Commit fd967956 authored by Andres Salomon's avatar Andres Salomon Committed by Linus Torvalds
Browse files

gxfb/lxfb: detect framebuffer size using an MSR if VSA2 isn't available 



If there's no VSA2 (ie, if we're using tinybios or OpenFirmware), use the
GLIU's P2D Range Offset Descriptor to determine how much memory we have
available for the framebuffer.

Originally based on a patch by Jordan Crouse.  Tested with OpenFirmware;
Pascal informs me that tinybios has a stub that fills in P2D_RO0.

Signed-off-by: default avatarAndres Salomon <dilinger@debian.org>
Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 61a517a0

drivers/video/geode/display_gx.c

+17 −1
Original line number Diff line number Diff line
@@ -25,7 +25,23 @@ unsigned int gx_frame_buffer_size(void) 
{

	unsigned int val;



	/* FB size is reported by a virtual register */

	if (!geode_has_vsa2()) {

		uint32_t hi, lo;



		/* The number of pages is (PMAX - PMIN)+1 */

		rdmsr(MSR_GLIU_P2D_RO0, lo, hi);



		/* PMAX */

		val = ((hi & 0xff) << 12) | ((lo & 0xfff00000) >> 20);

		/* PMIN */

		val -= (lo & 0x000fffff);

		val += 1;



		/* The page size is 4k */

		return (val << 12);

	}



	/* FB size can be obtained from the VSA II */

	/* Virtual register class = 0x02 */

	/* VG_MEM_SIZE(512Kb units) = 0x00 */

drivers/video/geode/lxfb_ops.c

+16 −0
Original line number Diff line number Diff line
@@ -329,6 +329,22 @@ unsigned int lx_framebuffer_size(void) 
{

	unsigned int val;



	if (!geode_has_vsa2()) {

		uint32_t hi, lo;



		/* The number of pages is (PMAX - PMIN)+1 */

		rdmsr(MSR_GLIU_P2D_RO0, lo, hi);



		/* PMAX */

		val = ((hi & 0xff) << 12) | ((lo & 0xfff00000) >> 20);

		/* PMIN */

		val -= (lo & 0x000fffff);

		val += 1;



		/* The page size is 4k */

		return (val << 12);

	}



	/* The frame buffer size is reported by a VSM in VSA II */

	/* Virtual Register Class    = 0x02                     */

	/* VG_MEM_SIZE (1MB units)   = 0x00                     */

include/asm-x86/geode.h

+2 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ extern int geode_get_dev_base(unsigned int dev); 


/* MSRS */



#define MSR_GLIU_P2D_RO0	0x10000029



#define MSR_LX_GLD_MSR_CONFIG	0x48002001

#define MSR_LX_MSR_PADSEL	0x48002011	/* NOT 0x48000011; the data

						 * sheet has the wrong value */

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