[PATCH 4.14 197/217] soc: imx: gpc: restrict register range for regmap access

Greg Kroah-Hartman
2018-08-23T08:38:46Z

From: Anson Huang <Anson.Huang@nxp.com>

[ Upstream commit de2d9b5284bcb5c159c5882ac69f6bfd4dec7c67 ]

GPC registers are NOT continuous, some registers are
reserved and accessing them from userspace will trigger
external abort, add regmap register access table to
avoid below abort:

root@imx6slevk:~# cat /sys/kernel/debug/regmap/20dc000.gpc/registers
[ 108.480477] Unhandled fault: imprecise external abort (0x1406) at 0xb6db5004
[ 108.487985] pgd = 42b54bfd
[ 108.490741] [b6db5004] *pgd=ba1b7831
[ 108.494386] Internal error: : 1406 [#1] SMP ARM
[ 108.498943] Modules linked in:
[ 108.502043] CPU: 0 PID: 389 Comm: cat Not tainted 4.18.0-rc1-00074-gc9f1f60-dirty #482
[ 108.509982] Hardware name: Freescale i.MX6 SoloLite (Device Tree)
[ 108.516123] PC is at regmap_mmio_read32le+0x20/0x24
[ 108.521031] LR is at regmap_mmio_read+0x40/0x60
[ 108.525586] pc : [<c059cf74>] lr : [<c059d1ac>] psr: 20060093
[ 108.531875] sp : eccf1d98 ip : eccf1da8 fp : eccf1da4
[ 108.537122] r10: ec2d3800 r9 : eccf1f60 r8 : ecfc0000
[ 108.542370] r7 : eccf1e2c r6 : eccf1e2c r5 : 00000028 r4 : ec338e00
[ 108.548920] r3 : 00000000 r2 : eccf1e2c r1 : f0980028 r0 : 00000000
[ 108.555474] Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none
[ 108.562720] Control: 10c5387d Table: acf4004a DAC: 00000051
[ 108.568491] Process cat (pid: 389, stack limit = 0xd4318a65)
[ 108.574174] Stack: (0xeccf1d98 to 0xeccf2000)

Fixes: 721cabf6c660 ("soc: imx: move PGC handling to a new GPC driver")
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/soc/imx/gpc.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

--- a/drivers/soc/imx/gpc.c
+++ b/drivers/soc/imx/gpc.c
@@ -27,9 +27,16 @@
#define GPC_PGC_SW2ISO_SHIFT 0x8
#define GPC_PGC_SW_SHIFT 0x0

+#define GPC_PGC_PCI_PDN 0x200
+#define GPC_PGC_PCI_SR 0x20c
+
#define GPC_PGC_GPU_PDN 0x260
#define GPC_PGC_GPU_PUPSCR 0x264
#define GPC_PGC_GPU_PDNSCR 0x268
+#define GPC_PGC_GPU_SR 0x26c
+
+#define GPC_PGC_DISP_PDN 0x240
+#define GPC_PGC_DISP_SR 0x24c

#define GPU_VPU_PUP_REQ BIT(1)
#define GPU_VPU_PDN_REQ BIT(0)
@@ -303,10 +310,24 @@ static const struct of_device_id imx_gpc
{ }
};

+static const struct regmap_range yes_ranges[] = {
+ regmap_reg_range(GPC_CNTR, GPC_CNTR),
+ regmap_reg_range(GPC_PGC_PCI_PDN, GPC_PGC_PCI_SR),
+ regmap_reg_range(GPC_PGC_GPU_PDN, GPC_PGC_GPU_SR),
+ regmap_reg_range(GPC_PGC_DISP_PDN, GPC_PGC_DISP_SR),
+};
+
+static const struct regmap_access_table access_table = {
+ .yes_ranges = yes_ranges,
+ .n_yes_ranges = ARRAY_SIZE(yes_ranges),
+};
+
static const struct regmap_config imx_gpc_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
+ .rd_table = &access_table,
+ .wr_table = &access_table,
.max_register = 0x2ac,
};