2022-03-31 09:08:16

by Maciej W. Rozycki

[permalink] [raw]
Subject: [RESEND][PATCH v2 0/2] x86/PCI: SiS PIRQ router updates

Hi,

This series was dropped from x86/irq due to a bug in a follow-up patch,
so resending verbatim after re-verification.

Nikolai has observed the trigger mode not being fixed up once it has been
incorrectly set by the BIOS for PCI devices, causing all kinds of usual
issues. As it turns out we don't have a PIRQ router defined for the
SiS85C497 southbridge, which Nikolai's system uses, and which is different
from the SiS85C503 southbridge we have support for.

As we use the generic `sis' infix (capitalised or not) for the SiS85C503
southbridge I have prepared this small patch series to first make the
existing SiS program entities use a more specific `sis503' infix, and then
provide a suitable PIRQ router for the SiS85C497 device.

See individual change descriptions for further details.

Please apply.

Maciej


2022-03-31 10:45:07

by Maciej W. Rozycki

[permalink] [raw]
Subject: [RESEND][PATCH v2 1/2] x86/PCI: Disambiguate SiS85C503 PIRQ router code entities

In preparation to adding support for the SiS85C497 PIRQ router add `503'
to the names of SiS85C503 PIRQ router code entities so that they clearly
indicate which device they refer to.

Also restructure `sis_router_probe' such that new device IDs will be
just new switch cases.

No functional change.

Signed-off-by: Maciej W. Rozycki <[email protected]>
---
No change from v1.
---
arch/x86/pci/irq.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)

linux-x86-pirq-router-sis85c503.diff
Index: linux-macro/arch/x86/pci/irq.c
===================================================================
--- linux-macro.orig/arch/x86/pci/irq.c
+++ linux-macro/arch/x86/pci/irq.c
@@ -641,11 +641,12 @@ static int pirq_cyrix_set(struct pci_dev
* bit 6-4 are probably unused, not like 5595
*/

-#define PIRQ_SIS_IRQ_MASK 0x0f
-#define PIRQ_SIS_IRQ_DISABLE 0x80
-#define PIRQ_SIS_USB_ENABLE 0x40
+#define PIRQ_SIS503_IRQ_MASK 0x0f
+#define PIRQ_SIS503_IRQ_DISABLE 0x80
+#define PIRQ_SIS503_USB_ENABLE 0x40

-static int pirq_sis_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
+static int pirq_sis503_get(struct pci_dev *router, struct pci_dev *dev,
+ int pirq)
{
u8 x;
int reg;
@@ -654,10 +655,11 @@ static int pirq_sis_get(struct pci_dev *
if (reg >= 0x01 && reg <= 0x04)
reg += 0x40;
pci_read_config_byte(router, reg, &x);
- return (x & PIRQ_SIS_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS_IRQ_MASK);
+ return (x & PIRQ_SIS503_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS503_IRQ_MASK);
}

-static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
+static int pirq_sis503_set(struct pci_dev *router, struct pci_dev *dev,
+ int pirq, int irq)
{
u8 x;
int reg;
@@ -666,8 +668,8 @@ static int pirq_sis_set(struct pci_dev *
if (reg >= 0x01 && reg <= 0x04)
reg += 0x40;
pci_read_config_byte(router, reg, &x);
- x &= ~(PIRQ_SIS_IRQ_MASK | PIRQ_SIS_IRQ_DISABLE);
- x |= irq ? irq: PIRQ_SIS_IRQ_DISABLE;
+ x &= ~(PIRQ_SIS503_IRQ_MASK | PIRQ_SIS503_IRQ_DISABLE);
+ x |= irq ? irq : PIRQ_SIS503_IRQ_DISABLE;
pci_write_config_byte(router, reg, x);
return 1;
}
@@ -966,13 +968,14 @@ static __init int serverworks_router_pro

static __init int sis_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
- if (device != PCI_DEVICE_ID_SI_503)
- return 0;
-
- r->name = "SIS";
- r->get = pirq_sis_get;
- r->set = pirq_sis_set;
- return 1;
+ switch (device) {
+ case PCI_DEVICE_ID_SI_503:
+ r->name = "SiS85C503";
+ r->get = pirq_sis503_get;
+ r->set = pirq_sis503_set;
+ return 1;
+ }
+ return 0;
}

static __init int cyrix_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)

2022-03-31 19:03:42

by Maciej W. Rozycki

[permalink] [raw]
Subject: [RESEND][PATCH v2 2/2] x86/PCI: Add support for the SiS85C497 PIRQ router

The SiS 85C496/497 486 Green PC VESA/ISA/PCI Chipset has support for PCI
steering and the ELCR register implemented. These features are handled
by the SiS85C497 AT Bus Controller & Megacell (ATM) ISA bridge, however
the device is wired as a peer bridge directly to the host bus and has
its PCI configuration registers decoded at addresses 0x80-0xff by the
accompanying SiS85C496 PCI & CPU Memory Controller (PCM) host bridge[1].
Therefore we need to match on the host bridge's vendor and device ID.

