[PATCH V3 1/6] PCI: rcar: Clean up remaining macros defining bits

[PATCH V3 1/6] PCI: rcar: Clean up remaining macros defining bits

[marek.vasut]

From: Marek Vasut <marek.vasut+renesas@gmail.com>

Replace macros using constants with BIT()s instead, no functional change.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
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
To: linux-pci@vger.kernel.org
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
V2: Bundle this patch with other cleanups before resending
V3: Add Wolfram's R-B
---
 drivers/pci/controller/pcie-rcar.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index c8febb009454..5b8736f0cd6b 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -46,14 +46,14 @@
 
 /* Transfer control */
 #define PCIETCTLR		0x02000
-#define  CFINIT			1
+#define  CFINIT			BIT(0)
 #define PCIETSTR		0x02004
-#define  DATA_LINK_ACTIVE	1
+#define  DATA_LINK_ACTIVE	BIT(0)
 #define PCIEERRFR		0x02020
 #define  UNSUPPORTED_REQUEST	BIT(4)
 #define PCIEMSIFR		0x02044
 #define PCIEMSIALR		0x02048
-#define  MSIFE			1
+#define  MSIFE			BIT(0)
 #define PCIEMSIAUR		0x0204c
 #define PCIEMSIIER		0x02050
 
-- 
2.20.1

[PATCH V3 2/6] PCI: rcar: Replace unsigned long with u32 in register accessors

[marek.vasut]

From: Marek Vasut <marek.vasut+renesas@gmail.com>

Replace unsigned long with u32 in register accessor functions,
since they access 32bit registers.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
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
To: linux-pci@vger.kernel.org
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
V2: Bundle this patch with other cleanups before resending
V3: Add Wolfram's R-B
---
 drivers/pci/controller/pcie-rcar.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index 5b8736f0cd6b..1408c8aa758b 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -152,14 +152,12 @@ struct rcar_pcie {
 	struct			rcar_msi msi;
 };
 
-static void rcar_pci_write_reg(struct rcar_pcie *pcie, unsigned long val,
-			       unsigned long reg)
+static void rcar_pci_write_reg(struct rcar_pcie *pcie, u32 val, u32 reg)
 {
 	writel(val, pcie->base + reg);
 }
 
-static unsigned long rcar_pci_read_reg(struct rcar_pcie *pcie,
-				       unsigned long reg)
+static u32 rcar_pci_read_reg(struct rcar_pcie *pcie, u32 reg)
 {
 	return readl(pcie->base + reg);
 }
-- 
2.20.1

[PATCH V3 3/6] PCI: rcar: Replace various variable types with unsigned ones for register values

[marek.vasut]

From: Marek Vasut <marek.vasut+renesas@gmail.com>

Replace various variable types with u32 or unsigned int type for
variables holding register values, since the registers are 32bit.
Note that rcar_pcie_msi_irq() still uses various variable types
because both find_first_bit() and __fls() require various variable
types as an argument.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
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
To: linux-pci@vger.kernel.org
---
V2: - s@unsigned long@various variable types@ in the commit message
    - Replace int with unsigned int for the $shift variable
    - Replace int with unsigned int / u32 in rcar_pcie_config_access()
V3: - Change shift from u32 to unsigned int
    - Change addr and data in phy_write_reg() from unsigned int to u32
---
 drivers/pci/controller/pcie-rcar.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index 1408c8aa758b..a2d3855b15ea 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -169,7 +169,7 @@ enum {
 
 static void rcar_rmw32(struct rcar_pcie *pcie, int where, u32 mask, u32 data)
 {
-	int shift = 8 * (where & 3);
+	unsigned int shift = 8 * (where & 3);
 	u32 val = rcar_pci_read_reg(pcie, where & ~3);
 
 	val &= ~(mask << shift);
@@ -179,7 +179,7 @@ static void rcar_rmw32(struct rcar_pcie *pcie, int where, u32 mask, u32 data)
 
 static u32 rcar_read_conf(struct rcar_pcie *pcie, int where)
 {
-	int shift = 8 * (where & 3);
+	unsigned int shift = 8 * (where & 3);
 	u32 val = rcar_pci_read_reg(pcie, where & ~3);
 
 	return val >> shift;
@@ -190,7 +190,8 @@ static int rcar_pcie_config_access(struct rcar_pcie *pcie,
 		unsigned char access_type, struct pci_bus *bus,
 		unsigned int devfn, int where, u32 *data)
 {
-	int dev, func, reg, index;
+	unsigned int dev, func, index;
+	u32 reg;
 
