From: Laurentiu Tudor <laurentiu.tu...@nxp.com> For HCs that have local memory, replace the current DMA API usage with a genalloc generic allocator to manage the mappings for these devices. This is in preparation for dropping the existing "coherent" dma mem declaration APIs. Current implementation was relying on a short circuit in the DMA API that in the end, was acting as an allocator for these type of devices.
For context, see thread here: https://lkml.org/lkml/2019/4/22/357 Signed-off-by: Laurentiu Tudor <laurentiu.tu...@nxp.com> --- drivers/usb/core/buffer.c | 15 +++++++++++---- drivers/usb/host/ohci-hcd.c | 23 ++++++++++++++++++----- include/linux/usb/hcd.h | 3 +++ 3 files changed, 32 insertions(+), 9 deletions(-) diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c index f641342cdec0..22a8f3f5679b 100644 --- a/drivers/usb/core/buffer.c +++ b/drivers/usb/core/buffer.c @@ -16,6 +16,7 @@ #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> @@ -124,10 +125,12 @@ void *hcd_buffer_alloc( if (size == 0) return NULL; + if (hcd->driver->flags & HCD_LOCAL_MEM) + return gen_pool_dma_alloc(hcd->localmem_pool, size, dma); + /* some USB hosts just use PIO */ if (!IS_ENABLED(CONFIG_HAS_DMA) || - (!is_device_dma_capable(bus->sysdev) && - !(hcd->driver->flags & HCD_LOCAL_MEM))) { + !is_device_dma_capable(bus->sysdev)) { *dma = ~(dma_addr_t) 0; return kmalloc(size, mem_flags); } @@ -152,9 +155,13 @@ void hcd_buffer_free( if (!addr) return; + if (hcd->driver->flags & HCD_LOCAL_MEM) { + gen_pool_free(hcd->localmem_pool, (unsigned long)addr, size); + return; + } + if (!IS_ENABLED(CONFIG_HAS_DMA) || - (!is_device_dma_capable(bus->sysdev) && - !(hcd->driver->flags & HCD_LOCAL_MEM))) { + !is_device_dma_capable(bus->sysdev)) { kfree(addr); return; } diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c index 210181fd98d2..f9462c372943 100644 --- a/drivers/usb/host/ohci-hcd.c +++ b/drivers/usb/host/ohci-hcd.c @@ -40,6 +40,7 @@ #include <linux/dmapool.h> #include <linux/workqueue.h> #include <linux/debugfs.h> +#include <linux/genalloc.h> #include <asm/io.h> #include <asm/irq.h> @@ -505,8 +506,15 @@ static int ohci_init (struct ohci_hcd *ohci) timer_setup(&ohci->io_watchdog, io_watchdog_func, 0); ohci->prev_frame_no = IO_WATCHDOG_OFF; - ohci->hcca = dma_alloc_coherent (hcd->self.controller, - sizeof(*ohci->hcca), &ohci->hcca_dma, GFP_KERNEL); + if (hcd->driver->flags & HCD_LOCAL_MEM) + ohci->hcca = gen_pool_dma_alloc(hcd->localmem_pool, + sizeof(*ohci->hcca), + &ohci->hcca_dma); + else + ohci->hcca = dma_alloc_coherent(hcd->self.controller, + sizeof(*ohci->hcca), + &ohci->hcca_dma, + GFP_KERNEL); if (!ohci->hcca) return -ENOMEM; @@ -990,9 +998,14 @@ static void ohci_stop (struct usb_hcd *hcd) remove_debug_files (ohci); ohci_mem_cleanup (ohci); if (ohci->hcca) { - dma_free_coherent (hcd->self.controller, - sizeof *ohci->hcca, - ohci->hcca, ohci->hcca_dma); + if (hcd->driver->flags & HCD_LOCAL_MEM) + gen_pool_free(hcd->localmem_pool, + (unsigned long)ohci->hcca, + sizeof(*ohci->hcca)); + else + dma_free_coherent(hcd->self.controller, + sizeof(*ohci->hcca), + ohci->hcca, ohci->hcca_dma); ohci->hcca = NULL; ohci->hcca_dma = 0; } diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index bb57b5af4700..1b0fc3cebc08 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -216,6 +216,9 @@ struct usb_hcd { #define HC_IS_RUNNING(state) ((state) & __ACTIVE) #define HC_IS_SUSPENDED(state) ((state) & __SUSPEND) + /* allocator for HCs having local memory */ + struct gen_pool *localmem_pool; + /* more shared queuing code would be good; it should support * smarter scheduling, handle transaction translators, etc; * input size of periodic table to an interrupt scheduler. -- 2.17.1
