Re: [PATCH] ohci1394: dma_pool_destroy while in_atomic() && irqs_disabled()
From: Parag Warudkar
Date: Mon Jan 31 2005 - 18:35:29 EST
Forgot to attach ohci.h diff which is affected by this change as well.
Meanwhile, David Brownell suggested it would be much simpler to move the
dma allocations to _probe and deallocations to _remove.
I am working on it and so far haven't got it to work.
Andrew - What do you think? If you too feel allocating pci_pool for the
legacy contexts (only disadvantage I see is that the pool will be
allocated even if it is not used, that is if ISO_LISTEN_CHANNEL isn't
called any time) in _probe an removing it in _remove is a better thing
to do, I will concentrate on getting that to work and we can forget
about this patch. I feel there might be some reason why the current code
treats the legacy IR and IT DMA ctxs differently (on-demand
allocation).. Ben?
Parag
Parag Warudkar wrote:
Attached is the reworked patch to take care of Andrew's suggestions -
1) Allocate the work struct dynamically in struct ti_ohci during
device probe, free it during device remove
2) In ohci1394_pci_remove, ensure queued work, if any, is flushed
before the device is removed (As I understand, this should work for
both device removal cases as well as module removal - correct?)
3) Rework the free_dma_rcv_ctx - It is called in multiple contexts by
different callers - teach it to free the dma according to caller's
wish - either direct free where caller determines the context is safe
to sleep OR delayed via schedule_work when caller wants to call it
from a context where it cannot sleep. So it now takes 2 extra
arguments - method to free - direct or delayed and if it is to be
freed delayed, an appropriate work_struct.
Andrew - flush_scheduled_work does not touch work which isn't
shceduled - so I don't think INIT_WORK in setup is necessary. Let me
know if I am missing something here. (I tried INIT_WORK in
ochi1394_pci_probe and putting flush_scheduled_work in
ohci1394_pci_remove - It did not result in calling the work function
after I did rmmod, since it wasn't scheduled.)
Parag
------------------------------------------------------------------------
--- drivers/ieee1394/ohci1394.c.orig 2004-12-24 16:35:25.000000000 -0500
+++ drivers/ieee1394/ohci1394.c 2005-01-30 20:00:42.000000000 -0500
@@ -99,6 +99,7 @@
#include <asm/uaccess.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
+#include <linux/workqueue.h>
#include <asm/pgtable.h>
#include <asm/page.h>
@@ -161,6 +162,10 @@
#define PRINT(level, fmt, args...) \
printk(level "%s: fw-host%d: " fmt "\n" , OHCI1394_DRIVER_NAME, ohci->host->id , ## args)
+/* Instruct free_dma_rcv_ctx how to free dma pools */
+#define OHCI_FREE_DMA_CTX_DIRECT 0
+#define OHCI_FREE_DMA_CTX_DELAYED 1
+
static char version[] __devinitdata =
"$Rev: 1223 $ Ben Collins <bcollins@xxxxxxxxxx>";
@@ -176,7 +181,8 @@
enum context_type type, int ctx, int num_desc,
int buf_size, int split_buf_size, int context_base);
static void stop_dma_rcv_ctx(struct dma_rcv_ctx *d);
-static void free_dma_rcv_ctx(struct dma_rcv_ctx *d);
+static void free_dma_rcv_ctx(struct dma_rcv_ctx *d , int method,
+ struct work_struct* work);
static int alloc_dma_trm_ctx(struct ti_ohci *ohci, struct dma_trm_ctx *d,
enum context_type type, int ctx, int num_desc,
@@ -184,6 +190,8 @@
static void ohci1394_pci_remove(struct pci_dev *pdev);
+static void ohci_free_irlc_pci_pool(void* data);
+
#ifndef __LITTLE_ENDIAN
static unsigned hdr_sizes[] =
{
@@ -1117,7 +1125,8 @@
if (ohci->ir_legacy_channels == 0) {
stop_dma_rcv_ctx(&ohci->ir_legacy_context);
- free_dma_rcv_ctx(&ohci->ir_legacy_context);
+ INIT_WORK(ohci->irlc_free_dma, ohci_free_irlc_pci_pool, ohci->ir_legacy_context.prg_pool);
+ free_dma_rcv_ctx(&ohci->ir_legacy_context, OHCI_FREE_DMA_CTX_DELAYED, ohci->irlc_free_dma);
DBGMSG("ISO receive legacy context deactivated");
}
break;
@@ -2876,7 +2885,8 @@
}
-static void free_dma_rcv_ctx(struct dma_rcv_ctx *d)
+static void free_dma_rcv_ctx(struct dma_rcv_ctx *d, int method,
+ struct work_struct* work)
