[Skiboot] [PATCH 2/2] hdat: Parse BMC nodes much earlier

[Oliver O'Halloran]

This moves the parsing of the BMC and LPC details to the start of the
HDAT parsing. This allows us to enable the Skiboot log console earlier
so we can get debug output while parsing the rest of the HDAT.

Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
Acked-by: Michael Neuling <mikey at neuling.org>
---
 hdata/fsp.c        | 28 +++++++++++++++++++++++++++-
 hdata/hdata.h      |  1 +
 hdata/spira.c      |  7 +++++--
 hdata/test/stubs.c |  1 +
 hw/lpc-uart.c      | 34 ++++++++++++++++++++++++++++++++++
 include/skiboot.h  |  1 +
 6 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/hdata/fsp.c b/hdata/fsp.c
index f44f6a9a9054..c427eb518ef4 100644
--- a/hdata/fsp.c
+++ b/hdata/fsp.c
@@ -385,6 +385,32 @@ static void bmc_create_node(const struct HDIF_common_hdr *sp)
 	);
 }
 
+/*
+ * Search for and instanciate BMC nodes. This is mostly the same as fsp_parse()
+ * below, but it can be called earlier since BMCs don't depend on the psihb
+ * nodes being added.
+ */
+void bmc_parse(void)
+{
+	bool found = false;
+	const void *sp;
+	int i;
+
+	sp = get_hdif(&spira.ntuples.sp_subsys, SPSS_HDIF_SIG);
+	if (!sp)
+		return;
+
+	for_each_ntuple_idx(&spira.ntuples.sp_subsys, sp, i, SPSS_HDIF_SIG) {
+		if (find_service_proc_type(sp, i) == SP_BMC) {
+			bmc_create_node(sp);
+			found = true;
+		}
+	}
+
+	if (found)
+		early_uart_init();
+}
+
 void fsp_parse(void)
 {
 	struct dt_node *fsp_root = NULL, *fsp_node;
@@ -418,7 +444,7 @@ void fsp_parse(void)
 			break;
 
 		case SP_BMC:
-			bmc_create_node(sp);
+			/* Handled above */
 			break;
 
 		case SP_BAD:
diff --git a/hdata/hdata.h b/hdata/hdata.h
index 1d0da1e9992e..53927a3acc5b 100644
--- a/hdata/hdata.h
+++ b/hdata/hdata.h
@@ -23,6 +23,7 @@ extern void memory_parse(void);
 extern int paca_parse(void);
 extern bool pcia_parse(void);
 extern void fsp_parse(void);
+extern void bmc_parse(void);
 extern void io_parse(void);
 extern struct dt_node *dt_add_vpd_node(const struct HDIF_common_hdr *hdr,
 				       int indx_fru, int indx_vpd);
diff --git a/hdata/spira.c b/hdata/spira.c
index 4ebbc43ee2aa..512784f105aa 100644
--- a/hdata/spira.c
+++ b/hdata/spira.c
@@ -1230,6 +1230,9 @@ int parse_hdat(bool is_opal)
 	dt_add_property_cells(dt_root, "#size-cells", 2);
 	dt_add_property_string(dt_root, "lid-type", is_opal ? "opal" : "phyp");
 
+	/* Add any BMCs and enable the LPC UART */
+	bmc_parse();
+
 	/* Create /vpd node */
 	dt_init_vpd_node();
 
@@ -1247,10 +1250,10 @@ int parse_hdat(bool is_opal)
 	/* Parse MS VPD */
 	memory_parse();
 
-	/* Add XSCOM node (must be before chiptod & IO ) */
+	/* Add XSCOM node (must be before chiptod, IO and FSP) */
 	add_xscom();
 
-	/* Add FSP */
+	/* Add any FSPs */
 	fsp_parse();
 
 	/* Add ChipTOD's */
diff --git a/hdata/test/stubs.c b/hdata/test/stubs.c
index bea433c2693f..f513aacbf5fe 100644
--- a/hdata/test/stubs.c
+++ b/hdata/test/stubs.c
@@ -100,3 +100,4 @@ STUB(fsp_preload_lid);
 STUB(fsp_wait_lid_loaded);
 STUB(fsp_adjust_lid_side);
 STUB(mem_reserve_hw);
+STUB(early_uart_init);
diff --git a/hw/lpc-uart.c b/hw/lpc-uart.c
index 9034fbd53070..6e349ef962d5 100644
--- a/hw/lpc-uart.c
+++ b/hw/lpc-uart.c
@@ -548,6 +548,37 @@ static bool uart_init_hw(unsigned int speed, unsigned int clock)
 	return false;
 }
 
+/*
+ * early_uart_init() is similar to uart_init() in that it configures skiboot
+ * console log to output via a UART. The main differences are that the early
+ * version only works with MMIO UARTs and will not setup interrupts or locks.
+ */
+void early_uart_init(void)
+{
+	struct dt_node *uart_node;
+	u32 clk, baud;
+
+	uart_node = dt_find_compatible_node(dt_root, NULL, "ns16550");
+	if (!uart_node)
+		return;
+
+	/* Try translate the address, if this fails then it's not a MMIO UART */
+	mmio_uart_base = (void *) dt_translate_address(uart_node, 0, NULL);
+	if (!mmio_uart_base)
+		return;
+
+	clk = dt_prop_get_u32(uart_node, "clock-frequency");
+	baud = dt_prop_get_u32(uart_node, "current-speed");
+
+	if (uart_init_hw(baud, clk)) {
+		set_console(&uart_con_driver);
+		prlog(PR_NOTICE, "UART: Using UART at %p\n", mmio_uart_base);
+	} else {
+		prerror("UART: Early init failed!");
+		mmio_uart_base = NULL;
+	}
+}
+
 void uart_init(void)
 {
 	const struct dt_property *prop;
@@ -555,6 +586,9 @@ void uart_init(void)
 	char *path __unused;
 	const uint32_t *irqp;
 
+	/* Clean up after early_uart_init() */
+	mmio_uart_base = NULL;
+
 	/* UART lock is in the console path and thus must block
 	 * printf re-entrancy
 	 */
diff --git a/include/skiboot.h b/include/skiboot.h
index 7904eee9e921..bb0a7b53e8f3 100644
--- a/include/skiboot.h
+++ b/include/skiboot.h
@@ -217,6 +217,7 @@ extern void phb4_preload_vpd(void);
 extern void probe_npu(void);
 extern void uart_init(void);
 extern void mbox_init(void);
+extern void early_uart_init(void);
 extern void homer_init(void);
 extern void occ_pstates_init(void);
 extern void slw_init(void);
-- 
2.9.3