diff options
Diffstat (limited to 'arch/powerpc/platforms/cell/spufs/lscsa_alloc.c')
| -rw-r--r-- | arch/powerpc/platforms/cell/spufs/lscsa_alloc.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/lscsa_alloc.c b/arch/powerpc/platforms/cell/spufs/lscsa_alloc.c new file mode 100644 index 000000000000..f4b3c052dabf --- /dev/null +++ b/arch/powerpc/platforms/cell/spufs/lscsa_alloc.c @@ -0,0 +1,181 @@ +/* + * 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) */ |