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-rw-r--r--kernel/dma/pool.c295
1 files changed, 295 insertions, 0 deletions
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
new file mode 100644
index 0000000000..b481c48a31
--- /dev/null
+++ b/kernel/dma/pool.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ * Copyright (C) 2020 Google LLC
+ */
+#include <linux/cma.h>
+#include <linux/debugfs.h>
+#include <linux/dma-map-ops.h>
+#include <linux/dma-direct.h>
+#include <linux/init.h>
+#include <linux/genalloc.h>
+#include <linux/set_memory.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+static struct gen_pool *atomic_pool_dma __ro_after_init;
+static unsigned long pool_size_dma;
+static struct gen_pool *atomic_pool_dma32 __ro_after_init;
+static unsigned long pool_size_dma32;
+static struct gen_pool *atomic_pool_kernel __ro_after_init;
+static unsigned long pool_size_kernel;
+
+/* Size can be defined by the coherent_pool command line */
+static size_t atomic_pool_size;
+
+/* Dynamic background expansion when the atomic pool is near capacity */
+static struct work_struct atomic_pool_work;
+
+static int __init early_coherent_pool(char *p)
+{
+ atomic_pool_size = memparse(p, &p);
+ return 0;
+}
+early_param("coherent_pool", early_coherent_pool);
+
+static void __init dma_atomic_pool_debugfs_init(void)
+{
+ struct dentry *root;
+
+ root = debugfs_create_dir("dma_pools", NULL);
+ debugfs_create_ulong("pool_size_dma", 0400, root, &pool_size_dma);
+ debugfs_create_ulong("pool_size_dma32", 0400, root, &pool_size_dma32);
+ debugfs_create_ulong("pool_size_kernel", 0400, root, &pool_size_kernel);
+}
+
+static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
+{
+ if (gfp & __GFP_DMA)
+ pool_size_dma += size;
+ else if (gfp & __GFP_DMA32)
+ pool_size_dma32 += size;
+ else
+ pool_size_kernel += size;
+}
+
+static bool cma_in_zone(gfp_t gfp)
+{
+ unsigned long size;
+ phys_addr_t end;
+ struct cma *cma;
+
+ cma = dev_get_cma_area(NULL);
+ if (!cma)
+ return false;
+
+ size = cma_get_size(cma);
+ if (!size)
+ return false;
+
+ /* CMA can't cross zone boundaries, see cma_activate_area() */
+ end = cma_get_base(cma) + size - 1;
+ if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
+ return end <= DMA_BIT_MASK(zone_dma_bits);
+ if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
+ return end <= DMA_BIT_MASK(32);
+ return true;
+}
+
+static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
+ gfp_t gfp)
+{
+ unsigned int order;
+ struct page *page = NULL;
+ void *addr;
+ int ret = -ENOMEM;
+
+ /* Cannot allocate larger than MAX_ORDER */
+ order = min(get_order(pool_size), MAX_ORDER);
+
+ do {
+ pool_size = 1 << (PAGE_SHIFT + order);
+ if (cma_in_zone(gfp))
+ page = dma_alloc_from_contiguous(NULL, 1 << order,
+ order, false);
+ if (!page)
+ page = alloc_pages(gfp, order);
+ } while (!page && order-- > 0);
+ if (!page)
+ goto out;
+
+ arch_dma_prep_coherent(page, pool_size);
+
+#ifdef CONFIG_DMA_DIRECT_REMAP
+ addr = dma_common_contiguous_remap(page, pool_size,
+ pgprot_dmacoherent(PAGE_KERNEL),
+ __builtin_return_address(0));
+ if (!addr)
+ goto free_page;
+#else
+ addr = page_to_virt(page);
+#endif
+ /*
+ * Memory in the atomic DMA pools must be unencrypted, the pools do not
+ * shrink so no re-encryption occurs in dma_direct_free().
