[PATCH v2 02/15] drm/ast: Move 32-bit register-access helpers to ast_drv.{c, h}
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: 2026-03-27 13:35:48
Subsystem:
drm driver for ast server graphics chips, drm drivers, drm drivers and misc gpu patches, the rest · Maintainers:
Dave Airlie, David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Linus Torvalds
The helpers ast_mindwm() and ast_moutdwm() access the I/O memory of the various IP modules on the Aspeed device. This is based on the "P-Bus to AHB Bridge" interface. Reimplement the access function with properly defined constants and helper macros. - Define P2A constants for the related registers and addresses. The P2A interface is located in the memory range at [0x00000000, 0x00010000]. - Memory access is segmented. An address' upper 16-bit select the memory segment, the lower 16-bit select the offset within the segment. Implement segment selection in a shared helper __ast_segsel(). Validate that the segment hs been changes. This logic has previously been part of __ast_moudwm() and __ast_mindwm(). Relax the CPU while busy-waiting. - Put intra-segment reads and writes in the helpers __ast_rdseg32() and __ast_wrseg32(). The helpers set the segment offset automatically. - Reimplement the existing interfaces on top of these helpers. Put the new implementation next to the other I/O helpers. v2: - fix typo in commit description (Jocelyn) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com> --- drivers/gpu/drm/ast/ast_drv.c | 59 ++++++++++++++++++++++++++++++++++ drivers/gpu/drm/ast/ast_drv.h | 59 +++++++++++++++++++++------------- drivers/gpu/drm/ast/ast_post.c | 38 ---------------------- drivers/gpu/drm/ast/ast_post.h | 3 -- drivers/gpu/drm/ast/ast_reg.h | 12 +++++++ 5 files changed, 108 insertions(+), 63 deletions(-)
diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
index b9a9b050b546..05ec3542ab62 100644
--- a/drivers/gpu/drm/ast/ast_drv.c
+++ b/drivers/gpu/drm/ast/ast_drv.c@@ -47,6 +47,65 @@ static int ast_modeset = -1; MODULE_PARM_DESC(modeset, "Disable/Enable modesetting"); module_param_named(modeset, ast_modeset, int, 0400); +/* + * Register access + */ + +/* Select R/W segment */ +static void __ast_selseg(void __iomem *regs, u32 r) +{ + u32 p2a04, p2a04_base; + + p2a04 = r & AST_REG_P2A04_BASE_MASK; + __ast_write32(regs, AST_REG_P2A04, p2a04); + __ast_write32(regs, AST_REG_P2A00, AST_REG_P2A00_PROTECTION_KEY); + + do { + cpu_relax(); + p2a04_base = __ast_read32(regs, AST_REG_P2A04); + p2a04_base &= AST_REG_P2A04_BASE_MASK; + } while (p2a04_base != p2a04); +} + +/* Read within segment */ +static u32 __ast_rdseg32(void __iomem *regs, u32 r) +{ + return __ast_read32(regs, AST_REG_P2A_ADDR(r)); +} + +/* Write within segment */ +static void __ast_wrseg32(void __iomem *regs, u32 r, u32 v) +{ + __ast_write32(regs, AST_REG_P2A_ADDR(r), v); +} + +u32 __ast_mindwm(void __iomem *regs, u32 r) +{ + __ast_selseg(regs, r); + + return __ast_rdseg32(regs, r); +} + +void __ast_moutdwm(void __iomem *regs, u32 r, u32 v) +{ + __ast_selseg(regs, r); + __ast_wrseg32(regs, r, v); +} + +u32 ast_mindwm(struct ast_device *ast, u32 r) +{ + return __ast_mindwm(ast->regs, r); +} + +void ast_moutdwm(struct ast_device *ast, u32 r, u32 v) +{ + __ast_moutdwm(ast->regs, r, v); +} + +/* + * AST device + */ + void ast_device_init(struct ast_device *ast, enum ast_chip chip, enum ast_config_mode config_mode,
diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 787e38c6c17d..3eedf8239333 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h@@ -259,26 +259,20 @@ static inline bool __ast_gen_is_eq(struct ast_device *ast, unsigned long gen) #define IS_AST_GEN6(__ast) __ast_gen_is_eq(__ast, 6) #define IS_AST_GEN7(__ast) __ast_gen_is_eq(__ast, 7) +/* + * MMIO access + */ + static inline u8 __ast_read8(const void __iomem *addr, u32 reg) { return ioread8(addr + reg); } -static inline u32 __ast_read32(const void __iomem *addr, u32 reg) -{ - return ioread32(addr + reg); -} - static inline void __ast_write8(void __iomem *addr, u32 reg, u8 val) { iowrite8(val, addr + reg); } -static inline void __ast_write32(void __iomem *addr, u32 reg, u32 val) -{ - iowrite32(val, addr + reg); -} - static inline u8 __ast_read8_i(void __iomem *addr, u32 reg, u8 index) { __ast_write8(addr, reg, index);
