2019-05-22 14:31:43

by Laurentiu Tudor

[permalink] [raw]
Subject: [PATCH v6 0/5] prerequisites for device reserved local mem rework

From: Laurentiu Tudor <[email protected]>

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.

Only compiled tested, so any volunteers willing to test are most welcome.

Thank you!

For context, see thread here: https://lkml.org/lkml/2019/4/22/357

Changes in v6:
- drop some unneeded initializations (Alan)
- use device name for genpool instead of misleading "ohci-hcd" (Alan)
- updated some comments (Alan, Fredrik)
- added Tested-By tags

Changes in v5:
- updated first patch to preserve bisectability (Christoph, Greg)
- fixed a few more places where dma api was still being
used (e.g. td_alloc, ed_alloc) (Fredrik)
- included patch from Fredrik adding gen_pool_dma_zalloc() api
- added patch that drops HCD_LOCAL_MEM altogether (Greg)
- set td_cache / ed_cache to null for devices with local mem (Fredrik)
- introduce usb_hcd_setup_local_mem() that sets up the genalloc
pool for drivers and updated drivers to use it

Changes in v4:
- created mapping for local mem
- fix genalloc misuse

Changes in v3:
- rearranged calls into genalloc simplifying the code a bit (Christoph)
- dropped RFC prefix

Changes in v2:
- use genalloc also in core usb (based on comment from Robin)
- moved genpool decl to usb_hcd to be accesible from core usb

Fredrik Noring (1):
lib/genalloc.c: Add gen_pool_dma_zalloc() for zeroed DMA allocations

Laurentiu Tudor (4):
USB: use genalloc for USB HCs with local memory
usb: host: ohci-sm501: init genalloc for local memory
usb: host: ohci-tmio: init genalloc for local memory
USB: drop HCD_LOCAL_MEM flag

drivers/usb/core/buffer.c | 17 ++++++++----
drivers/usb/core/hcd.c | 51 ++++++++++++++++++++++++++++------
drivers/usb/host/ehci-hcd.c | 2 +-
drivers/usb/host/fotg210-hcd.c | 2 +-
drivers/usb/host/ohci-hcd.c | 25 +++++++++++++----
drivers/usb/host/ohci-mem.c | 35 ++++++++++++++++++++---
drivers/usb/host/ohci-sm501.c | 50 +++++++++++++++------------------
drivers/usb/host/ohci-tmio.c | 15 ++++------
drivers/usb/host/ohci.h | 2 ++
drivers/usb/host/uhci-hcd.c | 2 +-
include/linux/genalloc.h | 1 +
include/linux/usb/hcd.h | 6 +++-
lib/genalloc.c | 29 ++++++++++++++++++-
13 files changed, 171 insertions(+), 66 deletions(-)

--
2.17.1


2019-05-22 15:30:36

by Laurentiu Tudor

[permalink] [raw]
Subject: [PATCH v6 2/5] USB: use genalloc for USB HCs with local memory

From: Laurentiu Tudor <[email protected]>

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 <[email protected]>
Signed-off-by: Fredrik Noring <[email protected]>
Tested-by: Fredrik Noring <[email protected]>
---
drivers/usb/core/buffer.c | 9 +++++++++
drivers/usb/core/hcd.c | 36 ++++++++++++++++++++++++++++++++++++
drivers/usb/host/ohci-hcd.c | 23 ++++++++++++++++++-----
drivers/usb/host/ohci-mem.c | 35 +++++++++++++++++++++++++++++++----
drivers/usb/host/ohci.h | 2 ++
include/linux/usb/hcd.h | 5 +++++
6 files changed, 101 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index f641342cdec0..d2064ad7ad14 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>

@@ -124,6 +125,9 @@ void *hcd_buffer_alloc(
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 (!IS_ENABLED(CONFIG_HAS_DMA) ||
(!is_device_dma_capable(bus->sysdev) &&
@@ -152,6 +156,11 @@ void hcd_buffer_free(
if (!addr)
return;

