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author | Marek Vasut <marek.vasut+renesas@gmail.com> | 2019-03-25 12:41:01 +0100 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-15 11:54:09 +0200 |
commit | c2c7b6fee389ebf3606f400c30eaa72db6592f41 (patch) | |
tree | ded0a6f10dcbe0670926013c7b16a3f8f0b52811 | |
parent | dd54e70c47de9ad5d2c966b374f635cad583b266 (diff) | |
download | linux-stable-c2c7b6fee389ebf3606f400c30eaa72db6592f41.tar.gz linux-stable-c2c7b6fee389ebf3606f400c30eaa72db6592f41.tar.bz2 linux-stable-c2c7b6fee389ebf3606f400c30eaa72db6592f41.zip |
PCI: rcar: Fix 64bit MSI message address handling
[ Upstream commit 954b4b752a4c4e963b017ed8cef4c453c5ed308d ]
The MSI message address in the RC address space can be 64 bit. The
R-Car PCIe RC supports such a 64bit MSI message address as well.
The code currently uses virt_to_phys(__get_free_pages()) to obtain
a reserved page for the MSI message address, and the return value
of which can be a 64 bit physical address on 64 bit system.
However, the driver only programs PCIEMSIALR register with the bottom
32 bits of the virt_to_phys(__get_free_pages()) return value and does
not program the top 32 bits into PCIEMSIAUR, but rather programs the
PCIEMSIAUR register with 0x0. This worked fine on older 32 bit R-Car
SoCs, however may fail on new 64 bit R-Car SoCs.
Since from a PCIe controller perspective, an inbound MSI is a memory
write to a special address (in case of this controller, defined by
the value in PCIEMSIAUR:PCIEMSIALR), which triggers an interrupt, but
never hits the DRAM _and_ because allocation of an MSI by a PCIe card
driver obtains the MSI message address by reading PCIEMSIAUR:PCIEMSIALR
in rcar_msi_setup_irqs(), incorrectly programmed PCIEMSIAUR cannot
cause memory corruption or other issues.
There is however the possibility that if virt_to_phys(__get_free_pages())
returned address above the 32bit boundary _and_ PCIEMSIAUR was programmed
to 0x0 _and_ if the system had physical RAM at the address matching the
value of PCIEMSIALR, a PCIe card driver could allocate a buffer with a
physical address matching the value of PCIEMSIALR and a remote write to
such a buffer by a PCIe card would trigger a spurious MSI.
Fixes: e015f88c368d ("PCI: rcar: Add support for R-Car H3 to pcie-rcar")
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-renesas-soc@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r-- | drivers/pci/controller/pcie-rcar.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c index 765c39911c0c..9b9c677ad3a0 100644 --- a/drivers/pci/controller/pcie-rcar.c +++ b/drivers/pci/controller/pcie-rcar.c @@ -892,7 +892,7 @@ static int rcar_pcie_enable_msi(struct rcar_pcie *pcie) { struct device *dev = pcie->dev; struct rcar_msi *msi = &pcie->msi; - unsigned long base; + phys_addr_t base; int err, i; mutex_init(&msi->lock); @@ -937,8 +937,8 @@ static int rcar_pcie_enable_msi(struct rcar_pcie *pcie) } base = virt_to_phys((void *)msi->pages); - rcar_pci_write_reg(pcie, base | MSIFE, PCIEMSIALR); - rcar_pci_write_reg(pcie, 0, PCIEMSIAUR); + rcar_pci_write_reg(pcie, lower_32_bits(base) | MSIFE, PCIEMSIALR); + rcar_pci_write_reg(pcie, upper_32_bits(base), PCIEMSIAUR); /* enable all MSI interrupts */ rcar_pci_write_reg(pcie, 0xffffffff, PCIEMSIIER); |