Commit fff9846b authored by Nathan Lynch's avatar Nathan Lynch Committed by Michael Ellerman
Browse files

powerpc/pseries/lparcfg: convert to papr_sysparm API 



/proc/powerpc/lparcfg derives the LPAR name and SPLPAR characteristics
it reports using bare calls to the RTAS ibm,get-system-parameter
function. Convert these to the higher-level papr_sysparm API, which
handles the tedious details.

While the SPLPAR string parsing code could stand to be updated, that
should be done in a separate change. It is minimally modified here to
reduce the risk of changing behavior.

Signed-off-by: default avatarNathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-16-26929c8cce78@linux.ibm.com
parent b8dc7177

arch/powerpc/platforms/pseries/lparcfg.c

+24 −80
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/errno.h>

#include <linux/proc_fs.h>

#include <linux/init.h>

#include <asm/papr-sysparm.h>

#include <linux/seq_file.h>

#include <linux/slab.h>

#include <linux/uaccess.h>
@@ -311,16 +312,6 @@ static void parse_mpp_x_data(struct seq_file *m) 
		seq_printf(m, "coalesce_pool_spurr=%ld\n", mpp_x_data.pool_spurr_cycles);

}



/*

 * PAPR defines, in section "7.3.16 System Parameters Option", the token 55 to

 * read the LPAR name, and the largest output data to 4000 + 2 bytes length.

 */

#define SPLPAR_LPAR_NAME_TOKEN	55

#define GET_SYS_PARM_BUF_SIZE	4002

#if GET_SYS_PARM_BUF_SIZE > RTAS_DATA_BUF_SIZE

#error "GET_SYS_PARM_BUF_SIZE is larger than RTAS_DATA_BUF_SIZE"

#endif



/*

 * Read the lpar name using the RTAS ibm,get-system-parameter call.

 *
@@ -332,46 +323,19 @@ static void parse_mpp_x_data(struct seq_file *m) 
 */

static int read_rtas_lpar_name(struct seq_file *m)

{

	int rc, len, token;

	union {

		char raw_buffer[GET_SYS_PARM_BUF_SIZE];

		struct {

			__be16 len;

			char name[GET_SYS_PARM_BUF_SIZE-2];

		};

	} *local_buffer;



	token = rtas_token("ibm,get-system-parameter");

	if (token == RTAS_UNKNOWN_SERVICE)

		return -EINVAL;

	struct papr_sysparm_buf *buf;

	int err;



	local_buffer = kmalloc(sizeof(*local_buffer), GFP_KERNEL);

	if (!local_buffer)

	buf = papr_sysparm_buf_alloc();

	if (!buf)

		return -ENOMEM;



	do {

		spin_lock(&rtas_data_buf_lock);

		memset(rtas_data_buf, 0, sizeof(*local_buffer));

		rc = rtas_call(token, 3, 1, NULL, SPLPAR_LPAR_NAME_TOKEN,

			       __pa(rtas_data_buf), sizeof(*local_buffer));

		if (!rc)

			memcpy(local_buffer->raw_buffer, rtas_data_buf,

			       sizeof(local_buffer->raw_buffer));

		spin_unlock(&rtas_data_buf_lock);

	} while (rtas_busy_delay(rc));



	if (!rc) {

		/* Force end of string */

		len = min((int) be16_to_cpu(local_buffer->len),

			  (int) sizeof(local_buffer->name)-1);

		local_buffer->name[len] = '\0';



		seq_printf(m, "partition_name=%s\n", local_buffer->name);

	} else

		rc = -ENODATA;

	err = papr_sysparm_get(PAPR_SYSPARM_LPAR_NAME, buf);

	if (!err)

		seq_printf(m, "partition_name=%s\n", buf->val);



	kfree(local_buffer);

	return rc;

	papr_sysparm_buf_free(buf);

	return err;

}



/*
@@ -397,7 +361,6 @@ static void read_lpar_name(struct seq_file *m) 
		pr_err_once("Error can't get the LPAR name");

}



#define SPLPAR_CHARACTERISTICS_TOKEN 20

#define SPLPAR_MAXLENGTH 1026*(sizeof(char))



/*
@@ -408,45 +371,25 @@ static void read_lpar_name(struct seq_file *m) 
 */

static void parse_system_parameter_string(struct seq_file *m)

{

	const s32 token = rtas_token("ibm,get-system-parameter");

	int call_status;

	struct papr_sysparm_buf *buf;



	unsigned char *local_buffer = kmalloc(SPLPAR_MAXLENGTH, GFP_KERNEL);

	if (!local_buffer) {

		printk(KERN_ERR "%s %s kmalloc failure at line %d\n",

		       __FILE__, __func__, __LINE__);

	buf = papr_sysparm_buf_alloc();

	if (!buf)

		return;

	}



	do {

		spin_lock(&rtas_data_buf_lock);

		memset(rtas_data_buf, 0, SPLPAR_MAXLENGTH);

		call_status = rtas_call(token, 3, 1, NULL, SPLPAR_CHARACTERISTICS_TOKEN,

					__pa(rtas_data_buf), RTAS_DATA_BUF_SIZE);

		memcpy(local_buffer, rtas_data_buf, SPLPAR_MAXLENGTH);

		local_buffer[SPLPAR_MAXLENGTH - 1] = '\0';

		spin_unlock(&rtas_data_buf_lock);

	} while (rtas_busy_delay(call_status));



	if (call_status != 0) {

		printk(KERN_INFO

		       "%s %s Error calling get-system-parameter (0x%x)\n",

		       __FILE__, __func__, call_status);

	if (papr_sysparm_get(PAPR_SYSPARM_SHARED_PROC_LPAR_ATTRS, buf)) {

		goto out_free;

	} else {

		const char *local_buffer;

		int splpar_strlen;

		int idx, w_idx;

		char *workbuffer = kzalloc(SPLPAR_MAXLENGTH, GFP_KERNEL);

		if (!workbuffer) {

			printk(KERN_ERR "%s %s kmalloc failure at line %d\n",

			       __FILE__, __func__, __LINE__);

			kfree(local_buffer);

			return;

		}

#ifdef LPARCFG_DEBUG

		printk(KERN_INFO "success calling get-system-parameter\n");

#endif

		splpar_strlen = local_buffer[0] * 256 + local_buffer[1];

		local_buffer += 2;	/* step over strlen value */



		if (!workbuffer)

			goto out_free;



		splpar_strlen = be16_to_cpu(buf->len);

		local_buffer = buf->val;



		w_idx = 0;

		idx = 0;
@@ -480,7 +423,8 @@ static void parse_system_parameter_string(struct seq_file *m) 
		kfree(workbuffer);

		local_buffer -= 2;	/* back up over strlen value */

	}

	kfree(local_buffer);

out_free:

	papr_sysparm_buf_free(buf);

}



/* Return the number of processors in the system.