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FPGA Configuration Space
Commit 04b4ceac authored by Wesley W. Terpstra's avatar Wesley W. Terpstra
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wishbone: deliver MSIs

parent 7160ddbb
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Showing with 117 additions and 6 deletions
pcie-wb/wishbone.c
View file @ 04b4ceac
......@@ -134,6 +134,85 @@ static void claim_msi(struct etherbone_master_context* context)
mutex_unlock(&wb->mutex);
}
/* Must be called with wb->mutex held */
static void advance_msi(struct wishbone* wb)
{
struct wishbone_request request;
struct etherbone_master_context *context;
uint8_t *wptr;
int index;
/* Don't process a second MSI while a previous is inflight */
if (wb->msi_pending) return;
retry:
/* If nothing to do, stop */
if (wb->wops->request(wb, &request) == 0) return;
/* The hardware should already have done this, but be safe */
request.addr &= wb->mask;
/* If no MSI handler, handle it immediately */
index = request.addr / ((wb->mask/WISHBONE_MAX_MSI_OPEN)+1);
if (!wb->msi_map[index]) {
wb->wops->reply(wb, 1, ~(wb_data_t)0);
goto retry;
}
/* Fill in the MSI data */
context = wb->msi_map[index];
wptr = &context->msi[0];
wptr[0] = ETHERBONE_BCA;
wptr[1] = request.mask;
if (request.write) {
wptr[2] = 1;
wptr[3] = 0;
wptr += sizeof(wb_data_t);
eb_from_cpu(wptr, request.addr);
wptr += sizeof(wb_data_t);
eb_from_cpu(wptr, request.data);
wptr += sizeof(wb_data_t);
} else {
wptr[2] = 0;
wptr[3] = 1;
wptr += sizeof(wb_data_t);
eb_from_cpu(wptr, WBA_DATA);
wptr += sizeof(wb_data_t);
eb_from_cpu(wptr, request.addr);
wptr += sizeof(wb_data_t);
}
wptr[0] = ETHERBONE_CYC | ETHERBONE_BCA | ETHERBONE_RCA;
wptr[1] = 0xf;
wptr[2] = 0;
wptr[3] = 1;
wptr += sizeof(wb_data_t);
eb_from_cpu(wptr, WBA_ERR);
wptr += sizeof(wb_data_t);
eb_from_cpu(wptr, 4); /* low bits of error status register */
wptr += sizeof(wb_data_t);
/* Mark the MSI pending */
context->msi_unread = wptr - &context->msi[0];
context->msi_pending = 1;
wb->msi_pending = 1;
/* Wake-up any reader of the device */
wake_up_interruptible(&context->waitq);
kill_fasync(&context->fasync, SIGIO, POLL_IN);
}
static void respond_msi(struct wishbone* wb, int error)
{
mutex_lock(&wb->mutex);
wb->wops->reply(wb, error, wb->msi_data);
wb->msi_pending = 0;
advance_msi(wb);
mutex_unlock(&wb->mutex);
}
static wb_data_t handle_read_cfg(struct etherbone_master_context* context, wb_addr_t addr)
{
struct wishbone *wb = context->wishbone;
......@@ -153,9 +232,28 @@ static wb_data_t handle_read_cfg(struct etherbone_master_context* context, wb_ad
static void handle_write_cfg(struct etherbone_master_context* context, wb_addr_t addr, wb_data_t data)
{
struct wishbone *wb = context->wishbone;
switch (addr) {
case 36: if (data == 1) claim_msi(context); break;
default: break;
case 36:
if (data == 1) {
claim_msi(context);
}
break;
case WBA_DATA:
if (context->msi_pending) {
mutex_lock(&wb->mutex);
wb->msi_data = data;
mutex_unlock(&wb->mutex);
}
break;
case WBA_ERR:
if (context->msi_pending) {
context->msi_pending = 0;
respond_msi(wb, data&1);
}
break;
}
}
......@@ -293,8 +391,9 @@ static int char_master_open(struct inode *inode, struct file *filep)
context->sent = 0;
context->processed = 0;
context->received = 0;
context->msi_unread = 0;
context->msi_index = -1;
context->msi_unread = 0;
context->msi_pending = 0;
filep->private_data = context;
......@@ -311,6 +410,12 @@ static int char_master_release(struct inode *inode, struct file *filep)
wb->wops->cycle(wb, 0);
}
/* Finish any unhandled MSI */
if (context->msi_pending) {
context->msi_pending = 0;
respond_msi(wb, 1);
}
/* Unhook any MSI access */
if (context->msi_index != -1) {
mutex_lock(&wb->mutex);
......@@ -457,6 +562,7 @@ int wishbone_register(struct wishbone* wb)
for (i = 0; i < WISHBONE_MAX_MSI_OPEN; ++i) {
wb->msi_map[i] = 0;
}
wb->msi_pending = 0;
mutex_lock(&wishbone_mutex);
......@@ -530,8 +636,9 @@ int wishbone_unregister(struct wishbone* wb)
void wishbone_slave_ready(struct wishbone* wb)
{
// wake_up_interruptible(&wb->waitq);
// kill_fasync(&wb->fasync, SIGIO, POLL_IN);
mutex_lock(&wb->mutex);
advance_msi(wb);
mutex_unlock(&wb->mutex);
}
static int __init wishbone_init(void)
......
pcie-wb/wishbone.h
View file @ 04b4ceac
......@@ -67,6 +67,8 @@ struct wishbone
/* internal (EB-MSI mapping for this hardware) */
struct mutex mutex;
struct etherbone_master_context *msi_map[WISHBONE_MAX_MSI_OPEN];
wb_data_t msi_data;
int msi_pending;
};
#define RING_SIZE 8192
......@@ -86,10 +88,12 @@ struct etherbone_master_context
unsigned char buf[RING_SIZE]; /* Ring buffer */
/* MSI resource ownership; -1 = nothing */
int msi_index;
/* MSI record data */
unsigned char msi[sizeof(wb_data_t)*6];
int msi_unread;
int msi_index;
int msi_pending;
};
#define RING_READ_LEN(ctx) RING_POS((ctx)->processed - (ctx)->sent)
......
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