B0L3FoM3Bl?=
 =?utf-8?B?dkc2dzRpTG1Ha0pjbHBONnZVYWlLTDBsVi9EU1Q4Umc4b0NoWHRXQ3Z2dzIw?=
 =?utf-8?B?QTFBS2oxeHpaU3NQWlJjeHBGbTI2Uk1nek9SbDI1UTVXS3B1ZUgrV1kxUGM4?=
 =?utf-8?B?V2F2akpjNW5EK2hva2NuenJ2anRmOUoyeXRZcnRtMDcrTGZLVVlCZEx4SnlB?=
 =?utf-8?B?MzQremkyRUF3TmlVeWVsMm0xb3FyWk14SE5PVjJQUDh4YmxTeXBFanJ3UVFo?=
 =?utf-8?B?OFh0elY2VUhsMC9sT0Rhclc0NGZRazk5c3NFVGt5T2JSV0V4cGdqVXlNMG1G?=
 =?utf-8?B?c3F2Q3pCUjBOYUpvMW50VVBHWUNYN0hPQ3Bhc2FRelpTUGp1U1FwcXlOZjJ4?=
 =?utf-8?B?TkdremNZUlBOSWVDY2lFQVpuOUh3Q1BVQURSUUhQVXllUXNObjdVd1V2alds?=
 =?utf-8?B?ZWw4TXIxWE95alNDaDJvVnBQeUdKaHlUOXdidjV4aUcwd1A0VXRRNHY0SXEw?=
 =?utf-8?B?RUNoVjZTZmVKbTJXb0NER1dJVk5RPT0=?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 79f8b021-3249-4774-8c70-08d9d5140026
X-MS-Exchange-CrossTenant-AuthSource: CO1PR10MB4722.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Jan 2022 15:06:53.0411
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: UY6T9kCPI04UBj08zmi/k/7ibT4YR5f5FHBWHAt5zANiyUkN7eDF2iUH04dFOe2jkKSZrh+MjLwuVATSwXZOwksd1a9gwl710jj+su95QvY=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR10MB1695
X-Proofpoint-Virus-Version: vendor=nai engine=6300 definitions=10223 signatures=668683
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxscore=0 phishscore=0
 mlxlogscore=999 spamscore=0 bulkscore=0 malwarescore=0 suspectscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000
 definitions=main-2201110089
X-Proofpoint-ORIG-GUID: 75_f1IQNOD_CiIF8mvQNlzMBMtB5VG5c
X-Proofpoint-GUID: 75_f1IQNOD_CiIF8mvQNlzMBMtB5VG5c
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 12/28/21 7:26 AM, Zhen Lei wrote:
> From: Chen Zhou <chenzhou10@huawei.com>
> 
> Move the definition and declaration of global variable crashk[_low]_res
> from kexec module to crash_core module, in preparation of adding generic
> reserve_crashkernel_mem[_low]() to crash_core.c, the latter refers to
> variable crashk[_low]_res. Due to the config KEXEC automatically selects
> CRASH_CORE, and the header crash_core.h is included by kexec.h, so there
> is no functional change.
> 
> Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>

 >
Acked-by: John Donnelly  <john.p.donnelly@oracle.com>

> ---
>   include/linux/crash_core.h |  4 ++++
>   include/linux/kexec.h      |  4 ----
>   kernel/crash_core.c        | 16 ++++++++++++++++
>   kernel/kexec_core.c        | 17 -----------------
>   4 files changed, 20 insertions(+), 21 deletions(-)
> 
> diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
> index 598fd55d83c169e..f5437c9c9411fce 100644
> --- a/include/linux/crash_core.h
> +++ b/include/linux/crash_core.h
> @@ -73,6 +73,10 @@ extern unsigned char *vmcoreinfo_data;
>   extern size_t vmcoreinfo_size;
>   extern u32 *vmcoreinfo_note;
>   
> +/* Location of a reserved region to hold the crash kernel. */
> +extern struct resource crashk_res;
> +extern struct resource crashk_low_res;
> +
>   Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
>   			  void *data, size_t data_len);
>   void final_note(Elf_Word *buf);
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index 0c994ae37729e1e..47e784d66ea8645 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -350,10 +350,6 @@ extern int kexec_load_disabled;
>   #define KEXEC_FILE_FLAGS	(KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
>   				 KEXEC_FILE_NO_INITRAMFS)
>   
> -/* Location of a reserved region to hold the crash kernel.
> - */
> -extern struct resource crashk_res;
> -extern struct resource crashk_low_res;
>   extern note_buf_t __percpu *crash_notes;
>   
>   /* flag to track if kexec reboot is in progress */
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index b7d024eb464d0ae..686d8a65e12a337 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -22,6 +22,22 @@ u32 *vmcoreinfo_note;
>   /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
>   static unsigned char *vmcoreinfo_data_safecopy;
>   
> +/* Location of the reserved area for the crash kernel */
> +struct resource crashk_res = {
> +	.name  = "Crash kernel",
> +	.start = 0,
> +	.end   = 0,
> +	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
> +	.desc  = IORES_DESC_CRASH_KERNEL
> +};
> +struct resource crashk_low_res = {
> +	.name  = "Crash kernel",
> +	.start = 0,
> +	.end   = 0,
> +	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
> +	.desc  = IORES_DESC_CRASH_KERNEL
> +};
> +
>   /*
>    * parsing the "crashkernel" commandline
>    *
> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> index 5a5d192a89ac307..1e0d4909bbb6b77 100644
> --- a/kernel/kexec_core.c
> +++ b/kernel/kexec_core.c
> @@ -54,23 +54,6 @@ note_buf_t __percpu *crash_notes;
>   /* Flag to indicate we are going to kexec a new kernel */
>   bool kexec_in_progress = false;
>   
> -
> -/* Location of the reserved area for the crash kernel */
> -struct resource crashk_res = {
> -	.name  = "Crash kernel",
> -	.start = 0,
> -	.end   = 0,
> -	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
> -	.desc  = IORES_DESC_CRASH_KERNEL
> -};
> -struct resource crashk_low_res = {
> -	.name  = "Crash kernel",
> -	.start = 0,
> -	.end   = 0,
> -	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
> -	.desc  = IORES_DESC_CRASH_KERNEL
> -};
> -
>   int kexec_should_crash(struct task_struct *p)
>   {
>   	/*