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authorDavid Daney <ddaney@caviumnetworks.com>2010-10-07 16:03:53 -0700
committerRalf Baechle <ralf@linux-mips.org>2010-10-29 19:08:43 +0100
commitc9941158fd8a539a56b0e8a4740ec1f6beb23ea3 (patch)
tree73e3868737061e1d5b0b61c182ea443e3ccd94e3 /arch/mips/cavium-octeon
parent468ffde46d429fbd291b0ef43a06afe9c837629f (diff)
MIPS: Octeon: Apply CN63XXP1 errata workarounds.
The CN63XXP1 needs a couple of workarounds to ensure memory is not written in unexpected ways. All PREF with hints in the range 0-4,6-24 are replaced with PREF 28. We pass a flag to the assembler to cover compiler generated code, and patch uasm for the dynamically generated code. The write buffer threshold is reduced to 4. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Patchwork: http://patchwork.linux-mips.org/patch/1672/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/cavium-octeon')
-rw-r--r--arch/mips/cavium-octeon/Kconfig11
-rw-r--r--arch/mips/cavium-octeon/setup.c42
2 files changed, 49 insertions, 4 deletions
diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index 475156b0c80..caae2285816 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -3,6 +3,17 @@ config CAVIUM_OCTEON_SPECIFIC_OPTIONS
depends on CPU_CAVIUM_OCTEON
default "y"
+config CAVIUM_CN63XXP1
+ bool "Enable CN63XXP1 errata worarounds"
+ depends on CAVIUM_OCTEON_SPECIFIC_OPTIONS
+ default "n"
+ help
+ The CN63XXP1 chip requires build time workarounds to
+ function reliably, select this option to enable them. These
+ workarounds will cause a slight decrease in performance on
+ non-CN63XXP1 hardware, so it is recommended to select "n"
+ unless it is known the workarounds are needed.
+
config CAVIUM_OCTEON_2ND_KERNEL
bool "Build the kernel to be used as a 2nd kernel on the same chip"
depends on CAVIUM_OCTEON_SPECIFIC_OPTIONS
diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
index c072b24f485..b0c3686c96d 100644
--- a/arch/mips/cavium-octeon/setup.c
+++ b/arch/mips/cavium-octeon/setup.c
@@ -356,8 +356,18 @@ void octeon_user_io_init(void)
cvmmemctl.s.wbfltime = 0;
/* R/W If set, do not put Istream in the L2 cache. */
cvmmemctl.s.istrnol2 = 0;
- /* R/W The write buffer threshold. */
- cvmmemctl.s.wbthresh = 10;
+
+ /*
+ * R/W The write buffer threshold. As per erratum Core-14752
+ * for CN63XX, a sc/scd might fail if the write buffer is
+ * full. Lowering WBTHRESH greatly lowers the chances of the
+ * write buffer ever being full and triggering the erratum.
+ */
+ if (OCTEON_IS_MODEL(OCTEON_CN63XX_PASS1_X))
+ cvmmemctl.s.wbthresh = 4;
+ else
+ cvmmemctl.s.wbthresh = 10;
+
/* R/W If set, CVMSEG is available for loads/stores in
* kernel/debug mode. */
#if CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0
@@ -375,14 +385,13 @@ void octeon_user_io_init(void)
* is max legal value. */
cvmmemctl.s.lmemsz = CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE;
+ write_c0_cvmmemctl(cvmmemctl.u64);
if (smp_processor_id() == 0)
pr_notice("CVMSEG size: %d cache lines (%d bytes)\n",
CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE,
CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE * 128);
- write_c0_cvmmemctl(cvmmemctl.u64);
-
/* Move the performance counter interrupts to IRQ 6 */
cvmctl = read_c0_cvmctl();
cvmctl &= ~(7 << 7);
@@ -758,6 +767,31 @@ EXPORT_SYMBOL(prom_putchar);
void prom_free_prom_memory(void)
{
+ if (OCTEON_IS_MODEL(OCTEON_CN63XX_PASS1_X)) {
+ /* Check for presence of Core-14449 fix. */
+ u32 insn;
+ u32 *foo;
+
+ foo = &insn;
+
+ asm volatile("# before" : : : "memory");
+ prefetch(foo);
+ asm volatile(
+ ".set push\n\t"
+ ".set noreorder\n\t"
+ "bal 1f\n\t"
+ "nop\n"
+ "1:\tlw %0,-12($31)\n\t"
+ ".set pop\n\t"
+ : "=r" (insn) : : "$31", "memory");
+
+ if ((insn >> 26) != 0x33)
+ panic("No PREF instruction at Core-14449 probe point.\n");
+
+ if (((insn >> 16) & 0x1f) != 28)
+ panic("Core-14449 WAR not in place (%04x).\n"
+ "Please build kernel with proper options (CONFIG_CAVIUM_CN63XXP1).\n", insn);
+ }
#ifdef CONFIG_CAVIUM_DECODE_RSL
cvmx_interrupt_rsl_enable();