[PATCH 0/6] ARM: OMAP3: Convert OMAP3 PM code to use generic sram driver

[PATCH 0/6] ARM: OMAP3: Convert OMAP3 PM code to use generic sram driver

[Dave Gerlach]

Hi,
This series adds support for OMAP3 platforms to use the generic SRAM driver
at drivers/misc/sram.c. It depends on the patches sent here [1], which were
sent as an RFC so if that series does not get accepted we will need to find
a different method of marking SRAM region as executable so this series will
need to change slightly.

The idea of this series is to add the ocmcram nodes to the DT files before
converting the pm34xx to use the genalloc API allocate space for the
sleep34xx.S code so that we do not break PM. After we do the conversion
we can drop the legacy mach-omap2 SRAM code for OMAP3 as we no longer will
have any dependency on it.

Tested suspend and off-mode on omap3-beaglexm and omap3-n900, cpuidle works
fine as well.

Regards,
Dave

[1] http://lkml.iu.edu/hypermail/linux/kernel/1605.1/01069.html

Dave Gerlach (6):
  Documentation: sram: ti: Add TI SRAM bindings
  ARM: dts: omap3: Add ocmcram node
  ARM: dts: omap3-n900: Add secure reserved region to ocmcram node
  ARM: OMAP2+: pm34xx: Convert to use generic sram driver for idle code
  ARM: OMAP2+: Remove legacy sram init code for omap3 platforms
  ARM: OMAP2+: sram: remove legacy OMAP3 code

 Documentation/devicetree/bindings/sram/ti-sram.txt | 47 +++++++++++
 arch/arm/boot/dts/omap3-n900.dts                   |  7 ++
 arch/arm/boot/dts/omap3.dtsi                       | 11 +++
 arch/arm/mach-omap2/pdata-quirks.c                 |  3 +-
 arch/arm/mach-omap2/pm34xx.c                       | 98 ++++++++++++++++++----
 arch/arm/mach-omap2/sram.c                         | 23 -----
 6 files changed, 147 insertions(+), 42 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/sram/ti-sram.txt

-- 
2.7.3

[PATCH 1/6] Documentation: sram: ti: Add TI SRAM bindings

[Dave Gerlach]

Add binding document for TI use of mmio-sram driver for purposes like
mapping the region as executable or reserving space needed by secure
silicon.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 Documentation/devicetree/bindings/sram/ti-sram.txt | 47 ++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sram/ti-sram.txt

diff --git a/Documentation/devicetree/bindings/sram/ti-sram.txt b/Documentation/devicetree/bindings/sram/ti-sram.txt
new file mode 100644
index 000000000000..68c4b733c78c
--- /dev/null
+++ b/Documentation/devicetree/bindings/sram/ti-sram.txt
@@ -0,0 +1,47 @@
+TI SRAM Node:
+-------------
+
+Many TI SoC's rely on SRAM for running low-level PM code as part of the
+suspend or cpuidle path. Because of this, regions in sram must be mapped
+as "memory-exec" or "memory-exec-nocache" in order for the region to be
+executable.
+
+Optional sub-node
+-----------------
+Some TI SoCs have secure variants that require a certain portion of
+the SRAM to be reserved for use by secure software. This can be
+marked in the parent SRAM node with a subnode as described in
+Documentation/devicetree/bindings/sram/sram.txt. This node can be
+added in two ways:
+
+- From board dts files for secure platforms to avoid adding it
+  for all SoC variants with a fixed size defined.
+- As a dummy node in the .dtsi sram node with any size that will be
+  modified by a bootloader to the correct size needed.
+
+Sub-node properties:
+- compatible : should be "ti,secure-sram"
+
+The rest of the properties should follow the generic mmio-sram discription
+found in Documentation/devicetree/bindings/sram/sram.txt
+
+Example:
+	/* In parent SoC .dtsi */
+	ocmcram: ocmcram at 40200000 {
+		compatible = "mmio-sram";
+		reg = <0x40200000 0x10000>; /* 64k */
+		memory-exec-nocache;
+		ranges = <0x0 0x40200000 0x10000>;
+
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+	};
+
+	/* In board .dts where secure silicon is present */
+	&ocmcram {
+		sram-hs at 0 {
+			compatible = "ti,secure-ram";
+			reg = <0x0 0xC000>;
+		};
+	};
-- 
2.7.3

[PATCH 2/6] ARM: dts: omap3: Add ocmcram node

[Dave Gerlach]

Add an ocmcram node to omap3 dtsi using the mmio-sram driver to
represent the 64kb of SRAM available on omap3 and it's derivatives.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 arch/arm/boot/dts/omap3.dtsi | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm/boot/dts/omap3.dtsi b/arch/arm/boot/dts/omap3.dtsi
index b41d07e8e765..a267616c3c68 100644
--- a/arch/arm/boot/dts/omap3.dtsi
+++ b/arch/arm/boot/dts/omap3.dtsi
@@ -59,6 +59,7 @@
 		mpu {
 			compatible = "ti,omap3-mpu";
 			ti,hwmods = "mpu";
+			sram = <&ocmcram>;
 		};
 
 		iva: iva {
@@ -153,6 +154,16 @@
 			};
 		};
 