@@ -307,16 +301,6 @@ static inline void __ast_write8_i_masked(void __iomem *addr, u32 reg, u8 index, __ast_write8_i(addr, reg, index, tmp | val); } -static inline u32 ast_read32(struct ast_device *ast, u32 reg) -{ - return __ast_read32(ast->regs, reg); -} - -static inline void ast_write32(struct ast_device *ast, u32 reg, u32 val) -{ - __ast_write32(ast->regs, reg, val); -} - static inline u8 ast_io_read8(struct ast_device *ast, u32 reg) { return __ast_read8(ast->ioregs, reg);
@@ -349,6 +333,39 @@ static inline void ast_set_index_reg_mask(struct ast_device *ast, u32 base, u8 i __ast_write8_i_masked(ast->ioregs, base, index, preserve_mask, val); } +/* + * Register access + */ + +static inline u32 __ast_read32(const void __iomem *addr, u32 reg) +{ + return ioread32(addr + reg); +} + +static inline void __ast_write32(void __iomem *addr, u32 reg, u32 val) +{ + iowrite32(val, addr + reg); +} + +static inline u32 ast_read32(struct ast_device *ast, u32 reg) +{ + return __ast_read32(ast->regs, reg); +} + +static inline void ast_write32(struct ast_device *ast, u32 reg, u32 val) +{ + __ast_write32(ast->regs, reg, val); +} + +u32 __ast_mindwm(void __iomem *regs, u32 r); +void __ast_moutdwm(void __iomem *regs, u32 r, u32 v); +u32 ast_mindwm(struct ast_device *ast, u32 r); +void ast_moutdwm(struct ast_device *ast, u32 r, u32 v); + +/* + * VBIOS + */ + struct ast_vbios_stdtable { u8 misc; u8 seq[4];
@@ -517,8 +534,6 @@ struct drm_device *ast_2600_device_create(struct pci_dev *pdev, /* ast post */ int ast_post_gpu(struct ast_device *ast); -u32 ast_mindwm(struct ast_device *ast, u32 r); -void ast_moutdwm(struct ast_device *ast, u32 r, u32 v); int ast_vga_output_init(struct ast_device *ast); int ast_sil164_output_init(struct ast_device *ast);
diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c
index b72914dbed38..5cec5d735b6a 100644
--- a/drivers/gpu/drm/ast/ast_post.c
+++ b/drivers/gpu/drm/ast/ast_post.c@@ -34,44 +34,6 @@ #include "ast_drv.h" #include "ast_post.h" -u32 __ast_mindwm(void __iomem *regs, u32 r) -{ - u32 data; - - __ast_write32(regs, 0xf004, r & 0xffff0000); - __ast_write32(regs, 0xf000, 0x1); - - do { - data = __ast_read32(regs, 0xf004) & 0xffff0000; - } while (data != (r & 0xffff0000)); - - return __ast_read32(regs, 0x10000 + (r & 0x0000ffff)); -} - -void __ast_moutdwm(void __iomem *regs, u32 r, u32 v) -{ - u32 data; - - __ast_write32(regs, 0xf004, r & 0xffff0000); - __ast_write32(regs, 0xf000, 0x1); - - do { - data = __ast_read32(regs, 0xf004) & 0xffff0000; - } while (data != (r & 0xffff0000)); - - __ast_write32(regs, 0x10000 + (r & 0x0000ffff), v); -} - -u32 ast_mindwm(struct ast_device *ast, u32 r) -{ - return __ast_mindwm(ast->regs, r); -} - -void ast_moutdwm(struct ast_device *ast, u32 r, u32 v) -{ - __ast_moutdwm(ast->regs, r, v); -} - int ast_post_gpu(struct ast_device *ast) { int ret;
diff --git a/drivers/gpu/drm/ast/ast_post.h b/drivers/gpu/drm/ast/ast_post.h
index aa5d247bebe8..41cd753b7f67 100644
--- a/drivers/gpu/drm/ast/ast_post.h
+++ b/drivers/gpu/drm/ast/ast_post.h@@ -35,9 +35,6 @@ struct ast_dramstruct { #define AST_DRAMSTRUCT_IS(_entry, _name) \ ((_entry)->index == __AST_DRAMSTRUCT_INDEX(_name)) -u32 __ast_mindwm(void __iomem *regs, u32 r); -void __ast_moutdwm(void __iomem *regs, u32 r, u32 v); - bool mmc_test(struct ast_device *ast, u32 datagen, u8 test_ctl); bool mmc_test_burst(struct ast_device *ast, u32 datagen);
diff --git a/drivers/gpu/drm/ast/ast_reg.h b/drivers/gpu/drm/ast/ast_reg.h
index 30578e3b07e4..ca9403efc7f9 100644
--- a/drivers/gpu/drm/ast/ast_reg.h
+++ b/drivers/gpu/drm/ast/ast_reg.h@@ -75,4 +75,16 @@ #define AST_IO_VGAIR1_R (0x5A) #define AST_IO_VGAIR1_VREFRESH BIT(3) +/* + * P-Bus to AHB Bridge (0x00000000 - 0x0001ffff) + */ + +#define AST_REG_P2A_BASE (0x00000000) +#define AST_REG_P2A(__offset) (AST_REG_P2A_BASE + (__offset)) +#define AST_REG_P2A_ADDR(__addr) AST_REG_P2A(0x10000 + ((__addr) & GENMASK(15, 0))) +#define AST_REG_P2A00 AST_REG_P2A(0xf000) +#define AST_REG_P2A00_PROTECTION_KEY (0x01) +#define AST_REG_P2A04 AST_REG_P2A(0xf004) +#define AST_REG_P2A04_BASE_MASK GENMASK(31, 16) + #endif
--
2.53.0