+ if (hcd->localmem_pool) {
+ 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))) {
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 94d22551fc1b..1aad11f4142c 100644
--- 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),
+ dev_name(hcd->self.sysdev));
+ 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 IS_ENABLED(CONFIG_USB_MON)
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 210181fd98d2..b200b19b44fa 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->localmem_pool)
+ 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->localmem_pool)
+ 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/drivers/usb/host/ohci-mem.c b/drivers/usb/host/ohci-mem.c
index 3965ac0341eb..4afe27cc7e46 100644
--- a/drivers/usb/host/ohci-mem.c
+++ b/drivers/usb/host/ohci-mem.c
@@ -36,6 +36,13 @@ static void ohci_hcd_init (struct ohci_hcd *ohci)

static int ohci_mem_init (struct ohci_hcd *ohci)
{
+ /*
+ * HCs with local memory allocate from localmem_pool so there's
+ * no need to create the below dma pools.
+ */
+ if (ohci_to_hcd(ohci)->localmem_pool)
+ return 0;
+
ohci->td_cache = dma_pool_create ("ohci_td",
ohci_to_hcd(ohci)->self.controller,
sizeof (struct td),
@@ -84,8 +91,12 @@ td_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
{
dma_addr_t dma;
struct td *td;
+ struct usb_hcd *hcd = ohci_to_hcd(hc);

- td = dma_pool_zalloc (hc->td_cache, mem_flags, &dma);
+ if (hcd->localmem_pool)
+ td = gen_pool_dma_zalloc(hcd->localmem_pool, sizeof(*td), &dma);
+ else
+ td = dma_pool_zalloc(hc->td_cache, mem_flags, &dma);
if (td) {
/* in case hc fetches it, make it look dead */
td->hwNextTD = cpu_to_hc32 (hc, dma);
@@ -99,6 +110,7 @@ static void
td_free (struct ohci_hcd *hc, struct td *td)
{
struct td **prev = &hc->td_hash [TD_HASH_FUNC (td->td_dma)];
+ struct usb_hcd *hcd = ohci_to_hcd(hc);

while (*prev && *prev != td)
prev = &(*prev)->td_hash;
@@ -106,7 +118,12 @@ td_free (struct ohci_hcd *hc, struct td *td)
*prev = td->td_hash;
else if ((td->hwINFO & cpu_to_hc32(hc, TD_DONE)) != 0)
ohci_dbg (hc, "no hash for td %p\n", td);
- dma_pool_free (hc->td_cache, td, td->td_dma);
+
+ if (hcd->localmem_pool)
+ gen_pool_free(hcd->localmem_pool, (unsigned long)td,
+ sizeof(*td));
+ else
+ dma_pool_free(hc->td_cache, td, td->td_dma);
}

/*-------------------------------------------------------------------------*/
@@ -117,8 +134,12 @@ ed_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
{
dma_addr_t dma;
struct ed *ed;
+ struct usb_hcd *hcd = ohci_to_hcd(hc);

- ed = dma_pool_zalloc (hc->ed_cache, mem_flags, &dma);
+ if (hcd->localmem_pool)
+ ed = gen_pool_dma_zalloc(hcd->localmem_pool, sizeof(*ed), &dma);
+ else
+ ed = dma_pool_zalloc(hc->ed_cache, mem_flags, &dma);
if (ed) {
INIT_LIST_HEAD (&ed->td_list);
ed->dma = dma;
@@ -129,6 +150,12 @@ ed_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
static void
ed_free (struct ohci_hcd *hc, struct ed *ed)
{
- dma_pool_free (hc->ed_cache, ed, ed->dma);
+ struct usb_hcd *hcd = ohci_to_hcd(hc);
+
+ if (hcd->localmem_pool)
+ gen_pool_free(hcd->localmem_pool, (unsigned long)ed,
+ sizeof(*ed));
+ else
+ dma_pool_free(hc->ed_cache, ed, ed->dma);
}

diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index ef4813bfc5bf..b015b00774b2 100644
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -385,6 +385,8 @@ struct ohci_hcd {

