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authorLinus Walleij <linus.walleij@linaro.org>2011-07-01 08:23:06 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-07-06 20:49:45 +0100
commit9715efb8dc9ffa629bf5a1215b11bf2f2f29908b (patch)
tree7c05fe2aaf27d60174a33da037fea05e1303b9e6 /arch/arm/kernel/tcm.c
parente4b6381009d740bd3a97e6b841d8efe7fc70c1b7 (diff)
ARM: 6984/1: enhance TCM robustness
The PB11MPCore reports "3" DTCM banks, but anything above 2 is an "undefined" value, so push this to become 0. Further add some checks if code is compiled to TCM even if there is no D/ITCM present in the system, and if we can really fit the compiled code. We don't do the BUG() since it's not helpful, it's better to deal with non-present TCM dynamically. If there is nothing compiled to the TCM and no TCM is detected, it will now just shut up even if TCM support is enabled. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/tcm.c')
-rw-r--r--arch/arm/kernel/tcm.c47
1 files changed, 39 insertions, 8 deletions
diff --git a/arch/arm/kernel/tcm.c b/arch/arm/kernel/tcm.c
index f5cf660eefc..d402d482952 100644
--- a/arch/arm/kernel/tcm.c
+++ b/arch/arm/kernel/tcm.c
@@ -134,6 +134,10 @@ static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
(tcm_region & 1) ? "" : "not ");
}
+ /* Not much fun you can do with a size 0 bank */
+ if (tcm_size == 0)
+ return 0;
+
/* Force move the TCM bank to where we want it, enable */
tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1;
@@ -165,12 +169,20 @@ void __init tcm_init(void)
u32 tcm_status = read_cpuid_tcmstatus();
u8 dtcm_banks = (tcm_status >> 16) & 0x03;
u8 itcm_banks = (tcm_status & 0x03);
+ size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data;
+ size_t itcm_code_sz = &__eitcm_text - &__sitcm_text;
char *start;
char *end;
char *ram;
int ret;
int i;
+ /* Values greater than 2 for D/ITCM banks are "reserved" */
+ if (dtcm_banks > 2)
+ dtcm_banks = 0;
+ if (itcm_banks > 2)
+ itcm_banks = 0;
+
/* Setup DTCM if present */
if (dtcm_banks > 0) {
for (i = 0; i < dtcm_banks; i++) {
@@ -178,6 +190,13 @@ void __init tcm_init(void)
if (ret)
return;
}
+ /* This means you compiled more code than fits into DTCM */
+ if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) {
+ pr_info("CPU DTCM: %u bytes of code compiled to "
+ "DTCM but only %lu bytes of DTCM present\n",
+ dtcm_code_sz, (dtcm_end - DTCM_OFFSET));
+ goto no_dtcm;
+ }
dtcm_res.end = dtcm_end - 1;
request_resource(&iomem_resource, &dtcm_res);
dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
@@ -186,12 +205,15 @@ void __init tcm_init(void)
start = &__sdtcm_data;
end = &__edtcm_data;
ram = &__dtcm_start;
- /* This means you compiled more code than fits into DTCM */
- BUG_ON((end - start) > (dtcm_end - DTCM_OFFSET));
- memcpy(start, ram, (end-start));
- pr_debug("CPU DTCM: copied data from %p - %p\n", start, end);
+ memcpy(start, ram, dtcm_code_sz);
+ pr_debug("CPU DTCM: copied data from %p - %p\n",
+ start, end);
+ } else if (dtcm_code_sz) {
+ pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no "
+ "DTCM banks present in CPU\n", dtcm_code_sz);
}
+no_dtcm:
/* Setup ITCM if present */
if (itcm_banks > 0) {
for (i = 0; i < itcm_banks; i++) {
@@ -199,6 +221,13 @@ void __init tcm_init(void)
if (ret)
return;
}
+ /* This means you compiled more code than fits into ITCM */
+ if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) {
+ pr_info("CPU ITCM: %u bytes of code compiled to "
+ "ITCM but only %lu bytes of ITCM present\n",
+ itcm_code_sz, (itcm_end - ITCM_OFFSET));
+ return;
+ }
itcm_res.end = itcm_end - 1;
request_resource(&iomem_resource, &itcm_res);
itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
@@ -207,10 +236,12 @@ void __init tcm_init(void)
start = &__sitcm_text;
end = &__eitcm_text;
ram = &__itcm_start;
- /* This means you compiled more code than fits into ITCM */
- BUG_ON((end - start) > (itcm_end - ITCM_OFFSET));
- memcpy(start, ram, (end-start));
- pr_debug("CPU ITCM: copied code from %p - %p\n", start, end);
+ memcpy(start, ram, itcm_code_sz);
+ pr_debug("CPU ITCM: copied code from %p - %p\n",
+ start, end);
+ } else if (itcm_code_sz) {
+ pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no "
+ "ITCM banks present in CPU\n", itcm_code_sz);
}
}