linux-kernel - [PATCH v1 10/12] MIPS: Loongson 3: Keep CPU physical (not virtual) addresses in shadow ROM resource

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Date:	Thu, 03 Mar 2016 10:55:11 -0600
From:	Bjorn Helgaas <bhelgaas@...gle.com>
To:	linux-pci@...r.kernel.org
Cc:	Matthew Garrett <mjg59@...f.ucam.org>,
	Tony Luck <tony.luck@...el.com>,
	DRI <dri-devel@...ts.freedesktop.org>,
	Fenghua Yu <fenghua.yu@...el.com>,
	Intel Graphics Development <intel-gfx@...ts.freedesktop.org>,
	linux-kernel@...r.kernel.org, Ralf Baechle <ralf@...ux-mips.org>,
	Andy Lutomirski <luto@...capital.net>,
	Bruno Prémont <bonbons@...ux-vserver.org>,
	Daniel Stone <daniel@...ishbar.org>,
	Alex Deucher <alexdeucher@...il.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ville Syrjälä <ville.syrjala@...ux.intel.com>
Subject: [PATCH v1 10/12] MIPS: Loongson 3: Keep CPU physical (not virtual)
 addresses in shadow ROM resource

Loongson 3 used the IORESOURCE_ROM_COPY flag for its ROM resource.  There
are two problems with this:

  - When IORESOURCE_ROM_COPY is set, pci_map_rom() assumes the resource
    contains virtual addresses, so it doesn't ioremap the resource.  This
    implies loongson_sysconf.vgabios_addr is a virtual address.  That's a
    problem because resources should contain CPU *physical* addresses not
    virtual addresses.

  - When IORESOURCE_ROM_COPY is set, pci_cleanup_rom() calls kfree() on the
    resource.  We did not kmalloc() the loongson_sysconf.vgabios_addr area,
    so it is incorrect to kfree() it.

If we're using a shadow copy in RAM for the Loongson 3 VGA BIOS area,
disable the ROM BAR and release the address space it was consuming.

Use IORESOURCE_ROM_SHADOW instead of IORESOURCE_ROM_COPY.  This means the
struct resource contains CPU physical addresses, and pci_map_rom() will
ioremap() it as needed.

Signed-off-by: Bjorn Helgaas <bhelgaas@...gle.com>
---
 arch/mips/pci/fixup-loongson3.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/mips/pci/fixup-loongson3.c b/arch/mips/pci/fixup-loongson3.c
index b66b1eb..c015ca1 100644
--- a/arch/mips/pci/fixup-loongson3.c
+++ b/arch/mips/pci/fixup-loongson3.c
@@ -48,9 +48,14 @@ static void pci_fixup_radeon(struct pci_dev *pdev)
 	if (!loongson_sysconf.vgabios_addr)
 		return;
 
-	res->start = loongson_sysconf.vgabios_addr;
+	pci_disable_rom(pdev);
+	if (res->parent)
+		release_resource(res);
+
+	res->start = virt_to_phys(loongson_sysconf.vgabios_addr);
 	res->end   = res->start + 256*1024 - 1;
-	res->flags |= IORESOURCE_ROM_COPY;
+	res->flags = IORESOURCE_MEM | IORESOURCE_ROM_SHADOW |
+		     IORESOURCE_PCI_FIXED;
 
 	dev_info(&pdev->dev, "BAR %d: assigned %pR for Radeon ROM\n",
 		 PCI_ROM_RESOURCE, res);