[PATCH V2 1/3] PCI: rcar: Move the inbound index check

[PATCH V2 1/3] PCI: rcar: Move the inbound index check

[marek.vasut]

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

Since the $idx variable value is stored across multiple calls to
rcar_pcie_inbound_ranges() function, and the $idx value is used to
index registers which are written, subsequent calls might cause
the $idx value to be high enough to trigger writes into nonexistent
registers.

Fix this by moving the $idx value check to the beginning of the loop.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-renesas-soc@vger.kernel.org
To: linux-pci@vger.kernel.org
---
V2: New patch
---
 drivers/pci/controller/pcie-rcar.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index f6a669a9af41..0f501acbc3bb 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -1048,6 +1048,10 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
 	mask &= ~0xf;
 
 	while (cpu_addr < cpu_end) {
+		if (idx > MAX_NR_INBOUND_MAPS) {
+			dev_err(pcie->dev, "Failed to map inbound regions!\n");
+			return -EINVAL;
+		}
 		/*
 		 * Set up 64-bit inbound regions as the range parser doesn't
 		 * distinguish between 32 and 64-bit types.
@@ -1067,11 +1071,6 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
 		pci_addr += size;
 		cpu_addr += size;
 		idx += 2;
-
-		if (idx > MAX_NR_INBOUND_MAPS) {
-			dev_err(pcie->dev, "Failed to map inbound regions!\n");
-			return -EINVAL;
-		}
 	}
 	*index = idx;
 
-- 
2.20.1

[PATCH V2 2/3] PCI: rcar: Do not abort on too many inbound dma-ranges

[marek.vasut]

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

In case the "dma-ranges" DT property contains either too many ranges
or the range start address is unaligned in such a way that populating
the range into the controller requires multiple entries, a situation
may occur where all ranges cannot be loaded into the controller.

Currently, the driver refuses to probe in such a situation. Relax this
behavior, load as many ranges as possible and warn if some ranges do
not fit anymore.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-renesas-soc@vger.kernel.org
To: linux-pci@vger.kernel.org
---
V2: Update on top of 1/3
---
 drivers/pci/controller/pcie-rcar.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index 0f501acbc3bb..ee760bdc7786 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -1049,8 +1049,9 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
 
 	while (cpu_addr < cpu_end) {
 		if (idx > MAX_NR_INBOUND_MAPS) {
-			dev_err(pcie->dev, "Failed to map inbound regions!\n");
-			return -EINVAL;
+			dev_warn(pcie->dev,
+				 "Too many inbound regions, not all are mapped.\n");
+			break;
 		}
 		/*
 		 * Set up 64-bit inbound regions as the range parser doesn't
-- 
2.20.1

[PATCH V2 3/3] PCI: rcar: Recalculate inbound range alignment for each controller entry

[marek.vasut]

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

Due to hardware constraints, the size of each inbound range entry
populated into the controller cannot be larger than the alignment
of the entry's start address. Currently, the alignment for each
"dma-ranges" inbound range is calculated only once for each range
and the increment for programming the controller is also derived
from it only once. Thus, a "dma-ranges" entry describing a memory
at 0x48000000 and size 0x38000000 would lead to multiple controller
entries, each 0x08000000 long.

This is inefficient, especially considering that by adding the size
to the start address, the alignment increases. This patch moves the
alignment calculation into the loop populating the controller entries,
thus updating the alignment for each controller entry.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-renesas-soc@vger.kernel.org
To: linux-pci@vger.kernel.org
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
---
V2: Update on top of 1/3
---
 drivers/pci/controller/pcie-rcar.c | 37 +++++++++++++++---------------
 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index ee760bdc7786..dd8da6ef8323 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -1029,30 +1029,31 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
 	if (restype & IORESOURCE_PREFETCH)
 		flags |= LAM_PREFETCH;
 
-	/*
-	 * If the size of the range is larger than the alignment of the start
-	 * address, we have to use multiple entries to perform the mapping.
-	 */
-	if (cpu_addr > 0) {
-		unsigned long nr_zeros = __ffs64(cpu_addr);
-		u64 alignment = 1ULL << nr_zeros;
-
-		size = min(range->size, alignment);
-	} else {
-		size = range->size;
-	}
-	/* Hardware supports max 4GiB inbound region */
-	size = min(size, 1ULL << 32);
-
-	mask = roundup_pow_of_two(size) - 1;
-	mask &= ~0xf;
-
 	while (cpu_addr < cpu_end) {
 		if (idx > MAX_NR_INBOUND_MAPS) {
 			dev_warn(pcie->dev,
 				 "Too many inbound regions, not all are mapped.\n");
 			break;
 		}
+		/*
+		 * If the size of the range is larger than the alignment of
+		 * the start address, we have to use multiple entries to
+		 * perform the mapping.
+		 */
+		if (cpu_addr > 0) {
+			unsigned long nr_zeros = __ffs64(cpu_addr);
+			u64 alignment = 1ULL << nr_zeros;
+
+			size = min(range->size, alignment);
+		} else {
+			size = range->size;
+		}
+		/* Hardware supports max 4GiB inbound region */
+		size = min(size, 1ULL << 32);
+
+		mask = roundup_pow_of_two(size) - 1;
+		mask &= ~0xf;
+
 		/*
 		 * Set up 64-bit inbound regions as the range parser doesn't
 		 * distinguish between 32 and 64-bit types.
-- 
2.20.1

Re: [PATCH V2 1/3] PCI: rcar: Move the inbound index check

[Geert Uytterhoeven]

Hi Marek,

On Fri, Aug 9, 2019 at 7:48 PM <marek.vasut@gmail.com> wrote:
> From: Marek Vasut <marek.vasut+renesas@gmail.com>
>
> Since the $idx variable value is stored across multiple calls to
> rcar_pcie_inbound_ranges() function, and the $idx value is used to
> index registers which are written, subsequent calls might cause
> the $idx value to be high enough to trigger writes into nonexistent
> registers.
>
> Fix this by moving the $idx value check to the beginning of the loop.
>
> 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
> @@ -1048,6 +1048,10 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
>         mask &= ~0xf;
>
>         while (cpu_addr < cpu_end) {
> +               if (idx > MAX_NR_INBOUND_MAPS) {

Shouldn't that check be "idx >= MAX_NR_INBOUND_MAPS - 1" now?

> +                       dev_err(pcie->dev, "Failed to map inbound regions!\n");
> +                       return -EINVAL;
> +               }
>                 /*
>                  * Set up 64-bit inbound regions as the range parser doesn't
>                  * distinguish between 32 and 64-bit types.
> @@ -1067,11 +1071,6 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
>                 pci_addr += size;
>                 cpu_addr += size;
>                 idx += 2;
> -
> -               if (idx > MAX_NR_INBOUND_MAPS) {
> -                       dev_err(pcie->dev, "Failed to map inbound regions!\n");
> -                       return -EINVAL;
> -               }
>         }
>         *index = idx;

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