[v4,05/25] pseries/fadump: introduce callbacks for platform specific operations

Introduce callback functions for platform specific operations like
register, unregister, invalidate & such. Also, define place-holders
for the same on pSeries platform.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
---
 arch/powerpc/kernel/fadump-common.h          |   33 ++++++
 arch/powerpc/kernel/fadump.c                 |   47 +--------
 arch/powerpc/platforms/pseries/Makefile      |    1 
 arch/powerpc/platforms/pseries/rtas-fadump.c |  134 ++++++++++++++++++++++++++
 4 files changed, 171 insertions(+), 44 deletions(-)
 create mode 100644 arch/powerpc/platforms/pseries/rtas-fadump.c

On 2019-07-16 17:02:30 Tue, Hari Bathini wrote:
> Introduce callback functions for platform specific operations like
> register, unregister, invalidate & such. Also, define place-holders
> for the same on pSeries platform.
> 
> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
> ---
>  arch/powerpc/kernel/fadump-common.h          |   33 ++++++
>  arch/powerpc/kernel/fadump.c                 |   47 +--------
>  arch/powerpc/platforms/pseries/Makefile      |    1 
>  arch/powerpc/platforms/pseries/rtas-fadump.c |  134 ++++++++++++++++++++++++++
>  4 files changed, 171 insertions(+), 44 deletions(-)
>  create mode 100644 arch/powerpc/platforms/pseries/rtas-fadump.c
> 
> diff --git a/arch/powerpc/kernel/fadump-common.h b/arch/powerpc/kernel/fadump-common.h
> index 09d6161..020d582 100644
> --- a/arch/powerpc/kernel/fadump-common.h
> +++ b/arch/powerpc/kernel/fadump-common.h
> @@ -50,6 +50,12 @@
>  #define FADUMP_UNREGISTER		2
>  #define FADUMP_INVALIDATE		3
>  
> +/* Firmware-Assited Dump platforms */
> +enum fadump_platform_type {
> +	FADUMP_PLATFORM_UNKNOWN = 0,
> +	FADUMP_PLATFORM_PSERIES,
> +};

Do we really need these ? Aren't we hiding all platform specific things
under fadump_ops functions ? I see that these values are used only for
assignements and not making any decision in code flow. Am I missing
anything here ?

Thanks,
-Mahesh.

