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authorTokunori Ikegami <ikegami@allied-telesis.co.jp>2018-06-03 23:02:01 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-03 11:21:30 +0200
commit256acf2c0a5e46d0c2a0fd43e3d97a1f99c5af6e (patch)
treed5c6c85633ab3a8c274f3e5b1322377346634a46 /arch
parent976c3f4c0e7c16c555e3d215c56c714e8413d614 (diff)
MIPS: BCM47XX: Enable 74K Core ExternalSync for PCIe erratum
commit 2a027b47dba6b77ab8c8e47b589ae9bbc5ac6175 upstream. The erratum and workaround are described by BCM5300X-ES300-RDS.pdf as below. R10: PCIe Transactions Periodically Fail Description: The BCM5300X PCIe does not maintain transaction ordering. This may cause PCIe transaction failure. Fix Comment: Add a dummy PCIe configuration read after a PCIe configuration write to ensure PCIe configuration access ordering. Set ES bit of CP0 configu7 register to enable sync function so that the sync instruction is functional. Resolution: hndpci.c: extpci_write_config() hndmips.c: si_mips_init() mipsinc.h CONF7_ES This is fixed by the CFE MIPS bcmsi chipset driver also for BCM47XX. Also the dummy PCIe configuration read is already implemented in the Linux BCMA driver. Enable ExternalSync in Config7 when CONFIG_BCMA_DRIVER_PCI_HOSTMODE=y too so that the sync instruction is externalised. Signed-off-by: Tokunori Ikegami <ikegami@allied-telesis.co.jp> Reviewed-by: Paul Burton <paul.burton@mips.com> Acked-by: Hauke Mehrtens <hauke@hauke-m.de> Cc: Chris Packham <chris.packham@alliedtelesis.co.nz> Cc: Rafał Miłecki <zajec5@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/19461/ Signed-off-by: James Hogan <jhogan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/bcm47xx/setup.c6
-rw-r--r--arch/mips/include/asm/mipsregs.h3
2 files changed, 9 insertions, 0 deletions
diff --git a/arch/mips/bcm47xx/setup.c b/arch/mips/bcm47xx/setup.c
index 6d38948f0f1e..4ca33175ec05 100644
--- a/arch/mips/bcm47xx/setup.c
+++ b/arch/mips/bcm47xx/setup.c
@@ -249,6 +249,12 @@ static int __init bcm47xx_cpu_fixes(void)
*/
if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
cpu_wait = NULL;
+
+ /*
+ * BCM47XX Erratum "R10: PCIe Transactions Periodically Fail"
+ * Enable ExternalSync for sync instruction to take effect
+ */
+ set_c0_config7(MIPS_CONF7_ES);
break;
#endif
}
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index e43aca183c99..15c183ce9d4f 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -605,6 +605,8 @@
#define MIPS_CONF7_WII (_ULCAST_(1) << 31)
#define MIPS_CONF7_RPS (_ULCAST_(1) << 2)
+/* ExternalSync */
+#define MIPS_CONF7_ES (_ULCAST_(1) << 8)
#define MIPS_CONF7_IAR (_ULCAST_(1) << 10)
#define MIPS_CONF7_AR (_ULCAST_(1) << 16)
@@ -2012,6 +2014,7 @@ __BUILD_SET_C0(status)
__BUILD_SET_C0(cause)
__BUILD_SET_C0(config)
__BUILD_SET_C0(config5)
+__BUILD_SET_C0(config7)
__BUILD_SET_C0(intcontrol)
__BUILD_SET_C0(intctl)
__BUILD_SET_C0(srsmap)