[Skiboot] [PATCH V3 01/21] hw: Move lpc firmware space helpers

Christophe Lombard clombard at linux.vnet.ibm.com
Sat Mar 19 01:35:59 AEDT 2022


Add new lpc helpers for doing a bulk io to firmware space.

Signed-off-by: Christophe Lombard <clombard at linux.vnet.ibm.com>
---
 hw/lpc.c      | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++
 include/lpc.h |  6 +++++
 2 files changed, 80 insertions(+)

diff --git a/hw/lpc.c b/hw/lpc.c
index bf3ab1fa..caaacc46 100644
--- a/hw/lpc.c
+++ b/hw/lpc.c
@@ -667,6 +667,80 @@ int64_t lpc_probe_read(enum OpalLPCAddressType addr_type, uint32_t addr,
 	return __lpc_read_sanity(addr_type, addr, data, sz, true);
 }
 
+int64_t lpc_fw_read(uint32_t off, void *buf, uint32_t len)
+{
+	int rc;
+
+	prlog(PR_TRACE, "Reading 0x%08x bytes at FW offset 0x%08x\n",
+	      len, off);
+
+	while (len) {
+		uint32_t chunk;
+		uint32_t dat;
+
+		/* XXX: make this read until it's aligned */
+		if (len > 3 && !(off & 3)) {
+			rc = lpc_read(OPAL_LPC_FW, off, &dat, 4);
+			if (!rc) {
+				/*
+				 * lpc_read swaps to CPU endian but it's not
+				 * really a 32-bit value, so convert back.
+				 */
+				*(__be32 *)buf = cpu_to_be32(dat);
+			}
+			chunk = 4;
+		} else {
+			rc = lpc_read(OPAL_LPC_FW, off, &dat, 1);
+			if (!rc)
+				*(uint8_t *)buf = dat;
+			chunk = 1;
+		}
+		if (rc) {
+			prlog(PR_ERR, "lpc_read failure %d to FW 0x%08x\n", rc, off);
+			return rc;
+		}
+		len -= chunk;
+		off += chunk;
+		buf += chunk;
+	}
+
+	return 0;
+}
+
+int64_t lpc_fw_write(uint32_t off, const void *buf, uint32_t len)
+{
+	int rc;
+
+	prlog(PR_TRACE, "Writing 0x%08x bytes at FW offset 0x%08x\n",
+	      len, off);
+
+	while (len) {
+		uint32_t chunk;
+
+		if (len > 3 && !(off & 3)) {
+			/* endian swap: see lpc_window_write */
+			uint32_t dat = be32_to_cpu(*(__be32 *)buf);
+
+			rc = lpc_write(OPAL_LPC_FW, off, dat, 4);
+			chunk = 4;
+		} else {
+			uint8_t dat = *(uint8_t *)buf;
+
+			rc = lpc_write(OPAL_LPC_FW, off, dat, 1);
+			chunk = 1;
+		}
+		if (rc) {
+			prlog(PR_ERR, "lpc_write failure %d to FW 0x%08x\n", rc, off);
+			return rc;
+		}
+		len -= chunk;
+		off += chunk;
+		buf += chunk;
+	}
+
+	return 0;
+}
+
 /*
  * The "OPAL" variant add the emulation of 2 and 4 byte accesses using
  * byte accesses for IO and MEM space in order to be compatible with
diff --git a/include/lpc.h b/include/lpc.h
index b641aa4e..ce9c33dc 100644
--- a/include/lpc.h
+++ b/include/lpc.h
@@ -102,6 +102,12 @@ extern int64_t lpc_probe_write(enum OpalLPCAddressType addr_type, uint32_t addr,
 extern int64_t lpc_probe_read(enum OpalLPCAddressType addr_type, uint32_t addr,
 			      uint32_t *data, uint32_t sz);
 
+/*
+ * helpers for doing a bulk io to firmware space.
+ */
+extern int64_t lpc_fw_read(uint32_t addr, void *buf, uint32_t sz);
+extern int64_t lpc_fw_write(uint32_t addr, const void *buf, uint32_t sz);
+
 /* Mark LPC bus as used by console */
 extern void lpc_used_by_console(void);
 
-- 
2.35.1



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