[Skiboot] [PATCH 2/2] hdata: Fix NULL pointer dereference in LPC setup

[Oliver O'Halloran]

The HDAT parser runs before the per-cpu structures have been
initialised and as a result get_chip() will always return
NULL. This seems to work though since the first few bytes of memory
are zeros and the LPC bus is usually attached to chip zero anyway.
Fix this by using the proper function to conver the HDAT chip ID
we get in the structure to a global chip ID using the low-level
__phys_map_get() instead.

Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
---
 hdata/fsp.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/hdata/fsp.c b/hdata/fsp.c
index 2c8254f930b2..5f8cffa540da 100644
--- a/hdata/fsp.c
+++ b/hdata/fsp.c
@@ -288,7 +288,8 @@ static void bmc_create_node(const struct HDIF_common_hdr *sp)
 	const struct spss_sp_impl *sp_impl;
 	struct dt_node *lpcm, *lpc, *n;
 	u64 lpcm_base, lpcm_end;
-	int chip_id, size;
+	uint32_t gcid;
+	int size;
 
 	bmc_node = dt_new(dt_root, "bmc");
 	assert(bmc_node);
@@ -318,9 +319,13 @@ static void bmc_create_node(const struct HDIF_common_hdr *sp)
 		return;
 
 #define GB (1024ul * 1024ul * 1024ul)
-	chip_id = be32_to_cpu(iopath->lpc.chip_id);
+	/*
+	 * convert the hdat chip ID the HW chip id so we get the right
+	 * phys map offset
+	 */
+	gcid = pcid_to_chip_id(be32_to_cpu(iopath->lpc.chip_id));
 
-	phys_map_get(get_chip(chip_id), LPC_BUS, 0, &lpcm_base, NULL);
+	__phys_map_get(gcid, LPC_BUS, 0, &lpcm_base, NULL);
 	lpcm = dt_new_addr(dt_root, "lpcm-opb", lpcm_base);
 	assert(lpcm);
 
@@ -330,7 +335,7 @@ static void bmc_create_node(const struct HDIF_common_hdr *sp)
 		"ibm,power9-lpcm-opb", "simple-bus");
 	dt_add_property_u64s(lpcm, "reg", lpcm_base, 0x100000000ul);
 
-	dt_add_property_cells(lpcm, "ibm,chip-id", chip_id);
+	dt_add_property_cells(lpcm, "ibm,chip-id", gcid);
 
 	/* Setup the ranges for the MMIO LPC */
 	lpcm_end = lpcm_base + 2 * GB;
@@ -347,7 +352,7 @@ static void bmc_create_node(const struct HDIF_common_hdr *sp)
 	io_bar = be32_to_cpu(iopath->lpc.io_bar);
 	internal_bar = be32_to_cpu(iopath->lpc.internal_bar);
 
-	prlog(PR_DEBUG, "LPC: IOPATH chip id = %x\n", chip_id);
+	prlog(PR_DEBUG, "LPC: IOPATH chip id = %x\n", gcid);
 	prlog(PR_DEBUG, "LPC: FW BAR       = %#x\n", fw_bar);
 	prlog(PR_DEBUG, "LPC: MEM BAR      = %#x\n", mem_bar);
 	prlog(PR_DEBUG, "LPC: IO BAR       = %#x\n", io_bar);
-- 
2.9.3