DMA: PL330: Support MEMTOMEM transmit w/o RMB, WMB
The DMAC PL330 r1p0 version fixed the lockup error being on r0p0.
This patch supports the DMA transmission without memory barrier
operation when the revision of DMAC PL330 is the next of r0p0.
Cc: Jassi Brar <jassisinghbrar@gmail.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Boojin Kim <boojin.kim@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index dd74c24..7253d17 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -151,6 +151,11 @@
#define CRD 0xe14
#define PERIPH_ID 0xfe0
+#define PERIPH_REV_SHIFT 20
+#define PERIPH_REV_MASK 0xf
+#define PERIPH_REV_R0P0 0
+#define PERIPH_REV_R1P0 1
+#define PERIPH_REV_R1P1 2
#define PCELL_ID 0xff0
#define CR0_PERIPH_REQ_SET (1 << 0)
@@ -344,6 +349,7 @@
enum pl330_dstcachectrl dcctl;
enum pl330_srccachectrl scctl;
enum pl330_byteswap swap;
+ struct pl330_config *pcfg;
};
/*
@@ -655,6 +661,11 @@
return id;
}
+static inline u32 get_revision(u32 periph_id)
+{
+ return (periph_id >> PERIPH_REV_SHIFT) & PERIPH_REV_MASK;
+}
+
static inline u32 _emit_ADDH(unsigned dry_run, u8 buf[],
enum pl330_dst da, u16 val)
{
@@ -1241,12 +1252,21 @@
const struct _xfer_spec *pxs, int cyc)
{
int off = 0;
+ struct pl330_config *pcfg = pxs->r->cfg->pcfg;
- while (cyc--) {
- off += _emit_LD(dry_run, &buf[off], ALWAYS);
- off += _emit_RMB(dry_run, &buf[off]);
- off += _emit_ST(dry_run, &buf[off], ALWAYS);
- off += _emit_WMB(dry_run, &buf[off]);
+ /* check lock-up free version */
+ if (get_revision(pcfg->periph_id) >= PERIPH_REV_R1P0) {
+ while (cyc--) {
+ off += _emit_LD(dry_run, &buf[off], ALWAYS);
+ off += _emit_ST(dry_run, &buf[off], ALWAYS);
+ }
+ } else {
+ while (cyc--) {
+ off += _emit_LD(dry_run, &buf[off], ALWAYS);
+ off += _emit_RMB(dry_run, &buf[off]);
+ off += _emit_ST(dry_run, &buf[off], ALWAYS);
+ off += _emit_WMB(dry_run, &buf[off]);
+ }
}
return off;
@@ -2619,6 +2639,7 @@
async_tx_ack(&desc->txd);
desc->req.peri = peri_id ? pch->chan.chan_id : 0;
+ desc->rqcfg.pcfg = &pch->dmac->pif.pcfg;
dma_async_tx_descriptor_init(&desc->txd, &pch->chan);