Commit c6c27e3d authored by Haren Myneni's avatar Haren Myneni Committed by Michael Ellerman
Browse files

selftests/powerpc: Use req_max_processed_len from sysfs NX capabilities 



On PowerVM, the hypervisor defines the maximum buffer length for
each NX request and the kernel exported this value via sysfs.

This patch reads this value if the sysfs entry is available and
is used to limit the request length.

Signed-off-by: default avatarHaren Myneni <haren@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ed908341b1eb7ca0183c028a4ed4a0cf48bfe0f6.camel@linux.ibm.com
parent 20ccb004

tools/testing/selftests/powerpc/nx-gzip/Makefile

+2 −2
Original line number Diff line number Diff line 
CFLAGS = -O3 -m64 -I./include

CFLAGS = -O3 -m64 -I./include -I../include



TEST_GEN_FILES := gzfht_test gunz_test

TEST_PROGS := nx-gzip-test.sh



include ../../lib.mk



$(TEST_GEN_FILES): gzip_vas.c
 
$(TEST_GEN_FILES): gzip_vas.c ../utils.c

tools/testing/selftests/powerpc/nx-gzip/gzfht_test.c

+15 −2
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ 
#include <assert.h>

#include <errno.h>

#include <signal.h>

#include "utils.h"

#include "nxu.h"

#include "nx.h"
@@ -70,6 +71,8 @@ FILE *nx_gzip_log; 
#define FNAME_MAX 1024

#define FEXT ".nx.gz"



#define SYSFS_MAX_REQ_BUF_PATH "devices/vio/ibm,compression-v1/nx_gzip_caps/req_max_processed_len"



/*

 * LZ counts returned in the user supplied nx_gzip_crb_cpb_t structure.

 */
@@ -244,6 +247,7 @@ int compress_file(int argc, char **argv, void *handle) 
	struct nx_gzip_crb_cpb_t *cmdp;

	uint32_t pagelen = 65536;

	int fault_tries = NX_MAX_FAULTS;

	char buf[32];



	cmdp = (void *)(uintptr_t)

		aligned_alloc(sizeof(struct nx_gzip_crb_cpb_t),
@@ -263,8 +267,17 @@ int compress_file(int argc, char **argv, void *handle) 
	assert(NULL != (outbuf = (char *)malloc(outlen)));

	nxu_touch_pages(outbuf, outlen, pagelen, 1);



	/*

	 * On PowerVM, the hypervisor defines the maximum request buffer

	 * size is defined and this value is available via sysfs.

	 */

	if (!read_sysfs_file(SYSFS_MAX_REQ_BUF_PATH, buf, sizeof(buf))) {

		chunk = atoi(buf);

	} else {

		/* sysfs entry is not available on PowerNV */

		/* Compress piecemeal in smallish chunks */

		chunk = 1<<22;

	}



	/* Write the gzip header to the stream */

	num_hdr_bytes = gzip_header_blank(outbuf);