> +
>  /*
>   * Copy the ascii values for first 8 characters from a string into u64
>   * variable at their respective indexes.
> @@ -84,6 +90,9 @@ struct fad_crash_memory_ranges {
>  	unsigned long long	size;
>  };
>  
> +/* Platform specific callback functions */
> +struct fadump_ops;
> +
>  /* Firmware-assisted dump configuration details. */
>  struct fw_dump {
>  	unsigned long	reserve_dump_area_start;
> @@ -106,6 +115,21 @@ struct fw_dump {
>  	unsigned long	dump_active:1;
>  	unsigned long	dump_registered:1;
>  	unsigned long	nocma:1;
> +
> +	enum fadump_platform_type	fadump_platform;
> +	struct fadump_ops		*ops;
> +};
> +
> +struct fadump_ops {
> +	ulong	(*init_fadump_mem_struct)(struct fw_dump *fadump_config);
> +	int	(*register_fadump)(struct fw_dump *fadump_config);
> +	int	(*unregister_fadump)(struct fw_dump *fadump_config);
> +	int	(*invalidate_fadump)(struct fw_dump *fadump_config);
> +	int	(*process_fadump)(struct fw_dump *fadump_config);
> +	void	(*fadump_region_show)(struct fw_dump *fadump_config,
> +				      struct seq_file *m);
> +	void	(*fadump_trigger)(struct fadump_crash_info_header *fdh,
> +				  const char *msg);
>  };
>  
>  /* Helper functions */
> @@ -116,4 +140,13 @@ void fadump_update_elfcore_header(struct fw_dump *fadump_config, char *bufp);
>  int is_fadump_boot_mem_contiguous(struct fw_dump *fadump_conf);
>  int is_fadump_reserved_mem_contiguous(struct fw_dump *fadump_conf);
>  
> +#ifdef CONFIG_PPC_PSERIES
> +extern int rtas_fadump_dt_scan(struct fw_dump *fadump_config, ulong node);
> +#else
> +static inline int rtas_fadump_dt_scan(struct fw_dump *fadump_config, ulong node)
> +{
> +	return 1;
> +}
> +#endif
> +
>  #endif /* __PPC64_FA_DUMP_INTERNAL_H__ */
> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
> index f571cb3..a901ca1 100644
> --- a/arch/powerpc/kernel/fadump.c
> +++ b/arch/powerpc/kernel/fadump.c
> @@ -112,24 +112,12 @@ static int __init fadump_cma_init(void) { return 1; }
>  int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
>  				      int depth, void *data)
>  {
> -	const __be32 *sections;
> -	int i, num_sections;
> -	int size;
> -	const __be32 *token;
> +	int ret;
>  
>  	if (depth != 1 || strcmp(uname, "rtas") != 0)
>  		return 0;
>  
> -	/*
> -	 * Check if Firmware Assisted dump is supported. if yes, check
> -	 * if dump has been initiated on last reboot.
> -	 */
> -	token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
> -	if (!token)
> -		return 1;
> -
> -	fw_dump.fadump_supported = 1;
> -	fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token);
> +	ret = rtas_fadump_dt_scan(&fw_dump, node);
>  
>  	/*
>  	 * The 'ibm,kernel-dump' rtas node is present only if there is
> @@ -139,36 +127,7 @@ int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
>  	if (fdm_active)
>  		fw_dump.dump_active = 1;
>  
> -	/* Get the sizes required to store dump data for the firmware provided
> -	 * dump sections.
> -	 * For each dump section type supported, a 32bit cell which defines
> -	 * the ID of a supported section followed by two 32 bit cells which
> -	 * gives teh size of the section in bytes.
> -	 */
> -	sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
> -					&size);
> -
> -	if (!sections)
> -		return 1;
> -
> -	num_sections = size / (3 * sizeof(u32));
> -
> -	for (i = 0; i < num_sections; i++, sections += 3) {
> -		u32 type = (u32)of_read_number(sections, 1);
> -
> -		switch (type) {
> -		case RTAS_FADUMP_CPU_STATE_DATA:
> -			fw_dump.cpu_state_data_size =
> -					of_read_ulong(&sections[1], 2);
> -			break;
> -		case RTAS_FADUMP_HPTE_REGION:
> -			fw_dump.hpte_region_size =
> -					of_read_ulong(&sections[1], 2);
> -			break;
> -		}
> -	}
> -
> -	return 1;
> +	return ret;
>  }
>  
>  /*
> diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
> index ab3d59a..e248724 100644
> --- a/arch/powerpc/platforms/pseries/Makefile
> +++ b/arch/powerpc/platforms/pseries/Makefile
> @@ -26,6 +26,7 @@ obj-$(CONFIG_IBMVIO)		+= vio.o
>  obj-$(CONFIG_IBMEBUS)		+= ibmebus.o
>  obj-$(CONFIG_PAPR_SCM)		+= papr_scm.o
>  obj-$(CONFIG_PPC_SPLPAR)	+= vphn.o
> +obj-$(CONFIG_FA_DUMP)		+= rtas-fadump.o
>  
>  ifdef CONFIG_PPC_PSERIES
>  obj-$(CONFIG_SUSPEND)		+= suspend.o
> diff --git a/arch/powerpc/platforms/pseries/rtas-fadump.c b/arch/powerpc/platforms/pseries/rtas-fadump.c
> new file mode 100644
> index 0000000..9e7c9bf
> --- /dev/null
> +++ b/arch/powerpc/platforms/pseries/rtas-fadump.c
> @@ -0,0 +1,134 @@
> +/*
> + * Firmware-Assisted Dump support on POWERVM platform.
> + *
> + * Copyright 2011, IBM Corporation
> + * Author: Mahesh Salgaonkar <mahesh@linux.ibm.com>
> + *
> + * Copyright 2019, IBM Corp.
> + * Author: Hari Bathini <hbathini@linux.ibm.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +
> +#undef DEBUG
> +#define pr_fmt(fmt) "rtas fadump: " fmt
> +
> +#include <linux/string.h>
> +#include <linux/memblock.h>
> +#include <linux/delay.h>
> +#include <linux/seq_file.h>
> +#include <linux/crash_dump.h>
> +
> +#include <asm/page.h>
> +#include <asm/prom.h>
> +#include <asm/rtas.h>
> +#include <asm/fadump.h>
> +
> +#include "../../kernel/fadump-common.h"
> +#include "rtas-fadump.h"
> +
> +static ulong rtas_fadump_init_mem_struct(struct fw_dump *fadump_conf)
> +{
> +	return fadump_conf->reserve_dump_area_start;
> +}
> +
> +static int rtas_fadump_register_fadump(struct fw_dump *fadump_conf)
> +{
> +	return -EIO;
> +}
> +
> +static int rtas_fadump_unregister_fadump(struct fw_dump *fadump_conf)
> +{
> +	return -EIO;
> +}
> +
> +static int rtas_fadump_invalidate_fadump(struct fw_dump *fadump_conf)
> +{
> +	return -EIO;
> +}
> +
> +/*
> + * Validate and process the dump data stored by firmware before exporting
> + * it through '/proc/vmcore'.
> + */
> +static int __init rtas_fadump_process_fadump(struct fw_dump *fadump_conf)
> +{
> +	return -EINVAL;
> +}
> +
> +static void rtas_fadump_region_show(struct fw_dump *fadump_conf,
> +				    struct seq_file *m)
> +{
> +}
> +
> +static void rtas_fadump_trigger(struct fadump_crash_info_header *fdh,
> +				const char *msg)
> +{
> +	/* Call ibm,os-term rtas call to trigger firmware assisted dump */
> +	rtas_os_term((char *)msg);
> +}
> +
> +static struct fadump_ops rtas_fadump_ops = {
> +	.init_fadump_mem_struct	= rtas_fadump_init_mem_struct,
> +	.register_fadump	= rtas_fadump_register_fadump,
> +	.unregister_fadump	= rtas_fadump_unregister_fadump,
> +	.invalidate_fadump	= rtas_fadump_invalidate_fadump,
> +	.process_fadump		= rtas_fadump_process_fadump,
> +	.fadump_region_show	= rtas_fadump_region_show,
> +	.fadump_trigger		= rtas_fadump_trigger,
> +};
> +
> +int __init rtas_fadump_dt_scan(struct fw_dump *fadump_conf, ulong node)
> +{
> +	const __be32 *sections;
> +	int i, num_sections;
> +	int size;
> +	const __be32 *token;
> +
> +	/*
> +	 * Check if Firmware Assisted dump is supported. if yes, check
> +	 * if dump has been initiated on last reboot.
> +	 */
> +	token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
> +	if (!token)
> +		return 1;
> +
> +	fadump_conf->ibm_configure_kernel_dump = be32_to_cpu(*token);
> +	fadump_conf->ops		= &rtas_fadump_ops;
> +	fadump_conf->fadump_platform	= FADUMP_PLATFORM_PSERIES;
> +	fadump_conf->fadump_supported	= 1;
> +
> +	/* Get the sizes required to store dump data for the firmware provided
> +	 * dump sections.
> +	 * For each dump section type supported, a 32bit cell which defines
> +	 * the ID of a supported section followed by two 32 bit cells which
> +	 * gives the size of the section in bytes.
> +	 */
> +	sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
> +					&size);
> +
> +	if (!sections)
> +		return 1;
> +
> +	num_sections = size / (3 * sizeof(u32));
> +
> +	for (i = 0; i < num_sections; i++, sections += 3) {
> +		u32 type = (u32)of_read_number(sections, 1);
> +
> +		switch (type) {
> +		case RTAS_FADUMP_CPU_STATE_DATA:
> +			fadump_conf->cpu_state_data_size =
> +					of_read_ulong(&sections[1], 2);
> +			break;
> +		case RTAS_FADUMP_HPTE_REGION:
> +			fadump_conf->hpte_region_size =
> +					of_read_ulong(&sections[1], 2);
> +			break;
> +		}
> +	}
> +
> +	return 1;
> +}
>