+ */
+ ret = set_memory_decrypted((unsigned long)page_to_virt(page),
+ 1 << order);
+ if (ret)
+ goto remove_mapping;
+ ret = gen_pool_add_virt(pool, (unsigned long)addr, page_to_phys(page),
+ pool_size, NUMA_NO_NODE);
+ if (ret)
+ goto encrypt_mapping;
+
+ dma_atomic_pool_size_add(gfp, pool_size);
+ return 0;
+
+encrypt_mapping:
+ ret = set_memory_encrypted((unsigned long)page_to_virt(page),
+ 1 << order);
+ if (WARN_ON_ONCE(ret)) {
+ /* Decrypt succeeded but encrypt failed, purposely leak */
+ goto out;
+ }
+remove_mapping:
+#ifdef CONFIG_DMA_DIRECT_REMAP
+ dma_common_free_remap(addr, pool_size);
+free_page:
+ __free_pages(page, order);
+#endif
+out:
+ return ret;
+}
+
+static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
+{
+ if (pool && gen_pool_avail(pool) < atomic_pool_size)
+ atomic_pool_expand(pool, gen_pool_size(pool), gfp);
+}
+
+static void atomic_pool_work_fn(struct work_struct *work)
+{
+ if (IS_ENABLED(CONFIG_ZONE_DMA))
+ atomic_pool_resize(atomic_pool_dma,
+ GFP_KERNEL | GFP_DMA);
+ if (IS_ENABLED(CONFIG_ZONE_DMA32))
+ atomic_pool_resize(atomic_pool_dma32,
+ GFP_KERNEL | GFP_DMA32);
+ atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
+}
+
+static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
+ gfp_t gfp)
+{
+ struct gen_pool *pool;
+ int ret;
+
+ pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
+ if (!pool)
+ return NULL;
+
+ gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL);
+
+ ret = atomic_pool_expand(pool, pool_size, gfp);
+ if (ret) {
+ gen_pool_destroy(pool);
+ pr_err("DMA: failed to allocate %zu KiB %pGg pool for atomic allocation\n",
+ pool_size >> 10, &gfp);
+ return NULL;
+ }
+
+ pr_info("DMA: preallocated %zu KiB %pGg pool for atomic allocations\n",
+ gen_pool_size(pool) >> 10, &gfp);
+ return pool;
+}
+
+static int __init dma_atomic_pool_init(void)
+{
+ int ret = 0;
+
+ /*
+ * If coherent_pool was not used on the command line, default the pool
+ * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER.
+ */
+ if (!atomic_pool_size) {
+ unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K);
+ pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES);
+ atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K);
+ }
+ INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);
+
+ atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size,
+ GFP_KERNEL);
+ if (!atomic_pool_kernel)
+ ret = -ENOMEM;
+ if (has_managed_dma()) {
+ atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size,
+ GFP_KERNEL | GFP_DMA);
+ if (!atomic_pool_dma)
+ ret = -ENOMEM;
+ }
+ if (IS_ENABLED(CONFIG_ZONE_DMA32)) {
+ atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
+ GFP_KERNEL | GFP_DMA32);
+ if (!atomic_pool_dma32)
+ ret = -ENOMEM;
+ }
+
+ dma_atomic_pool_debugfs_init();
+ return ret;
+}
+postcore_initcall(dma_atomic_pool_init);
+
+static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp)
+{
+ if (prev == NULL) {
+ if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
+ return atomic_pool_dma32;
+ if (atomic_pool_dma && (gfp & GFP_DMA))
+ return atomic_pool_dma;
+ return atomic_pool_kernel;
+ }
+ if (prev == atomic_pool_kernel)
+ return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma;
+ if (prev == atomic_pool_dma32)
+ return atomic_pool_dma;
+ return NULL;
+}
+
+static struct page *__dma_alloc_from_pool(struct device *dev, size_t size,
+ struct gen_pool *pool, void **cpu_addr,
+ bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
+{
+ unsigned long addr;
+ phys_addr_t phys;
+
+ addr = gen_pool_alloc(pool, size);
+ if (!addr)
+ return NULL;
+
+ phys = gen_pool_virt_to_phys(pool, addr);
+ if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) {
+ gen_pool_free(pool, addr, size);
+ return NULL;
+ }
+
+ if (gen_pool_avail(pool) < atomic_pool_size)
+ schedule_work(&atomic_pool_work);
+
+ *cpu_addr = (void *)addr;
+ memset(*cpu_addr, 0, size);
+ return pfn_to_page(__phys_to_pfn(phys));
+}
+
+struct page *dma_alloc_from_pool(struct device *dev, size_t size,
+ void **cpu_addr, gfp_t gfp,
+ bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
+{
+ struct gen_pool *pool = NULL;
+ struct page *page;
+
+ while ((pool = dma_guess_pool(pool, gfp))) {
+ page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
+ phys_addr_ok);
+ if (page)
+ return page;
+ }
+
+ WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev));
+ return NULL;
+}
+
+bool dma_free_from_pool(struct device *dev, void *start, size_t size)
+{
+ struct gen_pool *pool = NULL;
+
+ while ((pool = dma_guess_pool(pool, 0))) {
+ if (!gen_pool_has_addr(pool, (unsigned long)start, size))
+ continue;
+ gen_pool_free(pool, (unsigned long)start, size);
+ return true;
+ }
+
+ return false;
+}