[PATCH][next: 3.16] MIPS: BCM47XX: Slightly clean memory detection

[PATCH][next: 3.16] MIPS: BCM47XX: Slightly clean memory detection

[Rafał Miłecki]

Patch was tested on devices with 64 MiB and 256 MiB of RAM.
It documents every part nicely and drops this hacky part of code:
max = off | ((128 << 20) - 1);

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
---
 arch/mips/bcm47xx/prom.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/arch/mips/bcm47xx/prom.c b/arch/mips/bcm47xx/prom.c
index 0af808d..1a03a2f 100644
--- a/arch/mips/bcm47xx/prom.c
+++ b/arch/mips/bcm47xx/prom.c
@@ -69,15 +69,18 @@ static __init void prom_init_mem(void)
 	 * BCM47XX uses 128MB for addressing the ram, if the system contains
 	 * less that that amount of ram it remaps the ram more often into the
 	 * available space.
-	 * Accessing memory after 128MB will cause an exception.
-	 * max contains the biggest possible address supported by the platform.
-	 * If the method wants to try something above we assume 128MB ram.
 	 */
-	off = (unsigned long)prom_init;
-	max = off | ((128 << 20) - 1);
-	for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
-		if ((off + mem) > max) {
-			mem = (128 << 20);
+
+	/* Physical address, without mapping to any kernel segment */
+	off = CPHYSADDR((unsigned long)prom_init);
+
+	/* Accessing memory after 128 MiB will cause an exception */
+	max = 128 << 20;
+
+	for (mem = 1 << 20; mem < max; mem += 1 << 20) {
+		/* Loop condition may be not enough, off may be over 1 MiB */
+		if (off + mem >= max) {
+			mem = max;
 			printk(KERN_DEBUG "assume 128MB RAM\n");
 			break;
 		}
-- 
1.8.4.5

Re: [PATCH][next: 3.16] MIPS: BCM47XX: Slightly clean memory detection

[Rafał Miłecki]

On 19 April 2014 12:49, Rafał Miłecki <zajec5@gmail.com> wrote:
> Patch was tested on devices with 64 MiB and 256 MiB of RAM.
> It documents every part nicely and drops this hacky part of code:
> max = off | ((128 << 20) - 1);

I can't see this patch in any git tree. Am I missing some, or was this
patch forgotten?

Re: [PATCH][next: 3.16] MIPS: BCM47XX: Slightly clean memory detection

[Ralf Baechle]

On Fri, May 30, 2014 at 10:45:41AM +0200, Rafał Miłecki wrote:

> On 19 April 2014 12:49, Rafał Miłecki <zajec5@gmail.com> wrote:
> > Patch was tested on devices with 64 MiB and 256 MiB of RAM.
> > It documents every part nicely and drops this hacky part of code:
> > max = off | ((128 << 20) - 1);
> 
> I can't see this patch in any git tree. Am I missing some, or was this
> patch forgotten?

Nope - if it's in patchwork it's not forgotten.  Just slightly burried.
Really, patchwork is the ledger.  If a patch is there, don't resend or
I will hate you ;-)  If it's not there but should be, enquire.  If it's
marked "Accepted" but doesn't show up anywhere - enquire.

  Ralf