FSL DDR: Provide a generic set_ddr_laws()

Provide a helper function that will setup the last available
LAWs (upto 2) for DDR.  Useful for SPD/dyanmic DDR setting code.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

diff --git a/drivers/misc/fsl_law.c b/drivers/misc/fsl_law.c
index 48ece4f..e4e5c31 100644 (file)
--- a/drivers/misc/fsl_law.c
+++ b/drivers/misc/fsl_law.c
@@ -121,6 +121,45 @@ void print_laws(void)
        return;
 }
 
+/* use up to 2 LAWs for DDR, used the last available LAWs */
+int set_ddr_laws(u64 start, u64 sz, enum law_trgt_if id)
+{
+       u64 start_align, law_sz;
+       int law_sz_enc;
+
+       if (start == 0)
+               start_align = 1ull << (LAW_SIZE_32G + 1);
+       else
+               start_align = 1ull << (ffs64(start) - 1);
+       law_sz = min(start_align, sz);
+       law_sz_enc = __ilog2_u64(law_sz) - 1;
+
+       if (set_last_law(start, law_sz_enc, id) < 0)
+               return -1;
+
+       /* do we still have anything to map */
+       sz = sz - law_sz;
+       if (sz) {
+               start += law_sz;
+
+               start_align = 1ull << (ffs64(start) - 1);
+               law_sz = min(start_align, sz);
+               law_sz_enc = __ilog2_u64(law_sz) - 1;
+
+               if (set_last_law(start, law_sz_enc, id) < 0)
+                       return -1;
+       } else {
+               return 0;
+       }
+
+       /* do we still have anything to map */
+       sz = sz - law_sz;
+       if (sz)
+               return 1;
+
+       return 0;
+}
+
 void init_laws(void)
 {
        int i;

diff --git a/include/asm-ppc/fsl_law.h b/include/asm-ppc/fsl_law.h
index 227bf83..5bba08d 100644 (file)
--- a/include/asm-ppc/fsl_law.h
+++ b/include/asm-ppc/fsl_law.h
@@ -75,6 +75,7 @@ struct law_entry {
 extern void set_law(u8 idx, phys_addr_t addr, enum law_size sz, enum law_trgt_if id);
 extern int set_next_law(phys_addr_t addr, enum law_size sz, enum law_trgt_if id);
 extern int set_last_law(phys_addr_t addr, enum law_size sz, enum law_trgt_if id);
+extern int set_ddr_laws(u64 start, u64 sz, enum law_trgt_if id);
 extern void disable_law(u8 idx);
 extern void init_laws(void);
 extern void print_laws(void);