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-rw-r--r--drivers/usb/core/buffer.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
new file mode 100644
index 000000000..268ccbec8
--- /dev/null
+++ b/drivers/usb/core/buffer.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMA memory management for framework level HCD code (hc_driver)
+ *
+ * This implementation plugs in through generic "usb_bus" level methods,
+ * and should work with all USB controllers, regardless of bus type.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/genalloc.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+
+
+/*
+ * DMA-Coherent Buffers
+ */
+
+/* FIXME tune these based on pool statistics ... */
+static size_t pool_max[HCD_BUFFER_POOLS] = {
+ 32, 128, 512, 2048,
+};
+
+void __init usb_init_pool_max(void)
+{
+ /*
+ * The pool_max values must never be smaller than
+ * ARCH_KMALLOC_MINALIGN.
+ */
+ if (ARCH_KMALLOC_MINALIGN <= 32)
+ ; /* Original value is okay */
+ else if (ARCH_KMALLOC_MINALIGN <= 64)
+ pool_max[0] = 64;
+ else if (ARCH_KMALLOC_MINALIGN <= 128)
+ pool_max[0] = 0; /* Don't use this pool */
+ else
+ BUILD_BUG(); /* We don't allow this */
+}
+
+/* SETUP primitives */
+
+/**
+ * hcd_buffer_create - initialize buffer pools
+ * @hcd: the bus whose buffer pools are to be initialized
+ *
+ * Context: task context, might sleep
+ *
+ * Call this as part of initializing a host controller that uses the dma
+ * memory allocators. It initializes some pools of dma-coherent memory that
+ * will be shared by all drivers using that controller.
+ *
+ * Call hcd_buffer_destroy() to clean up after using those pools.
+ *
+ * Return: 0 if successful. A negative errno value otherwise.
+ */
+int hcd_buffer_create(struct usb_hcd *hcd)
+{
+ char name[16];
+ int i, size;
+
+ if (hcd->localmem_pool || !hcd_uses_dma(hcd))
+ return 0;
+
+ for (i = 0; i < HCD_BUFFER_POOLS; i++) {
+ size = pool_max[i];
+ if (!size)
+ continue;
+ snprintf(name, sizeof(name), "buffer-%d", size);
+ hcd->pool[i] = dma_pool_create(name, hcd->self.sysdev,
+ size, size, 0);
+ if (!hcd->pool[i]) {
+ hcd_buffer_destroy(hcd);
+ return -ENOMEM;
+ }
+ }
+ return 0;
+}
+
+
+/**
+ * hcd_buffer_destroy - deallocate buffer pools
+ * @hcd: the bus whose buffer pools are to be destroyed
+ *
+ * Context: task context, might sleep
+ *
+ * This frees the buffer pools created by hcd_buffer_create().
+ */
+void hcd_buffer_destroy(struct usb_hcd *hcd)
+{
+ int i;
+
+ if (!IS_ENABLED(CONFIG_HAS_DMA))
+ return;
+
+ for (i = 0; i < HCD_BUFFER_POOLS; i++) {
+ dma_pool_destroy(hcd->pool[i]);
+ hcd->pool[i] = NULL;
+ }
+}
+
+
+/* sometimes alloc/free could use kmalloc with GFP_DMA, for
+ * better sharing and to leverage mm/slab.c intelligence.
+ */
+
+void *hcd_buffer_alloc(
+ struct usb_bus *bus,
+ size_t size,
+ gfp_t mem_flags,
+ dma_addr_t *dma
+)
+{
+ struct usb_hcd *hcd = bus_to_hcd(bus);
+ int i;
+
+ if (size == 0)
+ return NULL;
+
+ if (hcd->localmem_pool)
+ return gen_pool_dma_alloc(hcd->localmem_pool, size, dma);
+
+ /* some USB hosts just use PIO */
+ if (!hcd_uses_dma(hcd)) {
+ *dma = ~(dma_addr_t) 0;
+ return kmalloc(size, mem_flags);
+ }
+
+ for (i = 0; i < HCD_BUFFER_POOLS; i++) {
+ if (size <= pool_max[i])
+ return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
+ }
+ return dma_alloc_coherent(hcd->self.sysdev, size, dma, mem_flags);
+}
+
+void hcd_buffer_free(
+ struct usb_bus *bus,
+ size_t size,
+ void *addr,
+ dma_addr_t dma
+)
+{
+ struct usb_hcd *hcd = bus_to_hcd(bus);
+ int i;
+
+ if (!addr)
+ return;
+
+ if (hcd->localmem_pool) {
+ gen_pool_free(hcd->localmem_pool, (unsigned long)addr, size);
+ return;
+ }
+
+ if (!hcd_uses_dma(hcd)) {
+ kfree(addr);
+ return;
+ }
+
+ for (i = 0; i < HCD_BUFFER_POOLS; i++) {
+ if (size <= pool_max[i]) {
+ dma_pool_free(hcd->pool[i], addr, dma);
+ return;
+ }
+ }
+ dma_free_coherent(hcd->self.sysdev, size, addr, dma);
+}
+
+void *hcd_buffer_alloc_pages(struct usb_hcd *hcd,
+ size_t size, gfp_t mem_flags, dma_addr_t *dma)
+{
+ if (size == 0)
+ return NULL;
+
+ if (hcd->localmem_pool)
+ return gen_pool_dma_alloc_align(hcd->localmem_pool,
+ size, dma, PAGE_SIZE);
+
+ /* some USB hosts just use PIO */
+ if (!hcd_uses_dma(hcd)) {
+ *dma = DMA_MAPPING_ERROR;
+ return (void *)__get_free_pages(mem_flags,
+ get_order(size));
+ }
+
+ return dma_alloc_coherent(hcd->self.sysdev,
+ size, dma, mem_flags);
+}
+
+void hcd_buffer_free_pages(struct usb_hcd *hcd,
+ size_t size, void *addr, dma_addr_t dma)
+{
+ if (!addr)
+ return;
+
+ if (hcd->localmem_pool) {
+ gen_pool_free(hcd->localmem_pool,
+ (unsigned long)addr, size);
+ return;
+ }
+
+ if (!hcd_uses_dma(hcd)) {
+ free_pages((unsigned long)addr, get_order(size));
+ return;
+ }
+
+ dma_free_coherent(hcd->self.sysdev, size, addr, dma);
+}