litmus-rt.git - The LITMUS^RT kernel.

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author	Paul Walmsley <paul@pwsan.com>	2009-03-12 15:11:43 -0400
committer	Russell King <rmk+kernel@arm.linux.org.uk>	2009-03-12 15:25:02 -0400
commit	e4707dd3e9d0cb57597b6568a5e51fea5d6fca41 (patch)
tree	c76a6cb54e4f90a8deebf380bf8fe8a5f6eb2750 /sound/soc/codecs/Makefile
parent	6dc4a47a0cf423879b505af0e29997fca4088630 (diff)

[ARM] 5422/1: ARM: MMU: add a Non-cacheable Normal executable memory type

This patch adds a Non-cacheable Normal ARM executable memory type, MT_MEMORY_NONCACHED. On OMAP3, this is used for rapid dynamic voltage/frequency scaling in the VDD2 voltage domain. OMAP3's SDRAM controller (SDRC) is in the VDD2 voltage domain, and its clock frequency must change along with voltage. The SDRC clock change code cannot run from SDRAM itself, since SDRAM accesses are paused during the clock change. So the current implementation of the DVFS code executes from OMAP on-chip SRAM, aka "OCM RAM." If the OCM RAM pages are marked as Cacheable, the ARM cache controller will attempt to flush dirty cache lines to the SDRC, so it can fill those lines with OCM RAM instruction code. The problem is that the SDRC is paused during DVFS, and so any SDRAM access causes the ARM MPU subsystem to hang. TI's original solution to this problem was to mark the OCM RAM sections as Strongly Ordered memory, thus preventing caching. This is overkill: since the memory is marked as non-bufferable, OCM RAM writes become needlessly slow. The idea of "Strongly Ordered SRAM" is also conceptually disturbing. Previous LAKML list discussion is here: http://www.spinics.net/lists/arm-kernel/msg54312.html This memory type MT_MEMORY_NONCACHED is used for OCM RAM by a future patch. Cc: Richard Woodruff <r-woodruff2@ti.com> Signed-off-by: Paul Walmsley <paul@pwsan.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Diffstat (limited to 'sound/soc/codecs/Makefile')

0 files changed, 0 insertions, 0 deletions

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/* * Generic hugetlb support. * (C) William Irwin, April 2004 */ #include <linux/gfp.h> #include <linux/list.h> #include <linux/init.h> #include <linux/module.h> #include <linux/mm.h> #include <linux/sysctl.h> #include <linux/highmem.h> #include <linux/mmu_notifier.h> #include <linux/nodemask.h> #include <linux/pagemap.h> #include <linux/mempolicy.h> #include <linux/cpuset.h> #include <linux/mutex.h> #include <linux/bootmem.h> #include <linux/sysfs.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/io.h> #include <linux/hugetlb.h> #include "internal.h" const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; static gfp_t htlb_alloc_mask = GFP_HIGHUSER; unsigned long hugepages_treat_as_movable; static int max_hstate; unsigned int default_hstate_idx; struct hstate hstates[HUGE_MAX_HSTATE]; __initdata LIST_HEAD(huge_boot_pages); /* for command line parsing */ static struct hstate * __initdata parsed_hstate; static unsigned long __initdata default_hstate_max_huge_pages; static unsigned long __initdata default_hstate_size; #define for_each_hstate(h) \ for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) /* * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages */ static DEFINE_SPINLOCK(hugetlb_lock); /* * Region tracking -- allows tracking of reservations and instantiated pages * across the pages in a mapping. * * The region data structures are protected by a combination of the mmap_sem * and the hugetlb_instantion_mutex. To access or modify a region the caller * must either hold the mmap_sem for write, or the mmap_sem for read and * the hugetlb_instantiation mutex: * * down_write(&mm->mmap_sem); * or * down_read(&mm->mmap_sem); * mutex_lock(&hugetlb_instantiation_mutex); */ struct file_region { struct list_head link; long from; long to; }; static