Message-ID: <20160628142543.GA32375@awelinux>
Date:	Tue, 28 Jun 2016 16:25:48 +0200
From:	Andreas Werner <andreas.werner@....de>
To:	<morbidrsa@...il.com>
CC:	<linux-kernel@...r.kernel.org>
Subject: [PATCH] mcb: Added bar descriptor support for non PCI bus MCB carrier

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@....de>
---
 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

Powered by blists - more mailing lists