[PATCH] mcb: Added bar descriptor support for non PCI bus MCB carrier

From: Andreas Werner
Date: Tue Jun 28 2016 - 10:26:55 EST


Added support for the bar descriptor. This type is used for FPGAs
connect to the LPC or to a non PCI bus.

The Bar descriptor could have a maximum of 6 BARs. Each of the
devices within the FPGA could be mapped to a different BAR.
The BAR descriptor is comparable to the PCI header.

Signed-off-by: Andreas Werner <andreas.werner@xxxxxx>
---
drivers/mcb/mcb-internal.h | 9 ++++
drivers/mcb/mcb-parse.c | 125 ++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 120 insertions(+), 14 deletions(-)

diff --git a/drivers/mcb/mcb-internal.h b/drivers/mcb/mcb-internal.h
index 5254e02..d6e6933 100644
--- a/drivers/mcb/mcb-internal.h
+++ b/drivers/mcb/mcb-internal.h
@@ -112,6 +112,15 @@ struct chameleon_bdd {
u32 size;
} __packed;

+struct chameleon_bar {
+ u32 addr;
+ u32 size;
+};
+
+#define BAR_CNT(x) ((x) & 0x07)
+#define CHAMELEON_BAR_MAX 6
+#define BAR_DESC_SIZE(x) ((x) * sizeof(struct chameleon_bar) + sizeof(__le32))
+
int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
void __iomem *base);

diff --git a/drivers/mcb/mcb-parse.c b/drivers/mcb/mcb-parse.c
index dbecbed..b652c25 100644
--- a/drivers/mcb/mcb-parse.c
+++ b/drivers/mcb/mcb-parse.c
@@ -26,19 +26,20 @@ static inline uint32_t get_next_dtype(void __iomem *p)
}

static int chameleon_parse_bdd(struct mcb_bus *bus,
- phys_addr_t mapbase,
+ struct chameleon_bar *cb,
void __iomem *base)
{
return 0;
}

static int chameleon_parse_gdd(struct mcb_bus *bus,
- phys_addr_t mapbase,
- void __iomem *base)
+ struct chameleon_bar *cb,
+ void __iomem *base, int bar_count)
{
struct chameleon_gdd __iomem *gdd =
(struct chameleon_gdd __iomem *) base;
struct mcb_device *mdev;
+ u32 dev_mapbase;
u32 offset;
u32 size;
int ret;
@@ -61,13 +62,39 @@ static int chameleon_parse_gdd(struct mcb_bus *bus,
mdev->group = GDD_GRP(reg2);
mdev->inst = GDD_INS(reg2);

+ /*
+ * If the BAR is missing, dev_mapbase is zero, or if the
+ * device is IO mapped we just print a warning and go on with the
+ * next device, instead of completely stop the gdd parser
+ */
+ if (mdev->bar > bar_count - 1) {
+ pr_info("No BAR for 16z%03d\n", mdev->id);
+ ret = 0;
+ goto err;
+ }
+
+ dev_mapbase = cb[mdev->bar].addr;
+ if (!dev_mapbase) {
+ pr_info("BAR not assigned for 16z%03d\n", mdev->id);
+ ret = 0;
+ goto err;
+ }
+
+ if (dev_mapbase & 0x01) {
+ pr_info("IO mapped Device (16z%03d) not yet supported\n",
+ mdev->id);
+ ret = 0;
+ goto err;
+ }
+
pr_debug("Found a 16z%03d\n", mdev->id);

mdev->irq.start = GDD_IRQ(reg1);
mdev->irq.end = GDD_IRQ(reg1);
mdev->irq.flags = IORESOURCE_IRQ;

- mdev->mem.start = mapbase + offset;
+ mdev->mem.start = dev_mapbase + offset;
+
mdev->mem.end = mdev->mem.start + size - 1;
mdev->mem.flags = IORESOURCE_MEM;