long region_add(struct list_head *head, long f, long t) { struct file_region *rg, *nrg, *trg; /* Locate the region we are either in or before. */ list_for_each_entry(rg, head, link) if (f <= rg->to) break; /* Round our left edge to the current segment if it encloses us. */ if (f > rg->from) f = rg->from; /* Check for and consume any regions we now overlap with. */ nrg = rg; list_for_each_entry_safe(rg, trg, rg->link.prev, link) { if (&rg->link == head) break; if (rg->from > t) break; /* If this area reaches higher then extend our area to * include it completely. If this is not the first area * which we intend to reuse, free it. */ if (rg->to > t) t = rg->to; if (rg != nrg) { list_del(&rg->link); kfree(rg); } } nrg->from = f; nrg->to = t; return 0; } static long region_chg(struct list_head *head, long f, long t) { struct file_region *rg, *nrg; long chg = 0; /* Locate the region we are before or in. */ list_for_each_entry(rg, head, link) if (f <= rg->to) break; /* If we are below the current region then a new region is required. * Subtle, allocate a new region at the position but make it zero * size such that we can guarantee to record the reservation. */ if (&rg->link == head || t < rg->from) { nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); if (!nrg) return -ENOMEM; nrg->from = f; nrg->to = f; INIT_LIST_HEAD(&nrg->link); list_add(&nrg->link, rg->link.prev); return t - f; } /* Round our left edge to the current segment if it encloses us. */ if (f > rg->from) f = rg->from; chg = t - f; /* Check for and consume any regions we now overlap with. */ list_for_each_entry(rg, rg->link.prev, link) { if (&rg->link == head) break; if (rg->from > t) return chg; /* We overlap with this area, if it extends futher than * us then we must extend ourselves. Account for its * existing reservation. */ if (rg->to > t) { chg += rg->to - t; t = rg->to; } chg -= rg->to - rg->from; } return chg; } static long region_truncate(struct list_head *head, long end) { struct file_region *rg, *trg; long chg = 0; /* Locate the region we are either in or before. */ list_for_each_entry(rg, head, link) if (end <= rg->to) break; if (&rg->link == head) return 0; /* If we are in the middle of a region then adjust it. */ if (end > rg->from) { chg = rg->to - end; rg->to = end; rg = list_entry(rg->link.next, typeof(*rg), link); } /* Drop any remaining regions. */ list_for_each_entry_safe(rg, trg, rg->link.prev, link) { if (&rg->link == head) break; chg += rg->to - rg->from; list_del(&rg->link); kfree(rg); } return chg; } static long region_count(struct list_head *head, long f, long t) { struct file_region *rg; long chg = 0; /* Locate each segment we overlap with, and count that overlap. */ list_for_each_entry(rg, head, link) { int seg_from; int seg_to; if (rg->to <= f) continue; if (rg->from >= t) break; seg_from = max(rg->from, f); seg_to = min(rg->to, t); chg += seg_to - seg_from; } return chg; } /* * Convert the address within this vma to the page offset within * the mapping, in pagecache page units; huge pages here. */ static pgoff_t vma_hugecache_offset(struct hstate *h, struct vm_area_struct *vma, unsigned long address) { return ((address - vma->vm_start) >> huge_page_shift(h)) + (vma->vm_pgoff >> huge_page_order(h)); } /* * Flags for MAP_PRIVATE reservations. These are stored in the bottom * bits of the reservation map pointer, which are always clear due to * alignment. */ #define HPAGE_RESV_OWNER (1UL << 0) #define HPAGE_RESV_UNMAPPED (1UL << 1) #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) /* * These helpers are used to track how many pages are reserved for * faults in a MAP_PRIVATE mapping. Only the process that called mmap() * is guaranteed to have their future faults succeed. * * With the exception of reset_vma_resv_huge_pages() which is called at fork(), * the reserve counters