[PATCH 1/8] msm: scm: Fix incorrect cache invalidation

[Stephen Boyd]

The cache invalidation in scm_call() correctly rounds down the
start address to invalidate the beginning of the cacheline but
doesn't properly round up the 'end' address to make it aligned.
The last chunk of the buffer won't be invalidated when 'end' is
not cacheline size aligned so make sure to invalidate the last
few bytes in such situations. It also doesn't do anything about
outer caches so make sure to invalidate and flush those as well.

Signed-off-by: Stephen Boyd <sboyd at codeaurora.org>
---
 arch/arm/mach-qcom/scm.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-qcom/scm.c b/arch/arm/mach-qcom/scm.c
index c536fd6bf827..820c72165e19 100644
--- a/arch/arm/mach-qcom/scm.c
+++ b/arch/arm/mach-qcom/scm.c
@@ -22,6 +22,7 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 
+#include <asm/outercache.h>
 #include <asm/cacheflush.h>
 
 #include "scm.h"
@@ -203,6 +204,7 @@ static int __scm_call(const struct scm_command *cmd)
 	 * side in the buffer.
 	 */
 	flush_cache_all();
+	outer_flush_all();
 	ret = smc(cmd_addr);
 	if (ret < 0)
 		ret = scm_remap_error(ret);
@@ -210,6 +212,20 @@ static int __scm_call(const struct scm_command *cmd)
 	return ret;
 }
 
+static void scm_inv_range(unsigned long start, unsigned long end)
+{
+	start = round_down(start, CACHELINESIZE);
+	end = round_up(end, CACHELINESIZE);
+	outer_inv_range(start, end);
+	while (start < end) {
+		asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
+		     : "memory");
+		start += CACHELINESIZE;
+	}
+	dsb();
+	isb();
+}
+
 /**
  * scm_call() - Send an SCM command
  * @svc_id: service identifier
@@ -227,6 +243,7 @@ int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_len,
 	int ret;
 	struct scm_command *cmd;
 	struct scm_response *rsp;
+	unsigned long start, end;
 
 	cmd = alloc_scm_command(cmd_len, resp_len);
 	if (!cmd)
@@ -243,17 +260,15 @@ int scm_call(u32 svc_id, u32 cmd_id, const void *cmd_buf, size_t cmd_len,
 		goto out;
 
 	rsp = scm_command_to_response(cmd);
+	start = (unsigned long)rsp;
+
 	do {
-		u32 start = (u32)rsp;
-		u32 end = (u32)scm_get_response_buffer(rsp) + resp_len;
-		start &= ~(CACHELINESIZE - 1);
-		while (start < end) {
-			asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
-			     : "memory");
-			start += CACHELINESIZE;
-		}
+		scm_inv_range(start, start + sizeof(*rsp));
 	} while (!rsp->is_complete);
 
+	end = (unsigned long)scm_get_response_buffer(rsp) + resp_len;
+	scm_inv_range(start, end);
+
 	if (resp_buf)
 		memcpy(resp_buf, scm_get_response_buffer(rsp), resp_len);
 out:
-- 
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