@@ -85,13 +112,76 @@ err:
return ret;
}

+static void chameleon_parse_bar(void __iomem *base,
+ struct chameleon_bar *cb, int bar_count)
+{
+ char __iomem *p = base;
+ int i;
+
+ /* skip reg1 */
+ p += sizeof(__le32);
+
+ for (i = 0; i < bar_count; i++) {
+ cb[i].addr = readl(p);
+ cb[i].size = readl(p + 4);
+
+ p += sizeof(struct chameleon_bar);
+ }
+}
+
+static int chameleon_get_bar(char __iomem **base, phys_addr_t mapbase,
+ struct chameleon_bar **cb)
+{
+ struct chameleon_bar *c;
+ int bar_count;
+ __le32 reg;
+ u32 dtype;
+
+ /*
+ * For those devices which are not connected
+ * to the PCI Bus (e.g. LPC) there is a bar
+ * descriptor located directly after the
+ * chameleon header. This header is comparable
+ * to a PCI header.
+ */
+ dtype = get_next_dtype(*base);
+ if (dtype == CHAMELEON_DTYPE_BAR) {
+ reg = readl(*base);
+
+ bar_count = BAR_CNT(reg);
+ if (bar_count <= 0 && bar_count > CHAMELEON_BAR_MAX)
+ return -ENODEV;
+
+ c = kcalloc(bar_count, sizeof(struct chameleon_bar),
+ GFP_KERNEL);
+ if (!c)
+ return -ENOMEM;
+
+ chameleon_parse_bar(*base, c, bar_count);
+ *base += BAR_DESC_SIZE(bar_count);
+ } else {
+ c = kzalloc(sizeof(struct chameleon_bar), GFP_KERNEL);
+ if (!c)
+ return -ENOMEM;
+
+ bar_count = 1;
+ c->addr = mapbase;
+ }
+
+ *cb = c;
+
+ return bar_count;
+}
+
int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
void __iomem *base)
{
- char __iomem *p = base;
struct chameleon_fpga_header *header;
- uint32_t dtype;
+ struct chameleon_bar *cb;
+ char __iomem *p = base;
int num_cells = 0;
+ uint32_t dtype;
+ int bar_count;
int ret = 0;
u32 hsize;

@@ -108,8 +198,8 @@ int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
if (header->magic != CHAMELEONV2_MAGIC) {
pr_err("Unsupported chameleon version 0x%x\n",
header->magic);
- kfree(header);
- return -ENODEV;
+ ret = -ENODEV;
+ goto free_header;
}
p += hsize;

@@ -119,16 +209,20 @@ int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
snprintf(bus->name, CHAMELEON_FILENAME_LEN + 1, "%s",
header->filename);

+ bar_count = chameleon_get_bar(&p, mapbase, &cb);
+ if (bar_count < 0)
+ goto free_header;
+
for_each_chameleon_cell(dtype, p) {
switch (dtype) {
case CHAMELEON_DTYPE_GENERAL:
- ret = chameleon_parse_gdd(bus, mapbase, p);
+ ret = chameleon_parse_gdd(bus, cb, p, bar_count);
if (ret < 0)
- goto out;
+ goto free_bar;
p += sizeof(struct chameleon_gdd);
break;
case CHAMELEON_DTYPE_BRIDGE:
- chameleon_parse_bdd(bus, mapbase, p);
+ chameleon_parse_bdd(bus, cb, p);
p += sizeof(struct chameleon_bdd);
break;
case CHAMELEON_DTYPE_END:
@@ -136,8 +230,8 @@ int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
default:
pr_err("Invalid chameleon descriptor type 0x%x\n",
dtype);
- kfree(header);
- return -EINVAL;
+ ret = -EINVAL;
+ goto free_bar;
}
num_cells++;
}
@@ -148,8 +242,11 @@ int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
kfree(header);
return num_cells;

-out:
+free_bar:
+ kfree(cb);
+free_header:
kfree(header);
+
return ret;
}
EXPORT_SYMBOL_GPL(chameleon_parse_cells);
--
2.6.2