[PATCH 03/15] ARM: tegra: use fixed PCI i/o mapping

On 07/08/2012 01:09 AM, Thierry Reding wrote:

On Fri, Jul 06, 2012 at 01:40:28PM -0500, Rob Herring wrote:

quoted

From: Rob Herring <redacted>

Move tegra PCI to fixed i/o mapping and remove io.h.

Signed-off-by: Rob Herring <redacted>
Cc: Colin Cross <redacted>
Cc: Olof Johansson <redacted>
Acked-by: Stephen Warren <redacted>
---
 arch/arm/Kconfig                         |    1 -
 arch/arm/mach-tegra/include/mach/io.h    |   46 ------------------------------
 arch/arm/mach-tegra/include/mach/iomap.h |    3 ++
 arch/arm/mach-tegra/io.c                 |    2 ++
 arch/arm/mach-tegra/pcie.c               |   43 ++++------------------------
 5 files changed, 10 insertions(+), 85 deletions(-)
 delete mode 100644 arch/arm/mach-tegra/include/mach/io.h

Hi Rob,

generally this looks good. However I've been working on a rewrite of the
Tegra PCIe support to make it work as a driver and add DT support. This
entails that PCIe support isn't initialized until very late in the
process because it makes use of deferred probe if some regulators aren't
available. One problem caused by this is that it suddenly requires a lot
of code marked as __init to be available after the init phase and I see
that you've introduced pci_map_io_single_pfn() that is __init annotated,
so it will cause problems when used with my patches.

This function can only be called during .map_io anyway, so the __init is
irrelevant.

I'm not very familiar with the inner workings of the iotable and the
mappings initialized by it, but I wonder if this can be done dynamically
at a later stage. The way this is currently done in this patch, the I/O
region is statically mapped from a fixed offset within the PCIe address
range. Part of the patches to add DT support is to allow this region to
be defined by the DT, so that will obviously also create problems.

Is the i/o address something you could extract from DT earlier? This can
be done separately if it doesn't require information from the driver.

I'm sure exactly how to do a fixed virtual mapping other than the
io_table mappings. There was some discussion of use fixmap region
previously, but doing so will be a bit more complex. I'll look into this
some.

Rob

If both of those issues can be easily addressed, then this certainly
looks very nice.

Thierry

quoted

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8fb7e4a..ac446e3 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig

@@ -644,7 +644,6 @@ config ARCH_TEGRA
 	select HAVE_CLK
 	select HAVE_SMP
 	select MIGHT_HAVE_CACHE_L2X0
-	select NEED_MACH_IO_H if PCI
 	select ARCH_HAS_CPUFREQ
 	help
 	  This enables support for NVIDIA Tegra based systems (Tegra APX,

diff --git a/arch/arm/mach-tegra/include/mach/io.h b/arch/arm/mach-tegra/include/mach/io.h
deleted file mode 100644
index fe700f9..0000000
--- a/arch/arm/mach-tegra/include/mach/io.h
+++ /dev/null

@@ -1,46 +0,0 @@
-/*
- * arch/arm/mach-tegra/include/mach/io.h
- *
- * Copyright (C) 2010 Google, Inc.
- *
- * Author:
- *	Colin Cross <ccross@google.com>
- *	Erik Gilling <konkers@google.com>
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
-
-#ifndef __MACH_TEGRA_IO_H
-#define __MACH_TEGRA_IO_H
-
-#define IO_SPACE_LIMIT 0xffff
-
-#ifndef __ASSEMBLER__
-
-#ifdef CONFIG_TEGRA_PCI
-extern void __iomem *tegra_pcie_io_base;
-
-static inline void __iomem *__io(unsigned long addr)
-{
-	return tegra_pcie_io_base + (addr & IO_SPACE_LIMIT);
-}
-#else
-static inline void __iomem *__io(unsigned long addr)
-{
-	return (void __iomem *)addr;
-}
-#endif
-
-#define __io(a)         __io(a)
-
-#endif
-
-#endif

diff --git a/arch/arm/mach-tegra/include/mach/iomap.h b/arch/arm/mach-tegra/include/mach/iomap.h
index 7e76da7..fee3a94 100644
--- a/arch/arm/mach-tegra/include/mach/iomap.h
+++ b/arch/arm/mach-tegra/include/mach/iomap.h

@@ -303,6 +303,9 @@
 #define IO_APB_VIRT	IOMEM(0xFE300000)
 #define IO_APB_SIZE	SZ_1M
 
+#define TEGRA_PCIE_BASE		0x80000000
+#define TEGRA_PCIE_IO_BASE	(TEGRA_PCIE_BASE + SZ_4M)
+
 #define IO_TO_VIRT_BETWEEN(p, st, sz)	((p) >= (st) && (p) < ((st) + (sz)))
 #define IO_TO_VIRT_XLATE(p, pst, vst)	(((p) - (pst) + (vst)))
 

diff --git a/arch/arm/mach-tegra/io.c b/arch/arm/mach-tegra/io.c
index 58b4baf..7a29e10 100644
--- a/arch/arm/mach-tegra/io.c
+++ b/arch/arm/mach-tegra/io.c

@@ -26,6 +26,7 @@
 
 #include <asm/page.h>
 #include <asm/mach/map.h>
+#include <asm/mach/pci.h>
 #include <mach/iomap.h>
 
 #include "board.h"