are updated with the hugetlb_lock held. It is safe * to reset the VMA at fork() time as it is not in use yet and there is no * chance of the global counters getting corrupted as a result of the values. * * The private mapping reservation is represented in a subtly different * manner to a shared mapping. A shared mapping has a region map associated * with the underlying file, this region map represents the backing file * pages which have ever had a reservation assigned which this persists even * after the page is instantiated. A private mapping has a region map * associated with the original mmap which is attached to all VMAs which * reference it, this region map represents those offsets which have consumed * reservation ie. where pages have been instantiated. */ static unsigned long get_vma_private_data(struct vm_area_struct *vma) { return (unsigned long)vma->vm_private_data; } static void set_vma_private_data(struct vm_area_struct *vma, unsigned long value) { vma->vm_private_data = (void *)value; } struct resv_map { struct kref refs; struct list_head regions; }; struct resv_map *resv_map_alloc(void) { struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); if (!resv_map) return NULL; kref_init(&resv_map->refs); INIT_LIST_HEAD(&resv_map->regions); return resv_map; } void resv_map_release(struct kref *ref) { struct resv_map *resv_map = container_of(ref, struct resv_map, refs); /* Clear out any active regions before we release the map. */ region_truncate(&resv_map->regions, 0); kfree(resv_map); } static struct resv_map *vma_resv_map(struct vm_area_struct *vma) { VM_BUG_ON(!is_vm_hugetlb_page(vma)); if (!(vma->vm_flags & VM_SHARED)) return (struct resv_map *)(get_vma_private_data(vma) & ~HPAGE_RESV_MASK); return 0; } static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) { VM_BUG_ON(!is_vm_hugetlb_page(vma)); VM_BUG_ON(vma->vm_flags & VM_SHARED); set_vma_private_data(vma, (get_vma_private_data(vma) & HPAGE_RESV_MASK) | (unsigned long)map); } static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) { VM_BUG_ON(!is_vm_hugetlb_page(vma)); VM_BUG_ON(vma->vm_flags & VM_SHARED); set_vma_private_data(vma, get_vma_private_data(vma) | flags); } static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) { VM_BUG_ON(!is_vm_hugetlb_page(vma)); return (get_vma_private_data(vma) & flag) != 0; } /* Decrement the reserved pages in the hugepage pool by one */ static void decrement_hugepage_resv_vma(struct hstate *h, struct vm_area_struct *vma) { if (vma->vm_flags & VM_NORESERVE) return; if (vma->vm_flags & VM_SHARED) { /* Shared mappings always use reserves */ h->resv_huge_pages--; } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { /* * Only the process that called mmap() has reserves for * private mappings. */ h->resv_huge_pages--; } } /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ void reset_vma_resv_huge_pages(struct vm_area_struct *vma) { VM_BUG_ON(!is_vm_hugetlb_page(vma)); if (!(vma->vm_flags & VM_SHARED)) vma->vm_private_data = (void *)0; } /* Returns true if the VMA has associated reserve pages */ static int vma_has_reserves(struct vm_area_struct *vma) { if (vma->vm_flags & VM_SHARED) return 1; if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) return 1; return 0; } static void clear_huge_page(struct page *page, unsigned long addr, unsigned long sz) { int i; might_sleep(); for (i = 0; i < sz/PAGE_SIZE; i++) { cond_resched(); clear_user_highpage(page + i, addr + i * PAGE_SIZE); } } static void copy_huge_page(struct page *dst, struct page *src, unsigned long addr, struct vm_area_struct *vma) { int i; struct hstate *h = hstate_vma(vma); might_sleep(); for (i = 0; i < pages_per_huge_page(h); i++) { cond_resched(); copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); } } static void enqueue_huge_page(struct hstate *h, struct page *page) { int