{
int i;
struct ti_ohci *ohci = d->ohci;
@@ -2903,8 +2913,20 @@
pci_pool_free(d->prg_pool, d->prg_cpu[i], d->prg_bus[i]);
OHCI_DMA_FREE("consistent dma_rcv prg[%d]", i);
}
- pci_pool_destroy(d->prg_pool);
- OHCI_DMA_FREE("dma_rcv prg pool");
+ if(method == OHCI_FREE_DMA_CTX_DIRECT)
+ {
+ pci_pool_destroy(d->prg_pool);
+ OHCI_DMA_FREE("dma_rcv prg pool");
+ }
+
+ else if(method == OHCI_FREE_DMA_CTX_DELAYED)
+ {
+ schedule_work(work);
+ }
+
+ else
+ PRINT(KERN_ERR, "Invalid method passed - %d", method);
+
kfree(d->prg_cpu);
kfree(d->prg_bus);
}
@@ -2938,7 +2960,7 @@
if (d->buf_cpu == NULL || d->buf_bus == NULL) {
PRINT(KERN_ERR, "Failed to allocate dma buffer");
- free_dma_rcv_ctx(d);
+ free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
return -ENOMEM;
}
memset(d->buf_cpu, 0, d->num_desc * sizeof(quadlet_t*));
@@ -2950,7 +2972,7 @@
if (d->prg_cpu == NULL || d->prg_bus == NULL) {
PRINT(KERN_ERR, "Failed to allocate dma prg");
- free_dma_rcv_ctx(d);
+ free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
return -ENOMEM;
}
memset(d->prg_cpu, 0, d->num_desc * sizeof(struct dma_cmd*));
@@ -2960,7 +2982,7 @@
if (d->spb == NULL) {
PRINT(KERN_ERR, "Failed to allocate split buffer");
- free_dma_rcv_ctx(d);
+ free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
return -ENOMEM;
}
@@ -2979,7 +3001,7 @@
} else {
PRINT(KERN_ERR,
"Failed to allocate dma buffer");
- free_dma_rcv_ctx(d);
+ free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
return -ENOMEM;
}
@@ -2991,7 +3013,7 @@
} else {
PRINT(KERN_ERR,
"Failed to allocate dma prg");
- free_dma_rcv_ctx(d);
+ free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
return -ENOMEM;
}
}
@@ -3005,7 +3027,7 @@
if (ohci1394_register_iso_tasklet(ohci,
&ohci->ir_legacy_tasklet) < 0) {
PRINT(KERN_ERR, "No IR DMA context available");
- free_dma_rcv_ctx(d);
+ free_dma_rcv_ctx(d, OHCI_FREE_DMA_CTX_DIRECT, NULL);
return -EBUSY;
}
@@ -3355,6 +3377,7 @@
/* the IR DMA context is allocated on-demand; mark it inactive */
ohci->ir_legacy_context.ohci = NULL;
+ ohci->ir_legacy_context.prg_pool = NULL;
/* same for the IT DMA context */
ohci->it_legacy_context.ohci = NULL;
@@ -3377,16 +3400,32 @@
if (hpsb_add_host(host))
FAIL(-ENOMEM, "Failed to register host with highlevel");
+ ohci->irlc_free_dma = kmalloc(sizeof(struct work_struct), GFP_KERNEL);
+ if(ohci->irlc_free_dma == NULL)
+ FAIL(-ENOMEM, "Failed to allocate memory for ohci->irlc_free_dma");
+
ohci->init_state = OHCI_INIT_DONE;
return 0;
#undef FAIL
}
+static void ohci_free_irlc_pci_pool(void *data)
+{
+ if(data == NULL)
+ return;
+ pci_pool_destroy(data);
+ OHCI_DMA_FREE("dma_rcv prg pool");
+ return;
+}
+
static void ohci1394_pci_remove(struct pci_dev *pdev)
{
struct ti_ohci *ohci;
struct device *dev;
+
+ /* Ensure all dma ctx are freed */
+ flush_scheduled_work();
ohci = pci_get_drvdata(pdev);
if (!ohci)
@@ -3432,18 +3471,21 @@
/* The ohci_soft_reset() stops all DMA contexts, so we
* dont need to do this. */
/* Free AR dma */
- free_dma_rcv_ctx(&ohci->ar_req_context);
- free_dma_rcv_ctx(&ohci->ar_resp_context);
+ free_dma_rcv_ctx(&ohci->ar_req_context, OHCI_FREE_DMA_CTX_DIRECT, NULL);
+ free_dma_rcv_ctx(&ohci->ar_resp_context, OHCI_FREE_DMA_CTX_DIRECT, NULL);
/* Free AT dma */
free_dma_trm_ctx(&ohci->at_req_context);
free_dma_trm_ctx(&ohci->at_resp_context);
/* Free IR dma */
- free_dma_rcv_ctx(&ohci->ir_legacy_context);
+ free_dma_rcv_ctx(&ohci->ir_legacy_context, OHCI_FREE_DMA_CTX_DIRECT, NULL);
/* Free IT dma */
free_dma_trm_ctx(&ohci->it_legacy_context);
+
+ /* Free work struct for IR Legacy DMA */
+ kfree(ohci->irlc_free_dma);
case OHCI_INIT_HAVE_SELFID_BUFFER:
pci_free_consistent(ohci->dev, OHCI1394_SI_DMA_BUF_SIZE,
--- drivers/ieee1394/ohci1394.h.orig 2004-12-24 16:34:00.000000000 -0500
+++ drivers/ieee1394/ohci1394.h 2005-01-31 18:16:31.000000000 -0500
@@ -197,6 +197,8 @@
it is safe to free the legacy API context */
struct dma_rcv_ctx ir_legacy_context;
+ struct work_struct* irlc_free_dma;
+
struct ohci1394_iso_tasklet ir_legacy_tasklet;
/* iso transmit */