/*
* SPU local store allocation routines
*
* Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
*
* 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, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <asm/spu.h>
#include <asm/spu_csa.h>
#include <asm/mmu.h>
static int spu_alloc_lscsa_std(struct spu_state *csa)
{
struct spu_lscsa *lscsa;
unsigned char *p;
lscsa = vmalloc(sizeof(struct spu_lscsa));
if (!lscsa)
return -ENOMEM;
memset(lscsa, 0, sizeof(struct spu_lscsa));
csa->lscsa = lscsa;
/* Set LS pages reserved to allow for user-space mapping. */
for (p = lscsa->ls; p < lscsa->ls + LS_SIZE; p += PAGE_SIZE)
SetPageReserved(vmalloc_to_page(p));
return 0;
}
static void spu_free_lscsa_std(struct spu_state *csa)
{
/* Clear reserved bit before vfree. */
unsigned char *p;
if (csa->lscsa == NULL)
return;
for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE)
ClearPageReserved(vmalloc_to_page(p));
vfree(csa->lscsa);
}
#ifdef CONFIG_SPU_FS_64K_LS
#define SPU_64K_PAGE_SHIFT 16
#define SPU_64K_PAGE_ORDER (SPU_64K_PAGE_SHIFT - PAGE_SHIFT)
#define SPU_64K_PAGE_COUNT (1ul << SPU_64K_PAGE_ORDER)
int spu_alloc_lscsa(struct spu_state *csa)
{
struct page **pgarray;
unsigned char *p;
int i, j, n_4k;
/* Check availability of 64K pages */
if (mmu_psize_defs[MMU_PAGE_64K].shift == 0)
goto fail;
csa->use_big_pages = 1;
pr_debug("spu_alloc_lscsa(csa=0x%p), trying to allocate 64K pages\n",
csa);
/* First try to allocate our 64K pages. We need 5 of them
* with the current implementation. In the future, we should try
* to separate the lscsa with the actual local store image, thus
* allowing us to require only 4 64K pages per context
*/
for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++) {
/* XXX This is likely to fail, we should use a special pool
* similiar to what hugetlbfs does.
*/
csa->lscsa_pages[i] = alloc_pages(GFP_KERNEL,
SPU_64K_PAGE_ORDER);
if (csa->lscsa_pages[i] == NULL)
goto fail;
}
pr_debug(" success ! creating vmap...\n");
/* Now we need to create a vmalloc mapping of these for the kernel
* and SPU context switch code to use. Currently, we stick to a
* normal kernel vmalloc mapping, which in our case will be 4K
*/
n_4k = SPU_64K_PAGE_COUNT * SPU_LSCSA_NUM_BIG_PAGES;
pgarray = kmalloc(sizeof(struct page *) * n_4k, GFP_KERNEL);
if (pgarray == NULL)
goto fail;
for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++)
for (j = 0; j < SPU_64K_PAGE_COUNT; j++)
/* We assume all the struct page's are contiguous
* which should be hopefully the case for an order 4
* allocation..
*/
pgarray[i * SPU_64K_PAGE_COUNT + j] =
csa->lscsa_pages[i] + j;
csa->lscsa = vmap(pgarray, n_4k, VM_USERMAP, PAGE_KERNEL);
kfree(pgarray);
if (csa->lscsa == NULL)
goto fail;
memset(csa->lscsa, 0, sizeof(struct spu_lscsa));
/* Set LS pages reserved to allow for user-space mapping.
*
* XXX isn't that a bit obsolete ? I think we should just
* make sure the page count is high enough. Anyway, won't harm
* for now
*/
for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE)
SetPageReserved(vmalloc_to_page(p));
pr_debug(" all good !\n");
return 0;
fail:
pr_debug("spufs: failed to allocate lscsa 64K pages, falling back\n");
spu_free_lscsa(csa);
return spu_alloc_lscsa_std(csa);
}
void spu_free_lscsa(struct spu_state *csa)
{
unsigned char *p;
int i;
if (!csa->use_big_pages) {
spu_free_lscsa_std(csa);
return;
}
csa->use_big_pages = 0;
if (csa->lscsa == NULL)
goto free_pages;
for (p = csa->lscsa->ls; p < csa->lscsa->ls + LS_SIZE; p += PAGE_SIZE)
ClearPageReserved(vmalloc_to_page(p));
vunmap(csa->lscsa);
csa->lscsa = NULL;
free_pages:
for (i = 0; i < SPU_LSCSA_NUM_BIG_PAGES; i++)
if (csa->lscsa_pages[i])
__free_pages(csa->lscsa_pages[i], SPU_64K_PAGE_ORDER);
}
#else /* CONFIG_SPU_FS_64K_LS */
int spu_alloc_lscsa(struct spu_state *csa)
{
return spu_alloc_lscsa_std(csa);
}
void spu_free_lscsa(struct spu_state *csa)
{
spu_free_lscsa_std(csa);
}
#endif /* !defined(CONFIG_SPU_FS_64K_LS) */
