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wctc4xxp: Allow the tx and rx descriptor rings to be different sizes

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Keeping the transmit descriptor ring shorter reduces the time it takes to send
CSM_ENCAP commands to the transcoding engine when the card is otherwise busy.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
This commit is contained in:
Shaun Ruffell 2014-05-08 13:40:45 -05:00 committed by Russ Meyerriecks
parent b6a8623203
commit ba05e31c8a
1 changed files with 31 additions and 18 deletions
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49
drivers/dahdi/wctc4xxp/base.c
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@ -182,8 +182,11 @@ struct csm_encaps_hdr {
#define MAX_FRAME_SIZE 1518
#define SFRAME_SIZE MAX_FRAME_SIZE
#define DRING_SIZE (1 << 7) /* Must be a power of two */
#define DRING_MASK (DRING_SIZE-1)
#define DEFAULT_RX_DRING_SIZE (1 << 6) /* Must be a power of two */
/* Keep the TX ring shorter in order to reduce the amount of time needed to
* bring up channels when sending high priority csm_encaps packets. */
#define DEFAULT_TX_DRING_SIZE (1 << 4) /* Must be a power of two */
#define MIN_PACKET_LEN 64
/* Transcoder buffer (tcb) */
@ -765,7 +768,7 @@ struct wctc4xxp_descriptor_ring {
/* Write ready buffers to the tail. */
unsigned int tail;
/* Array to save the kernel virtual address of pending commands. */
struct tcb *pending[DRING_SIZE];
struct tcb **pending;
/* PCI Bus address of the descriptor list. */
dma_addr_t desc_dma;
/*! either DMA_FROM_DEVICE or DMA_TO_DEVICE */
@ -778,6 +781,8 @@ struct wctc4xxp_descriptor_ring {
spinlock_t lock;
/*! PCI device for the card associated with this ring. */
struct pci_dev *pdev;
/*! The size of the dring. */
unsigned long size;
};
/**
@ -797,13 +802,14 @@ wctc4xxp_descriptor(struct wctc4xxp_descriptor_ring *dr, int index)
static int
wctc4xxp_initialize_descriptor_ring(struct pci_dev *pdev,
struct wctc4xxp_descriptor_ring *dr, u32 des1, unsigned int direction)
struct wctc4xxp_descriptor_ring *dr, u32 des1, unsigned int direction,
unsigned long size)
{
int i;
const u32 END_OF_RING = 0x02000000;
u8 cache_line_size = 0;
struct wctc4xxp_descriptor *d;
int add_padding;
struct wctc4xxp_descriptor *d = NULL;
BUG_ON(!pdev);
BUG_ON(!dr);
@ -812,6 +818,7 @@ wctc4xxp_initialize_descriptor_ring(struct pci_dev *pdev,
return -EIO;
memset(dr, 0, sizeof(*dr));
dr->size = size;
/*
* Add some padding to each descriptor to ensure that they are
@ -825,14 +832,19 @@ wctc4xxp_initialize_descriptor_ring(struct pci_dev *pdev,
if (add_padding)
dr->padding = (cache_line_size*sizeof(u32)) - sizeof(*d);
dr->desc = pci_alloc_consistent(pdev,
(sizeof(*d)+dr->padding)*DRING_SIZE, &dr->desc_dma);
if (!dr->desc)
dr->pending = kmalloc(sizeof(struct tcb *) * dr->size, GFP_KERNEL);
if (!dr->pending)
return -ENOMEM;
memset(dr->desc, 0, (sizeof(*d) + dr->padding) * DRING_SIZE);
for (i = 0; i < DRING_SIZE; ++i) {
dr->desc = pci_alloc_consistent(pdev,
(sizeof(*d)+dr->padding)*dr->size, &dr->desc_dma);
if (!dr->desc) {
kfree(dr->pending);
return -ENOMEM;
}
memset(dr->desc, 0, (sizeof(*d) + dr->padding) * dr->size);
for (i = 0; i < dr->size; ++i) {
d = wctc4xxp_descriptor(dr, i);
memset(d, 0, sizeof(*d));
d->des1 = cpu_to_le32(des1);
@ -880,7 +892,7 @@ wctc4xxp_submit(struct wctc4xxp_descriptor_ring *dr, struct tcb *c)
SET_OWNED(d); /* That's it until the hardware is done with it. */
dr->pending[dr->tail] = c;
dr->tail = (dr->tail + 1) & DRING_MASK;
dr->tail = (dr->tail + 1) & (dr->size-1);
++dr->count;
spin_unlock_irqrestore(&dr->lock, flags);
return 0;
@ -900,7 +912,7 @@ wctc4xxp_retrieve(struct wctc4xxp_descriptor_ring *dr)
SFRAME_SIZE, dr->direction);
c = dr->pending[head];
WARN_ON(!c);
dr->head = (++head) & DRING_MASK;
dr->head = (++head) & (dr->size-1);
d->buffer1 = 0;
--dr->count;
WARN_ON(!c);
@ -1484,7 +1496,7 @@ wctc4xxp_cleanup_descriptor_ring(struct wctc4xxp_descriptor_ring *dr)
if (!dr || !dr->desc)
return;
for (i = 0; i < DRING_SIZE; ++i) {
for (i = 0; i < dr->size; ++i) {
d = wctc4xxp_descriptor(dr, i);
if (d->buffer1) {
pci_unmap_single(dr->pdev, d->buffer1,
@ -1501,8 +1513,9 @@ wctc4xxp_cleanup_descriptor_ring(struct wctc4xxp_descriptor_ring *dr)
dr->head = 0;
dr->tail = 0;
dr->count = 0;
pci_free_consistent(dr->pdev, (sizeof(*d)+dr->padding) * DRING_SIZE,
pci_free_consistent(dr->pdev, (sizeof(*d)+dr->padding) * dr->size,
dr->desc, dr->desc_dma);
kfree(dr->pending);
}
static void wctc4xxp_timeout_all_commands(struct wcdte *wc)
@ -2697,7 +2710,7 @@ wctc4xxp_start_dma(struct wcdte *wc)
u32 reg;
struct tcb *cmd;
for (i = 0; i < DRING_SIZE; ++i) {
for (i = 0; i < wc->rxd->size; ++i) {
cmd = alloc_cmd(SFRAME_SIZE);
if (!cmd) {
WARN_ALWAYS();
@ -3463,7 +3476,7 @@ wctc4xxp_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
}
res = wctc4xxp_initialize_descriptor_ring(wc->pdev, wc->txd,
0xe0800000, DMA_TO_DEVICE);
0xe0800000, DMA_TO_DEVICE, DEFAULT_TX_DRING_SIZE);
if (res)
goto error_exit_swinit;
@ -3474,7 +3487,7 @@ wctc4xxp_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
}
res = wctc4xxp_initialize_descriptor_ring(wc->pdev, wc->rxd, 0,
DMA_FROM_DEVICE);
DMA_FROM_DEVICE, DEFAULT_RX_DRING_SIZE);
if (res)
goto error_exit_swinit;