Like with the SiS85C503 PIRQ router handle link value ranges of 1-4 and
0xc0-0xc3, corresponding respectively to PIRQ line numbers counted from
1 and link register PCI configuration space addresses.

References:

[1] "486 Green PC VESA/ISA/PCI Chipset, SiS 85C496/497", Rev 3.0,
Silicon Integrated Systems Corp., July 1995, Part IV, Section 3.
"PCI Configuration Space Registers (00h ~ FFh)", p. 114

Signed-off-by: Maciej W. Rozycki <[email protected]>
Tested-by: Nikolai Zhubr <[email protected]>
---
Changes from v1:

- Add Nikolai's Tested-by annotation.
---
arch/x86/pci/irq.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 80 insertions(+)

linux-x86-pirq-router-sis85c497.diff
Index: linux-macro/arch/x86/pci/irq.c
===================================================================
--- linux-macro.orig/arch/x86/pci/irq.c
+++ linux-macro/arch/x86/pci/irq.c
@@ -580,6 +580,81 @@ static int pirq_cyrix_set(struct pci_dev
return 1;
}

+
+/*
+ * PIRQ routing for the SiS85C497 AT Bus Controller & Megacell (ATM)
+ * ISA bridge used with the SiS 85C496/497 486 Green PC VESA/ISA/PCI
+ * Chipset.
+ *
+ * There are four PCI INTx#-to-IRQ Link registers provided in the
+ * SiS85C497 part of the peculiar combined 85C496/497 configuration
+ * space decoded by the SiS85C496 PCI & CPU Memory Controller (PCM)
+ * host bridge, at 0xc0/0xc1/0xc2/0xc3 respectively for the PCI INT
+ * A/B/C/D lines. Bit 7 enables the respective link if set and bits
+ * 3:0 select the 8259A IRQ line as follows:
+ *
+ * 0000 : Reserved
+ * 0001 : Reserved
+ * 0010 : Reserved
+ * 0011 : IRQ3
+ * 0100 : IRQ4
+ * 0101 : IRQ5
+ * 0110 : IRQ6
+ * 0111 : IRQ7
+ * 1000 : Reserved
+ * 1001 : IRQ9
+ * 1010 : IRQ10
+ * 1011 : IRQ11
+ * 1100 : IRQ12
+ * 1101 : Reserved
+ * 1110 : IRQ14
+ * 1111 : IRQ15
+ *
+ * We avoid using a reserved value for disabled links, hence the
+ * choice of IRQ15 for that case.
+ *
+ * References:
+ *
+ * "486 Green PC VESA/ISA/PCI Chipset, SiS 85C496/497", Rev 3.0,
+ * Silicon Integrated Systems Corp., July 1995
+ */
+
+#define PCI_SIS497_INTA_TO_IRQ_LINK 0xc0u
+
+#define PIRQ_SIS497_IRQ_MASK 0x0fu
+#define PIRQ_SIS497_IRQ_ENABLE 0x80u
+
+static int pirq_sis497_get(struct pci_dev *router, struct pci_dev *dev,
+ int pirq)
+{
+ int reg;
+ u8 x;
+
+ reg = pirq;
+ if (reg >= 1 && reg <= 4)
+ reg += PCI_SIS497_INTA_TO_IRQ_LINK - 1;
+
+ pci_read_config_byte(router, reg, &x);
+ return (x & PIRQ_SIS497_IRQ_ENABLE) ? (x & PIRQ_SIS497_IRQ_MASK) : 0;
+}
+
+static int pirq_sis497_set(struct pci_dev *router, struct pci_dev *dev,
+ int pirq, int irq)
+{
+ int reg;
+ u8 x;
+
+ reg = pirq;
+ if (reg >= 1 && reg <= 4)
+ reg += PCI_SIS497_INTA_TO_IRQ_LINK - 1;
+
+ pci_read_config_byte(router, reg, &x);
+ x &= ~(PIRQ_SIS497_IRQ_MASK | PIRQ_SIS497_IRQ_ENABLE);
+ x |= irq ? (PIRQ_SIS497_IRQ_ENABLE | irq) : PIRQ_SIS497_IRQ_MASK;
+ pci_write_config_byte(router, reg, x);
+ return 1;
+}
+
/*
* PIRQ routing for SiS 85C503 router used in several SiS chipsets.
* We have to deal with the following issues here:
@@ -969,6 +1044,11 @@ static __init int serverworks_router_pro
static __init int sis_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
switch (device) {
+ case PCI_DEVICE_ID_SI_496:
+ r->name = "SiS85C497";
+ r->get = pirq_sis497_get;
+ r->set = pirq_sis497_set;
+ return 1;
case PCI_DEVICE_ID_SI_503:
r->name = "SiS85C503";
r->get = pirq_sis503_get;