/*
* memory management for queue data structures
+ *
+ * @td_cache and @ed_cache are %NULL if &usb_hcd.localmem_pool is used.
*/
struct dma_pool *td_cache;
struct dma_pool *ed_cache;
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index bb57b5af4700..127560a4bfa0 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)

+ /* memory pool for HCs having local memory, or %NULL */
+ 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.
@@ -461,6 +464,8 @@ extern int usb_add_hcd(struct usb_hcd *hcd,
unsigned int irqnum, unsigned long irqflags);
extern void usb_remove_hcd(struct usb_hcd *hcd);
extern int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1);
+int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr,
+ dma_addr_t dma, size_t size);

struct platform_device;
extern void usb_hcd_platform_shutdown(struct platform_device *dev);
--
2.17.1

2019-05-23 06:59:30

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH v6 0/5] prerequisites for device reserved local mem rework

As we seem to be getting ready to merge this series: can the usb
maintainers please commit it to an immutable branch that I can pull
into the dma-mapping tree? These changes are a preparation for
reworking the per-device DMA coherent allocator, and I'd prefer not
to wait for the next merge window with the next steps.

2019-05-23 07:09:24

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH v6 0/5] prerequisites for device reserved local mem rework

On Thu, May 23, 2019 at 08:56:02AM +0200, Christoph Hellwig wrote:
> As we seem to be getting ready to merge this series: can the usb
> maintainers please commit it to an immutable branch that I can pull
> into the dma-mapping tree? These changes are a preparation for
> reworking the per-device DMA coherent allocator, and I'd prefer not
> to wait for the next merge window with the next steps.

I have no objection for you just taking this whole series as-is, no need
to worry about merge conflicts with the USB tree, I doubt anything will
be touching this area of code anytime soon.

So if you want to take it now, feel free to add:

Signed-off-by: Greg Kroah-Hartman <[email protected]>

to all of these.

Or, if you really like/want a branch to pull from, I can do that as
well, which ever is easiest for you to work with as you all are doing
the hard work here, not me :)

thanks,

greg k-h

2019-05-23 07:13:54

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH v6 0/5] prerequisites for device reserved local mem rework

On Thu, May 23, 2019 at 09:07:55AM +0200, Greg KH wrote:
> I have no objection for you just taking this whole series as-is, no need
> to worry about merge conflicts with the USB tree, I doubt anything will
> be touching this area of code anytime soon.
>
> So if you want to take it now, feel free to add:
>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
>
> to all of these.
>
> Or, if you really like/want a branch to pull from, I can do that as
> well, which ever is easiest for you to work with as you all are doing
> the hard work here, not me :)

Nah, I can happily take it. I'll open the dma-mapping tree after -rc2.

2019-05-28 06:02:34

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH v6 0/5] prerequisites for device reserved local mem rework

On Thu, May 23, 2019 at 09:07:55AM +0200, Greg KH wrote:
> I have no objection for you just taking this whole series as-is, no need
> to worry about merge conflicts with the USB tree, I doubt anything will
> be touching this area of code anytime soon.
>
> So if you want to take it now, feel free to add:
>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>

Given that I'll pull it in, shouldn't this be a Reviewed-by or Acked-by?

2019-05-28 06:49:21

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH v6 0/5] prerequisites for device reserved local mem rework

On Tue, May 28, 2019 at 07:58:31AM +0200, Christoph Hellwig wrote:
> On Thu, May 23, 2019 at 09:07:55AM +0200, Greg KH wrote:
> > I have no objection for you just taking this whole series as-is, no need
> > to worry about merge conflicts with the USB tree, I doubt anything will
> > be touching this area of code anytime soon.
> >
> > So if you want to take it now, feel free to add:
> >
> > Signed-off-by: Greg Kroah-Hartman <[email protected]>
>
> Given that I'll pull it in, shouldn't this be a Reviewed-by or Acked-by?

Good point, I don't usually do this, so I forgot:
Reviewed-by: Greg Kroah-Hartman <[email protected]>

2019-05-28 06:54:56

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH v6 0/5] prerequisites for device reserved local mem rework

Thanks.

Applied the whole series to dma-mapping for-next.