On 12/08/19 3:12 PM, Mahesh J Salgaonkar wrote:
> On 2019-07-16 17:02:30 Tue, Hari Bathini wrote:
>> Introduce callback functions for platform specific operations like
>> register, unregister, invalidate & such. Also, define place-holders
>> for the same on pSeries platform.
>>
>> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
>> ---
>>  arch/powerpc/kernel/fadump-common.h          |   33 ++++++
>>  arch/powerpc/kernel/fadump.c                 |   47 +--------
>>  arch/powerpc/platforms/pseries/Makefile      |    1 
>>  arch/powerpc/platforms/pseries/rtas-fadump.c |  134 ++++++++++++++++++++++++++
>>  4 files changed, 171 insertions(+), 44 deletions(-)
>>  create mode 100644 arch/powerpc/platforms/pseries/rtas-fadump.c
>>
>> diff --git a/arch/powerpc/kernel/fadump-common.h b/arch/powerpc/kernel/fadump-common.h
>> index 09d6161..020d582 100644
>> --- a/arch/powerpc/kernel/fadump-common.h
>> +++ b/arch/powerpc/kernel/fadump-common.h
>> @@ -50,6 +50,12 @@
>>  #define FADUMP_UNREGISTER		2
>>  #define FADUMP_INVALIDATE		3
>>  
>> +/* Firmware-Assited Dump platforms */
>> +enum fadump_platform_type {
>> +	FADUMP_PLATFORM_UNKNOWN = 0,
>> +	FADUMP_PLATFORM_PSERIES,
>> +};
> 
> Do we really need these ? Aren't we hiding all platform specific things
> under fadump_ops functions ? I see that these values are used only for
> assignements and not making any decision in code flow. Am I missing
> anything here ?

True. This isn't really useful. will drop it..

Thanks
Hari