Subject: [tip: x86/irq] x86/PCI: Disambiguate SiS85C503 PIRQ router code entities

The following commit has been merged into the x86/irq branch of tip:

Commit-ID: 5a0e5fa957db79177baa851d687b6f6aa5a0be96
Gitweb: https://git.kernel.org/tip/5a0e5fa957db79177baa851d687b6f6aa5a0be96
Author: Maciej W. Rozycki <[email protected]>
AuthorDate: Thu, 31 Mar 2022 08:10:39 +01:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Sun, 10 Apr 2022 12:48:14 +02:00

x86/PCI: Disambiguate SiS85C503 PIRQ router code entities

In preparation to adding support for the SiS85C497 PIRQ router add `503'
to the names of SiS85C503 PIRQ router code entities so that they clearly
indicate which device they refer to.

Also restructure `sis_router_probe' such that new device IDs will be
just new switch cases.

No functional change.

Signed-off-by: Maciej W. Rozycki <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

---
arch/x86/pci/irq.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c
index bd32e4b..e5bc9f7 100644
--- a/arch/x86/pci/irq.c
+++ b/arch/x86/pci/irq.c
@@ -641,11 +641,12 @@ static int pirq_cyrix_set(struct pci_dev *router, struct pci_dev *dev, int pirq,
* bit 6-4 are probably unused, not like 5595
*/

-#define PIRQ_SIS_IRQ_MASK 0x0f
-#define PIRQ_SIS_IRQ_DISABLE 0x80
-#define PIRQ_SIS_USB_ENABLE 0x40
+#define PIRQ_SIS503_IRQ_MASK 0x0f
+#define PIRQ_SIS503_IRQ_DISABLE 0x80
+#define PIRQ_SIS503_USB_ENABLE 0x40

-static int pirq_sis_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
+static int pirq_sis503_get(struct pci_dev *router, struct pci_dev *dev,
+ int pirq)
{
u8 x;
int reg;
@@ -654,10 +655,11 @@ static int pirq_sis_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
if (reg >= 0x01 && reg <= 0x04)
reg += 0x40;
pci_read_config_byte(router, reg, &x);
- return (x & PIRQ_SIS_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS_IRQ_MASK);
+ return (x & PIRQ_SIS503_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS503_IRQ_MASK);
}

-static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
+static int pirq_sis503_set(struct pci_dev *router, struct pci_dev *dev,
+ int pirq, int irq)
{
u8 x;
int reg;
@@ -666,8 +668,8 @@ static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, i
if (reg >= 0x01 && reg <= 0x04)
reg += 0x40;
pci_read_config_byte(router, reg, &x);
- x &= ~(PIRQ_SIS_IRQ_MASK | PIRQ_SIS_IRQ_DISABLE);
- x |= irq ? irq: PIRQ_SIS_IRQ_DISABLE;
+ x &= ~(PIRQ_SIS503_IRQ_MASK | PIRQ_SIS503_IRQ_DISABLE);
+ x |= irq ? irq : PIRQ_SIS503_IRQ_DISABLE;
pci_write_config_byte(router, reg, x);
return 1;
}
@@ -959,13 +961,14 @@ static __init int serverworks_router_probe(struct irq_router *r,

static __init int sis_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
- if (device != PCI_DEVICE_ID_SI_503)
- return 0;
-
- r->name = "SIS";
- r->get = pirq_sis_get;
- r->set = pirq_sis_set;
- return 1;
+ switch (device) {
+ case PCI_DEVICE_ID_SI_503:
+ r->name = "SiS85C503";
+ r->get = pirq_sis503_get;
+ r->set = pirq_sis503_set;
+ return 1;
+ }
+ return 0;
}

static __init int cyrix_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)

Subject: [tip: x86/irq] x86/PCI: Add support for the SiS85C497 PIRQ router

The following commit has been merged into the x86/irq branch of tip:

Commit-ID: fe62bc23620fa027162e05594a610ff5e556496a
Gitweb: https://git.kernel.org/tip/fe62bc23620fa027162e05594a610ff5e556496a
Author: Maciej W. Rozycki <[email protected]>
AuthorDate: Thu, 31 Mar 2022 08:10:46 +01:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Sun, 10 Apr 2022 12:48:14 +02:00

x86/PCI: Add support for the SiS85C497 PIRQ router

The SiS 85C496/497 486 Green PC VESA/ISA/PCI Chipset has support for PCI
steering and the ELCR register implemented. These features are handled
by the SiS85C497 AT Bus Controller & Megacell (ATM) ISA bridge, however
the device is wired as a peer bridge directly to the host bus and has
its PCI configuration registers decoded at addresses 0x80-0xff by the
accompanying SiS85C496 PCI & CPU Memory Controller (PCM) host bridge[1].
Therefore we need to match on the host bridge's vendor and device ID.

