lkml.org 
[lkml]   [2020]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [v3 3/6] PCI: endpoint: Add support to handle multiple base for mapping outbound memory
Hi Kishon,

Thank you for the review.

On Thu, Jan 9, 2020 at 6:25 AM Kishon Vijay Abraham I <kishon@ti.com> wrote:
>
> Hi Prabhakar,
>
> On 08/01/20 9:52 PM, Lad Prabhakar wrote:
> > R-Car PCIe controller has support to map multiple memory regions for
> > mapping the outbound memory in local system also the controller limits
> > single allocation for each region (that is, once a chunk is used from the
> > region it cannot be used to allocate a new one). This features inspires to
> > add support for handling multiple memory bases in endpoint framework.
> >
> > With this patch pci_epc_mem_init() now accepts multiple regions, also
> > page_size for each memory region is passed during initialization so as
> > to handle single allocation for each region by setting the page_size to
> > window_size.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > ---
> > .../pci/controller/cadence/pcie-cadence-ep.c | 12 +-
> > .../pci/controller/dwc/pcie-designware-ep.c | 31 ++-
> > drivers/pci/controller/pcie-rockchip-ep.c | 14 +-
> > drivers/pci/endpoint/functions/pci-epf-test.c | 29 +--
> > drivers/pci/endpoint/pci-epc-core.c | 7 +-
> > drivers/pci/endpoint/pci-epc-mem.c | 199 ++++++++++++++----
> > include/linux/pci-epc.h | 46 ++--
> > 7 files changed, 245 insertions(+), 93 deletions(-)
> >
> .
> .
> <snip>
> .
> .
> > diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> > index 2091508c1620..289c266c2d90 100644
> > --- a/drivers/pci/endpoint/pci-epc-core.c
> > +++ b/drivers/pci/endpoint/pci-epc-core.c
> > @@ -358,13 +358,15 @@ EXPORT_SYMBOL_GPL(pci_epc_unmap_addr);
> > * @epc: the EPC device on which address is allocated
> > * @func_no: the endpoint function number in the EPC device
> > * @phys_addr: physical address of the local system
> > + * @window: index to the window region where PCI address will be mapped
> > * @pci_addr: PCI address to which the physical address should be mapped
> > * @size: the size of the allocation
> > *
> > * Invoke to map CPU address with PCI address.
> > */
> > int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,
> > - phys_addr_t phys_addr, u64 pci_addr, size_t size)
> > + phys_addr_t phys_addr, int window,
> > + u64 pci_addr, size_t size)
> > {
> > int ret;
> > unsigned long flags;
> > @@ -376,7 +378,8 @@ int pci_epc_map_addr(struct pci_epc *epc, u8 func_no,
> > return 0;
> >
> > spin_lock_irqsave(&epc->lock, flags);
> > - ret = epc->ops->map_addr(epc, func_no, phys_addr, pci_addr, size);
> > + ret = epc->ops->map_addr(epc, func_no, phys_addr,
> > + window, pci_addr, size);
> > spin_unlock_irqrestore(&epc->lock, flags);
> >
> > return ret;
> > diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
> > index d2b174ce15de..f205f7819292 100644
> > --- a/drivers/pci/endpoint/pci-epc-mem.c
> > +++ b/drivers/pci/endpoint/pci-epc-mem.c
> > @@ -38,57 +38,77 @@ static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size)
> > /**
> > * __pci_epc_mem_init() - initialize the pci_epc_mem structure
> > * @epc: the EPC device that invoked pci_epc_mem_init
> > - * @phys_base: the physical address of the base
> > - * @size: the size of the address space
> > - * @page_size: size of each page
> > + * @windows: pointer to windows supported by the device
> > + * @num_windows: number of windows device supports
> > *
> > * Invoke to initialize the pci_epc_mem structure used by the
> > * endpoint functions to allocate mapped PCI address.
> > */
> > -int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size,
> > - size_t page_size)
> > +int __pci_epc_mem_init(struct pci_epc *epc, struct pci_epc_mem_window *windows,
> > + int num_windows)
> > {
> > - int ret;
> > - struct pci_epc_mem *mem;
> > - unsigned long *bitmap;
> > + struct pci_epc_mem *mem = NULL;
> > + unsigned long *bitmap = NULL;
> > unsigned int page_shift;
> > - int pages;
> > + size_t page_size;
> > int bitmap_size;
> > + int pages;
> > + int ret;
> > + int i;
> >
> > - if (page_size < PAGE_SIZE)
> > - page_size = PAGE_SIZE;
> > + epc->mem_windows = 0;
> >
> > - page_shift = ilog2(page_size);
> > - pages = size >> page_shift;
> > - bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
> > + if (!windows)
> > + return -EINVAL;
> >
> > - mem = kzalloc(sizeof(*mem), GFP_KERNEL);
> > - if (!mem) {
> > - ret = -ENOMEM;
> > - goto err;
> > - }
> > + if (num_windows <= 0)
> > + return -EINVAL;
> >
> > - bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> > - if (!bitmap) {
> > - ret = -ENOMEM;
> > - goto err_mem;
> > - }
> > + epc->mem = kcalloc(num_windows, sizeof(*mem), GFP_KERNEL);
> > + if (!epc->mem)
> > + return -EINVAL;
> > +
> > + for (i = 0; i < num_windows; i++) {
> > + page_size = windows[i].page_size;
> > + if (page_size < PAGE_SIZE)
> > + page_size = PAGE_SIZE;
> > + page_shift = ilog2(page_size);
> > + pages = windows[i].size >> page_shift;
> > + bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
> > +
> > + mem = kzalloc(sizeof(*mem), GFP_KERNEL);
> > + if (!mem) {
> > + ret = -ENOMEM;
> > + goto err_mem;
> > + }
> >
> > - mem->bitmap = bitmap;
> > - mem->phys_base = phys_base;
> > - mem->page_size = page_size;
> > - mem->pages = pages;
> > - mem->size = size;
> > + bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> > + if (!bitmap) {
> > + ret = -ENOMEM;
> > + goto err_mem;
> > + }
> >
> > - epc->mem = mem;
> > + mem->bitmap = bitmap;
> > + mem->window.phys_base = windows[i].phys_base;
> > + mem->page_size = page_size;
> > + mem->pages = pages;
> > + mem->window.size = windows[i].size;
> > + mem->window.map_size = 0;
> > +
> > + epc->mem[i] = mem;
> > + }
> > + epc->mem_windows = num_windows;
> >
> > return 0;
> >
> > err_mem:
> > - kfree(mem);
> > + for (; i >= 0; i--) {
>
> mem has to be reinitialized for every iteration of the loop.
not sure what exactly you mean here, could you please elaborate.