 	dev = PCI_SLOT(devfn);
 	func = PCI_FUNC(devfn);
@@ -294,8 +295,9 @@ static int rcar_pcie_write_conf(struct pci_bus *bus, unsigned int devfn,
 				int where, int size, u32 val)
 {
 	struct rcar_pcie *pcie = bus->sysdata;
-	int shift, ret;
+	unsigned int shift;
 	u32 data;
+	int ret;
 
 	ret = rcar_pcie_config_access(pcie, RCAR_PCI_ACCESS_READ,
 				      bus, devfn, where, &data);
@@ -505,10 +507,10 @@ static int phy_wait_for_ack(struct rcar_pcie *pcie)
 }
 
 static void phy_write_reg(struct rcar_pcie *pcie,
-				 unsigned int rate, unsigned int addr,
-				 unsigned int lane, unsigned int data)
+			  unsigned int rate, u32 addr,
+			  unsigned int lane, u32 data)
 {
-	unsigned long phyaddr;
+	u32 phyaddr;
 
 	phyaddr = WRITE_CMD |
 		((rate & 1) << RATE_POS) |
@@ -1116,7 +1118,7 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct rcar_pcie *pcie;
-	unsigned int data;
+	u32 data;
 	int err;
 	int (*phy_init_fn)(struct rcar_pcie *);
 	struct pci_host_bridge *bridge;
-- 
2.20.1

[PATCH V3 4/6] PCI: rcar: Replace (8 * n) with (n << 3)

[marek.vasut]

From: Marek Vasut <marek.vasut+renesas@gmail.com>

Replace (8 * n) with (n << 3) to make bit shift operations consistent.
No functional change.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
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
To: linux-pci@vger.kernel.org
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
V2: Bundle this patch with other cleanups before resending
V3: Add Wolfram's R-B
---
 drivers/pci/controller/pcie-rcar.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index a2d3855b15ea..f835e4341590 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -169,7 +169,7 @@ enum {
 
 static void rcar_rmw32(struct rcar_pcie *pcie, int where, u32 mask, u32 data)
 {
-	unsigned int shift = 8 * (where & 3);
+	unsigned int shift = (where & 3) << 3;
 	u32 val = rcar_pci_read_reg(pcie, where & ~3);
 
 	val &= ~(mask << shift);
@@ -179,7 +179,7 @@ static void rcar_rmw32(struct rcar_pcie *pcie, int where, u32 mask, u32 data)
 
 static u32 rcar_read_conf(struct rcar_pcie *pcie, int where)
 {
-	unsigned int shift = 8 * (where & 3);
+	unsigned int shift = (where & 3) << 3;
 	u32 val = rcar_pci_read_reg(pcie, where & ~3);
 
 	return val >> shift;
@@ -280,9 +280,9 @@ static int rcar_pcie_read_conf(struct pci_bus *bus, unsigned int devfn,
 	}
 
 	if (size == 1)
-		*val = (*val >> (8 * (where & 3))) & 0xff;
+		*val = (*val >> ((where & 3) << 3)) & 0xff;
 	else if (size == 2)
-		*val = (*val >> (8 * (where & 2))) & 0xffff;
+		*val = (*val >> ((where & 2) << 3)) & 0xffff;
 
 	dev_dbg(&bus->dev, "pcie-config-read: bus=%3d devfn=0x%04x where=0x%04x size=%d val=0x%08lx\n",
 		bus->number, devfn, where, size, (unsigned long)*val);
@@ -308,11 +308,11 @@ static int rcar_pcie_write_conf(struct pci_bus *bus, unsigned int devfn,
 		bus->number, devfn, where, size, (unsigned long)val);
 
 	if (size == 1) {
-		shift = 8 * (where & 3);
+		shift = (where & 3) << 3;
 		data &= ~(0xff << shift);
 		data |= ((val & 0xff) << shift);
 	} else if (size == 2) {
-		shift = 8 * (where & 2);
+		shift = (where & 2) << 3;
 		data &= ~(0xffff << shift);
 		data |= ((val & 0xffff) << shift);
 	} else
-- 
2.20.1

[PATCH V3 5/6] PCI: rcar: Clean up debug messages

[marek.vasut]

From: Marek Vasut <marek.vasut+renesas@gmail.com>

Drop useless casts from debug messages, they are no longer needed
due to the data type cleanup.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
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
To: linux-pci@vger.kernel.org
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
V2: - Bundle this patch with other cleanups before resending
    - Add R-B from Geert
V3: Add Wolfram's R-B
---
 drivers/pci/controller/pcie-rcar.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index f835e4341590..4d9e68ddcdd9 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -284,8 +284,8 @@ static int rcar_pcie_read_conf(struct pci_bus *bus, unsigned int devfn,
 	else if (size == 2)
 		*val = (*val >> ((where & 2) << 3)) & 0xffff;
 