+		ocmcram: ocmcram at 40200000 {
+			compatible = "mmio-sram";
+			reg = <0x40200000 0x10000>; /* 64k */
+			memory-exec-nocache;
+			ranges = <0x0 0x40200000 0x10000>;
+
+			#address-cells = <1>;
+			#size-cells = <1>;
+		};
+
 		aes: aes at 480c5000 {
 			compatible = "ti,omap3-aes";
 			ti,hwmods = "aes";
-- 
2.7.3

[PATCH 3/6] ARM: dts: omap3-n900: Add secure reserved region to ocmcram node

[Dave Gerlach]

Platforms with secure silicon, like omap3-n900, need to mark off a
section of the ocmcram as reserved because it is used by secure
software.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 arch/arm/boot/dts/omap3-n900.dts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/omap3-n900.dts b/arch/arm/boot/dts/omap3-n900.dts
index b3c26a96a726..448452a76c23 100644
--- a/arch/arm/boot/dts/omap3-n900.dts
+++ b/arch/arm/boot/dts/omap3-n900.dts
@@ -1004,3 +1004,10 @@
 &ssi_port2 {
 	status = "disabled";
 };
+
+&ocmcram {
+	sram-hs at 0 {
+		compatible = "ti,secure-ram";
+		reg = <0x0 0xC000>;
+	};
+};
-- 
2.7.3

[PATCH 4/6] ARM: OMAP2+: pm34xx: Convert to use generic sram driver for idle code

[Dave Gerlach]

Change to use the generic SRAM driver and genalloc framework to allocate
SRAM space for low-level ASM PM code instead of omap specific SRAM
allocator.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 arch/arm/mach-omap2/pm34xx.c | 82 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 81 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index d44e0e2f1106..5ebbf5c30c6e 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -24,17 +24,21 @@
 #include <linux/module.h>
 #include <linux/list.h>
 #include <linux/err.h>
+#include <linux/genalloc.h>
 #include <linux/gpio.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 #include <linux/omap-dma.h>
 #include <linux/omap-gpmc.h>
 #include <linux/platform_data/gpio-omap.h>
+#include <linux/sizes.h>
 
 #include <trace/events/power.h>
 
 #include <asm/fncpy.h>
+#include <asm/proc-fns.h>
 #include <asm/suspend.h>
 #include <asm/system_misc.h>
 
@@ -68,6 +72,9 @@ static LIST_HEAD(pwrst_list);
 
 static int (*_omap_save_secure_sram)(u32 *addr);
 void (*omap3_do_wfi_sram)(void);
+static struct gen_pool *sram_pool;
+static phys_addr_t ocmcram_location;
+static phys_addr_t secure_ocmcram_location;
 
 static struct powerdomain *mpu_pwrdm, *neon_pwrdm;
 static struct powerdomain *core_pwrdm, *per_pwrdm;
@@ -179,6 +186,71 @@ static void omap34xx_save_context(u32 *save)
 	*save++ = val;
 }
 
+/*
+ * Push functions to SRAM
+ *
+ * The minimum set of functions is pushed to SRAM for execution:
+ * - omap3_do_wfi for erratum i581 WA,
+ * - save_secure_ram_context for security extensions.
+ */
+static int omap3_prepare_push_sram_idle(void)
+{
+	struct device_node *np;
+
+	np = of_find_compatible_node(NULL, NULL, "ti,omap3-mpu");
+	if (!np) {
+		pr_warn("PM: %s: Unable to find device node for mpu\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	sram_pool = of_gen_pool_get(np, "sram", 0);
+
+	if (!sram_pool) {
+		pr_warn("PM: %s: Unable to get sram pool for ocmcram\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	ocmcram_location = gen_pool_alloc(sram_pool, omap3_do_wfi_sz);
+	if (!ocmcram_location) {
+		pr_warn("PM: %s: Unable to allocate memory from ocmcram for omap3_do_wfi_sz.\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	if (omap_type() != OMAP2_DEVICE_TYPE_GP) {
+		secure_ocmcram_location =
+				gen_pool_alloc(sram_pool,
+					       save_secure_ram_context_sz);
+		if (!secure_ocmcram_location) {
+			pr_warn("PM: %s: Unable to allocate memory from ocmcram for save_secure_ram_context.\n",
+				__func__);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int omap3_push_sram_idle(void)
+{
+	omap3_do_wfi_sram = fncpy((void *)ocmcram_location,
+				  &omap3_do_wfi,
+				  omap3_do_wfi_sz);
+
+	return 0;
+}
+
+static int omap3_push_sram_secure_idle(void)
+{
+	if (omap_type() != OMAP2_DEVICE_TYPE_GP)
+		_omap_save_secure_sram = fncpy((void *)secure_ocmcram_location,
+					       &save_secure_ram_context,
+					       save_secure_ram_context_sz);
+	return 0;
+}
+
 static int omap34xx_do_sram_idle(unsigned long save_state)
 {
 	omap34xx_cpu_suspend(save_state);
@@ -281,7 +353,8 @@ void omap_sram_idle(void)
 	    pwrdm_read_prev_pwrst(core_pwrdm) == PWRDM_POWER_OFF) {
 		omap3_core_restore_context();
 		omap3_cm_restore_context();
-		omap3_sram_restore_context();
+		omap3_push_sram_idle();
+		omap3_push_sram_secure_idle();
 		omap2_sms_restore_context();
 	} else {
 		/*
@@ -517,6 +590,13 @@ int __init omap3_pm_init(void)
 	per_clkdm = clkdm_lookup("per_clkdm");
 	wkup_clkdm = clkdm_lookup("wkup_clkdm");
 