@@ -59,5 +60,6 @@ static struct map_desc tegra_io_desc[] __initdata = {
 
 void __init tegra_map_common_io(void)
 {
+	pci_map_io_single(TEGRA_PCIE_IO_BASE);
 	iotable_init(tegra_io_desc, ARRAY_SIZE(tegra_io_desc));
 }

diff --git a/arch/arm/mach-tegra/pcie.c b/arch/arm/mach-tegra/pcie.c
index 0e09137..c989a8e 100644
--- a/arch/arm/mach-tegra/pcie.c
+++ b/arch/arm/mach-tegra/pcie.c

@@ -171,8 +171,6 @@ static void __iomem *reg_pmc_base = IO_ADDRESS(TEGRA_PMC_BASE);
  * 0x90000000 - 0x9fffffff - non-prefetchable memory
  * 0xa0000000 - 0xbfffffff - prefetchable memory
  */
-#define TEGRA_PCIE_BASE		0x80000000
-
 #define PCIE_REGS_SZ		SZ_16K
 #define PCIE_CFG_OFF		PCIE_REGS_SZ
 #define PCIE_CFG_SZ		SZ_1M

@@ -180,8 +178,6 @@ static void __iomem *reg_pmc_base = IO_ADDRESS(TEGRA_PMC_BASE);
 #define PCIE_EXT_CFG_SZ		SZ_1M
 #define PCIE_IOMAP_SZ		(PCIE_REGS_SZ + PCIE_CFG_SZ + PCIE_EXT_CFG_SZ)
 
-#define MMIO_BASE		(TEGRA_PCIE_BASE + SZ_4M)
-#define MMIO_SIZE		SZ_64K
 #define MEM_BASE_0		(TEGRA_PCIE_BASE + SZ_256M)
 #define MEM_SIZE_0		SZ_128M
 #define MEM_BASE_1		(MEM_BASE_0 + MEM_SIZE_0)

@@ -223,17 +219,7 @@ struct tegra_pcie_info {
 	struct clk		*pll_e;
 };
 
-static struct tegra_pcie_info tegra_pcie = {
-	.res_mmio = {
-		.name = "PCI IO",
-		.start = MMIO_BASE,
-		.end = MMIO_BASE + MMIO_SIZE - 1,
-		.flags = IORESOURCE_MEM,
-	},
-};
-
-void __iomem *tegra_pcie_io_base;
-EXPORT_SYMBOL(tegra_pcie_io_base);
+static struct tegra_pcie_info tegra_pcie;
 
 static inline void afi_writel(u32 value, unsigned long offset)
 {

@@ -403,7 +389,7 @@ static int tegra_pcie_setup(int nr, struct pci_sys_data *sys)
 		pp->res[0].end = pp->res[0].start + SZ_32K - 1;
 	} else {
 		pp->res[0].start = PCIBIOS_MIN_IO + SZ_32K;
-		pp->res[0].end = IO_SPACE_LIMIT;
+		pp->res[0].end = SZ_64K - 1;
 	}
 	pp->res[0].flags = IORESOURCE_IO;
 	if (request_resource(&ioport_resource, &pp->res[0]))

@@ -541,8 +527,8 @@ static void tegra_pcie_setup_translations(void)
 
 	/* Bar 2: downstream IO bar */
 	fpci_bar = ((__u32)0xfdfc << 16);
-	size = MMIO_SIZE;
-	axi_address = MMIO_BASE;
+	size = SZ_64K;
+	axi_address = TEGRA_PCIE_IO_BASE;
 	afi_writel(axi_address, AFI_AXI_BAR2_START);
 	afi_writel(size >> 12, AFI_AXI_BAR2_SZ);
 	afi_writel(fpci_bar, AFI_FPCI_BAR2);

@@ -776,7 +762,6 @@ static void tegra_pcie_clocks_put(void)
 
 static int __init tegra_pcie_get_resources(void)
 {
-	struct resource *res_mmio = &tegra_pcie.res_mmio;
 	int err;
 
 	err = tegra_pcie_clocks_get();

@@ -798,34 +783,16 @@ static int __init tegra_pcie_get_resources(void)
 		goto err_map_reg;
 	}
 
-	err = request_resource(&iomem_resource, res_mmio);
-	if (err) {
-		pr_err("PCIE: Failed to request resources: %d\n", err);
-		goto err_req_io;
-	}
-
-	tegra_pcie_io_base = ioremap_nocache(res_mmio->start,
-					     resource_size(res_mmio));
-	if (tegra_pcie_io_base == NULL) {
-		pr_err("PCIE: Failed to map IO\n");
-		err = -ENOMEM;
-		goto err_map_io;
-	}
-
 	err = request_irq(INT_PCIE_INTR, tegra_pcie_isr,
 			  IRQF_SHARED, "PCIE", &tegra_pcie);
 	if (err) {
 		pr_err("PCIE: Failed to register IRQ: %d\n", err);
-		goto err_irq;
+		goto err_req_io;
 	}
 	set_irq_flags(INT_PCIE_INTR, IRQF_VALID);
 
 	return 0;
 
-err_irq:
-	iounmap(tegra_pcie_io_base);
-err_map_io:
-	release_resource(&tegra_pcie.res_mmio);
 err_req_io:
 	iounmap(tegra_pcie.regs);
 err_map_reg:

-- 
1.7.9.5