-	dev_dbg(&bus->dev, "pcie-config-read: bus=%3d devfn=0x%04x where=0x%04x size=%d val=0x%08lx\n",
-		bus->number, devfn, where, size, (unsigned long)*val);
+	dev_dbg(&bus->dev, "pcie-config-read: bus=%3d devfn=0x%04x where=0x%04x size=%d val=0x%08x\n",
+		bus->number, devfn, where, size, *val);
 
 	return ret;
 }
@@ -304,8 +304,8 @@ static int rcar_pcie_write_conf(struct pci_bus *bus, unsigned int devfn,
 	if (ret != PCIBIOS_SUCCESSFUL)
 		return ret;
 
-	dev_dbg(&bus->dev, "pcie-config-write: bus=%3d devfn=0x%04x where=0x%04x size=%d val=0x%08lx\n",
-		bus->number, devfn, where, size, (unsigned long)val);
+	dev_dbg(&bus->dev, "pcie-config-write: bus=%3d devfn=0x%04x where=0x%04x size=%d val=0x%08x\n",
+		bus->number, devfn, where, size, val);
 
 	if (size == 1) {
 		shift = (where & 3) << 3;
-- 
2.20.1

[PATCH V3 6/6] PCI: rcar: Fix 64bit MSI message address handling

[marek.vasut]

From: Marek Vasut <marek.vasut+renesas@gmail.com>

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.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
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
To: linux-pci@vger.kernel.org
---
V2: - s/it's/its/ in commit message
    - Add R-B from Geert
V3: - Reworded commit message and thus dropped Geerts R-B
---
 drivers/pci/controller/pcie-rcar.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index 4d9e68ddcdd9..6bedd2167f3c 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -890,7 +890,7 @@ 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);
@@ -932,7 +932,7 @@ 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, base >> 32, PCIEMSIAUR);
 
 	/* enable all MSI interrupts */
 	rcar_pci_write_reg(pcie, 0xffffffff, PCIEMSIIER);
-- 
2.20.1

Re: [PATCH V3 1/6] PCI: rcar: Clean up remaining macros defining bits

[Geert Uytterhoeven]

On Sat, Mar 23, 2019 at 2:54 AM <marek.vasut@gmail.com> wrote:
> From: Marek Vasut <marek.vasut+renesas@gmail.com>
>
> Replace macros using constants with BIT()s instead, no functional change.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> 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
> To: linux-pci@vger.kernel.org
> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
> V2: Bundle this patch with other cleanups before resending
> V3: Add Wolfram's R-B

Seems you forgot to add mine?
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH V3 2/6] PCI: rcar: Replace unsigned long with u32 in register accessors

[Geert Uytterhoeven]

Hi Marek,

On Sat, Mar 23, 2019 at 2:54 AM <marek.vasut@gmail.com> wrote:
> From: Marek Vasut <marek.vasut+renesas@gmail.com>
>
> Replace unsigned long with u32 in register accessor functions,
> since they access 32bit registers.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> 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
> To: linux-pci@vger.kernel.org
> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
> V2: Bundle this patch with other cleanups before resending
> V3: Add Wolfram's R-B

Forgot mine?
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

> --- a/drivers/pci/controller/pcie-rcar.c
> +++ b/drivers/pci/controller/pcie-rcar.c
> @@ -152,14 +152,12 @@ struct rcar_pcie {
>         struct                  rcar_msi msi;
>  };
>
> -static void rcar_pci_write_reg(struct rcar_pcie *pcie, unsigned long val,
> -                              unsigned long reg)
> +static void rcar_pci_write_reg(struct rcar_pcie *pcie, u32 val, u32 reg)

reg is is not a register value, but a simple integer offset.

>  {
>         writel(val, pcie->base + reg);
>  }
>
> -static unsigned long rcar_pci_read_reg(struct rcar_pcie *pcie,
> -                                      unsigned long reg)
> +static u32 rcar_pci_read_reg(struct rcar_pcie *pcie, u32 reg)

Likewise.

>  {
>         return readl(pcie->base + reg);
>  }

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH V3 3/6] PCI: rcar: Replace various variable types with unsigned ones for register values

[Geert Uytterhoeven]

Hi Marek,

On Sat, Mar 23, 2019 at 2:54 AM <marek.vasut@gmail.com> wrote:
> From: Marek Vasut <marek.vasut+renesas@gmail.com>
>
> Replace various variable types with u32 or unsigned int type for
> variables holding register values, since the registers are 32bit.
> Note that rcar_pcie_msi_irq() still uses various variable types
> because both find_first_bit() and __fls() require various variable
> types as an argument.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>

Thanks for your patch!