> > + kfree(mem->bitmap);
> > + kfree(epc->mem[i]);
> > + }
> > + kfree(epc->mem);
> >
> > -err:
> > -return ret;
> > + return ret;
> > }
> > EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
> >
> > @@ -101,48 +121,127 @@ EXPORT_SYMBOL_GPL(__pci_epc_mem_init);
> > */
> > void pci_epc_mem_exit(struct pci_epc *epc)
> > {
> > - struct pci_epc_mem *mem = epc->mem;
> > + struct pci_epc_mem *mem;
> > + int i;
> > +
> > + if (!epc->mem_windows)
> > + return;
> > +
> > + for (i = 0; i <= epc->mem_windows; i++) {
> > + mem = epc->mem[i];
> > + kfree(mem->bitmap);
> > + kfree(epc->mem[i]);
> > + }
> > + kfree(epc->mem);
> >
> > epc->mem = NULL;
> > - kfree(mem->bitmap);
> > - kfree(mem);
> > + epc->mem_windows = 0;
> > }
> > EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
> >
> > +static int pci_epc_find_best_fit_window(struct pci_epc *epc, size_t size)
> > +{
> > + size_t window_least_size = 0;
> > + int best_fit_window = -1;
> > + struct pci_epc_mem *mem;
> > + size_t actual_size;
> > + size_t avail_size;
> > + int i;
> > +
> > + for (i = 0; i < epc->mem_windows; i++) {
> > + mem = epc->mem[i];
> > +
> > + actual_size = ALIGN(size, mem->page_size);
> > + avail_size = mem->window.size - mem->window.map_size;
> > +
> > + if (best_fit_window == -1) {
> > + if (actual_size <= avail_size) {
> > + best_fit_window = i;
> > + window_least_size = mem->window.size;
> > + }
> > + } else {
> > + if (actual_size <= avail_size &&
> > + mem->window.size < window_least_size) {
> > + best_fit_window = i;
> > + window_least_size = mem->window.size;
> > + }
> > + }
> > + }
> > +
> > + return best_fit_window;
> > +}
>
> This function shouldn't be required at all. Just loop over all the
> windows invoking bitmap_find_free_region(), breaking the loop if it
> succeeds and continuing if there is no free region.
sure will do.
> > +
> > /**
> > * pci_epc_mem_alloc_addr() - allocate memory address from EPC addr space
> > * @epc: the EPC device on which memory has to be allocated
> > * @phys_addr: populate the allocated physical address here
> > + * @window: populate the window here which will be used to map PCI address
> > * @size: the size of the address space that has to be allocated
> > *
> > * Invoke to allocate memory address from the EPC address space. This
> > * is usually done to map the remote RC address into the local system.
> > */
> > void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
> > - phys_addr_t *phys_addr, size_t size)
> > + phys_addr_t *phys_addr,
> > + int *window, size_t size)
> > {
> > + int best_fit = PCI_EPC_DEFAULT_WINDOW;
> > + void __iomem *virt_addr = NULL;
> > + struct pci_epc_mem *mem;
> > + unsigned int page_shift;
> > int pageno;
> > - void __iomem *virt_addr;
> > - struct pci_epc_mem *mem = epc->mem;
> > - unsigned int page_shift = ilog2(mem->page_size);
> > int order;
> >
> > + if (epc->mem_windows <= 0)
> > + return NULL;
> > +
> > + if (epc->mem_windows > 1) {
> > + best_fit = pci_epc_find_best_fit_window(epc, size);
> > + if (best_fit < 0)
> > + return NULL;
> > + }
> > +
> > + mem = epc->mem[best_fit];
> > size = ALIGN(size, mem->page_size);
> > + if (size > (mem->window.size - mem->window.map_size))
> > + return NULL;
> > + page_shift = ilog2(mem->page_size);
> > order = pci_epc_mem_get_order(mem, size);
> >
> > pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order);
> > if (pageno < 0)
> > return NULL;
>
> This has to be invoked now in a loop for the number of windows. If
> pageno < 0, continue the loop or else break.
> >
will fix that.

