On Tue, 21 May 2019 laurentiu.tudor@xxxxxxx wrote: > From: Laurentiu Tudor <laurentiu.tudor@xxxxxxx> > > For HCs that have local memory, replace the current DMA API usage > with a genalloc generic allocator to manage the mappings for these > devices. To help users, introduce a new HCD API, > usb_hcd_setup_local_mem() that will setup up the genalloc backing > up the device local memory. It will be used in subsequent patches. > 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.tudor@xxxxxxx> > Signed-off-by: Fredrik Noring <noring@xxxxxxxxxx> > --- > --- a/drivers/usb/core/hcd.c > +++ b/drivers/usb/core/hcd.c > @@ -29,6 +29,8 @@ > #include <linux/workqueue.h> > #include <linux/pm_runtime.h> > #include <linux/types.h> > +#include <linux/genalloc.h> > +#include <linux/io.h> > > #include <linux/phy/phy.h> > #include <linux/usb.h> > @@ -3039,6 +3041,40 @@ usb_hcd_platform_shutdown(struct platform_device *dev) > } > EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown); > > +int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr, > + dma_addr_t dma, size_t size) > +{ > + int err; > + void __iomem *local_mem; > + > + hcd->localmem_pool = devm_gen_pool_create(hcd->self.sysdev, PAGE_SHIFT, > + dev_to_node(hcd->self.sysdev), > + "ohci-hcd"); Surely that string is a mistake. You could use dev_name(hcd->self.sysdev) or a name passed by the caller. > + if (IS_ERR(hcd->localmem_pool)) > + return PTR_ERR(hcd->localmem_pool); > + > + local_mem = devm_memremap(hcd->self.sysdev, phys_addr, > + size, MEMREMAP_WC); > + if (!local_mem) > + return -ENOMEM; > + > + /* > + * Here we pass a dma_addr_t but the arg type is a phys_addr_t. > + * It's not backed by system memory and thus there's no kernel mapping > + * for it. > + */ > + err = gen_pool_add_virt(hcd->localmem_pool, (unsigned long)local_mem, > + dma, size, dev_to_node(hcd->self.sysdev)); > + if (err < 0) { > + dev_err(hcd->self.sysdev, "gen_pool_add_virt failed with %d\n", > + err); > + return err; > + } > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(usb_hcd_setup_local_mem); If you have a usb_hcd_setup_local_mem() function then you should also have a usb_hcd_remove_local_mem() function. > --- a/drivers/usb/host/ohci-mem.c > +++ b/drivers/usb/host/ohci-mem.c > @@ -36,6 +36,12 @@ static void ohci_hcd_init (struct ohci_hcd *ohci) > > static int ohci_mem_init (struct ohci_hcd *ohci) > { > + if (ohci_to_hcd(ohci)->localmem_pool) { > + ohci->td_cache = NULL; > + ohci->ed_cache = NULL; > + return 0; > + } This really isn't necessary. The entire ohci_hcd structure is initialized to 0 when it is first allocated. > --- 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 */ "allocator" is the wrong word -- an allocator is something that allocates. Perhaps "memory area" or something along those lines. Alan Stern
