[Skiboot] [PATCH] phb4: Enforce root complex config space size of 2048

[Michael Neuling]

The root complex config space size on PHB4 is 2048. This patch sets
that size and enforces it when trying to read/write the config space
in the root complex.

Without this someone reading the config space via /sysfs in linux will
cause an EEH on the PHB.

Signed-off-by: Michael Neuling <mikey at neuling.org>
---
 hw/phb4.c           | 6 ++++++
 include/phb4-regs.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/hw/phb4.c b/hw/phb4.c
index 49d4a0f4c9..28bf6f75d7 100644
--- a/hw/phb4.c
+++ b/hw/phb4.c
@@ -208,6 +208,9 @@ static int64_t phb4_rc_read(struct phb4 *p, uint32_t offset, uint8_t sz,
 	uint32_t reg = offset & ~3;
 	uint32_t oval;
 
+	if (reg >= PHB_RC_CONFIG_SIZE)
+		return OPAL_PARAMETER;
+
 	/* Some registers are handled locally */
 	switch (reg) {
 		/* Bridge base/limit registers are cached here as HW
@@ -257,6 +260,9 @@ static int64_t phb4_rc_write(struct phb4 *p, uint32_t offset, uint8_t sz,
 	uint32_t old, mask, shift;
 	int64_t rc;
 
+	if (reg > PHB_RC_CONFIG_SIZE)
+		return OPAL_PARAMETER;
+
 	/* If size isn't 4-bytes, do a RMW cycle
 	 *
 	 * XXX TODO: Filter out registers that do write-1-to-clear !!!
diff --git a/include/phb4-regs.h b/include/phb4-regs.h
index 548094907a..92bee88f6b 100644
--- a/include/phb4-regs.h
+++ b/include/phb4-regs.h
@@ -235,6 +235,7 @@
 
 // FIXME add more here
 #define PHB_RC_CONFIG_BASE			0x1000
+#define   PHB_RC_CONFIG_SIZE			0x800
 
 /* PHB4 REGB registers */
 #define PHB_PBL_CONTROL				0x1800
-- 
2.11.0