From 0112cb7bc68d85c9c98b496937bde7af50f13cc6 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 28 Apr 2015 10:55:37 -0400 Subject: [PATCH] Use pfn rather than struct page in ring buffer array First step to support permanent memory (e.g. pmem) which does not have struct page. Signed-off-by: Mathieu Desnoyers --- lib/ringbuffer/backend.h | 4 ++-- lib/ringbuffer/backend_types.h | 2 +- lib/ringbuffer/ring_buffer_backend.c | 27 ++++++++------------------- lib/ringbuffer/ring_buffer_mmap.c | 14 +++++++------- lib/ringbuffer/ring_buffer_splice.c | 11 ++++++----- 5 files changed, 24 insertions(+), 34 deletions(-) diff --git a/lib/ringbuffer/backend.h b/lib/ringbuffer/backend.h index e3a0a81a..6f3296bc 100644 --- a/lib/ringbuffer/backend.h +++ b/lib/ringbuffer/backend.h @@ -54,8 +54,8 @@ extern int __lib_ring_buffer_copy_to_user(struct lib_ring_buffer_backend *bufb, extern int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, size_t offset, void *dest, size_t len); -extern struct page ** -lib_ring_buffer_read_get_page(struct lib_ring_buffer_backend *bufb, size_t offset, +extern unsigned long * +lib_ring_buffer_read_get_pfn(struct lib_ring_buffer_backend *bufb, size_t offset, void ***virt); /* diff --git a/lib/ringbuffer/backend_types.h b/lib/ringbuffer/backend_types.h index 8c53d075..c1d8be18 100644 --- a/lib/ringbuffer/backend_types.h +++ b/lib/ringbuffer/backend_types.h @@ -28,7 +28,7 @@ struct lib_ring_buffer_backend_page { void *virt; /* page virtual address (cached) */ - struct page *page; /* pointer to page structure */ + unsigned long pfn; /* page frame number */ }; struct lib_ring_buffer_backend_pages { diff --git a/lib/ringbuffer/ring_buffer_backend.c b/lib/ringbuffer/ring_buffer_backend.c index 5466325f..83a6e39b 100644 --- a/lib/ringbuffer/ring_buffer_backend.c +++ b/lib/ringbuffer/ring_buffer_backend.c @@ -52,7 +52,6 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config unsigned long subbuf_size, mmap_offset = 0; unsigned long num_subbuf_alloc; struct page **pages; - void **virt; unsigned long i; num_pages = size >> PAGE_SHIFT; @@ -71,12 +70,6 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config if (unlikely(!pages)) goto pages_error; - virt = kmalloc_node(ALIGN(sizeof(*virt) * num_pages, - 1 << INTERNODE_CACHE_SHIFT), - GFP_KERNEL, cpu_to_node(max(bufb->cpu, 0))); - if (unlikely(!virt)) - goto virt_error; - bufb->array = kmalloc_node(ALIGN(sizeof(*bufb->array) * num_subbuf_alloc, 1 << INTERNODE_CACHE_SHIFT), @@ -89,7 +82,6 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config GFP_KERNEL | __GFP_ZERO, 0); if (unlikely(!pages[i])) goto depopulate; - virt[i] = page_address(pages[i]); } bufb->num_pages_per_subbuf = num_pages_per_subbuf; @@ -138,8 +130,8 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config for (i = 0; i < num_subbuf_alloc; i++) { for (j = 0; j < num_pages_per_subbuf; j++) { CHAN_WARN_ON(chanb, page_idx > num_pages); - bufb->array[i]->p[j].virt = virt[page_idx]; - bufb->array[i]->p[j].page = pages[page_idx]; + bufb->array[i]->p[j].virt = page_address(pages[page_idx]); + bufb->array[i]->p[j].pfn = page_to_pfn(pages[page_idx]); page_idx++; } if (config->output == RING_BUFFER_MMAP) { @@ -153,7 +145,6 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config * will not fault. */ wrapper_vmalloc_sync_all(); - kfree(virt); kfree(pages); return 0; @@ -168,8 +159,6 @@ depopulate: __free_page(pages[i]); kfree(bufb->array); array_error: - kfree(virt); -virt_error: kfree(pages); pages_error: return -ENOMEM; @@ -201,7 +190,7 @@ void lib_ring_buffer_backend_free(struct lib_ring_buffer_backend *bufb) kfree(bufb->buf_cnt); for (i = 0; i < num_subbuf_alloc; i++) { for (j = 0; j < bufb->num_pages_per_subbuf; j++) - __free_page(bufb->array[i]->p[j].page); + __free_page(pfn_to_page(bufb->array[i]->p[j].pfn)); kfree(bufb->array[i]); } kfree(bufb->array); @@ -961,15 +950,15 @@ int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, size_t offse EXPORT_SYMBOL_GPL(lib_ring_buffer_read_cstr); /** - * lib_ring_buffer_read_get_page - Get a whole page to read from + * lib_ring_buffer_read_get_pfn - Get a page frame number to read from * @bufb : buffer backend * @offset : offset within the buffer * @virt : pointer to page address (output) * * Should be protected by get_subbuf/put_subbuf. - * Returns the pointer to the page struct pointer. + * Returns the pointer to the page frame number unsigned long. */ -struct page **lib_ring_buffer_read_get_page(struct lib_ring_buffer_backend *bufb, +unsigned long *lib_ring_buffer_read_get_pfn(struct lib_ring_buffer_backend *bufb, size_t offset, void ***virt) { size_t index; @@ -986,9 +975,9 @@ struct page **lib_ring_buffer_read_get_page(struct lib_ring_buffer_backend *bufb CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE && subbuffer_id_is_noref(config, id)); *virt = &rpages->p[index].virt; - return &rpages->p[index].page; + return &rpages->p[index].pfn; } -EXPORT_SYMBOL_GPL(lib_ring_buffer_read_get_page); +EXPORT_SYMBOL_GPL(lib_ring_buffer_read_get_pfn); /** * lib_ring_buffer_read_offset_address - get address of a buffer location diff --git a/lib/ringbuffer/ring_buffer_mmap.c b/lib/ringbuffer/ring_buffer_mmap.c index c172fee7..2cc0dd24 100644 --- a/lib/ringbuffer/ring_buffer_mmap.c +++ b/lib/ringbuffer/ring_buffer_mmap.c @@ -38,7 +38,7 @@ static int lib_ring_buffer_fault(struct vm_area_struct *vma, struct vm_fault *vm struct channel *chan = buf->backend.chan; const struct lib_ring_buffer_config *config = &chan->backend.config; pgoff_t pgoff = vmf->pgoff; - struct page **page; + unsigned long *pfnp; void **virt; unsigned long offset, sb_bindex; @@ -53,14 +53,14 @@ static int lib_ring_buffer_fault(struct vm_area_struct *vma, struct vm_fault *vm buf->backend.chan->backend.subbuf_size)) return VM_FAULT_SIGBUS; /* - * ring_buffer_read_get_page() gets the page in the current reader's - * pages. + * ring_buffer_read_get_pfn() gets the page frame number for the + * current reader's pages. */ - page = lib_ring_buffer_read_get_page(&buf->backend, offset, &virt); - if (!*page) + pfnp = lib_ring_buffer_read_get_pfn(&buf->backend, offset, &virt); + if (!*pfnp) return VM_FAULT_SIGBUS; - get_page(*page); - vmf->page = *page; + get_page(pfn_to_page(*pfnp)); + vmf->page = pfn_to_page(*pfnp); return 0; } diff --git a/lib/ringbuffer/ring_buffer_splice.c b/lib/ringbuffer/ring_buffer_splice.c index bb91f45e..a1988f0b 100644 --- a/lib/ringbuffer/ring_buffer_splice.c +++ b/lib/ringbuffer/ring_buffer_splice.c @@ -126,7 +126,8 @@ static int subbuf_splice_actor(struct file *in, for (; spd.nr_pages < nr_pages; spd.nr_pages++) { unsigned int this_len; - struct page **page, *new_page; + unsigned long *pfnp, new_pfn; + struct page *new_page; void **virt; if (!len) @@ -143,11 +144,11 @@ static int subbuf_splice_actor(struct file *in, GFP_KERNEL | __GFP_ZERO, 0); if (!new_page) break; - + new_pfn = page_to_pfn(new_page); this_len = PAGE_SIZE - poff; - page = lib_ring_buffer_read_get_page(&buf->backend, roffset, &virt); - spd.pages[spd.nr_pages] = *page; - *page = new_page; + pfnp = lib_ring_buffer_read_get_pfn(&buf->backend, roffset, &virt); + spd.pages[spd.nr_pages] = pfn_to_page(*pfnp); + *pfnp = new_pfn; *virt = page_address(new_page); spd.partial[spd.nr_pages].offset = poff; spd.partial[spd.nr_pages].len = this_len; -- 2.34.1