+	ret = omap3_prepare_push_sram_idle();
+	if (ret)
+		goto err3;
+
+	omap3_push_sram_idle();
+	omap3_push_sram_secure_idle();
+
 	omap_common_suspend_init(omap3_pm_suspend);
 
 	arm_pm_idle = omap3_pm_idle;
-- 
2.7.3

[PATCH 5/6] ARM: OMAP2+: Remove legacy sram init code for omap3 platforms

[Dave Gerlach]

Remove omap3 platforms from using legacy sram init code in mach-omap2 as
the platforms will now use the generic mmio-sram driver like other omap
platforms already do.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 arch/arm/mach-omap2/pdata-quirks.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm/mach-omap2/pdata-quirks.c b/arch/arm/mach-omap2/pdata-quirks.c
index a935d28443da..1a5b8afdb2e3 100644
--- a/arch/arm/mach-omap2/pdata-quirks.c
+++ b/arch/arm/mach-omap2/pdata-quirks.c
@@ -579,8 +579,7 @@ void __init pdata_quirks_init(const struct of_device_id *omap_dt_match_table)
 	 * We still need this for omap2420 and omap3 PM to work, others are
 	 * using drivers/misc/sram.c already.
 	 */
-	if (of_machine_is_compatible("ti,omap2420") ||
-	    of_machine_is_compatible("ti,omap3"))
+	if (of_machine_is_compatible("ti,omap2420"))
 		omap_sdrc_init(NULL, NULL);
 
 	pdata_quirks_check(auxdata_quirks);
-- 
2.7.3

[PATCH 6/6] ARM: OMAP2+: sram: remove legacy OMAP3 code

[Dave Gerlach]

Now that we have converted OMAP3 PM code to use generic sram driver we
no longer need to provide OMAP3 specific SRAM code for the omap SRAM
API.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 arch/arm/mach-omap2/pm34xx.c | 16 ----------------
 arch/arm/mach-omap2/sram.c   | 23 -----------------------
 2 files changed, 39 deletions(-)

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 5ebbf5c30c6e..22d4c8742f99 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -502,22 +502,6 @@ static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
 	return omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
 }
 
-/*
- * Push functions to SRAM
- *
- * The minimum set of functions is pushed to SRAM for execution:
- * - omap3_do_wfi for erratum i581 WA,
- * - save_secure_ram_context for security extensions.
- */
-void omap_push_sram_idle(void)
-{
-	omap3_do_wfi_sram = omap_sram_push(omap3_do_wfi, omap3_do_wfi_sz);
-
-	if (omap_type() != OMAP2_DEVICE_TYPE_GP)
-		_omap_save_secure_sram = omap_sram_push(save_secure_ram_context,
-				save_secure_ram_context_sz);
-}
-
 static void __init pm_errata_configure(void)
 {
 	if (cpu_is_omap3630()) {
diff --git a/arch/arm/mach-omap2/sram.c b/arch/arm/mach-omap2/sram.c
index 83d0e61f49e6..7881304b5205 100644
--- a/arch/arm/mach-omap2/sram.c
+++ b/arch/arm/mach-omap2/sram.c
@@ -209,27 +209,6 @@ static inline int omap243x_sram_init(void)
 }
 #endif
 
-#ifdef CONFIG_ARCH_OMAP3
-
-void omap3_sram_restore_context(void)
-{
-	omap_sram_reset();
-
-	omap_push_sram_idle();
-}
-
-static inline int omap34xx_sram_init(void)
-{
-	omap3_sram_restore_context();
-	return 0;
-}
-#else
-static inline int omap34xx_sram_init(void)
-{
-	return 0;
-}
-#endif /* CONFIG_ARCH_OMAP3 */
-
 int __init omap_sram_init(void)
 {
 	omap_detect_sram();
@@ -239,8 +218,6 @@ int __init omap_sram_init(void)
 		omap242x_sram_init();
 	else if (cpu_is_omap2430())
 		omap243x_sram_init();
-	else if (cpu_is_omap34xx())
-		omap34xx_sram_init();
 
 	return 0;
 }
-- 
2.7.3