Commit 83f95671 authored by Heiko Carstens's avatar Heiko Carstens
Browse files

s390/hypfs: simplify memory allocation 



Simplify memory allocation for diagnose 204 memory buffer:

- allocate with __vmalloc_node() to enure page alignment
- allocate real / physical memory area also within vmalloc area and handle
  vmalloc to real / physical address translation within diag204().

Acked-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: default avatarMete Durlu <meted@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 5ac8c724

arch/s390/hypfs/hypfs_diag.c

+8 −32
Original line number Diff line number Diff line
@@ -29,7 +29,6 @@ static enum diag204_sc diag204_store_sc; /* used subcode for store */ 
static enum diag204_format diag204_info_type;	/* used diag 204 data format */



static void *diag204_buf;		/* 4K aligned buffer for diag204 data */

static void *diag204_buf_vmalloc;	/* vmalloc pointer for diag204 data */

static int diag204_buf_pages;		/* number of pages for diag204 data */



static struct dentry *dbfs_d204_file;
@@ -212,14 +211,7 @@ static inline __u64 phys_cpu__ctidx(enum diag204_format type, void *hdr) 


static void diag204_free_buffer(void)

{

	if (!diag204_buf)

		return;

	if (diag204_buf_vmalloc) {

		vfree(diag204_buf_vmalloc);

		diag204_buf_vmalloc = NULL;

	} else {

		free_pages((unsigned long) diag204_buf, 0);

	}

	vfree(diag204_buf);

	diag204_buf = NULL;

}
@@ -228,26 +220,6 @@ static void *page_align_ptr(void *ptr) 
	return (void *) PAGE_ALIGN((unsigned long) ptr);

}



static void *diag204_alloc_vbuf(int pages)

{

	/* The buffer has to be page aligned! */

	diag204_buf_vmalloc = vmalloc(array_size(PAGE_SIZE, (pages + 1)));

	if (!diag204_buf_vmalloc)

		return ERR_PTR(-ENOMEM);

	diag204_buf = page_align_ptr(diag204_buf_vmalloc);

	diag204_buf_pages = pages;

	return diag204_buf;

}



static void *diag204_alloc_rbuf(void)

{

	diag204_buf = (void*)__get_free_pages(GFP_KERNEL,0);

	if (!diag204_buf)

		return ERR_PTR(-ENOMEM);

	diag204_buf_pages = 1;

	return diag204_buf;

}



static void *diag204_get_buffer(enum diag204_format fmt, int *pages)

{

	if (diag204_buf) {
@@ -256,15 +228,19 @@ static void *diag204_get_buffer(enum diag204_format fmt, int *pages) 
	}

	if (fmt == DIAG204_INFO_SIMPLE) {

		*pages = 1;

		return diag204_alloc_rbuf();

	} else {/* DIAG204_INFO_EXT */

		*pages = diag204((unsigned long)DIAG204_SUBC_RSI |

				 (unsigned long)DIAG204_INFO_EXT, 0, NULL);

		if (*pages <= 0)

			return ERR_PTR(-ENOSYS);

		else

			return diag204_alloc_vbuf(*pages);

	}

	diag204_buf = __vmalloc_node(array_size(*pages, PAGE_SIZE),

				     PAGE_SIZE, GFP_KERNEL, NUMA_NO_NODE,

				     __builtin_return_address(0));

	if (!diag204_buf)

		return ERR_PTR(-ENOMEM);

	diag204_buf_pages = *pages;

	return diag204_buf;

}



/*

arch/s390/kernel/diag.c

+22 −2
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/cpu.h>

#include <linux/seq_file.h>

#include <linux/debugfs.h>

#include <linux/vmalloc.h>

#include <asm/asm-extable.h>

#include <asm/diag.h>

#include <asm/trace/diag.h>
@@ -168,11 +169,30 @@ static inline int __diag204(unsigned long *subcode, unsigned long size, void *ad 
	return rp.odd;

}



/**

 * diag204() - Issue diagnose 204 call.

 * @subcode: Subcode of diagnose 204 to be executed.

 * @size: Size of area in pages which @area points to, if given.

 * @addr: Vmalloc'ed memory area where the result is written to.

 *

 * Execute diagnose 204 with the given subcode and write the result to the

 * memory area specified with @addr. For subcodes which do not write a

 * result to memory both @size and @addr must be zero. If @addr is

 * specified it must be page aligned and must have been allocated with

 * vmalloc(). Conversion to real / physical addresses will be handled by

 * this function if required.

 */

int diag204(unsigned long subcode, unsigned long size, void *addr)

{

	diag_stat_inc(DIAG_STAT_X204);

	if (addr) {

		if (WARN_ON_ONCE(!is_vmalloc_addr(addr)))

			return -1;

		if (WARN_ON_ONCE(!IS_ALIGNED((unsigned long)addr, PAGE_SIZE)))

			return -1;

	}

	if ((subcode & DIAG204_SUBCODE_MASK) == DIAG204_SUBC_STIB4)

		addr = (void *)__pa(addr);

		addr = (void *)pfn_to_phys(vmalloc_to_pfn(addr));

	diag_stat_inc(DIAG_STAT_X204);

	size = __diag204(&subcode, size, addr);

	if (subcode)

		return -1;