Like with the SiS85C503 PIRQ router handle link value ranges of 1-4 and
0xc0-0xc3, corresponding respectively to PIRQ line numbers counted from
1 and link register PCI configuration space addresses.

References:

[1] "486 Green PC VESA/ISA/PCI Chipset, SiS 85C496/497", Rev 3.0,
Silicon Integrated Systems Corp., July 1995, Part IV, Section 3.
"PCI Configuration Space Registers (00h ~ FFh)", p. 114

Signed-off-by: Maciej W. Rozycki <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Nikolai Zhubr <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

---
arch/x86/pci/irq.c | 80 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 80 insertions(+)

diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c
index e5bc9f7..4b0e008 100644
--- a/arch/x86/pci/irq.c
+++ b/arch/x86/pci/irq.c
@@ -580,6 +580,81 @@ static int pirq_cyrix_set(struct pci_dev *router, struct pci_dev *dev, int pirq,
return 1;
}

+
+/*
+ * PIRQ routing for the SiS85C497 AT Bus Controller & Megacell (ATM)
+ * ISA bridge used with the SiS 85C496/497 486 Green PC VESA/ISA/PCI
+ * Chipset.
+ *
+ * There are four PCI INTx#-to-IRQ Link registers provided in the
+ * SiS85C497 part of the peculiar combined 85C496/497 configuration
+ * space decoded by the SiS85C496 PCI & CPU Memory Controller (PCM)
+ * host bridge, at 0xc0/0xc1/0xc2/0xc3 respectively for the PCI INT
+ * A/B/C/D lines. Bit 7 enables the respective link if set and bits
+ * 3:0 select the 8259A IRQ line as follows:
+ *
+ * 0000 : Reserved
+ * 0001 : Reserved
+ * 0010 : Reserved
+ * 0011 : IRQ3
+ * 0100 : IRQ4
+ * 0101 : IRQ5
+ * 0110 : IRQ6
+ * 0111 : IRQ7
+ * 1000 : Reserved
+ * 1001 : IRQ9
+ * 1010 : IRQ10
+ * 1011 : IRQ11
+ * 1100 : IRQ12
+ * 1101 : Reserved
+ * 1110 : IRQ14
+ * 1111 : IRQ15
+ *
+ * We avoid using a reserved value for disabled links, hence the
+ * choice of IRQ15 for that case.
+ *
+ * References:
+ *
+ * "486 Green PC VESA/ISA/PCI Chipset, SiS 85C496/497", Rev 3.0,
+ * Silicon Integrated Systems Corp., July 1995
+ */
+
+#define PCI_SIS497_INTA_TO_IRQ_LINK 0xc0u
+
+#define PIRQ_SIS497_IRQ_MASK 0x0fu
+#define PIRQ_SIS497_IRQ_ENABLE 0x80u
+
+static int pirq_sis497_get(struct pci_dev *router, struct pci_dev *dev,
+ int pirq)
+{
+ int reg;
+ u8 x;
+
+ reg = pirq;
+ if (reg >= 1 && reg <= 4)
+ reg += PCI_SIS497_INTA_TO_IRQ_LINK - 1;
+
+ pci_read_config_byte(router, reg, &x);
+ return (x & PIRQ_SIS497_IRQ_ENABLE) ? (x & PIRQ_SIS497_IRQ_MASK) : 0;
+}
+
+static int pirq_sis497_set(struct pci_dev *router, struct pci_dev *dev,
+ int pirq, int irq)
+{
+ int reg;
+ u8 x;
+
+ reg = pirq;
+ if (reg >= 1 && reg <= 4)
+ reg += PCI_SIS497_INTA_TO_IRQ_LINK - 1;
+
+ pci_read_config_byte(router, reg, &x);
+ x &= ~(PIRQ_SIS497_IRQ_MASK | PIRQ_SIS497_IRQ_ENABLE);
+ x |= irq ? (PIRQ_SIS497_IRQ_ENABLE | irq) : PIRQ_SIS497_IRQ_MASK;
+ pci_write_config_byte(router, reg, x);
+ return 1;
+}
+
/*
* PIRQ routing for SiS 85C503 router used in several SiS chipsets.
* We have to deal with the following issues here:
@@ -962,6 +1037,11 @@ static __init int serverworks_router_probe(struct irq_router *r,
static __init int sis_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
switch (device) {
+ case PCI_DEVICE_ID_SI_496:
+ r->name = "SiS85C497";
+ r->get = pirq_sis497_get;
+ r->set = pirq_sis497_set;
+ return 1;
case PCI_DEVICE_ID_SI_503:
r->name = "SiS85C503";
r->get = pirq_sis503_get;