> > - *phys_addr = mem->phys_base + ((phys_addr_t)pageno << page_shift);
> > + *phys_addr = mem->window.phys_base +
> > + ((phys_addr_t)pageno << page_shift);
> > virt_addr = ioremap(*phys_addr, size);
> > - if (!virt_addr)
> > + if (!virt_addr) {
> > bitmap_release_region(mem->bitmap, pageno, order);
> > + } else {
> > + mem->window.map_size += size;
>
> The map_size shouldn't be required.
> > + *window = best_fit;
>
> Can't the platform driver get the window based on the address? Let's try
> to avoid modifying API's for platform specific requirements.
should be possible, will do that.

> > + }
> >
> > return virt_addr;
> > }
> > EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
> >
> > +static int pci_epc_get_matching_window(struct pci_epc *epc,
> > + phys_addr_t phys_addr)
> > +{
> > + struct pci_epc_mem *mem;
> > + int i;
> > +
> > + for (i = 0; i < epc->mem_windows; i++) {
> > + mem = epc->mem[i];
> > +
> > + if (mem->window.phys_base == phys_addr)
> > + return i;
> > + }
> > +
> > + return -EINVAL;
> > +}
> > +
> > /**
> > * pci_epc_mem_free_addr() - free the allocated memory address
> > * @epc: the EPC device on which memory was allocated
> > @@ -155,16 +254,26 @@ EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
> > void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
> > void __iomem *virt_addr, size_t size)
> > {
> > + struct pci_epc_mem *mem;
> > + unsigned int page_shift;
> > + int window = 0;
> > int pageno;
> > - struct pci_epc_mem *mem = epc->mem;
> > - unsigned int page_shift = ilog2(mem->page_size);
> > int order;
> >
> > + if (epc->mem_windows > 1) {
> > + window = pci_epc_get_matching_window(epc, phys_addr);
> > + if (window < 0)
> > + return;
> > + }
> > +
> > + mem = epc->mem[window];
> > + page_shift = ilog2(mem->page_size);
> > iounmap(virt_addr);
> > - pageno = (phys_addr - mem->phys_base) >> page_shift;
> > + pageno = (phys_addr - mem->window.phys_base) >> page_shift;
> > size = ALIGN(size, mem->page_size);
> > order = pci_epc_mem_get_order(mem, size);
> > bitmap_release_region(mem->bitmap, pageno, order);
> > + mem->window.map_size -= size;
> > }
> > EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr);
> >
> > diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
> > index 56f1846b9d39..89daafa0d19f 100644
> > --- a/include/linux/pci-epc.h
> > +++ b/include/linux/pci-epc.h
> > @@ -48,7 +48,8 @@ struct pci_epc_ops {
> > void (*clear_bar)(struct pci_epc *epc, u8 func_no,
> > struct pci_epf_bar *epf_bar);
> > int (*map_addr)(struct pci_epc *epc, u8 func_no,
> > - phys_addr_t addr, u64 pci_addr, size_t size);
> > + phys_addr_t addr, int window,
> > + u64 pci_addr, size_t size);
> > void (*unmap_addr)(struct pci_epc *epc, u8 func_no,
> > phys_addr_t addr);
> > int (*set_msi)(struct pci_epc *epc, u8 func_no, u8 interrupts);
> > @@ -64,17 +65,31 @@ struct pci_epc_ops {
> > struct module *owner;
> > };
> >
> > +#define PCI_EPC_DEFAULT_WINDOW 0
> > +
> > +/**
> > + * struct pci_epc_mem_window - address window of the endpoint controller
> > + * @phys_base: physical base address of the PCI address window
> > + * @size: the size of the PCI address window
> > + * @map_size: size of allocated chunk in window
> > + * @page_size: size of each page
> > + */
> > +struct pci_epc_mem_window {
> > + phys_addr_t phys_base;
> > + size_t size;
> > + size_t map_size;
>
> mem->bitmap already holds the map_size information. This structure can
> be used only for passing info about the mem windows from platform to the
> core. So map_size shouldn't be required.
>
agreed will drop it.

Cheers,
--Prabhakar

\
 
 \ /
  Last update: 2020-01-10 19:09    [W:0.071 / U:0.500 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site