168 lines
3.6 KiB
C
168 lines
3.6 KiB
C
/*
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* DMA memory management for framework level HCD code (hc_driver)
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*
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* This implementation plugs in through generic "usb_bus" level methods,
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* and should work with all USB controllers, regardless of bus type.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/device.h>
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#include <linux/mm.h>
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#include <linux/io.h>
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#include <linux/dma-mapping.h>
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#include <linux/dmapool.h>
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#include <linux/usb.h>
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#include <linux/usb/hcd.h>
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/*
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* DMA-Coherent Buffers
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*/
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/* FIXME tune these based on pool statistics ... */
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static size_t pool_max[HCD_BUFFER_POOLS] = {
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32, 128, 512, 2048,
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};
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void __init usb_init_pool_max(void)
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{
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/*
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* The pool_max values must never be smaller than
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* ARCH_KMALLOC_MINALIGN.
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*/
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if (ARCH_KMALLOC_MINALIGN <= 32)
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; /* Original value is okay */
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else if (ARCH_KMALLOC_MINALIGN <= 64)
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pool_max[0] = 64;
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else if (ARCH_KMALLOC_MINALIGN <= 128)
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pool_max[0] = 0; /* Don't use this pool */
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else
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BUILD_BUG(); /* We don't allow this */
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}
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/* SETUP primitives */
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/**
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* hcd_buffer_create - initialize buffer pools
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* @hcd: the bus whose buffer pools are to be initialized
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* Context: !in_interrupt()
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*
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* Call this as part of initializing a host controller that uses the dma
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* memory allocators. It initializes some pools of dma-coherent memory that
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* will be shared by all drivers using that controller.
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*
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* Call hcd_buffer_destroy() to clean up after using those pools.
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*
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* Return: 0 if successful. A negative errno value otherwise.
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*/
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int hcd_buffer_create(struct usb_hcd *hcd)
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{
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char name[16];
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int i, size;
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if (!IS_ENABLED(CONFIG_HAS_DMA) ||
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(!hcd->self.controller->dma_mask &&
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!(hcd->driver->flags & HCD_LOCAL_MEM)))
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return 0;
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for (i = 0; i < HCD_BUFFER_POOLS; i++) {
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size = pool_max[i];
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if (!size)
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continue;
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snprintf(name, sizeof(name), "buffer-%d", size);
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hcd->pool[i] = dma_pool_create(name, hcd->self.controller,
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size, size, 0);
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if (!hcd->pool[i]) {
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hcd_buffer_destroy(hcd);
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return -ENOMEM;
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}
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}
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return 0;
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}
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/**
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* hcd_buffer_destroy - deallocate buffer pools
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* @hcd: the bus whose buffer pools are to be destroyed
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* Context: !in_interrupt()
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*
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* This frees the buffer pools created by hcd_buffer_create().
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*/
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void hcd_buffer_destroy(struct usb_hcd *hcd)
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{
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int i;
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if (!IS_ENABLED(CONFIG_HAS_DMA))
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return;
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for (i = 0; i < HCD_BUFFER_POOLS; i++) {
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struct dma_pool *pool = hcd->pool[i];
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if (pool) {
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dma_pool_destroy(pool);
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hcd->pool[i] = NULL;
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}
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}
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}
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/* sometimes alloc/free could use kmalloc with GFP_DMA, for
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* better sharing and to leverage mm/slab.c intelligence.
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*/
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void *hcd_buffer_alloc(
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struct usb_bus *bus,
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size_t size,
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gfp_t mem_flags,
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dma_addr_t *dma
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)
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{
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struct usb_hcd *hcd = bus_to_hcd(bus);
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int i;
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/* some USB hosts just use PIO */
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if (!IS_ENABLED(CONFIG_HAS_DMA) ||
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(!bus->controller->dma_mask &&
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!(hcd->driver->flags & HCD_LOCAL_MEM))) {
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*dma = ~(dma_addr_t) 0;
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return kmalloc(size, mem_flags);
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}
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for (i = 0; i < HCD_BUFFER_POOLS; i++) {
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if (size <= pool_max[i])
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return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
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}
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return dma_alloc_coherent(hcd->self.controller, size, dma, mem_flags);
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}
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void hcd_buffer_free(
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struct usb_bus *bus,
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size_t size,
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void *addr,
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dma_addr_t dma
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)
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{
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struct usb_hcd *hcd = bus_to_hcd(bus);
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int i;
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if (!addr)
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return;
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if (!IS_ENABLED(CONFIG_HAS_DMA) ||
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(!bus->controller->dma_mask &&
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!(hcd->driver->flags & HCD_LOCAL_MEM))) {
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kfree(addr);
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return;
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}
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for (i = 0; i < HCD_BUFFER_POOLS; i++) {
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if (size <= pool_max[i]) {
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dma_pool_free(hcd->pool[i], addr, dma);
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return;
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}
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}
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dma_free_coherent(hcd->self.controller, size, addr, dma);
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}
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