nid = page_to_nid(page); list_add(&page->lru, &h->hugepage_freelists[nid]); h->free_huge_pages++; h->free_huge_pages_node[nid]++; } static struct page *dequeue_huge_page(struct hstate *h) { int nid; struct page *page = NULL; for (nid = 0; nid < MAX_NUMNODES; ++nid) { if (!list_empty(&h->hugepage_freelists[nid])) { page = list_entry(h->hugepage_freelists[nid].next, struct page, lru); list_del(&page->lru); h->free_huge_pages--; h->free_huge_pages_node[nid]--; break; } } return page; } static struct page *dequeue_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, unsigned long address, int avoid_reserve) { int nid; struct page *page = NULL; struct mempolicy *mpol; nodemask_t *nodemask; struct zonelist *zonelist = huge_zonelist(vma, address, htlb_alloc_mask, &mpol, &nodemask); struct zone *zone; struct zoneref *z; /* * A child process with MAP_PRIVATE mappings created by their parent * have no page reserves. This check ensures that reservations are * not "stolen". The child may still get SIGKILLed */ if (!vma_has_reserves(vma) && h->free_huge_pages - h->resv_huge_pages == 0) return NULL; /* If reserves cannot be used, ensure enough pages are in the pool */ if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) return NULL; for_each_zone_zonelist_nodemask(zone, z, zonelist, MAX_NR_ZONES - 1, nodemask) { nid = zone_to_nid(zone); if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && !list_empty(&h->hugepage_freelists[nid])) { page = list_entry(h->hugepage_freelists[nid].next, struct page, lru); list_del(&page->lru); h->free_huge_pages--; h->free_huge_pages_node[nid]--; if (!avoid_reserve) decrement_hugepage_resv_vma(h, vma); break; } } mpol_cond_put(mpol); return page; } static void update_and_free_page(struct hstate *h, struct page *page) { int i; h->nr_huge_pages--; h->nr_huge_pages_node[page_to_nid(page)]--; for (i = 0; i < pages_per_huge_page(h); i++) { page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | 1 << PG_private | 1<< PG_writeback); } set_compound_page_dtor(page, NULL); set_page_refcounted(page); arch_release_hugepage(page); __free_pages(page, huge_page_order(h)); } struct hstate *size_to_hstate(unsigned long size) { struct hstate *h; for_each_hstate(h) { if (huge_page_size(h) == size) return h; } return NULL; } static void free_huge_page(struct page *page) { /* * Can't pass hstate in here because it is called from the * compound page destructor. */ struct hstate *h = page_hstate(page); int nid = page_to_nid(page); struct address_space *mapping; mapping = (struct address_space *) page_private(page); set_page_private(page, 0); BUG_ON(page_count(page)); INIT_LIST_HEAD(&page->lru); spin_lock(&hugetlb_lock); if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { update_and_free_page(h, page); h->surplus_huge_pages--; h->surplus_huge_pages_node[nid]--; } else { enqueue_huge_page(h, page); } spin_unlock(&hugetlb_lock); if (mapping) hugetlb_put_quota(mapping, 1); } /* * Increment or decrement surplus_huge_pages. Keep node-specific counters * balanced by operating on them in a round-robin fashion. * Returns 1 if an adjustment was made. */ static int adjust_pool_surplus(struct hstate *h, int delta) { static int prev_nid; int nid = prev_nid; int ret = 0; VM_BUG_ON(delta != -1 && delta != 1); do { nid = next_node(nid, node_online_map); if (nid == MAX_NUMNODES) nid = first_node(node_online_map); /* To shrink on this node, there must be a surplus page */ if (delta < 0 && !h->surplus_huge_pages_node[nid]) continue; /* Surplus cannot exceed the total number of pages */ if (delta > 0 && h->surplus_huge_pages_node[nid] >= h->nr_huge_pages_node[nid]) continue; h->surplus_huge_pages += delta; h->surplus_huge_pages_node[nid] += delta; ret = 1; break; } while (nid != prev_nid); prev_nid = nid; return ret; }


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