Orange Pi5 kernel

// 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: !in_interrupt()
 *
 * 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: !in_interrupt()
 *
 * 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);
}