Re: [PATCH v6 10/25] ppc440_sdram: Implement enable bit in the DDR2 SDRAM controller

[Daniel Henrique Barboza]

On 9/24/22 09:27, BALATON Zoltan wrote:

To allow removing the do_init hack we need to improve the DDR2 SDRAM
controller model to handle the enable/disable bit that it ignored so
far.

Signed-off-by: BALATON Zoltan <bala...@eik.bme.hu>
---

Reviewed-by: Daniel Henrique Barboza <danielhb...@gmail.com>

  hw/ppc/ppc440_uc.c | 34 ++++++++++++++++++++++++++++++++--
  1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/hw/ppc/ppc440_uc.c b/hw/ppc/ppc440_uc.c
index 900b7ab998..3fbfe4ad13 100644
--- a/hw/ppc/ppc440_uc.c
+++ b/hw/ppc/ppc440_uc.c
@@ -485,6 +485,7 @@ void ppc4xx_sdr_init(CPUPPCState *env)
  /* SDRAM controller */
  typedef struct ppc440_sdram_t {
      uint32_t addr;
+    uint32_t mcopt2;
      int nbanks;
      Ppc4xxSdramBank bank[4];
  } ppc440_sdram_t;
@@ -600,7 +601,7 @@ static void sdram_map_bcr(ppc440_sdram_t *sdram)
      int i;

for (i = 0; i < sdram->nbanks; i++) {

-        if (sdram->bank[i].size != 0) {
+        if (sdram->bank[i].size) {
              sdram_set_bcr(sdram, i, sdram_bcr(sdram->bank[i].base,
                                                sdram->bank[i].size), 1);
          } else {
@@ -609,6 +610,17 @@ static void sdram_map_bcr(ppc440_sdram_t *sdram)
      }
  }

+static void sdram_unmap_bcr(ppc440_sdram_t *sdram)

+{
+    int i;
+
+    for (i = 0; i < sdram->nbanks; i++) {
+        if (sdram->bank[i].size) {
+            sdram_set_bcr(sdram, i, sdram->bank[i].bcr & ~1, 0);
+        }
+    }
+}
+
  static uint32_t dcr_read_sdram(void *opaque, int dcrn)
  {
      ppc440_sdram_t *sdram = opaque;
@@ -640,7 +652,7 @@ static uint32_t dcr_read_sdram(void *opaque, int dcrn)
              ret = 0x80000000;
              break;
          case 0x21: /* SDRAM_MCOPT2 */
-            ret = 0x08000000;
+            ret = sdram->mcopt2;
              break;
          case 0x40: /* SDRAM_MB0CF */
              ret = 0x00008001;
@@ -662,6 +674,8 @@ static uint32_t dcr_read_sdram(void *opaque, int dcrn)
      return ret;
  }

+#define SDRAM_DDR2_MCOPT2_DCEN BIT(27)

+
  static void dcr_write_sdram(void *opaque, int dcrn, uint32_t val)
  {
      ppc440_sdram_t *sdram = opaque;
@@ -684,6 +698,21 @@ static void dcr_write_sdram(void *opaque, int dcrn, 
uint32_t val)
          switch (sdram->addr) {
          case 0x00: /* B0CR */
              break;
+        case 0x21: /* SDRAM_MCOPT2 */
+            if (!(sdram->mcopt2 & SDRAM_DDR2_MCOPT2_DCEN) &&
+                (val & SDRAM_DDR2_MCOPT2_DCEN)) {
+                trace_ppc4xx_sdram_enable("enable");
+                /* validate all RAM mappings */
+                sdram_map_bcr(sdram);
+                sdram->mcopt2 |= SDRAM_DDR2_MCOPT2_DCEN;
+            } else if ((sdram->mcopt2 & SDRAM_DDR2_MCOPT2_DCEN) &&
+                       !(val & SDRAM_DDR2_MCOPT2_DCEN)) {
+                trace_ppc4xx_sdram_enable("disable");
+                /* invalidate all RAM mappings */
+                sdram_unmap_bcr(sdram);
+                sdram->mcopt2 &= ~SDRAM_DDR2_MCOPT2_DCEN;
+            }
+            break;
          default:
              break;
          }
@@ -698,6 +727,7 @@ static void sdram_reset(void *opaque)
      ppc440_sdram_t *sdram = opaque;

sdram->addr = 0;

+    sdram->mcopt2 = SDRAM_DDR2_MCOPT2_DCEN;
  }

void ppc440_sdram_init(CPUPPCState *env, int nbanks,