Hello Alan, On 21.05.2019 20:20, Alan Stern wrote: > 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://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.org%2Flkml%2F2019%2F4%2F22%2F357&data=02%7C01%7Claurentiu.tudor%40nxp.com%7Cdc4a76b04b874b75bd5408d6de109d86%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636940560281957207&sdata=JQ1iJc%2Fw%2BwHdTFvaOT%2FYHBx%2BVQlpHWlf346q7sclfcg%3D&reserved=0 >> >> 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. Sorry, missed that. Will go with dev_name() if that's ok with you. >> + 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. Even if all resources that are allocated are device managed? >> --- 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. Will drop. >> --- 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. Alright, I will rework. --- Thanks & Best Regards, Laurentiu