> --- a/drivers/pci/controller/pcie-rcar.c
> +++ b/drivers/pci/controller/pcie-rcar.c

> @@ -190,7 +190,8 @@ static int rcar_pcie_config_access(struct rcar_pcie *pcie,
>                 unsigned char access_type, struct pci_bus *bus,
>                 unsigned int devfn, int where, u32 *data)
>  {
> -       int dev, func, reg, index;
> +       unsigned int dev, func, index;
> +       u32 reg;

"reg" is not a register value, but an (unsigned) register offset, so IMHO
"unsigned int" is the right type.

With that fixed:
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH V3 4/6] PCI: rcar: Replace (8 * n) with (n << 3)

[Geert Uytterhoeven]

Hi Marek,

On Sat, Mar 23, 2019 at 2:54 AM <marek.vasut@gmail.com> wrote:
> From: Marek Vasut <marek.vasut+renesas@gmail.com>
>
> Replace (8 * n) with (n << 3) to make bit shift operations consistent.
> No functional change.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>

Thanks for your patch!

Where is the inconsistency? The driver consistently uses
  1. multiplications for bit offset calculations,
  2. shifts for bit field extraction or insertion.

While technically equivalent, I think your change makes the code harder
to read: the values are multiplied by eight to convert from number of
bytes to number of bits, so IMHO "BITS_PER_BYTE * n" would be more
readable.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH V3 6/6] PCI: rcar: Fix 64bit MSI message address handling

[Geert Uytterhoeven]

On Sat, Mar 23, 2019 at 2:54 AM <marek.vasut@gmail.com> wrote:
> From: Marek Vasut <marek.vasut+renesas@gmail.com>
>
> 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.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>

Thanks for the nice explanation!

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH V3 2/6] PCI: rcar: Replace unsigned long with u32 in register accessors

[Marek Vasut]

On 3/25/19 9:07 AM, Geert Uytterhoeven wrote:
> Hi Marek,
> 
> On Sat, Mar 23, 2019 at 2:54 AM <marek.vasut@gmail.com> wrote:
>> From: Marek Vasut <marek.vasut+renesas@gmail.com>
>>
>> Replace unsigned long with u32 in register accessor functions,
>> since they access 32bit registers.
>>
>> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
>> 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
>> To: linux-pci@vger.kernel.org
>> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
>> ---
>> V2: Bundle this patch with other cleanups before resending
>> V3: Add Wolfram's R-B
> 
> Forgot mine?
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> 
>> --- a/drivers/pci/controller/pcie-rcar.c
>> +++ b/drivers/pci/controller/pcie-rcar.c
>> @@ -152,14 +152,12 @@ struct rcar_pcie {
>>         struct                  rcar_msi msi;
>>  };
>>
>> -static void rcar_pci_write_reg(struct rcar_pcie *pcie, unsigned long val,
>> -                              unsigned long reg)
>> +static void rcar_pci_write_reg(struct rcar_pcie *pcie, u32 val, u32 reg)
> 
> reg is is not a register value, but a simple integer offset.
> 
>>  {
>>         writel(val, pcie->base + reg);
>>  }
>>
>> -static unsigned long rcar_pci_read_reg(struct rcar_pcie *pcie,
>> -                                      unsigned long reg)
>> +static u32 rcar_pci_read_reg(struct rcar_pcie *pcie, u32 reg)
> 
> Likewise.

Sure

-- 
Best regards,
Marek Vasut

Re: [PATCH V3 4/6] PCI: rcar: Replace (8 * n) with (n << 3)

[Marek Vasut]

On 3/25/19 9:26 AM, Geert Uytterhoeven wrote:
> Hi Marek,
> 
> On Sat, Mar 23, 2019 at 2:54 AM <marek.vasut@gmail.com> wrote:
>> From: Marek Vasut <marek.vasut+renesas@gmail.com>
>>
>> Replace (8 * n) with (n << 3) to make bit shift operations consistent.
>> No functional change.
>>
>> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> 
> Thanks for your patch!
> 
> Where is the inconsistency? The driver consistently uses
>   1. multiplications for bit offset calculations,
>   2. shifts for bit field extraction or insertion.
> 
> While technically equivalent, I think your change makes the code harder
> to read: the values are multiplied by eight to convert from number of
> bytes to number of bits, so IMHO "BITS_PER_BYTE * n" would be more
> readable.

Sure

-- 
Best regards,
Marek Vasut